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
Claims 1-11, 13, 15-18, 37-38, 54, and 56 are pending. Claims 12, 14, 19-36, 39-53, 55, and 57-77 are cancelled.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-11, 13, 15-18 and 37-38, and the species of polypropylene from Genus (A), heating from Genus (B) and organism from Genus (C), in the reply filed on 9/30/2025 is acknowledged.
Claims 17-18, 37-38, 54, and 56 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention and species, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 9/30/2025.
Claims 1-11, 13, and 15-16 are examined herein.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-11, 13, 15-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “optionally mixing the depolymerized residue with an adjuvant selected from a surfactant, a nitrogen source, a phosphate source, a carbohydrate source, a source of mineral, or a combination thereof, to form a culture medium, wherein when used, the surfactant comprises a synthetic nonionic biodegradable surfactant.” It is unclear whether the surfactant is required or not given the conditional language (“when used”). In addition, since step (b) is optional, there is a lack of antecedent basis for “the culture medium” in step (c) for the case where step (b) is not performed.
Claim 2 recites wherein step (c) comprises introducing an enzyme or an organism that expresses a fatty acid biosynthetic pathway; enhances metabolism of polyalkylene residues; increases flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways; increases the uptake of polyalkylene residues from the medium; or combinations thereof. It is unclear whether claim 2 is further modifying step (c) by including additional steps (such as introducing another enzyme, introducing an organism that expresses a fatty acid biosynthetic pathway, enhancing metabolism of polyalkylene residues, etc.), or claim 2 is requiring that the step of introducing an enzyme or an organism into the culture medium (step (c)) has the effects of enhancing the metabolism of polyalkylene residues, increasing flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways; or increasing the uptake of polyalkylene residues from the medium.
Claim 3 recites wherein step (c) comprises introducing an organism comprising a gene, the gene encoding an enzyme that enhances metabolism of polyalkylene residues or encoding essential enzymes to increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways. It is unclear whether claim 3 further limits the organism already introduced in step (c) by requiring that the organism comprises a specific gene or whether claim 3 is introducing an additional organism in step (c) (i.e. step (c) comprises introducing an enzyme or organism into the culture medium as well as introducing an organism comprising a gene).
Claim 4 recites wherein step (c) comprises introducing an organism comprising a gene, the gene encoding a transport protein that increases the uptake of polyalkylene residues from the medium. It is unclear whether claim 4 is further limiting the organism already introduced in step (c) by requiring that the organism comprises a specific gene or whether claim 4 is further limiting step (c) by requiring the introduction of another organism that comprises a gene (i.e. step (c) comprises introducing an enzyme or an organism to the culture medium as well as introducing an organism with a gene encoding the transport protein).
Claim 6 recites polypropylene (including high density polypropylene and/or low density polypropylene). The parentheses render the claim indefinite because it is unclear whether the phrases inside the parentheses are part of the claimed invention. In the event that the phrases in parenthesis are part of the claimed invention, there is both a broad limitation (polypropylene) as well as narrower limitations (high density polypropylene or low density polypropylene) within the same claim, further rendering the claim indefinite. The claim suffers from the same deficiencies with respect to the limitation polyethylene (including high density polyethylene and/or low density polyethylene).
Regarding claim 9, the phrase "such as" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 10 recites a neat or heterologous mixture of the polyalkylene containing plastic material. Although “heterologous mixture” is defined in the specification as a non-uniform composition, (see lines 11-13 on page 24), it is unclear whether this refers to the polyalkylene containing plastic material itself (as in the plastic material contains multiple different kinds of plastics, such as a mixture of different types of polystyrene with polypropylene) or whether the claim scope is mixtures of polyalkylene containing plastic material (for example, polyalkylene-containing plastic bags mixed with polyalkylene-containing plastic bottles).
Claims 2-11, 13, and 15-16 are rejected for depending from a rejected base claim and not rectifying the sources of indefiniteness discussed above.
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1 and 3-4 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 3 recites introducing an organism comprising a gene, the gene encoding an enzyme that enhances metabolism of polyalkylene residues or encoding essential enzymes to increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways.
