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
Applicant filed a claim amendment on 26 November 2025.
Claims 1, 3, 5-10, 12-14 and 16-23 are pending.
Claims 5 and 19 are withdrawn from consideration as being drawn to nonelected species. Election was made without traverse in the reply filed on 12 August 2024 to the Restriction/Election Office Action mailed 10 June 2024.
Claims 1, 3, 6-10, 12-14, 16-18 and 20-23 are rejected.
Priority
Applicant’s claim for the benefit of a prior-filed application under 35 U.S.C. §119(e) or under 35 U.S.C. §120, §121, or §365(c) is acknowledged. As noted in the Non-Final Office Action mailed 06 November 2024, Applicant designates the instant application a "DIV" of 16/767,948.
Applicant has complied with all of the conditions for receiving the benefit of an earlier filing date under 35 U.S.C. §120 or §365(c).
Claim 9 has the effective filing date of 14 December 2018.
Claims 1, 3, 6-8, 10, 12-14, 16-18 and 20-23 have the effective filing date of 15 December 2017.
Claim Interpretations
(1) The claim subject matter recites the phrases “not providing supplemental O2” (claim 1), and “not providing supplemental CO2” (claims 3, 7 and 12).
The specification recites: “…, the term ‘supplemental oxygen’ or ‘supplemental O2’ refers to any external source of oxygen and thus excludes oxygen produced by the organism from photosynthesis. In certain implementations, the requirement of not providing supplemental oxygen to an algae culture is satisfied by culturing the algae in a closed system” (originally-filed specification, pg. 6, para. [0023]); and “…, the term ‘supplemental carbon dioxide’ or ‘supplemental CO2’ refers to any external source of CO2. Accordingly, supplemental CO2 does not to the CO2 produced from cellular respiration. In certain implementations, the requirement of not providing supplemental CO2 to an algae culture is satisfied by culturing the algae in a closed system” (spec., pg. 6, para. [0024]).
Therefore, prior art which shows a closed system incorporated into a method for large-scale cultivation of algae or which shows a system in which supplemental oxygen or carbon dioxide is not actively provided as a necessary step in the method or in which the provision of supplemental O2 or CO2 is not described, explained or defined, will be considered to be applicable prior art.
In addition, one of ordinary skill in the art of phototrophic algae propagation would understand that algae which are cultivated under phototrophic conditions (i.e., in the presence of light and a carbon (dioxide) source) would (inherently) produce oxygen (O2)- and, therefore, would have no need for supplemental O2.
Therefore, prior art which describes the phototrophic or mixotrophic propagation of algae under light conditions will be considered to be applicable prior art (even if the prior art document does not explicitly state that no supplemental oxygen was provided)- again, because it would be understood that algae (including mixotrophic algae) which generate oxygen under phototrophic conditions would have no need for supplemental O2.
(2) Claim 1 recites: "..., administering a feedstock comprising a mixotrophic substrate to the cultivation apparatus,..."
(a) The specification does not define, describe or explain what is meant by the term 'feedstock' within the context of the claimed subject matter. The specification does recite: "..., chemical feedstock (raw material),..." (originally filed specification, pg. 1, para. [0004]. An American English dictionary definition of the word 'feedstock' is: raw material to supply or fuel a machine or industrial process.
Therefore, prior art which shows adding a raw material which is understood to comprise solid raw material (e.g., in the form of nutrients) to a cultivation apparatus will be considered to be applicable prior art.
(b) The claimed subject matter recites the term “mixotrophic substrate” (claims 1, 8, 10, 14 and 17) or ‘mixotrophic’ (claim 18).
The specification recites: “…, the term ‘mixotrophic substrate’ refers to sugars, sugar alcohols, oligosaccharides, polysaccharides amino acids, and fatty acids. For example, D-glucose, D-mannose, D-galactose, D-fructose, L-sorbose, D-fucose, L-fucose, L-rhamnose, D-arabinose, Larabinase, D-lyxose, D-ribose, D-xylose, L-xylose, D-manitol, D-sorbitol, dulcitol, L-fucitol, adonitol, xylitol, L-arabitol, D-arbitol, glycerol, sucrose, oligosaccharides and polysaccharides with the aforementioned monomers, all amino acids, and acetate. In some aspects, ‘mixotrophic substrate’ encompasses cellulosic sugars” (spec., pg. 6, para. [0020]).
Therefore, prior art which teaches the term ‘mixotrophic substrate’ or which shows any of the compounds recited in the Markush group above as a substrate or medium to be used in the implementation of mixotrophic algal propagation will be considered to be applicable prior art.
