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 .
Amendments Received
Amendments to the claims were received and entered on 02/03/2026.
Status of Claims
Claims 1-5 are cancelled.
Claims 6-10 are currently pending and under consideration.
Priority
The present application claims status as a 371 (National Stage) of PCT/KR2020/016710 filed on 11/24/2020 and claims priority to Korean application KR-10-2020-0138518 filed on 10/23/2020. 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 Korean 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.
Withdrawn Objections
In view of Applicant’s amendments, the objection to claim 10 is hereby withdrawn.
Withdrawn Rejections
In view of Applicant’s cancellation of claims 1-5, all rejections of claims 1-5 are now moot and are hereby withdrawn.
In view of Applicant’s amendments, the rejection of claims 6-10 under 35 USC § 112(a) is hereby withdrawn.
In view of Applicant’s amendments, the rejection of claims 6-10 as being indefinite due to the recitation of “2,3-butanediol producing bacterium” under 35 USC § 112(b) is hereby withdrawn.
New Rejections
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.
Claim 8 is 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 8 recites, “wherein the synthesis gas is added further before the partial pressure of carbon monoxide is decreased to 5 kPa or below.” However, the scope of this limitation is unclear when read in light of claim 6. Specifically, claim 6 recites continuously adding synthesis gas comprising carbon monoxide such that carbon monoxide exists above 0 kPa, but does not require carbon monoxide to ever exceed 5 kPa. Thus, claim 6 encompasses embodiments in which the partial pressure of carbon monoxide remains at or below 5 kPa throughout the entire process. Accordingly, it is unclear how the limitation of claim 8 is to be applied in embodiments where the carbon monoxide partial pressure never decreases from a value above 5 kPa to a value of 5 kPa or below. Because claim 8 appears to require a condition that is not necessarily present within the scope of claim 6, the metes and bounds of claim 8 are unclear.
Furthermore, because claim 6 already recites a step of continuously adding synthesis gas, it’s unclear as to what additional action is required by the recitation that the synthesis gas is “added further”. In the response filed on 02/03/2026, Applicant refers to Experimental Example 3-1 which demonstrates that “synthesis gas is re-added before carbon monoxide is completely consumed”, however, claim 6 already recites a step of continuously adding synthesis gas. It’s unclear whether further adding synthesis gas in claim 8 refers to increasing the rate of addition, adding an additional quantity of synthesis gas, or some other action, due to the fact that the synthesis gas is already in a state of being continuously added, “such that the carbon monoxide exists above 0 kPa”.
For the purposes of prior art examination, the examiner is unable to ascertain with reasonable certainty the scope of the limitation “the synthesis gas is added further before the partial pressure of carbon monoxide is decreased to 5 kPa or below”. The claim language reasonably encompasses multiple interpretations, including merely continuing the continuous addition already required by claim 6, increasing the rate of synthesis gas addition, introducing an additional quantity of synthesis gas, or maintaining carbon monoxide above a threshold value. Because the claim does not provide objective boundaries for determining which interpretation is intended, the metes and bounds of claim 8 cannot be determined with reasonable certainty.
Maintained/Modified Rejections Necessitated by Amendment
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Krispin et al. (US Patent No. 9765366 B2, cited in a previous office action), as evidenced by Kopke et al. (Butanediol Production by Acetogenic Bacteria, an Alternative Route to Chemical Synthesis, Using Industrial Waste Gas . Appl Environ Microbiol 77, cited in PTO-892).