Claim 4 recites introducing an organism comprising a gene, the gene encoding a transport protein that increases the update of polyalkylene residues from the medium.
Polyalkylene materials include a diverse range of polymers such as polypropylene, polyester, polystyrene, polyurethane, polyethylene and others.
The specification discloses measuring the growth of Yarrowia lipolytic ATCC strain 46482 on OP5 medium (lines 21-22 and 32 on page 49), which contains polypropylene residues (lines 12 on page 44). The specification discloses that introducing genes that help with organophosphate degradation improved cell lipid content (lines 30-31 on page 59). The specification also discloses the growth of Escherichia coli and Bacillus subtilis in polyester derived medium (lines 6-7 on page 8, Figure 19), as well as the growth of Candida famata in polyester derived medium (lines 23-25 on page 7, Figure 10).
In summary, the specification does not disclose any genes encoding an enzyme that enhances metabolism of polyalkylene residues, genes encoding essential enzymes to increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways, or genes encoding a transport protein that increases the update of polyalkylene residues from the medium. Rather, the examples in the specification involve microorganisms not genetically modified to include any specific genes with the claimed functions, nor are any native genes within these microorganisms with the claimed functions disclosed.
Danso et al. (Applied and environmental microbiology 85.19 (2019): e01095-19), which is a review article summarizing the state of the art with respect to the microbial degradation of plastics, teaches that a variety of microorganisms have been affiliated with assumed polyethylene degradation (paragraph bridging pages 6-7). However, Danso points out that the authors report on degradation of the polymers using commercial polymers that possibly contain chemical additives and degradation was determined by measuring weight loss and by Fourier transform infrared spectroscopy (paragraph 2 on page 7). Weight loss and surface structure changes are most likely attributed to the degradation of chemical additives (paragraph 2 on page 7). None of these studies revealed biochemical mechanisms and enzymes involved in PE breakdown (paragraph 2 on page 7). Penicillium-derived laccase is potentially involved in PE breakdown, but no detailed biochemical characterization was performed, and no sequence of the protein or the corresponding gene was deposited (paragraph 2 on page 7).
With respect to polystyrene, Danso teaches that some brown rot fungi are able to depolymerize polystyrene. However, no enzymes involved in the depolymerizing reaction have been identified (paragraph 6 on page 8). Danso teaches that some bacteria are capable of metabolizing the monomer (styrene) (bottom paragraph on page 8). The key enzymes are a styrene monooxygenase, a styrene oxide isomerase, and a phenylacetaldehyde dehydrogenase (paragraph 1 on page 9).
With respect to polypropylene degradation, no defined enzymes or pathways that are responsible for the degradation are known (bottom paragraph on page 9).
With respect to polyurethane, some bacterial lipases are reported to act on ester-based polyurethane, including PueB lipase from Pseudomonas chlororaphis bottom paragraph on page 5). No enzymes have yet been described acting on polyurethane ethers (paragraph 6 on page 6).
Notably, there are no transport proteins that increase the uptake of polyalkylene residues from the medium or essential enzymes that increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways taught by the prior art. Although some enzymes that enhance metabolism of polyalkkylene residues are known for specific polyalkylenes, such as ester-based polyurethane and polystyrene, no species of enzymes that enhance metabolism of other polyalkylene residues (e.g. polypropylene, polyethylene, and polyurethane ethers) are taught by the prior art.
Lastly, there is no structure-function relationship disclosed in the specification or the prior art regarding enzymes that enhance metabolism of polyalkylene residues, essential enzymes that increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways or transport proteins that increases the update of polyalkylene residues from the medium.
Based on the above analysis, the person of ordinary skill in the art would not have recognized that the inventors had possession of the claimed genus of genes encoding an enzyme that enhance metabolism of polyalkylene residues, genes encoding essential enzymes to increase flux of polyalkylene-derived compounds through fatty acid biosynthetic pathways, or genes encoding a transport protein that increase the update of polyalkylene residues from the medium.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-2, 5-6, and 8-10 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Karthigesan et al. (J. Cheni. Tech. Bioteclinol. 1981, 31, 55-65; cited in the Requirement for Restriction mailed on 8/14/2025).
