Microalgae are efficient fatty acid producers owing to their high photosynthetic activities. They can act as sources of biofuel, feed, and various bioactive compounds. This study aimed to determine optimal culture conditions, including culture medium, temperature, and light intensity, to enhance the biomass and fatty acid content of the indigenous freshwater microalga, Tetradesmus obliquus. Evaluation using a high-throughput photobioreactor revealed that the optimal culture temperature and light intensity were 25°C and 300 μmol m-2 s-1, respectively. Additionally, we optimized components (N, P, and Mg) of the BG-11 medium to enhance the microalgal biomass. Modified BG-11 medium increased the T. obliquus biomass by 37% compared to the standard BG-11 medium. Subsequently, the culture medium was replaced with N- and P-depleted media to determine the abiotic stress factor that could increase the cellular fatty acid content. Notably, fatty acid content was significantly increased from 8.5% up to 14.6% on day 7 of culture in N-deficient (N-P+ and N-P-) media. Sequential optimization effectively increased the biomass by 83% and fatty acid content by >76% in T. obliquus. Our optimization method can be used to enhance the biomass and fatty acid contents of various other microalgae.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 미세조류주 및 유지
    2.2. T. obliquus 의 최적 생장 온도 및 광도 조건 탐색
    2.3. T. obliquus 의 생장 증대를 위한 배지 조성 최적화
    2.4. T. obliquus 의 생장 최적화 배지의 검증
    2.5. 질소와 인의 결핍에 따른 T. obliquus 의 생장 및지방산 분석
    2.6. T. obliquus 의 지방산의 함량 및 조성 분석
3. 결과 및 고찰
    3.1. T. obliquus 생장 온도 및 광도 조건 탐색
    3.2. BBD 모델을 이용한 T. obliquus 배지 최적화
    3.3. 최적 배양배지를 이용한 T. obliquus 의 생장 검증
    3.4. 질소와 인의 결핍에 따른 미세조류 생장 및지방산 분석
4. 결 론
적 요
CRediT authorship contribution statement
Declaration of Competing Interest
사 사
REFERENCES
APPENDIX

• 윤신영(인하대학교 생명공학과) | Shin-young Yun (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea)
• 정민주(인하대학교 생명공학과) | Min-ju Jeong (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea)
• 지현종(인하대학교 생명공학과) | Hyeon-jong Ji (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea)
• 홍선우(인하대학교 생명공학과) | Sun-Woo Hong (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea)
• 장희수(인하대학교 생명공학과) | Huisoo Jang (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea)
• 홍성주(인하대학교 생명공학과, 인하대학교 산학융합 인터랙티브 바이오공정 혁신 교육연구단) | Seong-Joo Hong (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea, Industry-Academia Interactive R&E Center for Bioprocess Innovation, Inha University, Incheon 22212, Republic of Korea)
• 이철균(인하대학교 생명공학과, 인하대학교 산학융합 인터랙티브 바이오공정 혁신 교육연구단) | Choul-Gyun Lee (Department of Biological Engineering, Inha University, Incheon 22212, Republic of Korea, Industry-Academia Interactive R&E Center for Bioprocess Innovation, Inha University, Incheon 22212, Republic of Korea)
• 이창수(국립낙동강생물자원관 생물자원연구실) | Chang Soo Lee (Biological Resources Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• 윤석민(국립낙동강생물자원관 생물자원연구실) | Suk Min Yun (Biological Resources Research Department, Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea) Corresponding author
• 이승환(전남대학교 생물공학과) | Seung Hwan Lee (Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea)
• 장현진(제주대학교 식품영양학과) | Hyun-Jin Jang (Department of Food Science and Nutrition, Jeju National University, Jeju 63243, Republic of Korea)
• 김지훈((주)휴에버그린팜 바이오텍 연구개발센터) | Z-Hun Kim (Biotech R&D center, Hu EverGreen Pharm Inc., Incheon 21447, Republic of Korea) Corresponding author