Regarding claim 6, Krispin et al. teaches a method for producing a C4 compound, the method comprising: contacting an acetogenic bacterial cell in an aqueous medium with syngas under anaerobic conditions in the absence of carbohydrates, wherein the aqueous medium comprises ethanol, an acetate, or both, in a total concentration of at least 0.1 g L −1 , wherein at least a portion of the ethanol, acetate, or both, is present in the aqueous medium before the acetogenic bacterial cell is brought into contact with the aqueous medium, thereby obtaining a mixture; and incubating the mixture at a temperature between 0 and 100°C for at least 30 minutes, to obtain a C4 compound (claim 1, Abstract and Specification, column 1, lines 5-12). Krispin et al. explicitly teaches acetogenic bacteria including, inter alia, Clostridium autoethanogenum and Clostridium ljungdahlii (column 3, lines 46-62), which are disclosed in the instant specification as 2,3-butanediol producing bacteria and which were known in the art as bacteria capable of producing 2,3-butanediol via pyruvate from acetyl coA, as evidenced by Kopke et al. (Abstract and pg. 5470). Thus, Krispin et al. teaches acetogenic bacteria that fall within the scope of the presently claimed 2,3-butanediol producing bacterium. With respect to the claimed product, Krispin et al. teaches several examples of C4 compounds, including 2,3-butanediol (column 4, lines 21-23). Therefore, Krispin et al. teaches a method for producing a C4 compound, wherein the C4 compound can be 2,3-butandiol, comprising contacting an acetogenic bacterium capable of producing 2,3,-butanediol, in an aqueous medium comprising ethanol with syngas (i.e., synthesis gas). Furthermore, Krispin et al. teaches that syngas is the main carbon source for production of the disclosed C4 compounds and teaches syngas compositions comprising 40 to 95% carbon monoxide (column 2, lines 34-37). Because syngas is consumed during acetogenic fermentation, it would have been obvious to continuously supply syngas during cultivation in order to maintain availability of the carbon source and sustain production of the desired C4 compound. Under the operating conditions taught by Krispin et al., carbon monoxide would necessarily exist at a partial pressure above 0 kPa whenever syngas is supplied. Additionally, Krispin et al. experimentally demonstrates that the addition of ethanol significantly increases production of butyric acid, a disclosed C4 compound (Example 1). Accordingly, Krispin et al. teaches the advantageous use of ethanol during syngas fermentation to enhance production of C4 compounds.
Regarding claim 7, Krispin et al. teaches “the pressure of the syngas applied is, in a preferred embodiment, 0.5 to 10 bars, more preferably 0.8 to 8, even more preferably 1.5 to 6 bar” (column 7, lines 4-6), which encompasses the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (MPEP 2144.05).
Regarding claim 8, as described above, Krispin et al. teaches supplying synthesis gas comprising 40 to 95% carbon monoxide at pressures of 0.5 to 10 bars. For example, at a total pressure of 1 bar (100 kPa), a synthesis gas comprising 40% carbon monoxide would result in a partial pressure of CO of 40 kPa. Optimization of the timing and amount of synthesis gas supplied during fermentation in order to maintain desired carbon monoxide levels would have been within the routine skill of the art.
Regarding claim 9, Krispin et al. discloses an exemplary process using C. carboxidivorans (Example 1, columns 8-9), wherein “the culture was grown at 37°C and 100 rpm”, which lies within the claimed range.
Regarding claim 10, Krispin et al. teaches a preferred embodiment wherein some of the reaction mixture is removed following incubation and the ethanol therein is recycled back to the aqueous medium to maintain its concentration (column 6, lines 1-17 and 25-35), thereby “further adding” ethanol one or more times. With respect to the claimed range of 0.2-5 g/L, depending on the starting concentration, which encompasses the claimed range, as taught by Krispin et al., it would have been customary for a person of ordinary skill in the art to determine the optimal concentration of ethanol required to add to the aqueous medium.
An invention would have been obvious to a person of ordinary skill in the art if some teaching in the prior art would have led that person to arrive at the claimed invention. Before the effective filing date of the claimed invention, the teachings of Krispin et al. that acetogenic bacteria may be cultured in a medium comprising ethanol and synthesis gas to produce C4 compounds, together with the express disclosure that 2,3-butanediol is one such C4 compound, would have led a person of ordinary skill in the art to employ an acetogenic bacterium in the disclosed method for the purpose of producing 2,3-butanediol. Krispin et al. further teaches that the presence of ethanol enhances production of C4 compounds and that synthesis gas serves as the principal carbon source for production of such compounds. Furthermore, Krispin et al. expressly identifies 2,3-butanediol as a member of the disclosed genus of C4 compounds and teaches acetogenic bacteria suitable for use in the disclosed process. Selecting 2,3-butanediol from the finite set of expressly disclosed C4 compounds would have represented no more than the predictable use of a known prior-art option. Accordingly, a person of ordinary skill in the art would have had a reasonable expectation of success in using the teachings of Krispin et al. to produce 2,3-butanediol, and therefore the invention as a whole would have been prima facie obvious before the effective filing date of the claimed invention.
