Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Claim 8 is newly cancelled. The rejection of claim 8 under 35 U.S.C. 103 is rendered moot by Applicant’s cancellation of claim 8.
Claims 1, 3, 9, 11, 15-16, 18, 29, 38 and 40-41 are currently pending. Claim 18 is withdrawn. Claims 1, 3, 9, 11, 15-16, 29, 38 and 40-41 are under examination on their merits.
The objection to the drawings is withdrawn in view of Applicant’s replacement drawings filed 8/27/2025.
Response to Arguments
Applicant’s arguments filed 8/27/2025 have been fully considered but they are not persuasive.
Applicant traverses the rejections of record under 35 U.S.C. 103 on the grounds that the prior art of record does not teach that in high cell density cultures of non-GMO microorganisms that produce DPEase, the specific epimerase activity (U/g DCW) decreases significantly as culture proceeds, even when cell mass increases (Arguments, lines 1-2 on page 8).
This argument is unpersuasive because Applicant’s claimed invention is not limited to non-GMO microorganisms or high cell density cultures. In addition, a decrease in specific epimerase activity as a culture proceeds would have been predictable based on the prior art of Gu et al. (cited in the Non-Final Action mailed on 5/28/2025), who teaches that the accumulation of fermentation by-products inhibits protein production (Gu et al., paragraph bridging pages 1775-1776). Decreased protein production necessarily corresponds to decreased specific enzyme activity since less enzyme is produced per g DCW.
Applicant argues that specific DPEase activity per g DCW was maintained as cell concentration increases when the additional medium has a C/N of 5/1 and the magnesium ion concentration is 0.5, 1.0 or 2.0 mM (Arguments, paragraph 2 on page 8). Applicant argues that this result is unexpected and that the variables at issue (additional medium C/N, metal-ion concentration) were not recognized in the art as results-effective variables (Arguments, paragraph 1 on page 9).
This argument is not persuasive, as the prior art of Gu teaches optimizing the feeding strategy: the feeding strategy is reported to affect the metabolic pathway fluxes, cell density, specific productivity of recombinant proteins, and formation of by-products such as acetic acid (page 1775, right column, bottom paragraph). In addition, the prior art teaches that psicose epimerase is metal-dependent: see Izumori (cited in the Final Action mailed on 4/1/2022; column 3, point (5)(3)), Abstract of Zhang et al. (Journal of agricultural and food chemistry 61.47 (2013): 11468-11476) and Abstract of Zhang 2015 et al. (Journal of Molecular Catalysis B: Enzymatic 120 (2015): 68-74). In addition, Kim teaches a concentration of magnesium in the culture medium within the claimed range (see Kim [0084]).
Applicant argues further that the examiner’s general motivation (“to avoid substrate accumulation” does not supply a teaching of Applicant’s coordinated constraints, nor does it provide a reasonable expectation that those constraints together with the additional medium C/N window and 0.5-2 mM metal ions would stabilize per cell DPEase activity as biomass rises (Arguments, bottom paragraph on page 10). Applicant argues that the specification shows why the range is critical: at higher C/N (e.g. 20/1) per-cell activity is initially higher but falls off sharply with increasing biomass and overall productivity suffers (Arguments, paragraph 1 on page 10).
In response, Applicant has not presented convincing arguments or evidence as to why these results are unexpected. C/N ratio is an art-recognized variable for optimization of protein production and cell growth. See, for example, Aiyer, "Effect of C: N ratio on alpha amylase production by Bacillus licheniformis SPT 27." African journal of Biotechnology 3.10 (2004): 519-522. The claimed invention includes a step of culturing a microorganism capable of producing psicose epimerase and then converting a fructose substrate into psicose by reacting the fructose substrate with the cultured microorganism. In other words, the claimed invention requires making the enzyme (a protein) and then the enzyme catalyzing the reaction with a substrate. The measured enzyme activity per g DCW is both an effect of the amount of enzyme (protein) produced per g DCW and the enzyme’s catalytic efficiency. The person of ordinary skill in the art would have expected that at higher C/N ratios, protein production drops (the amount of enzyme per g DCW) because one of the major constituents of proteins (nitrogen) becomes limiting. Consequently, the person of ordinary skill in the art would have expected that the specific enzyme activity (enzyme activity per g DCW) at higher C/N also drops. Therefore, it would have been obvious to the person of ordinary skill in the art to optimize the C/N ratio by routine experimentation, as well as the other variables known in the art (such as pH and substrate concentration) in order to maximize specific enzyme activity.