(3) Claim 4 recites the abbreviation “PAR”.
The specification recites: “…, the term ‘photosynthetically active radiation’ is abbreviated as PAR” (spec., pg. 6, para. [0021]). (See also claim 9.)
Claim Rejections - 35 U.S.C. § 103
The rejection of Claims 1-4, 6-10, 12-14, 18, 20 and 21 under 35 U.S.C. §103 as being unpatentable over Bhatnagar et al. in view of Schmidt et al., and Huang, Q. et al., in the Non-Final Office Action mailed 04 September 2025, is withdrawn in view of Applicants' amendment received 26 November 2025.
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 of this title, 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.
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.
Claims 1, 3, 6-10, 12-14, 18 and 20-21 are rejected under 35 U.S.C. §103 as being unpatentable over Bhatnagar et al. (U.S. Patent Application Publication No. 2012/0028338 A1) in view of Schmidt et al. ((2005) Biotechnol. Bioeng. 90(1): 77-84).
Regarding claim 1, pertaining to a method for large-scale cultivation of algae, the method comprises cultivating algae in a cultivation apparatus, providing light to the cultivation apparatus, not providing supplemental O2 to the cultivation apparatus, Bhatnagar et al. teaches methods of generating an algal biomass, comprising: (a) forming an algal culture by combining: (i) a population of algal cells characterized as proliferating in a culture medium comprising an industry wastewater (pg. 1, para. [0007]). Certain photobioreactors for use herein comprise an enclosed bioreactor system such as, but not limited to, a polybag, as contrasted with an
open bioreactor, such as a pond or other open body of water, open tanks, open channels such as a raceway, and the like (pg. 6, para. [0057]). Bhatnagar et al. does not describe providing supplemental oxygen.
Further regarding claim 1, pertaining to administering a feedstock comprising a mixotrophic substrate to the cultivation apparatus, Bhatnagar et al. teaches that a culture medium comprising an industry wastewater may contain a nutritional supplement comprising an organic carbon source suitable for supporting the proliferation of a mixotrophic algal species (pg. 1, para. [0007]). At least one organic carbon source selected from the group consisting of: glucose, sucrose, arabinose, fructose, glycerol, methanol, acetate, a plant-based hydrolyzate, and any combination thereof (pg. 9, para. [0084]). Bhatnagar et al. teaches that mixotrophic algae can simultaneously drive photoautotrophy and heterotrophy to utilize both inorganic (CO2) and organic carbon substrates (pg. 1, para. [0006]). That is, mixotrophic algae exhibit the characteristics of both autotrophic and heterotrophic growth.
Bhatnagar et al. does not teach: 1) the stoichiometric oxygen supply in the cultivation apparatus is less than the stoichiometric carbon concentration introduced into the cultivation apparatus by the mixotrophic substrate in the feedstock as defined by the equation CO2+ H2O + PAR ↔ CH2O + O2 [Claim 1].
Schmidt et al. teaches that growth stoichiometry and kinetics was studied in batch cultures under heterotrophic growth. As the concentration of biomass increased in batch cultures, the oxygen consumption also increased, leading to a gradual decrease of dissolved oxygen tension in the growth medium (pg. 81, column 1, para. 1-2). Cultures were maintained under constant light (30-50 μmol mol photons m-2 s-1) by sequential transfer into photo-autotroph batch cultures (= PAR) (pg. 78, column 1, para. 1). Schmidt et al. further teaches that when the dissolved oxygen tension increased by more than 10% of air saturation (i.e., all added sugar was consumed), one new pulse of feed medium was added. Thereby, the sugar concentration was always maintained low and the sugar remained the growth limiting substrate (pg. 78, column 2, lines 16-19). That is, in a closed heterotrophic (or mixotrophic) system the stoichiometric oxygen supply of the algae culture is less than the stoichiometric carbon concentration introduced into the algae culture by the mixotrophic substrate in the feedstock as defined by the equation CO2 + H2O + PAR ↔ CH2O + O2.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have modified the method for large-scale cultivation of algae via cultivation of mixotrophic algae, as shown by Bhatnagar et al., by introducing the feedstock comprising mixotrophic substrate into the algal culture system so that the stoichiometric oxygen supply of the algae culture is less than the stoichiometric carbon concentration introduced by said mixotrophic substrate with a reasonable expectation of success. One of ordinary skill in the art would have been motivated to have made that modification, because Schmidt et al. teaches that a stoichiometric oxygen supply or level that is less than the stoichiometric carbon supply would indicate that the algae are actively utilizing the carbon sources in the supplied feedstock, and, therefore, are actively producing (more) biomass. That is, maintenance of this stoichiometric relationship (such as CO2 + H2O + PAR ↔ CH2O + O2) in a photobioreactor would result in an effective large-scale cultivation of algae. Schmidt et al. teaches that a decrease in dissolved oxygen tension in (closed system) fed-batch cultures naturally results from an increase in carbon concentration (as an increase in the addition of a mixotrophic substrate), the latter of which, in turn, results in an increase in biomass which, in turn, results in an increase in oxygen consumption, which, in turn, results in a decrease in oxygen in the culture medium (MPEP 2143 (l)(G)). Schmidt et al. describes this stoichiometric phenomenon as attributable to heterotrophic growth, which is also the type of growth exhibited by mixotrophic algae, which exhibit both autotrophic and heterotrophic growth properties.
