DETAILED ACTION
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 .
Election/Restrictions
Applicant’s election of Group I (claims 1-15, 17-18 and newly added claims 19-21, directed to a method for producing 2,4-dihydroxybutyrate or L-threonine), E. coli for Genus A (production strain), D-threo-aldose-1-dehydrogenase, D-arabinonate dehydratase, D- fructose-6-phosphate aldolase, and gluconolactonase for Genus B (additional genetic information to be expressed according to the method of claim 5). and Ec.Mdh 7Q for Genus C (mutated variant of L-malate dehydrogenase from E. coli) in the reply filed on 10/28/2025 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
According to the restriction requirement of 09/16/2025, an election of “a single and specific enzyme to be expressed in the method according to claim 5” was required, and applicant was directed to “see claims 6 and 8-10”. Applicant’s response, as indicated above and in the remarks of 10/28/2025, did not clearly identify which specific enzyme within Genus B was elected. Accordingly, the examiner contacted Applicant’s representative, Ursula Day, on 12/29/2025 to clarify the election. During the telephone conversation, Applicant confirmed an election of D-threo-aldose-1-dehydrogenase (claim 6), under Genus B. In view of this clarification, claims 8-10 and 19-21, which are directed to non-elected species of Genus B, and claims 11-15 which depend therefrom, are withdrawn from further consideration.
Claims 8-21 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention and nonelected species, there being no allowable generic or linking claim.
Status of Claims
Claims 1-21 are currently pending.
Claims 1-7 are under consideration, as claims 8-21 are withdrawn.
Priority
The present application claims status as a 371 (National Stage) of PCT/DE2022/100042 filed on 01/18/2022 and claims priority to German application DE10 2021 101 004.7, filed on 01/19/2021. Acknowledgment is made of applicant' s claim for foreign priority and papers submitted under 35 U.S.C. 119 (a)-(d). Please note that the German application is in a foreign language and therefore cannot be reviewed. In future actions, the effective filing date may change due to amendments or further review of priority documents.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 07/18/2023 is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement has been considered by the examiner.
Drawings
The drawings are objected to because they contain text and labels written in a foreign language, rather than English. Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Objections
Claims 1-2 and 6 are objected to because of the following informalities:
Claim 1 recites “O-phospho-L-homoserine” in line 16 and then recites “O-phospho-homoserine” in line 18. However, Applicant’s Fig. 1 depicts the conversion of O-phospho-L-homoserine to L-threonine, indicating that the compound recited as “O-phospho-homoserine” in line 18 is intended to be the same O-phospho-L-homoserine in line 16. Accordingly, it is suggested that the O-phospho-homoserine in line 18 be amended to recite “O-phospho-L-homoserine”.
Claim 2 currently recites: “The method according to claim 1, expression of the genes is achieved by using plasmids or by integration of genes in the genome.” To maintain consistency, it is suggested that claim 2 be amended to recite, “wherein expression of the genes is achieved by using plasmids or by integration of genes in the genome.”
Regarding claim 6, in line 3, the word “from” is missing a space following “dehydrogenase.” It is suggested that claim 6 be corrected to read “dehydrogenase from”.
Additionally, claim 6 recites “introduced into a genome of the production strain” in line 8, whereas the production strain has already been introduced. It is suggested that claim 6 be amended to recite “introduced into the genome of the production strain.”
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
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 1-7 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 is indefinite because it recites multiple enzymatic conversions using a combination of “and”, “or”, and “followed by” language, such that it is unclear which enzymatic steps are required and in what sequence. Specifically, the claim recites four enzymatic conversions ending with 2-keto-4-hydroxybutyrate (OHB), “and further comprising, enzymatic conversion of 2-keto-4-hydroxybutyrate(OHB)to 2,4-dihydroxybutyrate (DHB) using a OHB reductase, or enzymatically converting 2-keto-4-hydroxybutyrate to L-homoserine using an L-homoserine transaminase, followed by a step of enzymatically converting L-homoserine to O-phospho-L-homoserine using a homoserine kinase using ATP consumption, and enzymatically converting O-phospho-homoserine to L-threonine using an L-threonine synthase...” One interpretation is that (a) enzymatic conversion of OHB to DHB is then “followed by” the conversion of L-homoserine to O-phospho-L-homoserine “and” the conversion of O-phospho-homoserine to L-threonine. Another interpretation is that (b) enzymatic conversion of OHB to L-homoserine is then “followed by” the conversion of L-homoserine to O-phospho-L-homoserine, “and” the conversion of O-phospho-homoserine to L-threonine. Yet another interpretation is that the claim requires (c) enzymatic conversion of OHB to DHB “and” conversion of O-phospho-homoserine to L-threonine.