Karthigesan teaches pyrolyzing (depolymerizing) polypropylene or polyethylene by heating and mixing polyethylene pyrolysate into culture medium comprising several adjuvants, including a phosphate source and a nitrogen source (See Abstract, page 57, sections 2.2.2. Culture medium and 2.2.4. Dispersal of carbon sources in culture medium; Table 2 on page 56). Karthigesan cultures Candida tropicalis in the culture medium to produce protein (page 61, 3.2.2.Fermentation of pyrolysis products, paragraph 1, Title and Abstract). Utilization of pyrolysate was 49.0% (page 61, 3.2.2 Fermentation of pyrolysis products, line 4).
Regarding claim 2, utilization of pyrolysate was 49.0% (page 61, 3.2.2 Fermentation of pyrolysis products, line 4), so the organism increases the update of polyalkylene residues from the medium.
Regarding claim 5, Candida tropicalis is a naturally occurring organism because the cultures are revived from freeze-dried stocks and used without genetic modification (page 57, 2.2.1. Organism and maintenance).
Regarding claim 6, Karthigesan pyrolyzes both polypropylene and polyethylene (Table 2) and cultures C. tropicalis using polyethylene pyrolysate as the sole carbon source (page 60, 3.2.1. Dispersal of waxy pyrolysates in aqueous culture media).
Regarding claims 8-9, the polyethylene is derived from post-consumer waste material (see “Form” column of Table 1 on page 56), which include a milk bottle (“cast plastic packaging material) and plastic bags (“films”).
Regarding claim 10, “heterologous mixture” is interpreted as combinations of different plastics within the same material. Karthigesan teaches pyrolyzing comprises heating the polyethylene present in plastic objects (“heterologous mixture”) to a temperature of 560°C (Table 1 header), which is a temperature within the claimed range of greater than 350°C.
Claim Rejections - 35 USC § 103
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.
Claims 1-2, 6-10, 13, and 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) in view of Kuttiraja et al. (Applied biochemistry and biotechnology 180.8 (2016): 1586-1600; cited in the IDS filed on 5/15/2023) as evidenced by Tao et al. (Journal of microbiology and biotechnology 33.2 (2022): 151).
Stubblefield teaches preparing a growth medium from polypropylene from a carpet waste ([0082]). Stubblefield teaches heating the polypropylene, then adding a dispersant mix comprising the oleic acid ([0083]). The polypropylene mixture is heated again and mixed with a diluent to form a culture medium ([0085]). Stubblefield also teaches combining the depolymerized residue with lactose glucose, fructose, maltose, ribose (carbohydrate sources) or yeast extract (Stubblefield claim 14). Yeast extract comprises nitrogen, phosphate, and minerals, as evidenced by Tao (page 151, Introduction, paragraph 1; page 156, paragraphs 2-3). Stubblefield teaches dispersing the polymeric material by adding a non-ionic biodegradable surfactant (Stubblefield claims 9-10). Heating the polypropylene is performed at 300°C ([0084]), at which temperature the polypropylene is pyrolyzed ([0041]). Stubblefield then cultures Yarrowia lipolytica within the culture medium ([0087]). The culture medium comprising the polypropylene is taken up by the cell ([0090]).
Stubblefield does not teach accumulating a product (claim 1) or specifically accumulating a fatty acid product (claims 15-16).
Kuttiraja teaches culturing Yarrowia lipolytica in a glycerol culture medium to produce lipids comprising fatty acids (Abstract and paragraph bridging pages 1588-1589, paragraph 1 on page 1599 and Table 4).
Regarding claims 1 and 15-16, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of Stubblefield by adding glycerol to the culture medium and to culture Yarrowia lipolytica in order to produce lipids, which contain fatty acids. The person of ordinary skill in the art would have had a reasonable expectation of success in the modification given that Kuttiraja teaches that Yarrowia lipolytica is capable of utilizing glycerol to produce lipids.
Regarding claim 2, Yarrowia lipolytica increases the uptake of the polypropylene residues from the medium (Stubblefield [0090]). Yarrowia lipolytica also necessarily expresses a fatty acid biosynthetic pathway because Y. lipolytica synthesizes lipids, which contain fatty acids (Kuttiraja Abstract).