Regarding claims 3, 6, 7 and 12, Bhatnagar et al. teaches photobioreactors comprising an enclosed bioreactor system such as, but not limited to, a polybag, as contrasted with an open bioreactor, such as a pond or other open body of water, open tanks, open channels such as a raceway, and the like (pg. 6, para. [0057]). Bhatnagar et al. does not mention providing supplemental CO2 to the cultivation apparatus.
Regarding claims 8, 10 and 14, Bhatnagar et al. teaches methods of generating an algal biomass, comprising: (a) forming an algal culture by combining: (i) a population of algal cells characterized as proliferating in a culture medium comprising an industry wastewater are disclosed (pg. 1, para. [0007]). The terms ‘photobioreactor’, ‘photobioreactor apparatus’, or ‘reactor’ refer to an apparatus containing a liquid medium comprising at least one species of photosynthetic organism and having either a source of light capable of driving photosynthesis associated therewith or having at least one surface at least a portion of which is partially transparent to light of a wavelength capable of driving photosynthesis (i.e. light of a wavelength between about 400-700 nm) (pg. 6, para. [0057]).
Regarding claim 9, to determine whether organisms could grow heterotrophically under dark conditions and perform mixotrophic metabolism, they were cultured in BG 11 medium. Light intensity was 80-100 μmoles/m2/s. After 7 days of incubation, growth was observed in terms of both chlorophyll a and biomass (pg. 10, para. [0105]).
Regarding claim 13, Schmidt et al. teaches experiments in which the mixotrophic algal strain Galdieria sulphuraria 074G is grown in medium supplemented with glucose, fructose, sucrose or sugar beet molasses in heterotrophic and mixotrophic conditions (pg. 78, column 1, para. 1 [nexus to Bhatnagar et al.- culturing mixotrophic algae in medium supplemented with the organic carbon source sugar]). Galdieria sulphuraria belongs to the group of Cyandiophyceae.
Regarding claim 18, Bhatnagar et al. teaches mixotrophic algae such as, but not limited to, Chlorella minutissima, Chlorella sorokiniana, Chlamydomonas globosa and Scenedesmus bijuga, either individually or as a consortium of these strains can be used for culturing in municipal wastewater (pg. 7, para. [0063]). In certain embodiments, the population of algal cells may comprise an algal genus selected from the group consisting of: Scenedesmus, Chlorella, and Chlamydomonas (pg. 9, para. [0094]).
Regarding claim 20, Bhatnagar et al. teaches that three green algae, Chlamydomonas globosa, Chlorella minutissima, and Scenedesmus bijuga were isolated and maintained in BG 11 medium (pg. 10, para. [0101]).
Regarding claim 21, Schmidt et al. teaches that bioreactor cultures were continuously stirred at 500 rpm by a four-bladed Rushton turbine (pg. 78, column 1, para. 2).
Claims 16 and 17 are rejected under 35 U.S.C. §103 as being unpatentable over Bhatnagar et al. in view of Schmidt et al., as applied to claims 1, 3, 6-10, 12-14, 18 and 20-21 above, and further in view of Zhan et al. (Intl. J. Hydrogen Energy 2016, pp. 1-13).
Bhatnagar et al. in view of Schmidt et al. do not show: 1) the cultivation apparatus is a tubular photobioreactor [Claim 16]; and 2) the feedstock provides an excess amount of mixotrophic substrate relative to the cultivation time period for the algae culture or algae in the cultivation apparatus [Claim 17].