Thus, claims 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Krispin et al.
Response to Arguments for Prior Art Rejections
In the response filed February 3, 2026, Applicant argues that Krispin et al. does not teach or suggest the presently claimed method because: (1) Krispin et al. merely identifies 2,3-butanediol as a general example of a C4 body while its working examples are limited to butyric acid production; (2) butyric acid and 2,3-butanediol possess different functional groups, chemical properties, and biosynthetic pathways; (3) Krispin et al. allegedly discloses only bacteria capable of producing butyric acid and does not disclose bacteria capable of producing 2,3-butanediol via pyruvate derived from acetyl-CoA under synthesis gas fermentation; and (4) the production pathway recited in amended claim 6 is fundamentally different from the process disclosed by Krispin et al. Applicant’s arguments have been considered in full but are not persuasive.
Krispin et al. expressly teaches methods for producing C4 bodies using acetogenic bacteria cultured in an aqueous medium comprising ethanol and/or acetate in the presence of syngas. Importantly, Krispin et al. defines C4 bodies broadly and expressly identifies 2,3-butanediol as an example of a C4 body. Thus, contrary to Applicant’s assertion, Krispin et al. does not limit its disclosure solely to butyric acid. While certain working examples evaluate butyric acid production, a reference is not limited to its working examples or preferred embodiments, and must be considered for all that it reasonably teaches to a person of ordinary skill in the art (see MPEP 2123, “Rejection Over Prior Art’s Broad Disclosure Instead of Preferred Embodiments”).
Applicant’s argument that butyric acid and 2,3-butanediol possess different functional groups and biosynthetic pathways is likewise unpersuasive. The rejection does not rely on an assertion that butyric acid and 2,3-butanediol are chemically identical compounds. Rather, Krispin et al. expressly teaches production of C4 bodies, including 2,3-butanediol, using acetogenic bacteria in the presence of ethanol and syngas. Furthermore, it was known in the art prior the present invention that acetogenic bacteria such as C. autoethanogenum and C. ljungdahlii produce 2,3-butanediol from syngas through pathways involving conversion of acetyl-CoA to pyruvate, as evidenced by Kopke et al. Accordingly, the recited pyruvate-derived pathway does not distinguish the claimed method from the known capabilities of the acetogenic bacteria taught by Krispin et al.
Furthermore, Applicant’s assertion that Krispin et al. discloses only bacteria capable of producing butyric acid is not supported by the record. Krispin et al. expressly identifies multiple acetogenic bacterial species, including Clostridium autoethanogenum and Clostridium ljungdahlii. The instant specification likewise identifies acetogenic bacteria, including Clostridium autoethanogenum and Clostridium ljungdahlii, as microorganisms capable of producing 2,3-butanediol under synthesis gas fermentation conditions. Accordingly, the acetogenic bacteria taught by Krispin et al. teaches acetogenic bacteria that fall within the scop of Applicant’s recited 2,3-butanediol producing bacteria.
Accordingly, the Examiner maintains that Krispin et al. teaches or at least renders obvious a method comprising culturing an acetogenic bacterium in a medium comprising ethanol and contacting the bacterium with syngas to produce a C4 body, wherein 2,3-butanediol is expressly identified as one such C4 body. Therefore, the rejection of claims 6-10 under 35 U.S.C. 103 is maintained.
Conclusion
No claim is in condition for allowance.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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
/ROBERT B MONDESI/Supervisory Patent Examiner, Art Unit 1652
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