Applicant argues that Kim's teaching of "pH 7 or less" for enzyme activity is a broad statement about enzyme optima, not a teaching of the ΔpH constraint or of coordinating ΔpH with the f-value and low residual carbon to preserve per-cell activity in high density culture (Arguments, paragraph 1 on page 11).
In response, Kim 2004 (not Kim) is relied on to teach the motivation for optimizing the ΔpH constraint: Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract). Therefore, Kim 2004 supplies the rationale for a ΔpH constraint.
Applicant argues further that the results of the claimed process are unexpected rather than the result of routine optimization because the claimed process arrests the decline of specific DPEase activity that accompanies high-density growth (Arguments, paragraph 2 on page 1).
In response, this argument is unpersuasive because there is no requirement within the claims for “high-density growth.” Therefore, there is a nexus lacking between Applicant’s arguments of unexpected results and the claimed invention.
Regarding the nonstatutory double patenting rejections of record, Applicant does not present new arguments not already addressed above.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
The following rejections are necessitated by Applicant’s amendment.
Claims 1, 3, 9, 11, 15-16, and 41 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US20170298400A1; 26 August 2020 IDS Document; previously cited) in view of Izumori (US9057062B2; previously cited) and Kim 2004 (Kim et al. High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat, 2004, Bioprocess and Biosystems Engineering, 26, 147-150; previously cited).
Regarding claims 1 and 41, Kim teaches a method of preparing D-psicose, comprising a step of reacting D-fructose as a substrate and an epimerase thereof in microorganisms at a temperature of 40° C or higher (Kim Claim 1). The reaction of D-fructose as a substrate and an epimerase thereof is performed in microorganisms, and thus microorganisms may be cultured in a medium containing D-fructose [as recited in claim 41] (Kim ¶ 43). The microorganisms may express an epimerase endogenously or by transformation. When an epimerase is expressed in the microorganisms, D-psicose generated by the reaction of D-fructose and the epimerase may be continuously produced in the microorganisms (Kim ¶ 17). Kim teaches the gram-positive bacteria may be Bacillus, Corynebacterium, Actinomyces, lactic acid bacteria or combinations thereof (Kim ¶ 28, lines 7-11).
Regarding the initial carbon source concentration in the initial culture medium, Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). Because the claimed range lies inside ranges disclosed by the prior art, a prima facie case of obviousness exists. Regarding the pH of the initial culture medium, Kim discloses a medium at pH 7 (Kim ¶ 101).
Kim does not explicitly teach an initial culture medium in which the ratio of carbon source to organic nitrogen source (C/N ratio) is 1/1 to 10/1, culturing the microorganism in 0.001 g/L to 5 g/L of psicose to induce or stabilize the psicose epimerase, supplying the additional medium intermittently or continuously to maintain the carbon source concentration at 0.001 g/L to 5 g/L, wherein the additional medium has a C/N ratio of 10/2 to 10/1, wherein the increase of the carbon source concentration in the initial culture medium after supplying the additional medium is 0.2 to 0.5, or the pH of the initial culture medium is maintained such that a variation in pH is between 0.05 to 0.5.
However, Kim does teach varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). In an example, Kim discloses a minimal medium comprising 2 g/L urea (nitrogen source) and 40% fructose (Kim ¶ 100, lines 3-7), which is a higher C/N ratio. Kim discloses the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7). Kim also teaches the pH at which D-psicose 3-epimerases exhibit optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9).
Izumori discloses a culture of Arthrobacter globiformis containing 0.2% D-psicose (2 g/L) as a carbon source (Izumori Col. 8, lines 37-41). Izumori further teaches that, since the enzyme of the disclosed bacteria was produced in the presence of D-psicose, the enzyme was found to be an enzyme induced by D-psicose (Izumori Col. 9, lines 34-36).
Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract). The pH-stat is a simple indirect feedback control scheme that couples nutrient feeding with measurement of pH. It is based on the fact that pH rises due to excretion of ammonium ions when the principal carbon source is depleted (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to combine the fructose in the culturing step in Kim's method for producing psicose with the psicose taught by Izumori, because they are both disclosed as carbon sources for enzyme-producing microorganisms. The combination of fructose and psicose in the culturing step would have yielded nothing more than predictable results, because they both function as carbon sources and one of ordinary skill would reasonably expect no change in their respective functions. It would have been further obvious to modify the culturing step in Kim's method by supplying an additional medium comprising a carbon source intermittently to avoid accumulation of substrate in the culture broth (Kim 2004, Abstract, lines 1-3; Pg. 147, Col. 1, ¶ 2). Kim discloses culturing microorganisms with a carbon substrate and Kim 2004 teaches steps to improve a similar culturing method; therefore, one of ordinary skill in the art would have reasonably expected Kim 2004's strategy of supplying the additional medium intermittently to work in Kim's method. One of ordinary skill in the art would have been motivated to modify Kim's method by maintaining the change in carbon source concentration in the culture medium and the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9) and pH is affected by depletion of carbon source (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6). One of ordinary skill in the art would have been motivated to optimize the change in carbon source concentration in the culture medium through routine experimentation.
One of ordinary skill in the art would have been motivated to optimize the concentration of D-fructose (C/N ratio) within prior art conditions disclosed by Kim (Kim ¶ 45). Routine optimization of D-fructose (carbon source) in Kim's medium would have led to the claimed ratio of carbon to organic nitrogen of 1/1 to 10/1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2g/L nitrogen source (urea). There would have been a reasonable expectation of success because the claimed range and the range disclosed by the prior art overlap. Optimization through routine experimentation of the carbon source concentration in Kim's additional medium would have led to the claimed range of 0.001 g/L to 5 g/L because Kim teaches carbon source concentration in media at an approaching range of 1 to 80% w/v carbon source. There would have been a reasonable expectation of success because the claimed range and the range disclosed by the prior art are close.
Routine optimization of D-fructose (carbon source) in Kim's additional medium would have led to the claimed ratio of carbon to organic nitrogen of 10/2 to 10/1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2g/L nitrogen source (urea). There would have been a reasonable expectation of success because the claimed range and the range disclosed by the prior art overlap.
Regarding Applicant’s amendment to claim 1 to recite the concentration of metal ions, Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim exemplifies a culture medium containing 0.4 g MgSO4·7H2O, which is equivalent to 1.6 mM. 1.6 mM is within the claimed range of 0.5 mM to 2 mM metal ions. Therefore, a prima facie case of obviousness exists. See MPEP 2144.05.
Regarding claim 3, Kim teaches the culture be a continuous, semi-continuous, or batch type culture (Kim ¶ 47).
Regarding claim 9, Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim teaches the seed culture was inoculated into a minimal medium (1 g K2HPO4, 10 g(NH4)2SO4, 0.4 g MgSO47H2O (equivalent to 1.6 mM magnesium), 20 mg FeSO47H2O, 20 mg MnSO45H2O, 50 mg NaCl, 2 g urea , 0.1 mg biotin, and 0.1 mg thiamine per liter) containing 10 g/L of glucose and 20 ug/mL of kanamycin and then subjected to main culture (initial culture medium) (Kim ¶ 84, lines 5-10). Kim also teaches the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7).
Regarding claim 11, Kim teaches the pH at which D-psicose 3-epimerases exhibit optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9).
Kim does not teach supplying an additional medium is performed in a pH stat feeding method, wherein the pH stat feeding method supplies an additional medium comprising a carbon source so that a pH variation in a culture solution is 0.05 to 0.5.
Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the culturing step in Kim's method by supplying an additional medium with pH-stat to avoid accumulation of substrate in the culture broth (Kim 2004, Abstract, lines 103; Pg. 147, Col. 1, ¶ 2). Kim discloses culturing microorganisms with a carbon substrate and Kim 2004 teaches steps to improve a similar culturing method; therefore, one of ordinary skill would reasonably expect Kim's strategy of supplying an additional medium via pH-stat to work in Kim's method. One of ordinary skill would have been motivated to modify Kim's method by maintaining the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9). Therefore, it would be obvious to maintain the culture medium at a stable pH without high fluctuations so enzyme activity is maintained.
Regarding claim 15, Kim teaches the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Kim and Kim 2004 by optimizing the carbon source concentration in the additional medium by routine experimentation. Optimization through routine experimentation of the carbon source concentration in Kim's additional medium would have led to the claimed range of 0.001 g/L to 5 g/L, because Kim teaches carbon source concentration in media at an approaching range of 1 to 80% w/v carbon source. There is a reasonable expectation of success, because the claimed range and the range disclosed by the prior art are close.