Regarding claims 6-8, Stubblefield teaches preparing a growth medium from polypropylene from a carpet waste ([0082]), so the plastic material consists essentially of polypropylene and is also post-consumer waste material.
Regarding claim 9, polypropylene derived from carpet waste is a fibrous material.
Regarding claim 10, Stubblefield teaches that depolymerizing may be performed by heating the mixture to greater than 300°C ([0041]), which overlaps with the claimed range of 350°C or greater.
Regarding claim 13, Stubblefield does not teach the carbon to nitrogen ratio of the culture medium.
Kuttiraja teaches optimizing the substrate concentration and carbon/nitrogen ratio to produce the maximum amount of lipids using Yarrowia lipolytica (Abstract and Figure 4). Low C/N ratios favor biomass production (Figure 4A), whereas higher C/N ratios favor lipid production (Figure 4C). Similarly, the yield (g/g) of biomass and lipids is dependent on the C/N ratio (Fig. 6).
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 by routine experimentation the carbon to nitrogen ratio of the culture medium in order to maximize the production of lipids by Yarrowia lipolytica. The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of C/N ratio, given that C/N ratio has a predictable effect on biomass and lipid production.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) in view of Kuttiraja et al. (Applied biochemistry and biotechnology 180.8 (2016): 1586-1600; cited in the IDS filed on 5/15/2023) as evidenced by Tao et al. (Journal of microbiology and biotechnology 33.2 (2022): 151), as applied to claims 1-2, 7-10, 13, and 15-16 above, further evidenced by Jach (Molecules 27.7 (2022): 2300).
Regarding claim 5, Yarrowia lipolytica is widespread in nature and can be easily isolated from various environments including water and soil, as evidenced by Jach (1. Introduction, paragraph 2), so the organism is naturally occurring.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) in view Kuttiraja et al. (Applied biochemistry and biotechnology 180.8 (2016): 1586-1600; cited in the IDS filed on 5/15/2023) as evidenced by Tao et al. (Journal of microbiology and biotechnology 33.2 (2022): 151), as applied to claims 1-2, 7-10, 13, and 15-16 above, further evidenced by Hujuri et al. (Journal of Applied Polymer Science 119.4 (2011): 2318-2325).
See discussion of Stubblefield and Kuttiraja above, which is incorporated into this rejection as well.
Regarding claim 11, polypropylene pyrolysis degradation products comprise hydrocarbons within the claimed range of C6-C36 as evidenced by Hujuri (see Figure 7). The hydrocarbons comprise alkenes (Hujuri page 23,22, right column, bottom paragraph). Furthermore, the alkenes are branched: see page 2323, reaction 4a and 4b of top formula of Hujuri.
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.
Claim 1 is rejected on the ground of nonstatutory double patenting as being unpatentable over claim 7 of U.S. Patent No. 12,037,466 (‘466). Although the claims at issue are not identical, they are not patentably distinct from each other because claim 1 is anticipated by claim 7 of ‘466.
Claim 1 of ‘466 recites a method of producing a biopolymer comprising introducing a host cell into a microbial culture medium, accumulating the biopolymer in the host cell by culturing the host cell and recovering the biopolymer produced by the host cell, wherein the culture medium is prepared from a polymeric plastic material by heating the plastic material with a solvent to depolymerize the plastic material and form a bioavailable polymeric mixture, processing the mixture to form a resin, and combining the resin with an adjuvant to form the microbial culture medium.
Claim 7 of ‘466 depends from claim 1 of ‘466.
Regarding claim 1, claim 7 of ‘466 recites heating the non-biodegradable polymeric plastic material at 300°C to form a bioavailable polymeric mixture, which necessarily depolymerizes the plastic material.
Therefore, instant claim 1 is anticipated by claim 7 of ‘466.
Claims 1 and 6-11 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 5, and 7-9 of U.S. Patent No. 12,037,466 (‘466) in view of Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) as evidenced by Tao et al. (Journal of microbiology and biotechnology 33.2 (2022): 151) and by Hujuri et al. (Journal of Applied Polymer Science 119.4 (2011): 2318-2325).
