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
This office action is a response to applicant’s communication submitted May 18, 2026, wherein claims 1 and 3 are amended, claim 2 is canceled, and new claims 5-7 are introduced. This application is a national stage application of PCT/KR2922/005170, filed April 11, 2022, which claims benefit of foreign application KR10-2021-00572333, filed May 3, 2021.
Claims 1 and 3-7 are pending in this application.
Claims 1 and 3-7 as amended are examined on the merits herein.
Withdrawn Rejections
Applicant’s amendment, submitted May 18, 2026, with respect to the rejection of claims 1, 3, and 4 under 35 USC 103 for being obvious over Soetaert et al. in view of Bailande et al., has been fully considered and found to be persuasive to remove the rejection as base claim 1 has been amended to require the use of specific ultrafiltration membranes. Therefore the rejection is withdrawn.
The following rejections of record in the previous action are maintained and applied to the pending claims as newly amended:
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.
Claims 1, 3, and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Soetaert et al. (US pre-grant publication 2016/0168612, of record in previous action) in view of Bailande biochemical Co. (Foreign patent publication CN106282264, Reference and English machine translation of record in previous action, all citations herein are to the English machine translation) in view of Isa et al. (Reference of record in previous action)
Independent claim 1 is directed to a process for purifying sophorolipids from a starting material which is a culture fluid of a genus Candida fungus. As recited in paragraph 5 of the present specification, Candida bombicola is considered to be such a fungus. The process involves steps of ultrafiltering the sophorolipid precipitate from the culture, adding and then removing ethanol and activated carbon to remove impurities, and then adding water and adjusting the pH to a value between 5 and 7.
Soetaert et al. discloses a method of producing bolaamphilic glycolipids form a yeast. (p. 1 paragraphs 10-11) In a preferred embodiment the yeast is Starmerella (Candida) bombicola. (p. 2 paragraph 13) Soetaert et al. further discloses using ultrafiltration to purify the glycolipids, particularly sequential ultrafiltration. (p. 2 paragraph 20, p. 5 paragraph 71) The bolaform glycolipid can be a sophorolipid. (p. 2 paragraph 22) In a specific example (ex. 7, p. 10) a sophorolipid containing mixture was subjected to 30 kDa and then 5 kDa ultrafiltration. The resulting sophorolipids were then rendered into an aqueous solution and NaOH was added to adjust the pH for stability testing. (p. 10 paragraph 121) The stable range was seen to be pH 2-6.5, which substantially overlaps the claimed range of 5-7. (p. 10 table 4) Soetaert et al. further discloses that an ultrafiltration with a 1 kDa MWCO membrane can be used to separate acidic sophorolipids from carbohydrates. (p. 10 paragraph 122) Therefore Soetaert discloses steps (1) and (3) but does not describe a step of adsorbing in ethanol and activated carbon.
However, Bailande discloses a method of purifying sophorolipids form fermentation broth wherein ethanol is added to the fermentation broth, followed by activated carbon, followed by the removal of the activated carbon and the evaporation of the ethanol. (step 9 on pp. 3-4 of the English translation) It would therefore have been obvious to one of ordinary skill in the art to add such a step to the method described by Soetaert et al. to further purify the sophorolipids purified therein, thereby resulting in a process infringing claims 1 and 4.
Soetaert et al. in view of Bailande et al. also does not specifically describe a method wherein one of the ultrafiltration steps is a 10 MWCO ultrafiltration as opposed to 30 kDa.
However, Isa et al. discloses a method for isolating a different biosurfactant by two-step ultrafiltration. (p. 52 right column second paragraph) different ultrafiltration membranes with different MWCO were tested including 30 and 10 kDa. (p. 52 right column section 2.2.1) In vow of this disclosure, one of ordinary skill in the art would have considered the molecular weight cutoff of the ultrafiltration membranes to be a result-effective variable, and would have performed appropriate experimentation to determine the optimal MWCO values to use in the two steps of the ultrafiltration described by Soetaert et al.
Regarding claims 3 and 6, step 9 described by Bailande describes adding 1% activated charcoal to culture broth to which an equal volume of 95% ethanol is added. This results in about 2.1 parts activated charcoal per 100 parts ethanol. However, one of ordinary skill in the art, considering this disclosure, would have reasonably found it to be obvious to attempt to further optimize the amount of activated charcoal to use in any adsorption step to ensure optimal removal of contaminants from the sophorolipid-containing solution. For example, the aforementioned process described by Bailande utilizes two sequential treatments with activated carbon for 0.5h each. The use of two separate steps adds to the total time required of the process, and replacing it would a single step using a greater amount of activated carbon could potentially speed up the process, resulting in improved efficiency.
Regarding claim 5, Bailande discloses using pharmaceutical grade powdered activated carbon as the activated carbon. (p. 4 eleventh paragraph) Regarding claim 7, Bailande et al. suggests evaporating ethanol from the activated carbon treatment to concentrate the filtrate, using reduced pressure. (p. 6 first paragraph) Reduced pressure is reasonably considered to fall within the scope of vacuum concentration.
For these reasons the invention taken as a whole is prima facie obvious.
Response to Argument: Applicant’s arguments, submitted May 18, 2026, with respect to the above grounds of rejection, have been fully considered and found to be persuasive to remove the rejection. Applicant recites the various elements of present claim 1 and then states that Soetaert et al. fails to disclose, teach, or suggest said elements. Applicant firstly argues that Jin et al. (Referred to as Bailande above) describes ethanol and aqueous activated carbon treatment but does not suggest applying such treatment to a residue from two-stage ultrafiltration as described in present claim 1. However, looking to both of the disclosures of Soetaert and Jin, one of ordinary skill in the art would have seen that both techniques (two-stage ultrafiltration and ethanol/activated carbon treatment) are useful for similar purposes of removing impurities from sophorolipid containing culture medium. Based on this fact it would be reasonable for one of ordinary skill in the art to conclude that performing both purification techniques in sequence on a sophorolipid containing culture medium would result in a superior purification than performing only one of the two techniques.
Applicant further argues that the optimization of the molecular weight cutoff (MWCO) of the ultrafiltration membranes is not simply an arbitrary optimization, but rather a specific sequence designed to remove both high and low molecular weight impurities while retaining sophorolipids. However, looking to the disclosure of Soetaert et al., the idea of sequential filtration was already described. (See p. 10 example 7) In this example a 30 kDa MWCO membrane excludes high mw contaminants such a proteins and then a second 5 kDa membrane is used to retain the sophorolipids while removing low mw contaminants such as sugars and salts. Therefore one of ordinary skill in the art would have already known that a two-stage filtration having the same operating principle as that recited in the present claims would produce the same result of removing both high and low molecular weight contaminants while retaining sophorolipids. The only difference between two-stage filtration as described by Soetaert and the two-stage filtration described in present claim 1 is the specific MWCO of the membranes used. Therefore the difference between the prior art and the claimed method would in fact come down to a matter of routine optimization.
For these reasons the rejection is deemed proper and maintained.
Conclusion
No claims are allowed in this action. THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/ANDREA OLSON/ Primary Examiner, Art Unit 1693 7/7/2026
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