Regarding claim 16, Kim teaches the microorganisms may express an epimerase endogenously or by transformation (Kim ¶ 17, lines 1-2).
Claims 29, 38 and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US20170298400A1; 26 August 2020 IDS Document; previously cited) in view of Kim 2004 (Kim, B. S. et al, High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat, 2004, Bioprocess and Biosystems Engineering, 26, 147-150; previously cited).
Regarding claim 29, Kim teaches a method of preparing D-psicose, comprising a step of reacting D-fructose (inducer as per Instant Specification Pg. 3, lines 1-2) as a substrate and an epimerase thereof in microorganisms at a temperature of 40° C or higher (Kim Claim 1). The reaction of D-fructose as a substrate and an epimerase thereof is performed in microorganisms, and thus microorganisms may be cultured in a medium containing D-fructose (Kim ¶ 43). The microorganisms may express an epimerase endogenously or by transformation. When an epimerase is expressed in the microorganisms, D-psicose generated by the reaction of D-fructose and the epimerase may be continuously produced in the microorganisms (Kim ¶ 17). The medium may be a defined medium commonly used in the art, containing carbon sources including glucose, glycerol and the like; nitrogen sources including ammonia, urea, and the like (Kim ¶ 46, lines 1-4). In an example, Kim discloses a minimal medium comprising 2g/L urea (nitrogen source) and 10 g/L glucose (carbon source) (Kim ¶ 84, lines 5-10). Kim teaches the gram-positive bacteria may be Bacillus, Corynebacterium, Actinomyces, lactic acid bacteria or combinations thereof (Kim ¶ 28, lines 7-11).
Concerning the concentration of the psicose inducer, Kim teaches a concentration of D-fructose contained in the medium may be 1 to 80% (w/v) (10 g/L to 800 g/L) (Kim ¶ 45, lines 1-3), but does not teach a microorganism is cultured in a range of the inducer concentration of 0.001-5 g/L.
Regarding the initial carbon source concentration in the initial culture medium, Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). Because the claimed range lies inside ranges disclosed by the prior art, a prima facie case of obviousness exists. Regarding the pH of the initial culture medium, Kim discloses a medium at pH 7 (Kim ¶ 101).
Regarding Applicant’s amendment to claims 29 and 40 to recite the concentration of metal ions, Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim exemplifies a culture medium containing 0.4 g MgSO4·7H2O, which is equivalent to 1.6 mM and falls within the claimed range of 0.5 mM to 2 mM.
Kim does not teach the additional medium is added intermittently or continuously, wherein the increase of the carbon source concentration in the initial culture medium after supplying the additional medium is 0.2 to 0.5, or the pH of the medium is maintained such that a variation in pH is between 0.05 to 0.5. Kim does not teach the C/N ratio of the additional medium is between 10/2 and 10/1.
Kim 2004 teaches exponential feeding is a simple method that allows cells to grow at a constant growth rate. With E. coli, acetate production, which can inhibit cell growth as well as product formation, could be minimized by controlling the specific growth rate below the critical value for acetate formation. This feeding strategy without feedback cannot avoid the accumulation of substrate in culture broth when the substrate is oversupplied. The pH-stat is a simple indirect feedback control scheme that couples nutrient feeding with measurement of pH. It is based on the fact that pH rises due to excretion of ammonium ions when the principal carbon source is depleted (Kim 2004, Pg. 147, Col. 1, ¶ 2-Col. 2, ¶ 1). Exponential feeding combined with pH-stat is suggested to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004 Abstract). Kim 2004 teaches to achieve high cell density with reducing the formation of acetate, glucose concentration had to be kept low by controlling the specific growth rate at a low value (Kim 2004, Pg. 150, ¶ 2, lines 4-7). Kim 2004 suggests the exponential feeding combined with pH-stat overcomes the limitation of simple exponential feeding (inhibition of cell growth and product formation), and can be applied to high cell density cultures for the production of various metabolites (Kim 2004, Pg. 150, ¶ 2, lines 8-12).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to reduce the inducer concentration and maintain the concentration by pH-stat in the culturing step in Kim's method to avoid accumulation of substrate (inducer) in the culture broth (Kim 2004, Abstract, lines 103; Pg. 147, Col. 1, ¶ 2) and to control the rate of microorganism growth and product formation. Kim discloses culturing microorganisms with a carbon substrate and Kim 2004 teaches methods to improve a similar culturing method; therefore, one of ordinary skill would reasonably expect Kim's strategy of maintaining the inducer concentration by pH-stat to work in Kim's method. One of ordinary skill would have been motivated to modify Kim's method by maintaining the change in carbon source concentration in the culture medium and the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9) and pH is affected by depletion of carbon source (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6). Therefore, it would be obvious to maintain the culture medium at a stable pH without fluctuations so enzyme activity is maintained. One of ordinary skill would have been motivated to optimize the change in carbon source concentration in the culture medium after supplying the additional medium through routine experimentation to maintain the culture medium at a stable pH without fluctuations so enzyme activity is maintained.