Claim 1 of ‘466 recites a method of producing a biopolymer comprising introducing a host cell into a microbial culture medium, accumulating the biopolymer in the host cell by culturing the host cell and recovering the biopolymer produced by the host cell, wherein the culture medium is prepared from a polymeric plastic material by heating the plastic material with a solvent to depolymerize the plastic material and form a bioavailable polymeric mixture, processing the mixture to form a resin, and combining the resin with an adjuvants to form the microbial culture medium.
Claim 5 of ‘466 recites that the plastic material is derived from a carpet fiber.
Claim 7 of ‘466 recites heating the non-biodegradable polymeric plastic material with a solvent at a temperature from 50°C. to 300°C.
Claim 8 of ‘466 recites wherein depolymerizing the non-degradable polymeric plastic material is not carried out by enzymatic reaction.
Claim 9 of ‘466 recites introducing a host cell into the microbial culture medium, accumulating the biological material, wherein the culture medium is prepared from a polymeric plastic material by heating the plastic material with a solvent to depolymerize the plastic material and form a bioavailable polymeric mixture, processing the mixture to form a resin, and combining the resin within one or more adjuvants to form the medium.
Regarding instant claims 6-8, claims 1, 5, and 7-9 of ‘466 do not recite that the plastic material consists essentially of polypropylene from post-consumer waste material.
Stubblefield teaches preparing a growth medium from polypropylene from a carpet waste ([0082]). Stubblefield teaches mixing the depolymerized residue of polypropylene with yeast extract powder ([0085]) or sugars, which are carbohydrates (Stubblefield claim 14), or a non-ionic biodegradable surfactant (Stubblefield claims 9-10). Yeast extract comprises nitrogen, phosphate, and minerals, as evidenced by Tao (page 151, Introduction, paragraph 1; page 156, paragraphs 2-3).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use Stubblefield’s carpet waste-derived polypropylene in the method of claims 1, 5, and 7-9 of ‘466. Claim 5 of ‘466 already recites that the polymeric plastic material is derived from a carpet fiber. Thus, the person of ordinary skill in the art would have had a reasonable expectation of success in using the polypropylene derived from carpet waste for the method of claims 1, 5, and 7-9 of ‘466.
Regarding the optional limitation in claim 1, it would have been further obvious to combine any of Stubblefield’s adjuvants (such as sugars and yeast extract) with the culture medium in the method of claims 1, 5, and 7-9 of ‘466 in order to enhance its nutrients for microbial growth. It would also have been obvious to combine the non-ionic biodegradable surfactant taught by Stubblefield in order to disperse the depolymerized residues. The person of ordinary skill in the art would have had a reasonable expectation of success in these modifications.
Regarding claim 9, polypropylene derived from carpet waste is a fibrous material.
Regarding claim 10, claim 7 of ‘466 recites heating the non-biodegradable polymeric plastic material with a solvent at a temperature from 50°C. to 300°C, which is less than the claimed range.
Stubblefield teaches that depolymerizing may be performed by heating the mixture to greater than 300°C ([0041]), which overlaps with the claimed range of 350°C or greater.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the heating conditions of Stubblefield to the method of claim 5 of ‘466. The person of ordinary skill in the art would have had a reasonable expectation of success because both methods are aimed at depolymerizing the same plastic material (carpet waste).
Regarding claim 11, polypropylene pyrolysis degradation products comprise hydrocarbons within the claimed range of C6-C36 as evidenced by Hujuri (see Figure 7). The hydrocarbons comprise alkenes (Hujuri page 23,22, right column, bottom paragraph). Furthermore, the alkenes are branched: see page 2323, reaction 4a and 4b of top formula of Hujuri.
Claims 2, 5, 13, and 15-16 are rejected on the ground of nonstatutory double patenting as being unpatentable over claim 9 of U.S. Patent No. 12,037,466 (‘466) in view of Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) and Kuttiraja et al. (Applied biochemistry and biotechnology 180.8 (2016): 1586-1600; cited in the IDS filed on 5/15/2023) as evidenced by Jach (Molecules 27.7 (2022): 2300)..