Claim 1 also recites, in part, “introducing at least one gene of such genes as are necessary for expression of the said enzymes into the production strain.” The phrase “such genes” lacks antecedent basis in the claim. The claim does not previously introduce or define a set of “genes” to which this phrase refers. As a result, it is unclear which genes are encompassed by this limitation, rendering the scope of the claim indefinite.
Additionally, claim 1 is indefinite and unclear due to the recitation of “introducing at least one gene” that is “necessary for expression of the said enzymes,” while the claim requires multiple enzymatic conversions carried out by multiple distinct enzymes. It is therefore unclear which enzyme or enzymes are encompassed by “the said enzymes”, whether introduction of a single gene is intended to support expression of all required enzymes, or whether multiple genes are required and, if so, which genes correspond to which enzymatic steps.
Claim 2 depends from claim 1 and refers to “the genes” without clear antecedent basis. As discussed above, claim 1 does not clearly identify or define a set of genes. Accordingly, it is unclear which genes are being expressed by plasmid-based expression or genomic integration, rendering claim 2 indefinite.
Claim 3 is indefinite and unclear due to the recitation of “wherein the production strain already has one or more enzymes required for the metabolic pathway in the wild type form”. It is unclear whether the phrase “enzymes required for the metabolic pathway” refers specifically to the enzymatic steps recited in claim 1, or whether it encompasses additional enzymes associated with the pathway but not explicitly recited in the claim. The claim does not identify which enzymes may be present in wild-type form, nor does it clarify how such enzymes relate to the introduced genes or enzymatic steps of claim 1.
Claim 6 recites, in part, “the enzyme D-threo-aldose-1-dehydrogenase”, “the enzyme D-arabinose dehydrogenase”, and “the enzyme L-fucose dehydrogenase”. However, these enzymes are not previously recited or introduced in claims 1 and 3-5, upon which claim 6 depends from. Accordingly, the recited enzymes lack antecedent basis, and it is unclear as to how they relate to the claimed method.
For the same reasons described above for claim 6, claim 7 is also unclear and lacks antecedent basis for “the enzyme D-arabinonate dehydratase”, which is not previously recited or introduced in the claims from which claim 7 depends.
Claims 4-5 are included in this rejection because they depend, directly or indirectly, from claims 1-3 and do not further limit or clarify the indefinite subject matter of the claims.
Claim Rejections - 35 USC § 112(a)
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 1-3 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.
It is noted that MPEP 2111.01 states that “[d]uring examination, the claims must be interpreted as broadly as their terms reasonably allow.” Claim 1 has been broadly interpreted as encompassing a genus of methods for producing 2,4-dihydroxybutyrate or L-threonine using a microbial metabolic pathway expressed in any microbial production strain, wherein the strain is modified from a wild-type form by introducing at least one gene necessary for expression of the recited enzymes.
MPEP 2163 states that to satisfy the written description requirement, a patent specification must describe the claimed invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention at the time of filing. Possession may be shown by disclosure of representative species or by disclosure of common structural or functional features sufficient to permit one skilled in the art to recognize that the inventor had possession of the full scope of the claimed genus.
In the instant case, claim 1 recites expression of a multi-enzyme engineered metabolic pathway in a “microbial production strain” without limitation as to microbial class, genus, or species. When given its broadest reasonable interpretation, this language encompasses expression of the claimed pathway in any microorganism, including but not limited to bacteria, archaea, fungi, and other microbial hosts. The specification, however, does not demonstrate possession of the claimed invention across the full scope of this broadly claimed microbial genus. The disclosure is directed primarily to specific bacterial systems and exemplary enzymes derived from particular microbial sources. The specification does not describe representative species across the full breadth of “microbial production strains,” nor does it identify common structural, genetic, or physiological characteristics that would permit one skilled in the art to reasonably extrapolate successful expression of the entire claimed pathway across all microbial hosts encompassed by the claim.