Regarding claim 16, Zhan et al. teaches that plate photobioreactor, tubular photobioreactor and vertical column photobioreactor are three main closed photobioreactor culture systems, and it was proposed that a tubular photobioreactor could be more suitable for large-scale cultivation because of its higher surface to volume ratio (pg. 2, column 2, para. 3 [nexus to Bhatnagar et al.- large-scale cultivation of algae]).
Regarding claim 17, Zhan et al. teaches that, in mixotrophy culture, it is very important to optimize the balance between the relative heterotrophic and photoautotrophic metabolic activities. Light-dark cycle regime is one of the strategies to realize this purpose. Under light period, microalgae perform photoreduction that absorbs light energy and stores it in energy-carrying molecules such as ATP and NADPH. Under dark period, carbon dioxide was fixed via Calvin cycle using ATP and NADPH from the photoreduction, and microalgae are stimulated to oxides [sic] supplement organic substrates by heterotrophy for energy and then produce biomass and useful products such as lipid, sugar, protein (pg. 5, column 2, last para. thru pg. 6, column 1, lines 1-3). Since both CO2 utilization and organic carbon utilization exist under mixotrophic condition, CO2 and organic compounds supplies need to be finely optimized to achieve the best productivities in mixotrophic condition. CO2 is found to be a major limiting factor for algal growth and its excess strongly enhances photosynthetic productivity at an appropriate range (pg. 6, column 1, para. 3-4).
As it is during the heterotrophic stage of mixotrophic growth that biomass is produced, it would have been obvious to one of ordinary skill in the art of large-scale cultivation of algae to provide an excess of mixotrophic substrate, which supplies the organic carbon source(s) suitable for supporting the proliferation of a mixotrophic algal species, and the formation of carbon dioxide for use in the phototrophic phases of algal growth.
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to have modified the method for large-scale cultivation of algae via cultivation of mixotrophic algae, as shown by Bhatnagar et al. in view of Schmidt et al., by employing a tubular photobioreactor [Claim 16], as taught by Zhan et al., with a reasonable expectation of success, because Zhan et al. teaches that a tubular photobioreactor is one of several types of closed bioreactor systems which can be used to overcome the weakness of open pond system for implementing the autotrophic phase of the mixotrophic cultivation of algae, which is the method of large-scale algal cultivation shown by Bhatnagar et al. (MPEP 2143 (I)(G)).
One of ordinary skill in the art would have been motivated to have made that modification, because Zhan et al. teaches that closed photobioreactors overcome the weaknesses of the open pond system, and that a tubular photobioreactor could be more suitable for large-scale cultivation because of its higher surface to volume ratio (Zhan et al., pg. 2, column 2, para. 3).
It would have been further obvious (and one of ordinary skill in the art would have been motivated) to have provided an excess amount of mixotrophic substrate in the feedstock relative to the cultivation time period for the algae culture [Claim 17], with a reasonable expectation of success, because Zhan et al. teaches that it is very important to optimize the balance between the relative heterotrophic and photoautotrophic metabolic activities, and that the heterotrophic activity is the phase during which the algae utilize organic carbon sources to produce biomass and carbon dioxide. (Also refer to Applicant’s Figure 1 for a schematic of the mixotrophic growth process.)
Therefore, one of ordinary skill in the art would have been motivated to have provided an excess of mixotrophic substrate (containing said organic carbon sources) in order to supply carbon dioxide for use during the autotrophic stage of algal growth, and to increase algal biomass, which is the purpose of large-scale cultivation of algae. Zhan et al. teaches that cell density and biomass are important factors for microalgae large-scale production and application. For some microalgae that can grow under mixotrophic conditions, the biomass accumulation is improved by mixotrophic cultivation (Zhan et al., pg. 4, column 2, para. 1).
The mixotrophic cultivation may be one optimal culture method for microalgae large-scale culture and application. It also provides a new insight into the economically viable application of microalgae in the synergistic combination of environmental bioremediation and biofuel production (Zhan et al., pg. 8, column 2, para. 1). In addition, rather than remaining as a waste product, algae biomass used for bio-hydrogen photolysis production could be good substrates for biogas production from dark fermentation by using anaerobic fermentation as final step (pg. 9, column 2, lines 6-9).
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
Claims 22 and 23 are rejected under 35 U.S.C. §103 as being unpatentable over Bhatnagar et al. in view of Schmidt et al., as applied to claims 1, 3, 6-10, 12-14, 18 and 20-21 above, and further in view of Schwerna et al. ((2017 Sept) Eng. Life Sci. 17(2): 140-144).
