Page 52 - 《水产学报》2025年第5期

胡澄溪，等 水产学报, 2025, 49(5): 059104

Effects of expressing exogenous microalgal DGAT genes on the growth and
lipids of Saccharomyces cerevisiae

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HU Chengxi , LIU Wei , BI Yanhui , ZHOU Zhigang 2*
1. Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education,
Shanghai Ocean University, Shanghai 201306, China;
2. International Research Center for Marine Biosciences, Ministry of Science and Technology,
Shanghai Ocean University, Shanghai 201306, China

Abstract: The H1246 mutant of Saccharomyces cerevisiae, which is deficient in triacylglycerol (TAG) synthesis, is commonly
used to elucidate the functions of exogenous genes encoding diacylglycerol acyltransferase (DGAT). To investigate the effects
of exogenous DGATs on lipid synthesis and yeast cell growth, one type Ⅰ (DGAT1) and three type Ⅱ DGAT (DGAT2a,
DGAT2b, DGAT2c) genes of Myrmecia incisa were individually transformed into the H1246 strain, yielding four transgenic
yeast strains. The morphology, lipid droplet formation, cell density, volumetric biomass, biomass productivity, total lipids, total
fatty acids, and TAG content of S. cerevisiae were analyzed using microscopic observation, spectrophotometry, gravimetry,
Rod thin-layer chromatography, and gas chromatography-mass spectrometry. Microscopic observation during the stable growth
phase revealed oil droplets in all four transgenic strains, indicating that the exogenous genes promoted TAG synthesis and stor-
age. Lipid component analysis showed that the tDGAT1 strain exhibited the highest TAG and fatty acid content among all the
transgenic strains and the wild-type Scy62. Growth performance analysis revealed that cell densities of strains transformed with
the exogenous genes reached the levels comparable to Scy62 yeast, likely due to the consumption of free fatty acids
during TAG synthesis, thereby reducing cellular damage. However, the tDGAT1 strain exhibited the lowest growth, attributed
to a significantly prolonged period of growth retardation. Differences in growth performance and lipid components among the
transgenic strains may be due to unique domains with the DGATs. This study provides a foundation for producing desired lip-
ids using genetically engineered yeast strains.
Key words: Saccharomyces cerevisiae; Myrmecia incisa; diacylglycerol acyltransferase (DGAT); triacylglycerol (TAG);
growth
Corresponding author: ZHOU Zhigang. E-mail: zgzhou@shou.edu.cn
Funding projects: National Natural Science Foundation of China (31772821); National "Double First-class" Aquatic Science

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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