See discussion of claim 9 of ‘466 above, which is incorporated into this rejection as well.
Claim 9 of ’466 does not recite that the biological material is a fatty acid product (claims 15-16).
Kuttiraja teaches culturing Yarrowia lipolytica in a glycerol culture medium to produce lipids comprising fatty acids (Abstract and paragraph bridging pages 1588-1589, Table 4).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of claim 9 of ‘466 by adding glycerol to the culture medium and to culture Yarrowia lipolytica in order to produce lipids, which contain fatty acids. The person of ordinary skill in the art would have had a reasonable expectation of success in the modification given that Kuttiraja teaches that Yarrowia lipolytica is capable of utilizing glycerol to produce lipids.
Regarding claim 13, claim 9 of ‘466 does not recite the carbon to nitrogen ratio of the culture medium.
Kuttiraja teaches optimizing the substrate concentration and carbon/nitrogen ratio to produce the maximum amount of lipids using Yarrowia lipolytica (Abstract and Figure 4). Low C/N ratios favor biomass production (Figure 4A), whereas higher C/N ratios favor lipid production (Figure 4C). Similarly, the yield (g/g) of biomass and lipids is dependent on the C/N ratio (Fig. 6).
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 by routine experimentation the carbon to nitrogen ratio of the culture medium of claim 9 of ‘466 in order to maximize the production of lipids by Yarrowia lipolytica. The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of C/N ratio, given that C/N ratio has a predictable effect on biomass and lipid production.
Regarding instant claim 2, Yarrowia lipolytica necessarily expresses a fatty acid biosynthetic pathway because Y. lipolytica synthesizes lipids, which contain fatty acids (Kuttiraja Abstract).
Regarding instant claim 5, Yarrowia lipolytica is widespread in nature and can be easily isolated from various environments including water and soil, as evidenced by Jach (1. Introduction, paragraph 2), so the organism is naturally occurring.
Claims 1-2, 5-11, 13, and 15-16 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 3, and 8-9 of U.S. Patent No. 10,822,469 (‘489) in view of Stubblefield et al. (US 2018/0230286 A1; cited on the IDS filed on 12/22/2022) and ) and Kuttiraja et al. (Applied biochemistry and biotechnology 180.8 (2016): 1586-1600; cited in the IDS filed on 5/15/2023) as evidenced by Tao et al. (Journal of microbiology and biotechnology 33.2 (2022): 151), by Hujuri et al. (Journal of Applied Polymer Science 119.4 (2011): 2318-2325) and by Jach (Molecules 27.7 (2022): 2300).
Claim 1 of ‘469 recites a method of making a microbial culture medium from a polymeric plastic material comprising heating the plastic material with a solvent to depolymerize the material and form a mixture, processing the mixture to form a resin, and combining the resin with an adjuvant to form the medium.
Claim 3 of ‘469 recites that the plastic material is derived from carpet fiber.
Claim 8 of ‘469 recites that the heating is from 50°C to 300°C.
Claim 9 of ‘469 recites adding one or more adjuvants selected from lactose, glucose, fructose, maltose, ribose, and yeast extract. Glucose, fructose, maltose, and ribose are carbohydrate sources. Yeast extract contains nitrogen, phosphate and minerals as evidenced by Tao (page 151, Introduction, paragraph 1; page 156, paragraphs 2-3).
Claims 1, 3, and 8-9 of ‘469 do not recite introducing an organism into the culture medium or accumulating at least one product produced by the organism (claim 1).
Claims 1, 3, and 8-9 of ’469 do not recite accumulating a fatty acid product produced by the organism (claims 15-16).
Regarding instant claims 1 and 6-8, claims 1, 3, and 8-9 of ‘469 do not recite that the plastic material consists essentially of polypropylene from post-consumer waste material.
Stubblefield teaches preparing a growth medium from polypropylene from a carpet waste ([0082]). Stubblefield teaches heating the polypropylene, then adding a dispersant mix comprising oleic acid ([0083]). The heating is performed at 300°C ([0084]), at which temperature the polypropylene is pyrolyzed ([0041]). The polypropylene mixture is heated again and mixed with a diluent to form a culture medium ([0085]). Stubblefield then cultures Yarrowia lipolytica within the culture medium ([0087]).