Bhatnagar et al. in view of Schmidt et al. do not teach: 1) limiting the presence of oxygen in the cultivation apparatus [Claim 22]; and 2) maintaining photosynthetic oxygen evolution as the primary source of oxidant for respiration within the cultivation apparatus [Claim 23].
Schwerna et al. teaches a study investigating the quantification of oxygen production and respiration rates in a mixotrophic cultivation of microalgae in nonstirred photobioreactors. In the study, the mixotrophic cultivation of Galdieria sulphuraria is monitored and its fermentation optimized in nonstirred photobioreactors (PBR) (pg. 140, Title and Abstract [nexus to Bhatnagar et al.- mixotrophic fermentation of algae] [nexus to Schmidt et al.- cultivation of Galdieria sulphuraria]). The air supply via pressurized air is switched to pure gaseous nitrogen during illumination of mixotrophic cultivation of the acidophilic red algae G. sulphuraria (pg. 141, column 2, last para. [nexus to Bhatnagar et al.- closed system not providing supplemental O2 or CO2]).
Regarding claim 22, Schwerna et al. teaches that when illumination was switched off, the dissolved oxygen (DO) signal decreased by almost 7.4% during further incubation due to complete change from mixotrophic cultivation to heterotrophic cultivation conditions (pg. 142, column 1, lines 1-4). The drop in DO signal without illumination is described by Eq. (3) and represents the real OUR (oxygen uptake rate) in the process (OURD = OUR) (pg. 142, column 1, lines 10-12). That is, Schwerna et al. teaches that by controlling the amount of illumination or light that enters the PBR the presence of oxygen, in the form of DO, the presence of oxygen in the photobioreactor can be limited.
Regarding claim 23, Schwerna et al. teaches that the cells are continuously producing oxygen even if the air supply was switched over to pure nitrogen in the presence of an organic carbon source. Therefore, the oxygen concentration was shifted to higher values over time (pg. 142, column 1, lines 21-26). The data resulting from the study predict the relationship between the zone in which oxygen is net produced to the area where cell respiration dominates in a PBR, which has a major impact to optimize cell growth along with the formation of different products of interest such as pigments (pg. 140, Abstract). In a closed system without providing supplemental O2 (and CO2) (i.e., pure nitrogen), the oxygen concentration rises over time. That is, because the system lacks supplemental O2, the only/primary source of oxygen is via photosynthetic oxygen evolution. This oxygen supply would, in turn, be available for respiration of algal cells in the cultivation apparatus, as taught by Schwerna et al.
Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention, to have modified the method for large-scale cultivation of algae via cultivation of mixotrophic algae, as shown by Bhatnagar et al. in view of Schmidt et al., by: 1) limiting the presence of oxygen in the cultivation apparatus [Claim 22], as shown by Schwerna et al., with a reasonable expectation of success. Schwerna et al. shows a study investigating the quantification of oxygen production and respiration rates in the mixotrophic cultivation of microalgae (specifically, Galdieria sulphuraria) in photobioreactors. In the study, Schwerna et al. shows the relationship between illumination and the oxygen level in the PBR (measured as dissolved oxygen (DO)) and that the presence of oxygen in the cultivation apparatus can be limited by switching off or decreasing the amount of illumination/light (MPEP 2143 (I)(G)). The mixotrophic cultivation protocols shown by Bhatnagar et al. and Schmidt et al. show the use of illumination during phase(s) of the cultivation period to encourage the algal growth via the auxotrophic growth process.
It would have been further obvious to have maintained photosynthetic oxygen evolution as the primary source of oxidant for respiration within the cultivation apparatus [Claim 23], as shown by Schwerna et al., with a reasonable expectation of success, because Schwerna et al. shows that, in a closed system in which only nitrogen was sparged into the PBR, the algal cells continuously produce oxygen (MPEP 2143 (I)(G)). Therefore, despite not providing supplemental O2, as described in instant claim 1 and shown by Schwerna et al., the algal cells still produced oxygen for use by those cells undergoing the heterotrophic period of mixotrophic growth. Schwerna et al. teaches this in concluding that the data resulting from the study predict the relationship between the zone in which oxygen is net produced to the area where cell respiration dominates in a PBR, which has a major impact to optimize cell growth.