Regarding the C/N ratio of the additional medium, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to optimize D-fructose (carbon source) in Kim's additional medium by routine experimentation and such optimization would have led to the claimed ratio of carbon to organic nitrogen of 10/2 to 10/1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2 g/L nitrogen source (urea). There would have been a reasonable expectation of success because the claimed range and the range disclosed by the prior art overlap.
Regarding claim 38, Kim teaches the microorganisms may express an epimerase endogenously or by transformation (Kim ¶ 17, lines 1-2).
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP §§ 706.02(l)(1) - 706.02(l)(3) for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/process/file/efs/guidance/eTD-info-I.jsp.
The following rejections are necessitated by Applicant’s amendment.
Claims 1, 3, 9, 11, 15-16, 29, 38, 40 and 41 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1 and 3 of U.S. Patent No. 11,066,640 in view of Kim (US20170298400A1; 26 August 2020 IDS Document; previously cited), Izumori (US9057062B2; previously cited) and Kim 2004 (Kim, B. S. et al, High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat, 2004, Bioprocess and Biosystems Engineering, 26, 147-150; previously cited).
Patent claim 1 recites a method for producing psicose from fructose in the presence of manganese ion (Mn2+), comprising: contacting the fructose with a microbial cell of Microbacterium foliorum having psicose conversion activity to produce psicose from fructose, a culture of Microbacterium foliorum, a culture supernatant of Microbacterium foliorum, a culture extract of Microbacterium foliorum, and/or a lysate of Microbacterium foliorum, wherein the Microbacterium foliorum has an increased psicose conversion activity in the presence of manganese ion (Mn2+) compared to absence of manganese ion. Patent claim 3 recites the method for producing the psicose of claim 1, wherein the contacting comprises culturing the Microbacterium foliorum in a medium containing the fructose.
The patent claims do not teach an initial culture medium with a C/N ratio of 1/1 to 10/1, culturing a microorganism in the presence of 0.001 g/L to 5 g/L of psicose, a pH variation of 0.05 to 0.5, an additional medium comprising a carbon source is supplied intermittently or continuously so the concentration is maintained at 0.001-5 g/L, wherein the additional medium has a C/N ratio of 10/2 to 10/1, wherein the increase of the carbon source concentration in the initial culture medium after supplying the additional medium is 0.2 to 0.5, or the pH of the initial culture medium is maintained such that a variation in pH is between 0.05 to 0.5 in claim 1, the step of culturing is performed in batch, fed-batch, or continuously in claim 3, supplying an additional medium by pH stat feeding in claim 11, or the microorganism is a non-genetically modified microorganism comprising an internal gene encoding psicose epimerase in claim 16.
Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). In an example, Kim discloses a minimal medium comprising 2g/L urea (nitrogen source) and 40% fructose (Kim ¶ 100, lines 3-7), which is a higher C/N ratio. The culture be a continuous, semi-continuous, or batch type culture (Kim ¶ 47). Kim teaches the pH at which D-psicose 3-epimerases exhibit optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9). Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim teaches the seed culture was inoculated into a minimal medium (1 g K2HPO4, 10 g(NH4)2SO4, 0.4 g MgSO47H20 (equivalent to 1.6 mM magnesium), 20 mg FeSO47H2O, 20 mg MnSO45H2O, 50 mg NaCl, 2 g urea , 0.1 mg biotin, and 0.1 mg thiamine per liter) containing 10 g/L of glucose and 20 ug/mL of kanamycin and then subjected to main culture (initial culture medium) (Kim ¶ 84, lines 5-10). Kim also teaches the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7). The microorganisms may express an epimerase endogenously or by transformation (Kim ¶ 17, lines 1-2).
