DETAILED ACTION
Status of claim rejections
The rejections of record under 35 USC 103 are maintained in view of Applicant’s arguments in the response filed 04/27/2026.
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.
First rejection
Claims 1, 6, 13-14, 21, 24, 64, 69, 90, 93, 96-97, 99, 101, 103, 111, 113, 117-121, 123-126, and 130-135 are rejected under 35 U.S.C. 103 as being unpatentable over De Jong et al (US 20150335043 A1; published 26 Nov 2015; hereinafter “De Jong”; prior art of record) in view of Ferreira et al (Immunological Exercises for Beginners; 1996 Biochemical Education 24(3): 176-178; cited in 24 Oct 2022 IDS; hereinafter “Ferreira”; prior art of record) and BluwaChina ("Cationic Polymer Flocculant Polydadmac"; available online 14 Nov 2017 retrieved online 08/01/25 from https://www.bluwatchina.com/cationic-polymer-flocculant-polydadmac-3609878.html; hereinafter “Bluwa”) .
De Jong teaches a method for isolating a soluble plant protein from a plant material on an industrial scale (process for making purified protein from a plant material as in claim 1), wherein the method comprises the steps of: i) mechanically disrupting the plant cells of said plant material to obtain a plant juice, wherein before, during, or after the step of disrupting the plant cells an extraction composition comprising at least one of a reducing agent and a divalent ion source is added to said plant material, said plant cells and/or said plant juice (providing plant material in a buffer solution comprising reducing agent as in claim 1 and 125; lysing plant material as in claim 1 and 125), ii) treating the plant juice to cause aggregation of chloroplast membranes (coagulation of chlorophyll as in claim 1), iii) separating said aggregated chloroplast membranes from the soluble plant protein in said treated plant juice by precipitation and/or microfiltration to provide a plant juice supernatant or plant juice permeate comprising the soluble plant protein (separating coagulated chlorophyll from a liquid phase as in claim 1 and 125), iv) subjecting the plant juice supernatant or plant juice permeate to ultrafiltration (filtering liquid phase to yield purified protein as in claim 1 and 125), to provide a soluble plant protein concentrate, preferably comprising 25-50 wt % of protein, wherein said soluble plant protein concentrate is essentially free of salts and phenolic compounds (see claim 1). De Jong also teaches the steps of any steps (i) (mechanical disrupting, i.e., lysing as in claim 1 and 125), (iii), (iv), and (v) are performed under low temperature, preferably a temperature in the range of about 0-15°C (lysing at temperatures below 45 deg C as in claim 1) (see claim 8; paragraph 0041). De Jong also teaches addition of starch (i.e., a polymer; see paragraph 0087), and teaches aggregation of the chloroplasts by adding salts such as calcium/magnesium/cadmium/etc. salts (see paragraph 0032-33).
The difference between De Jong and the instant claims is that De Jong does not explicitly teach the plant material is from a Lemna plant.
However, Ferreira teaches the purification of RuBisCO from duckweed (Lemna minor), where the duckweed was grown autotrophically under sterile conditions at 25 deg C where the protein can be conveniently purified by sequential use of anion exchange chromatography on Mono Q column and gel filtration on the Superose 12 column (pg. 176, col 1, paragraphs 1-3). Ferreira also teaches that the protein can be purified via ultracentrifugation or isolation methods (pg. 176, col 2, paragraph 1). Ferreira teaches that samples of plant material were frozen, ground, and extracted in 100 mM Tris-HC1 buffer, pH 7.5, containing 1 mM PMSF and 10 mM 2-mercaptoethanol before the homogenate was squeezed through four layers of cheesecloth, clarified by centrifugation at 44000 ×g for 30 min at 2°C and desalted on a PD-10 prepacked Sephadex G-25 M column (pg. 176, col 2, paragraph 3) before subsequent immunoprecipitation (pg. 176, col 2, paragraph 5-pg. 177, col 1, paragraph 1).