One of ordinary skill in the art would have been motivated to have made those modifications, because it would be understood by one of ordinary skill in the art of propagating algal cells under mixotrophic conditions that either scenario (i.e., limiting the presence of oxygen, and maintaining photosynthetic oxygen evolution as the primary source of oxidant for respiration) could be easily implemented because they are, in turn, based on basic knowledge of the dynamic between autotrophic and heterotrophic growth during mixotrophic algal cultivation. (That is, it would be obvious to expect that: 1) the practitioner could limit the presence of oxygen (as DO) by decreasing or eliminating the level of illumination to the mixotrophic culture; and/or 2) in a closed system in which no supplemental O2 was being provided, only the oxygen produced from photosynthesis would be available for respiration (during the heterotrophic phase).)
Therefore, the invention as a whole would have been prima facie obvious to a person of ordinary skill before the effective filing date of the claimed invention.
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 2146 et seq. 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 filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/ patent/patents-forms. The actual 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/apply/applying-online/eterminal-disclaimer.
Claims 1, 3, 6-9 and 13 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-4 of Patent No. 11,814,616 B2.
The claimed subject matter of instant Application No. 18/484,359 is:
Claim 1. A method for large-scale cultivation of algae. The method comprises: cultivating algae in a cultivation apparatus, providing light to the cultivation apparatus, not providing supplemental O2 to the cultivation apparatus, and administering a feedstock comprising a mixotrophic substrate to the cultivation apparatus. The stoichiometric oxygen supply in the cultivation apparatus is less than the stoichiometric carbon concentration introduced into the cultivation apparatus by the mixotrophic substrate in the feedstock as defined by the equation CO2 + H2O + PAR ↔ CH2O + O2.
Claim 3. Not providing supplemental CO2 to the cultivation apparatus.
Claim 6. The cultivation apparatus is a closed culture system.
Claim 7. Not providing supplemental CO2 to the cultivation apparatus.
Claim 8. The mixotrophic substrate comprises wastewater and feedstock is introduced to the cultivation apparatus when the cultivation apparatus is exposed to light intensity sufficient to support photosynthesis.
Claim 9. The intensity of light sufficient to support photosynthesis is greater than 50 μmol photosynthetically active radiation per square meter per second.
Claim 13. The algae cultivated in the cultivation apparatus comprises Cyanidiophyceae.
The claimed subject matter of Patent No. 11,814,616 is:
Claim 1. A method of increasing algae biomass productivity in an algae culture comprising Cyanidiophyceae. The method comprises: introducing a feedstock comprising a mixotrophic substrate to an algae culture when the algae culture is exposed to light at an intensity sufficient to support photosynthesis; not providing supplemental O2 to the algae culture; and not providing supplemental CO2 to the algae culture. The algae culture is a closed culture system.
Claim 2. The intensity of light sufficient to support photosynthesis is greater than 50 μmol photosynthetically active radiation per square meter per second.
Claim 3. The stoichiometric oxygen supply in the cultivation apparatus is less than the stoichiometric carbon concentration introduced into the cultivation apparatus by the mixotrophic substrate in the feedstock as defined by the equation CO2 + H2O + PAR ↔ CH2O + O2.
Claim 4. The mixotrophic substrate comprises wastewater.
Although the claims are not identical, they are not patentably distinct from each other because, as demonstrated above in the claim sets from each application, the method of increasing algae biomass productivity in an algae culture, described in Patent No. 11,814,616 B2, anticipates the method for large-scale cultivation of algae, described in instant Application No. 18/484,359.
Response to Arguments
Applicant’s arguments, pp. 7-9, filed 26 November 2025, with respect to the prior art references cited in the 35 U.S.C. §103 rejections, have been fully considered, but they are not persuasive.
Applicant also argues against the double patenting rejection (Remarks, pp. 5-6).
Applicant has filed an affidavit under 37 CFR 1.132 authored by one of the inventors, Peter J. Lammers.
It is noted that a reference has been added for evidentiary purposes (see MPEP 2144.03 (D)).
1. Applicant remarks (pg. 7, para. 4-5 thru pg. 8), with regard to the 103 rejections, that the Office asserts that the secondary reference of Schmidt teaches the subject matter with regard to " the stoichiometric oxygen supply in the cultivation apparatus is less than the stoichiometric carbon concentration introduced into the cultivation apparatus by the mixotrophic substrate in the feedstock as defined by the equation CO2 + H2O + PAR ↔ CH2O + O2". The statement in Schmidt is unrelated to the stoichiometric oxygen supply and its relationship to the stoichiometric carbon concentration. Instead, this statement from Schmidt is a dynamic observation about levels of oxygen dissolved in the growth medium.
