Prosecution Insights
Last updated: April 19, 2026
Application No. 18/551,667

METHOD FOR INCREASING YIELD OF EICOSAPENTAENOIC ACID IN SCHIZOCHYTRIUM SP.

Non-Final OA §103§112
Filed
Sep 21, 2023
Examiner
FRONDA, CHRISTIAN L
Art Unit
1652
Tech Center
1600 — Biotechnology & Organic Chemistry
Assignee
Yhsn Technology Ltd.
OA Round
1 (Non-Final)
82%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
96%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
1099 granted / 1333 resolved
+22.4% vs TC avg
Moderate +14% lift
Without
With
+14.1%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
44 currently pending
Career history
1377
Total Applications
across all art units

Statute-Specific Performance

§101
4.5%
-35.5% vs TC avg
§103
26.2%
-13.8% vs TC avg
§102
7.2%
-32.8% vs TC avg
§112
37.1%
-2.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1333 resolved cases

Office Action

§103 §112
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claims 1-9 are under pending and under consideration in this Office Action. Claim Rejections - 35 USC § 112(b) or 35 U.S.C. 112 (pre-AIA ) 2nd Paragraph 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 1-9 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 pre-AIA the applicant regards as the invention. Claims 1-9 recite the phrase “characterized in that” which renders the claim vague and indefinite since it is unclear if the claims are limited to the subject matter recited after the phrase “characterized in that”. Appropriate correction is required. Claims 4 recites the limitation “a formula of a trace element solution (g/L) contained in the fermentation culture medium comprises: disodium EDTA 5-8, cobalt chloride 0.005-0.02, manganese chloride 0.5-1, zinc sulfate 1-3, ferrous sulfate 0.05-1, copper sulfate 0.5-1, sodium molybdate 0.005-0.02, and nickel sulfate 0.05-1.” There is insufficient antecedent basis for this limitation in the claim. Claim 6 recites the limitation “the content of glucose is ensured to be maintained at 10-30 g/L during the fermentation”. There is insufficient antecedent basis for this limitation in the claim. Claim 7 recites the limitation “the time for fermentation reaction after changing the temperature is 96 h±4 h”. There is insufficient antecedent basis for this limitation in the claim. Claim 8 recites the limitation "the fermentation conditions are as follows: a pH value of 5.5-7, a ventilation rate of 3-5 L/min, and a rotation speed of 300- 700 rpm”. There is insufficient antecedent basis for this limitation in the claim. 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 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. Claims 1-9 are rejected under 35 U.S.C. 103 as being unpatentable over CN105018539 (2015-11-04; IDS filed 09/21/2023) in view of US20090004219 (01/01/2009; PTO 892), CN103882072 (2014-06-25; IDS filed 09/21/2023), CN108707360 (10/26/2018; IDS filed 09/21/2023). CN105018539 teaches a method for increasing the yield of Schizochytrium ATCC 20888 docosahexaenoic acid (DHA), comprising culturing at a temperature of 25-35°C, 150-250 rpm, a pH of 5.5-6.5, and a ventilation amount of 0.3-0.5 vvm until glucose is exhausted; inoculating into a fermentation tank for fermentation culture, in which the temperature is 22-33°C, the ventilation amount is 0.3-0.5 vvm, a glucose content of 30-50 g/L is maintained, and after 70-100 h, culturing for 30-50 hat a low temperature of 18-22°C. See document TRANSLATION INTERNATIONAL SEARCH REPORT dated 09/21/2023 cited in the IDS filed 09/21/2023); and attached TRANSLATION WRITTEN OPINION OF THE INTERNATIONAL SEARCHING AUTHORITY, mailing dated 20 January 2022. CN105018539 teaches that the seed culture medium is: 40-50 g/L of glucose, 10-25 g/L of a yeast extract, 5.0-10.0 g/L of sodium sulfate, 0.6-0.8 g/L of potassium chloride, 1.8-2.2 g/L of magnesium sulfate, 1.9-2.1 g/L of potassium dihydrogen phosphate, 0.14-0.16 g/L of calcium chloride, 0.8-1.2 g/L of ammonium sulfate, 1.68-1.72 mg/L of manganese chloride tetrahydrate, 2.8-3.0 mg/L of zinc sulfate heptahydrate, 1.4-1.6 mg/L of copper sulfate pentahydrate, 0-0.05 mg/L of sodium molybdate dihydrate, and 0-0.05 mg/L of cobalt chloride hexahydrate. CN105018539 teaches that the fermentation medium is: 75.0-85.0 g/L of glucose, 15-20 g/L of corn steep liquor dry powder, 2.9-3.1 g/L of a yeast extract, 5.0-15.0 g/L of sodium glutamate, 5.0-10.0 g/L of sodium sulfate, 0.6-0.8 g/L of potassium chloride, 1.8-2.2 g/L of magnesium sulfate, 1.9-2.1 g/L of potassium dihydrogen phosphate, 0.14-0.16 g/L of calcium chloride, 0.8-1.2 g/L of ammonium sulfate, 1.68-1.72 mg/L of manganese chloride tetrahydrate, 2.8-3.0 mg/L of zinc sulfate heptahydrate, 1.4-1.6 mg/L of copper sulfate pentahydrate, 0-0.05 mg/L of sodium molybdate dihydrate, and 0-0.05 mg/L of cobalt chloride hexahydrate (see claims 1 and 2). CN105018539 teaches that the method reduces the cost of fermentation and the difficulty of controlling the fermentation process. The dry weight of the cells reaches 120-150 g/L, the DHA reaches 40-50 g/L, and productivity is 1.2-1.5 times higher than the productivity of reported DHA (see description, paragraph [0019]). CN105018539 teaches a temperature change strategy in which early and middle phases have a high temperature and a later phase has a low temperature so as to increase the DHA yield of Schizochytrium where the temperature range and the temperature change range before and after the temperature change both overlap; and teaches a ventilation amount parameter that is similar to the dissolved oxygen values recited in the claims. The teachings of the reference differ from the claims in that the reference does not teach the specific recited conditions including method steps for changing the temperatures and dissolved oxygen. US20090004219 teaches novel mutant strain of Schizochytrium limacinum having the Accession No. MTCC 5249, which produces lipids and extracellular polysaccharide (EPS) simultaneously (see entire publication and claims especially paragraphs [0017]-[0033]. US20090004219 teaches the following in the claims: 1. A novel mutant strain of Schizochytrium limacinum having the Accession No. MTCC 5249 that produces lipids and extracellular polysaccharides (EPS) simultaneously. 