Further, the claimed invention requires coordinated expression of multiple heterologous enzymatic steps within a single production strain. The specification does not provide guidance demonstrating that the inventors possessed the ability to implement the complete pathway in the full range of microbial production strains encompassed by claim 1 at the time of filing. Accordingly, the specification does not reasonably convey possession of the claimed method across the full scope of “a microbial production strain” as recited in claim 1.
Claim 2, which further recites that expression of the genes is achieved by using plasmids or by integration of genes into the genome, and claim 3, which recites that the production strain already contains one or more enzymes of the pathway in wild-type form, depend from claim 1 and retain the same overbreadth with respect to the recited microbial production strain. These limitations do not meaningfully narrow the scope of the claimed microbial genus or remedy the written description deficiencies noted above. Accordingly, claims 1–3 are rejected under 35 U.S.C. §112(a) for failure to satisfy the written description requirement.
Relevant Art
Garrabou et al. (Asymmetric Self- and Cross-Aldol Reactions of Glycolaldehyde Catalyzed by D-Fructose-6-phosphate Aldolase. 2009. Angewandte Chemie International Edition, 48: 5521-5525, cited in PTO-892) discloses enzymatic aldol reactions involving glycolaldehyde that can result in the formation of tetrose sugars, including threose, under aqueous reaction conditions. The work demonstrates that glycolaldehyde can participate in enzyme-mediated carbon–carbon bond formation reactions; however, Garrabou et al. does not teach or suggest the construction of a microbial metabolic pathway, nor do they teach any downstream enzymatic conversions of threose toward threonate, 2-keto-4-hydroxybutyrate, or 2,4-dihydroxybutyrate.
Walther et al. (Construction of a synthetic metabolic pathway for the production of 2,4-dihydroxybutyric acid from homoserine, Metabolic Engineering Vol 45 (2018) pg. 237-245, cited in the IDS) teaches a synthetic microbial pathway for producing 2,4-dihydroxybutyrate (DHB) starting from L-homoserine via homoserine transaminase–catalyzed deamination to form 2-oxo-4-hydroxybutyrate, followed by reduction to DHB using an OHB reductase. Walther et al. explicitly note that no annotated metabolic pathway exists for the microbial production of DHB from sugars and focuses their work on a homoserine-based route, rather than on any upstream pathway beginning from glycolaldehyde.
Chen et al. (WO 2016/050959, cited in PTO-892) discloses genetically modified microorganisms for producing derivatives of 4-hydroxy-2-ketobutyrate, including 2,4-dihydroxybutyrate, by improving the conversion of L-homoserine to 4-hydroxy-2-ketobutyrate using a mutant glutamate dehydrogenase. Chen et al. are directed to optimizing a specific enzymatic step within a homoserine-derived production pathway and do not disclose or suggest an alternative upstream biosynthetic pathway beginning from glycolaldehyde.
While Garrabou et al. discloses enzymatic reactions involving glycolaldehyde that can result in the formation of threose, there is no teaching or suggestion in Garrabou et al., Walther et al., or Chen et al. that would have led a person of ordinary skill in the art to construct or engineer a microbial metabolic pathway starting from glycolaldehyde and proceeding through the sequential enzymatic conversions recited in claim 1 to produce 2,4-dihydroxybutyrate. Furthermore, prior to the present invention, the cited art does not disclose or suggest the specific combination and ordering of enzymatic steps required to convert glycolaldehyde to threose, threose to threono-1,4-lactone, the threonolactone to threonate, and threonate to 2-keto-4-hydroxybutyrate within a microbial production strain, let alone using the specifically recited enzymes. Accordingly, the cited references collectively describe isolated reactions or downstream pathway segments, but do not provide guidance that would render the claimed pathway an obvious engineering route that a skilled artisan would have reasonably pursued.
Conclusion
No claim is in condition for allowance.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to NAGHMEH NINA MOAZZAMI whose telephone number is (703)756-4770. The examiner can normally be reached Monday-Friday, 9:00-5:00.
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/NAGHMEH NINA MOAZZAMI/Examiner, Art Unit 1652
/RICHARD G HUTSON/Primary Examiner, Art Unit 1652