In addition, in Schmidt O2 is supplied in excess by aeration (p. 78 "Batch Cultures"), and the process is managed to avoid O2 limitation. Schmidt states that "the sugar concentration was always maintained low and the sugar remained the growth-limiting substrate" (p. 78, "Fed-Batch Cultures"). Thus, a person having ordinary skill in the art would not find any teaching or suggestion of the stoichiometric oxygen supply being less than the stoichiometric carbon concentration from Schmidt. Lammers Declaration, para. 9.
Declarant remarks (pg. 3, para. 9) that in all cases, O2 is supplied in excess by aeration and sugar is the growth-limiting substrate. There is no teaching or suggestion in Schmidt of intentionally limiting O2 supply below the stoichiometric requirement for complete oxidation of the carbon substrate. Nothing in Schmidt teaches or suggests that intentionally limiting O2 supply below the stoichiometric requirement would be beneficial for enhanced biomass production.
However, in response to Applicant and Declarant, although Schmidt et al. shows aeration of Galdieria algal cultures in the batch culture experiments (pg. 78, column 1, para. 2), there is no indication that the cultures in the fed-batch experiments were aerated (pg. 78, column 1, last para. thru column 2). There is only a description of the addition of feed medium based on the increase in the oxygen concentration due to the photosynthetic activity of the algae. Schmidt et al. also shows that when the dissolved oxygen tension increased by more than 10% of air saturation (i.e., when all added sugar was consumed), one new pulse of feed medium was added (pg.78, column 2, lines 16-19).
This teaching of Schmidt et al. alone would motivate one of ordinary skill in the art of maximizing algal growth in a large-scale cultivation of algae to maintain an "oxygen supply" in the cultivation apparatus that is less than the carbon concentration introduced into the cultivation apparatus so as to avoid a culture environment that is completely devoid of feedstock (here, sugar (glucose, fructose or sucrose)) which would, in turn, potentially reduce the concentration of the mixotrophic algal population.
2. Applicant remarks (pg. 8, para. 1) that the claimed method is not merely the result of operating a closed or low-oxygen system, nor is it an incidental outcome of process design, Lammers Dec. para. 6. Instead, the claimed subject matter requires a deliberate and calculated approach to controlling the stoichiometric relationship between oxygen supply and carbon substrate input in the cultivation apparatus. The dissolved oxygen is less than the amount required to fully oxidize the introduced mixotrophic substrate.
However, in response to Applicant and Declarant, although Schmidt et al. does not explicitly teach the claimed stoichiometric relationship, the observations of algal culture activity, as noted above, implies that a constant stoichiometric relationship between oxygen supply and carbon concentration would benefit the health and growth of the algal culture. Schmidt et al. also shows algal growth in carbon limited fed-batch cultures in which biomass dry weight increased over time (pg. 82, column 1, para. 2 thru column 2). The graph in Figure 4B shows the % oxygen saturation remaining at a constant low level, while the carbon feed increased over time (pg. 82, column 1, Fig. 4).
In addition, Ganuza et al. (Pub. No. WO 2014/07479 A2 (provided here)) shows systems and methods for culturing microorganisms mixotrophically. Embodiments describe optimized growth and control of contamination in a culture with an organic carbon source, oxidative agents, and gas transfer (pg. 4, para. [0009] [nexus to Bhatnagar et al. and Schmidt et al.- algae grown mixotrophically]). The relationship between the oxygen limitation and mechanical design allows changes in the mechanical design to correspondingly alter the dissolved oxygen conditions of the culture. The oxygen demand based on stoichiometry is calculated in Example 11 (pg. 29, para. [0117]). Example 11 shows that the stoichiometric consumption of oxygen follows the relationship: CH3COOH + 2O2 → 2CO2 + 2H2O, which is the equation cited in instant claim 1 (Ganuza et al., pg. 42, para. [0146], Example 11).
That is, Ganuza et al. acknowledges the importance of propagating mixotrophic microorganisms according to the stoichiometric relationship between oxygen and carbon source.
In addition, Applicant's working examples do not explicitly show how the equation is applied.
3. Applicant remarks (pg. 8, para. 2) that this intentional limitation is achieved by restricting or eliminating supplemental oxygen input and by carefully managing the quantity and timing of substrate addition. Lammers Declaration, para. 7. Declarant remarks (pg. 2, para. 7) that the microaerobic condition generated by the algae culture only having oxygen produced from photosynthesis is sufficient and maximizes growth under mixotrophic conditions. The claimed process maintains this stoichiometric imbalance, rather than simply relying on the absence of aeration or the use of a closed vessel.