Regarding claims 1 and 6-8, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to use Stubblefield’s carpet waste-derived polypropylene in the method of claims 1, 3, and 8-9 of ‘469 and to add Yarrowia lipolytica to the microbial culture medium. Claim 3 of ‘469 already recites that the polymeric plastic material is derived from a carpet fiber. Thus, the person of ordinary skill in the art would have recognized that polypropylene derived from carpet waste would have had a reasonable expectation of success in using the polypropylene for the method of claims 1, 3, and 8-9 of ‘469. In addition, since the method of claims 1, 3, and 8-9 of ‘469 produces a microbial culture medium, it would have been obvious to add a microorganism such as Yarrowia lipolytica to the medium and to culture the microorganism.
Stubblefield does not teach what product is produced by culturing Yarrowia lipolytica.
Kuttiraja teaches culturing Yarrowia lipolytica in a glycerol culture medium to produce lipid comprising fatty acids (Abstract and paragraph bridging pages 1588-1589, and Table 4).
Regarding claims 15-16, it would have been further obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify the method of claims 1, 3, and 8-9 of ‘469 modified by Stubblefield by adding glycerol to the culture medium and to culture Yarrowia lipolytica in order to produce lipids, which contain fatty acids. The person of ordinary skill in the art would have had a reasonable expectation of success in the modification given that Kuttiraja teaches that Yarrowia lipolytica is capable of utilizing glycerol to produce lipids.
Regarding instant claim 2, Yarrowia lipolytica necessarily expresses a fatty acid biosynthetic pathway because Y. lipolytica synthesizes lipids, which contain fatty acids (Kuttiraja Abstract and Table 4).
Regarding instant claim 5, Yarrowia lipolytica is widespread in nature and can be easily isolated from various environments including water and soil, as evidenced by Jach (1. Introduction, paragraph 2), so the organism is naturally occurring.
Regarding claim 9, polypropylene derived from carpet waste is a fibrous material.
Regarding claim 10, claim 8 of ‘469 recites heating the non-biodegradable polymeric plastic material with a solvent at a temperature from 50°C. to 300°C, which is less than the claimed range.
Stubblefield teaches that depolymerizing may be performed by heating the mixture to greater than 300°C ([0041]), which overlaps with the claimed range of 350°C or greater.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to apply the heating conditions of Stubblefield to the method of claim 3 of ‘469 modified by Stubblefield and Kuttiraja. The person of ordinary skill in the art would have had a reasonable expectation of success because both methods are aimed at depolymerizing the same plastic material (carpet waste).
Regarding claim 11, polypropylene pyrolysis degradation products comprise hydrocarbons within the claimed range of C6-C36 as evidenced by Hujuri (see Figure 7). The hydrocarbons comprise alkenes (Hujuri page 23,22, right column, bottom paragraph). Furthermore, the alkenes are branched: see page 2323, reaction 4a and 4b of top formula of Hujuri.
Regarding claim 13, claims 1, 3, and 8-9 of ‘469 do not recite the carbon to nitrogen ratio of the culture medium.
Kuttiraja teaches optimizing the substrate concentration and carbon/nitrogen ratio to produce the maximum amount of lipids using Yarrowia lipolytica (Abstract and Figure 4). Low C/N ratios favor biomass production (Figure 4A), whereas higher C/N ratios favor lipid production (Figure 4C). Similarly, the yield (g/g) of biomass and lipids is dependent on the C/N ratio (Fig. 6).
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 by routine experimentation the carbon to nitrogen ratio of the culture medium of in the method of claims 1, 3, and 8-9 of ‘469 modified by Stubblefield and Kuttiraja in order to maximize the production of lipids by Yarrowia lipolytica. The person of ordinary skill in the art would have had a reasonable expectation of success in the routine optimization of C/N ratio, given that C/N ratio has a predictable effect on biomass and lipid production.
Conclusion
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/LOUISE W HUMPHREY/Supervisory Patent Examiner, Art Unit 1657
/CANDICE LEE SWIFT/Examiner, Art Unit 1657