Therefore, it would have been prima facie obvious to one of ordinary skill at the time of filing to modify the plant protein purification method of De Jong by purifying plant material from Lemna minor as taught by Ferreira to arrive at the claimed invention. As the claimed invention relies on the purification of protein (specifically RuBisCO protein) from plant material, one of ordinary skill would have been motivated to perform a simple substitution of one known element (the plant material of De Jong) with another (the Lemna minor plant material of Ferreira) with a reasonable expectation of success (successful purification of RuBisCO from plant material). One of ordinary skill would have been motivated to perform the substitution because Ferreira teaches that RuBisCO can be successfully purified from Lemna minor plants via extraction and precipitation.
DeJong teaches use of flocculants (see paragraphs 0031-0033), but neither reference explicitly teaches the flocculant is an alkylamine epichlorohydrin, polydimethyldiallylammonium chloride, a polyamine, polyacrylamide, polyacromide, or polyethyleneimine.
However, Bluwa teaches polydimethyldiallylammonium chloride (i.e., polyDADMAC) is a cationic polymer flocculant that helps remove suspended solids, and works efficiently as a primary coagulant and charge neutralization agents in liquid-solid separation processes in a wide variety of industries (see pg. 1, paragraph 1 and 2). Bluwa further teaches that polyDADMAC is soluble in water, safe, non-toxic, has good hydrolytic stability, good adaptability to the changes in pH value, and is widely applied as a sugar and juice decolorant (see “What is polyDADMAC?” section, and “Application Fields” section).
Therefore, it would have been prima facie obvious to one of ordinary skill at the time of filing to modify the plant protein purification method of De Jong and Ferreira by including the polyDADMAC flocculant to arrive at the claimed invention. One of ordinary skill would have been motivated to perform a simple substitution of one known element (the flocculants of DeJong) for another (the polyDADMAC of Bluwa) with a reasonable expectation of flocculating the chlorophyll of DeJong because Bluwa explicitly teaches that polyDADMAC advantageously is a cationic polymer flocculant that helps remove suspended solids, and works efficiently as a primary coagulant and charge neutralization agent in liquid-solid separation processes in a wide variety of industries, is safe, non-toxic, has good hydrolytic stability, and good adaptability to the changes in pH value.
Regarding claim 6, De Jong teaches using metabisulfite, specifically sodium metabisulfite (see claim 3, and paragraph 0031).
Regarding claim 13, De Jong teaches various chelating agents (see paragraph 0087-88).
Regarding claim 14, De Jong teaches that the optimum pH for the solution may depend on the protein source, but will generally between pH 6-8 (see paragraph 0097)
Regarding claim 21, De Jong teaches adding divalent ions (see above).
Regarding claim 24, De Jong teaches mechanical disruption.
Regarding claim 64, De Jong teaches separation (see step iv of De Jong) can occur between 0-15 deg C (see above).
Regarding claim 69, De Jong teaches precipitation, centrifugation, and/or microfiltration (see paragraph 0115).
Regarding claim 90 and 93, De Jong teaches the yield of protein is 25-50% (see claim 1).
Regarding claim 96, De Jong does not specifically teach that the chlorophyll to protein weight ratio is less than 1:1000, 1:1500, 1:2000, or 1:2500. However, De Jong teaches the protein preparation is essentially free of chlorophyll, the ratio of chlorophyll to protein would be, absent evidence to the contrary, have a weight ratio of less than the claimed ratios.
Regarding claim 97, 99, and 101, De Jong teaches that the protein product is white, essentially without polyphenols, and was odourless. (see claim 1, paragraph 0066, and paragraph 0167).
Regarding claim 103, De Jong teaches that the protein is RuBisCo (see claim 10; paragraph 0045)
Regarding claim 111, De Jong teaches short mild-heat treatment between 1 minute and 3 hours, preferably between 10 and 30 mins (see paragraph 0030) and cooling quickly thereafter (see paragraph 0030).