Izumori discloses a culture of Arthrobacter globiformis containing 0.2% D-psicose (2 g/L) as a carbon source (Izumori Col. 8, lines 37-41). Izumori further teaches since the enzyme of the disclosed bacteria was produced in the presence of D-psicose, the enzyme was found to be an enzyme induced by D-psicose (Izumori Col. 9, lines 34-36).
Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract). The pH-stat is a simple indirect feedback control scheme that couples nutrient feeding with measurement of pH. It is based on the fact that pH rises due to excretion of ammonium ions when the principal carbon source is depleted (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the patent claim's method for producing psicose by optimizing culture conditions, such as C/N ratio of medium, and concentration of metal ions within prior art conditions disclosed by Kim, and supplying additional medium by pH stat feeding, as taught by Kim 2004, to avoid accumulation of substrate in the culture broth (Kim 2004, Abstract, lines 103; Pg. 147, Col. 1, ¶ 2) and to improve the production amount and production rate of D-psicose (Kim ¶ 67).
Routine optimization of D-fructose (carbon source) in the medium would have led to the claimed ratio of carbon to organic nitrogen of 1/1 to 10/1 in claim 1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2g/L nitrogen source (urea). There is a reasonable expectation of success, because the claimed range and the range disclosed by the prior art overlap.
One of ordinary skill would have been motivated to maintain the change in carbon source concentration in the culture medium and the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9) and pH is affected by depletion of carbon source (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6). One of ordinary skill would have been motivated to optimize the change in carbon source concentration in the culture medium through routine experimentation.
One of ordinary skill would have been motivated to combine the fructose in the culturing step with the psicose taught by Izumori, because they are both carbon sources for enzyme producing microorganisms. The combination would have yielded nothing more than predictable results, because they both function as carbon sources and one of ordinary skill would reasonably expect no change in their respective functions.
Claims 1, 3, 9, 11, 15-16, 29, 38, 40 and 41 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-2 of U.S. Patent No. 9,951,361 in view of Kim (US20170298400A1; 26 August 2020 IDS Document; previously cited), Izumori (US9057062B2; previously cited) and Kim 2004 (Kim, B. S. et al, High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat, 2004, Bioprocess and Biosystems Engineering, 26, 147-150; previously cited).
Patent claim 1 recites a method of producing psicose from fructose by using an Ensifer sp. strain, comprising: reacting an Ensifer sp. strain with fructose, wherein reacting the Ensifer sp. strain with fructose is performed by culturing the Ensifer sp. strain on culture medium containing fructose; mixing the fructose with at least one selected from the group consisting of: an Ensifer sp. strain cell, an Ensifer sp. strain cell culture, and an Ensifer sp. strain cell lysate; or contacting the fructose with a support immobilized with at least one selected from the group consisting of an Ensifer sp. strain cell, an Ensifer sp. strain cell culture, and an Ensifer sp. strain cell lysate, and wherein the Ensifer sp. strain is Ensifer adhaerens. Patent claim 2 recites the method of claim 1, wherein the method further comprises a step of adding at least one metal ion selected from the group consisting of Cu, Mn, Ca, Mg, Zn, Ni, Co, Fe and Al ions.
The patent claims do not teach an initial culture medium with a C/N ratio of 1/1 to 10/1, culturing a microorganism in the presence of 0.001 g/L to 5 g/L of psicose, a pH variation of 0.05 to 0.5, an additional medium comprising a carbon source is supplied intermittently or continuously so the concentration is maintained at 0.001-5 g/L, wherein the additional medium has a C/N ratio of 10/2 to 10/1, wherein the increase of the carbon source concentration in the initial culture medium after supplying the additional medium is 0.2 to 0.5, or the pH of the initial culture medium is maintained such that a variation in pH is between 0.05 to 0.5 in claim 1, the step of culturing is performed in batch, fed-batch, or continuously in claim 3, supplying an additional medium by pH stat feeding in claim 11, or the microorganism is a non-genetically modified microorganism comprising an internal gene encoding psicose epimerase in claim 16.
Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). In an example, Kim discloses a minimal medium comprising 2g/L urea (nitrogen source) and 40% fructose (Kim ¶ 100, lines 3-7), which is a higher C/N ratio. The culture be a continuous, semi-continuous, or batch type culture (Kim ¶ 47). Kim teaches the pH at which D-psicose 3-epimerases exhibit optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9). Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim teaches the seed culture was inoculated into a minimal medium (1 g K2HPO4, 10 g(NH4)2SO4, 0.4 g MgSO47H20 (equivalent to 1.6 mM magnesium), 20 mg FeSO47H20, 20 mg MnSO25H20, 50 mg NaCl, 2 g urea , 0.1 mg biotin, and 0.1 mg thiamine per liter) containing 10 g/L of glucose and 20 ug/mL of kanamycin and then subjected to main culture (initial culture medium) (Kim ¶ 84, lines 5-10). Kim also teaches the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7). The microorganisms may express an epimerase endogenously or by transformation (Kim ¶ 17, lines 1-2). Regarding the pH of the initial culture medium, Kim discloses a medium at pH 7 (Kim ¶ 101).
Izumori discloses a culture of Arthrobacter globiformis containing 0.2% D-psicose (2 g/L) as a carbon source (Izumori Col. 8, lines 37-41). Izumori further teaches since the enzyme of the disclosed bacteria was produced in the presence of D-psicose, the enzyme was found to be an enzyme induced by D-psicose (Izumori Col. 9, lines 34-36).
Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract). The pH-stat is a simple indirect feedback control scheme that couples nutrient feeding with measurement of pH. It is based on the fact that pH rises due to excretion of ammonium ions when the principal carbon source is depleted (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the patent claim's method for producing psicose by optimizing culture conditions, such as C/N ratio of medium and concentration of metal ions within prior art conditions disclosed by Kim, and supplying additional medium by pH stat feeding, as taught by Kim 2004, to avoid accumulation of substrate in the culture broth (Kim 2004, Abstract, lines 103; Pg. 147, Col. 1, ¶ 2) and to improve the production amount and production rate of D-psicose (Kim ¶ 67).
Routine optimization of D-fructose (carbon source) in the medium would have led to the claimed ratio of carbon to organic nitrogen of 1/1 to 10/1 in claim 1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2g/L nitrogen source (urea). There is a reasonable expectation of success, because the claimed range and the range disclosed by the prior art overlap.
Regarding the initial carbon source concentration in the initial culture medium, Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). Because the claimed range lies inside ranges disclosed by the prior art, a prima facie case of obviousness exists.
One of ordinary skill would have been motivated to maintain the change in carbon source concentration in the culture medium and the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9) and pH is affected by depletion of carbon source (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6). One of ordinary skill would have been motivated to optimize the change in carbon source concentration in the culture medium through routine experimentation.
One of ordinary skill would have been motivated to combine the fructose in the culturing step with the psicose taught by Izumori, because they are both carbon sources for enzyme producing microorganisms. The combination would have yielded nothing more than predictable results, because they both function as carbon sources and one of ordinary skill would reasonably expect no change in their respective functions.
Claims 1, 3, 9, 11, 15-16, 29, 38, 40 and 41 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 1 of U.S. Patent No. 11,859,226 in view of Kim (US20170298400A1; 26 August 2020 IDS Document; previously cited), Izumori (US9057062B2; previously cited) and Kim 2004 (Kim, B. S. et al, High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat, 2004, Bioprocess and Biosystems Engineering, 26, 147-150; previously cited).
Patent claim 1 recites a method for producing a psicose from a fructose-containing substrate using a bacterium belonging to the genus Microbacterium having a psicose conversion activity, comprising reacting the fructose-containing substrate with at least one selected from the group consisting of a microbial cell of the bacterium, a culture of the bacterium, and a lysate of the bacterium in the presence of at least one metal ion selected from the group consisting of manganese ion and cobalt ion, wherein the bacterium belonging to the genus Microbacterium is Microbacterium phyllosphaerae, wherein the Microbacterium phyllosphaerae is a strain deposited as an accession number KCCM12034P.
The patent claim does not teach an initial culture medium with a C/N ratio of 1/1 to 10/1, culturing a microorganism in the presence of 0.001 g/L to 5 g/L of psicose, a pH variation of 0.05 to 0.5, an additional medium comprising a carbon source is supplied intermittently or continuously so the concentration is maintained at 0.001-5 g/L, wherein the additional medium has a C/N ratio of 10/2 to 10/1, wherein the increase of the carbon source concentration in the initial culture medium after supplying the additional medium is 0.2 to 0.5, or the pH of the initial culture medium is maintained such that a variation in pH is between 0.05 to 0.5 in claim 1,, the step of culturing is performed in batch, fed-batch, or continuously in claim 3, supplying an additional medium by pH stat feeding in claim 11, or the microorganism is a non-genetically modified microorganism comprising an internal gene encoding psicose epimerase in claim 16.