2. The novel mutant strain according to claim 1, wherein the lipid comprises myristic acid, palmitic acid, oleic acid, linoleic acid, docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). 3. The novel mutant strain according to claim 1, wherein the extracellular polysaccharides (EPS) comprises sulphated polysaccharides. 4. A process for simultaneous production of lipids and extracellular polysaccharides (EPS) from a novel mutant strain of Schizochytrium limacinum wherein said process comprising: a) culturing the cells of novel mutant strain of Schizochytrium limacinum having the Accession No. MTCC 5249 in a culture medium having pH in the range of 5.0-9.0; b) incubating the cells at a temperature in the range of 25-37° C. for a period of 3-7 days to obtain a culture; c) obtaining cell biomass and culture filtrate from the culture; d) extracting lipids from said cell biomass; and e) extracting extracellular polysaccharides (EPS) from the culture filtrate using solvents. 5. The process according to claim 4, wherein said lipids comprise myristic acid, palmitic acid, oleic acid, linoleic acid, docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA). 6. The process according to claim 5, wherein the concentration of docosahexaenoic acid (DHA) is in the range of 25-32%. 7. The process as according to claim 4, wherein said extracellular polysaccharide (EPS) comprises sulphated polysaccharide. 8. The process according to claim 4, wherein said culture medium comprises an organic carbon source, a nitrogen source and a vitamin source and other micronutrients. 9. The process according to claim 8, wherein the organic carbon source is selected from a group consisting of glucose, cotton seed flour, starch, glycerol, molasses and corn syrup. 10. The process according to claim 8, wherein the nitrogen source is selected from a group consisting of peptone, corn steep liquor, yeast extract, ammonium sulphate and ammonium nitrate. CN103882072 teaches optimized fermentation for DHA/EPA in Schizochytrium including pH, and temperature control (see entire publication and claims especially Summary of the invention section). CN108707360 teaches regulation and control method improving EPA content in Schizochytrium where bacterial strain Schizochytrium sp.MYA1381 are activated by tablet and secondary seed, seed liquor is prepared, is inoculated in Fluorine pyridine ketone is added in the different phase of schizochytrium limacinum growth in fermentation medium (see entire publication and claims especially Examples 1-2). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify and/or combine the reference teachings to make the claimed invention by modifying the method of CN105018539 to incorporate method steps as taught and suggested by the teachings of US20090004219, CN103882072, CN108707360 to include fermenting it under an aerobic condition, changing the temperature upon fermenting to the middle of a logarithmic phase, continuing to ferment it, and controlling a dissolved oxygen value to be 2%-10% after changing the temperature with the step of changing the temperature comprises increasing an initial fermentation temperature of 25-30 °C to 32-37 °C. One of ordinary skill in the art before the effective filing date of the claimed invention would have been motivated to do this in order to obtain a method for producing eicosapentaenoic acid by the Schizochytrium with increased yields. It would have been obvious to adjust all the conditions of fermentation, temperature, time for fermentation, pH, amounts of oxygen, amounts of the culture medium components and glucose, amounts of trace element solution components, and use Schizochytrium sp. ATCC 20888 as routine optimization for producing eicosapentaenoic acid by the Schizochytrium with increased yields. One of ordinary skill in the art at the time the invention was made would have a reasonable expectation of success because using Schizochytrium to produce fatty acids including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are known in the art as shown by the above reference teachings. Hence, the claimed invention as a whole is prima facie obvious. Conclusion No claim is allowed. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Christian L Fronda whose telephone number is (571)272 0929. The examiner can normally be reached Monday-Thursday and alternate Fridays between 9:00AM-5:00PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Robert Mondesi can be reached on (408)918-7584. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /CHRISTIAN L FRONDA/Primary Examiner, Art Unit 1652
Read full office action

Prosecution Timeline

Sep 21, 2023
Application Filed
Feb 02, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
82%
Grant Probability
96%
With Interview (+14.1%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 1333 resolved cases by this examiner. Grant probability derived from career allow rate.

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