Regarding claim 113 and 126, De Jong teaches addition of flocculation agents (see paragraph 0031-0033), and Bluwa explicitly teaches polyDADMAC flocculant (see above).
Regarding claim 117 and 132, Ferreira teaches use of Lemna minor (see above).
Regarding claim 118-119, De Jong teaches drying to provide a powder of functional plant protein, preferably said drying is performed by lyophilisation or spray drying (see claim 1).
Regarding claim 120, De Jong teaches the protein is a protein isolate (see claims 12-14).
Regarding claim 121, De Jong teaches that the purity of the protein is purified at least 95% by weight, more preferably at least 99.8% by weight (see paragraph 0076).
Regarding claim 123, the temperature of lysing is at 0-15 deg C (see above).
Regarding claim 120 and 124, De Jong teaches the use of the protein for gelation and foaming (see claim 14).
Regarding claim 130-131, De Jong teaches adsorbent resins (paragraph 0037-0040) and use of activated carbon to adsorb and remove polyphenols because it is low cost and convenient (paragraph 00129).
Regarding claims 133-135, Bluwat teaches polyDADMAC, which is cationic.
Accordingly, the claimed invention was prima facie obvious, especially in the absence of evidence to the contrary.
Response to Arguments
Applicant's arguments and the Declaration under 37 CFR 1.132 filed 04/27/2026 is insufficient to overcome the rejection of the claims as set forth in the last Office action for the reasons set forth below.
On pg. 7-11, Applicant argues a PHOSITA would not have contemplated a combination of the polyDADMAC of Bluwa with the process of DeJong. Specifically, Applicant argues that DeJong expressly teaches away from the use of flocculants because DeJong teaches “although flocculants can in principle be used to improve precipitation of chloroplast membranes, the addition of flocculants may hinder further application for the. . . fragments and is therefore not preferred” (see paragraph 0118). From this, Applicant argues DeJong is expressly directed to intended purpose of selecting a flocculant that would not hinder further application. Applicant also argues that DeJong’s principle of operation relies on gentle ionic flocculation that preserves chloroplastic fragments and substituting polyDADMAC changes the mechanism to polymeric membrane interaction and charge disruption such that the Office is “proposing a change in the principle of operation that runs expressly counter to the guidance of De Jong”. Applicant argues that “De Jong’s concern is functional incompatibility and that polyDADMAC’s known membrane disruptive behavior introduces process risk not routine optimization and a PHOSITA would lack reasonable expectation of success in substituting a cationic polymer flocculant, particularly one known to damage membranes” and that “there is no guidance that PDADMAC could achieve chlorophyll separation without compromising downstream protein integrity and yield. Applicant argues that De Jong uses divalent ions for efficient flocculation to improve yield, process speed, and reduced process cost. Applicant argues that the combination of DeJong and Bluwat forms an improper basis for obviousness, (citing to In re Gurley), Bluwat does not address protein recovery, RuBisCO preservation, etc. and that the use of polyDADMAC would clearly result in damage to the fragments to run counter to the intended purpose of the publication (citing to Benammoun et al regarding PDADMAC making gram positive and gram negative cell walls permeable).
In response, the examiner disagrees. De Jong recites advantages and disadvantages of use of flocculants in general (see paragraph 0118) and recites preferrential embodiments of flocculants for use in the claimed method, but this does not constitute a teaching away from Applicant's claimed polymer flocculant. While De Jong utilizes divalent flocculants as a preferred way to coagulate chlorophyll, this would not stop one of ordinary skill from looking beyond the De Jong reference for teachings regarding other flocculants for use in the claimed method, because a PHOSITA has access to any and all references relevant to the claimed invention and is not limited to just the De Jong reference (which is the essence of a rejection under 35 USC 103).