However, in response to Applicant and Declarant, Schmidt et al. shows this phenomenon in the fed-batch experiments in which carbon feed was limited. One of ordinary skill in the art of cultivating photosynthetic microorganisms (autotrophic or mixotrophic algae) would recognize that oxygen would be generated by algae that are actively photosynthesizing. Therefore, because supplemental O2 is not provided (or needed), it would be obvious to regulate the growth of the algae via intermittent feed addition, based on the oxygen levels in the fed-batch photobioreactors.
4. Applicant remarks (pg. 8, para. 3 thru pg. 9) that the claimed method yields several important and unexpected advantages, which are not taught or suggested by the cited references. The claimed method creates conditions where any photosynthetic oxygen is immediately consumed, allowing the facilitation of anaerobic processes without the negative side effects such as photo respiratory yield losses from buildup of oxygen. Lammers Declaration, para. 12. The claimed method also enhances substrate utilization and biomass productivity and suppresses contaminating heterotrophs. Lammers Declaration, para 12. These results were not predictable from the cited references and constitute strong evidence of nonobviousness.
The working examples presented in the detailed description of the present application demonstrate these benefits. As explained by Dr. Lammers, Table 2 and Table 4 both show that substrate yields are higher under the claimed microaerobic (O2-limited) mixotrophic conditions than under aerobic conditions. Paragraphs [0046] and [0047] of the detailed description explain that biomass yield is improved when photosynthesis is the source of oxygen for mitochondrial function during mixotrophic growth. This was not understood prior to Dr. Lammers research that led to the present application.
However, in response to Applicant and Declarant, the data in Table 2 show the use of a flat panel PBR (photobioreactor) for the "excess O2" data point and a helix tubular PBR for the "microaerobic" data points. In addition, algal culture in the flat panel PBR was run for 5 days (May 30-Jun 4) (with an ending cell density of 5.85g/L), while the helix tubular PBR was run for 3 days (ending cell density 3.56g/L) or 4 days (ending cell density 2.9-5.8g/L). Mean values were calculated for the helix tubular PBR data, but it is not clear if the flat panel PBR data are endpoints or mean values. It would be difficult to make a firm conclusion with regard to the substrate yield data (gram of biomass per gram of carbon feed consumed) because of the noted disparities. It is not clear that "biomass productivity" has been increased, because the ending cell density for the flat panel PBR is higher than that of the helix tubular PBR densities. It is not clear that the benefits of the stoichiometric maintenance are unequivocally evident. The experiments do not show that contaminating heterotrophs have been suppressed.
Table 4 shows that over time in a helix tubular PBR, the substrate yield does not increase uniformly, but increases (0.7, 1.06, 1.14 over Nov. 14- Nov. 16), then decreases (0.7 on Nov. 17), then increases (0.83 (as an average?) over Nov. 18-21). Therefore, it appears as though the maintenance of a (stoichiometric) oxygen supply that is less than the (stoichiometric) carbon concentration does not provide a consistent substrate yield over time, nor is it clear that the longer the algae are in culture, the higher the substrate yield will become. It is not clear that the benefits of the stoichiometric maintenance are unequivocally evident.
In addition, Applicant's working examples do not explicitly show how the equation is applied.
5. Applicant remarks (pp. 5-6), with regard to the double patenting rejection, that the present application is a divisional application filed to pursue patent protection for the unelected Group 2 claims. Accordingly, because the present claims are directed to subject matter that was restricted and unelected in the parent application, Applicant requests that the double patenting rejection of claims 1, 2, 4, 6-9, and 13 be withdrawn.
However, in response to Applicant, the claimed subject matter described in parent application 16/767,948, which resulted in patent no. US 11,814,616, was not one of the original inventions as described in the Restriction/Election Office Action. The two inventive groups cited in the Restriction/Election Office Action for parent application 16/767,948 were: 1) a method of increasing algae biomass product (Group I); and 2) a method for large-scale cultivation of algae (Group II). The claimed subject matter of patent no. 11,814,616 is: a method of increasing algae biomass productivity, not a method of increasing an algae biomass product. Therefore, although Applicant claims instant application 18/484,359 to be a DIV of 16/767,948, it is not clear that this application is a true divisional application.
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 extension fee 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 date of this final action.
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/SMP/Examiner, Art Unit 1657