Kim teaches varying concentrations of D-fructose (carbon source) in the medium. For example, the concentration may be 1 to 80% (w/v) (Kim ¶ 45). In an example, Kim discloses a minimal medium comprising 2g/L urea (nitrogen source) and 40% fructose (Kim ¶ 100, lines 3-7), which is a higher C/N ratio. The culture be a continuous, semi-continuous, or batch type culture (Kim ¶ 47). Kim teaches the pH at which D-psicose 3-epimerases exhibit optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9). Kim teaches the medium contains essential metal ions including sodium, potassium, calcium, magnesium, manganese, cobalt, and the like (Kim ¶ 46, 4-6). Kim teaches the seed culture was inoculated into a minimal medium (1 g K2HPO4, 10 g(NH4)2SO4, 0.4 g MgSO47H20 (equivalent to 1.6 mM magnesium), 20 mg FeSO47H20, 20 mg MnSO45H20, 50 mg NaCl, 2 g urea , 0.1 mg biotin, and 0.1 mg thiamine per liter) containing 10 g/L of glucose and 20 ug/mL of kanamycin and then subjected to main culture (initial culture medium) (Kim ¶ 84, lines 5-10). Kim also teaches the microorganisms resuspended in a simple conversion reaction medium (additional medium) containing 20 ug/mL kanamycin, 40% (w/v) D-fructose as a substrate, and 0.1 mM concentration of manganese or cobalt known as a primary cofactor of D-psicose 3-epimerase (Kim ¶ 115, lines 3-7). The microorganisms may express an epimerase endogenously or by transformation (Kim ¶ 17, lines 1-2). Regarding the pH of the initial culture medium, Kim discloses a medium at pH 7 (Kim ¶ 101).
Izumori discloses a culture of Arthrobacter globiformis containing 0.2% D-psicose (2 g/L) as a carbon source (Izumori Col. 8, lines 37-41). Izumori further teaches since the enzyme of the disclosed bacteria was produced in the presence of D-psicose, the enzyme was found to be an enzyme induced by D-psicose (Izumori Col. 9, lines 34-36).
Kim 2004 teaches a feeding strategy combined with pH-stat to avoid the accumulation of substrate in culture broth. Exponential feeding was stopped whenever a predetermined amount of limiting substrate was supplied and then pH change was observed. When pH rose above an upper limit due to the depletion of substrate, feeding was restarted (intermittent) (Kim 2004, Abstract). The pH-stat is a simple indirect feedback control scheme that couples nutrient feeding with measurement of pH. It is based on the fact that pH rises due to excretion of ammonium ions when the principal carbon source is depleted (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the patent claim’s method for producing psicose by optimizing culture conditions, such as C/N ratio of medium and concentration of metal ions within prior art conditions taught by Kim, and supplying additional medium by pH stat feeding, as taught by Kim 2004, to avoid accumulation of substrate in the culture broth (Kim 2004, Abstract, lines 103; Pg. 147, Col. 1, ¶ 2) and to improve the production amount and production rate of D-psicose (Kim ¶ 67).
Routine optimization of D-fructose (carbon source) in the medium would have led to the claimed ratio of carbon to organic nitrogen of 1/1 to 10/1 in claim 1, because Kim teaches an overlapping range at 1 to 80% w/v (1 g/100 ml – 80 g/100 ml) carbon source and 2g/L nitrogen source (urea). There is a reasonable expectation of success, because the claimed range and the range disclosed by the prior art overlap.
One of ordinary skill would have been motivated to maintain the change in carbon source concentration in the culture medium and the pH during culturing so that the culture medium does not have high fluctuations in pH (vary more than 0.5), because Kim teaches optimal activity is as low as 7 or less (Kim ¶ 27, lines 8-9) and pH is affected by depletion of carbon source (Kim 2004, Pg. 147, Col. 2, [1], lines 2-6). One of ordinary skill would have been motivated to optimize the change in carbon source concentration in the culture medium through routine experimentation.
One of ordinary skill would have been motivated to combine the fructose in the culturing step with the psicose taught by Izumori, because they are both carbon sources for enzyme producing microorganisms. The combination would have yielded nothing more than predictable results, because they both function as carbon sources and one of ordinary skill would reasonably expect no change in their respective functions.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/CANDICE LEE SWIFT/Examiner, Art Unit 1657
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