Second, DeJong expressly provides one of ordinary skill a reason to choose (or not to choose) a flocculant generally for chloroplast aggregation, as evidenced by DeJong’s own express teachings that flocculants improve precipitation of chloroplast membranes (see paragraph 0118). While DeJong cites flocculants as a non-preferred embodiment, disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. In re Susi, 440 F.2d 442, 169 USPQ 423 (CCPA 1971). "A known or obvious composition does not become patentable simply because it has been described as somewhat inferior to some other product for the same use." In re Gurley, 27 F.3d 551, 554, 31 USPQ2d 1130, 1132 (Fed. Cir. 1994). Furthermore, "[t]he prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004) (see MPEP 2123(II). Indeed, DeJong does not discourage one of ordinary skill from using other known flocculants, just that flocculants may be somewhat inferior to the divalent ions disclosed by DeJong.
Third, Bluwat explicitly teaches that polyDADMAC is a cationic polymer flocculant that advantageously helps remove suspended solids, and works efficiently as a primary coagulant and charge neutralization agent in liquid-solid separation processes in a wide variety of industries, is safe, non-toxic, has good hydrolytic stability, and good adaptability to the changes in pH value. De Jong outlines the same method steps as instantly claimed, and Bluwat provides one of ordinary skill the teaching, suggestion, and motivation to substitute the divalent flocculants with a polymer flocculant.
On pg. 11-13, Applicant argues the total protein and amount of RuBisCO protein from Lemna plant biomass generated by the method steps would have resulted in the observed attributes from those described in the application. Applicant points to the Declaration (given its fullest consideration) citing to the steps performed using PDADMAC vs calcium chloride divalent ion, showing a 44% higher production of Lemna protein powder than when using calcium chloride as a clarifying agent and 15% higher amount of RuBisCO protein (see exhibit A).
In response, the examiner disagrees. Looking at Exhibit A, Applicant describes a process where samples were clarified with CaCl2 (BC), skipping clarification with CaCl2 (E1), or using polyDADMAC flocculant (E2) (see pg. 11 of the arguments. Further, the left figure seems to compare the amount of protein yield when either skipping the use of CaCl2 as a flocculant (E1) versus use of PDADMAC (E2); and the same for the RuBisCO content in the right figure (no CaCl2 flocculant (E1) vs. PDADMAC (E2)). So, the data provided in exhibit A seems to confirm that PDADMAC flocculant is good for extracting protein from Lemna plant material versus no purification/clarification step at all. However, other than the labelling of the legend in the graphs, there is no actual comparative data/graphic for when CaCl2 (BC; as described in the Declaration) is used as a flocculant vs. PDADMAC (E2). Indeed, neither graphic in exhibit A seem to support Applicant’s argument that PDADMAC’s role as a flocculant is unexpectedly better than CaCl2.
Furthermore, as discussed above, Bluwat explicitly teaches that polyDADMAC is a cationic polymer flocculant that advantageously helps remove suspended solids, and works efficiently as a primary coagulant and charge neutralization agent in liquid-solid separation processes in a wide variety of industries, is safe, non-toxic, has good hydrolytic stability, and good adaptability to the changes in pH value. Thus, a PHOSITA would have recognized PDADMAC as a suitable flocculant, as confirmed by Applicant’s data. "A greater than expected result is an evidentiary factor pertinent to the legal conclusion of obviousness ... of the claims at issue." In re Corkill, 771 F.2d 1496, 226 USPQ 1005 (Fed. Cir. 1985). However, a greater than additive effect is not necessarily sufficient to overcome a prima facie case of obviousness because such an effect can either be expected or unexpected. Applicants must further show that the results were greater than those which would have been expected from the prior art to an unobvious extent, and that the results are of a significant, practical advantage. Ex parte The NutraSweet Co., 19 USPQ2d 1586 (Bd. Pat. App. & Inter. 1991) (see MPEP 716.029(a)). Thus, the rejections are maintained as set forth above.
Conclusion
NO CLAIMS ALLOWED.
THIS ACTION IS MADE FINAL. 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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/G.C.R./Examiner, Art Unit 1651
/THOMAS J. VISONE/Supervisory Patent Examiner, Art Unit 1672
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