Identification of oleaginous yeast strains able to accumulate high intracellular lipids when cultivated in alkaline pretreated corn stover.
Identification of oleaginous yeast strains able to accumulate high intracellular lipids when cultivated in alkaline pretreated corn stover.
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DOI：
10.1007/s00253-014-5944-8
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发表时间：
2014-09
影响因子：
5
通讯作者：
Boundy-Mills KL
中科院分区：
文献类型：
--
作者：
Sitepu IR;Jin M;Fernandez JE;da Costa Sousa L;Balan V;Boundy-Mills KL
微生物油是食品/植物源生物柴油燃料的潜在替代品。我们之前的筛选研究使用已知可刺激脂质积累的特定实验室培养基，鉴定了多种产油酵母种类。在这项研究中，我们在合成水解产物 (SynH) 和真正的氨纤维膨胀 (AFEX™) 预处理的玉米秸秆水解产物 (ACSH) 中进一步研究了这些酵母生长和积累脂质的能力。大多数测试的酵母菌株能够在 SynH 中积累脂质，但只有少数能够在 ACSH 培养基中生长并积累脂质。当在 ACSH 中生长时，腐殖隐球菌 UCDFST 10-1004 能够积累高达 15.5 g/L 的脂质，而细胞生物量总计为 36 g/L，细胞脂质含量为细胞干重的 40%。对于在真正的水解产物中生长的产油酵母来说，这种脂质产量是报道的最高值之一。在 SynH 培养基中以木糖作为唯一碳源进行预培养，使酵母能够在随后的水解产物培养基中更有效地同化葡萄糖和木糖。这项研究表明，ACSH 是某些产油酵母将木质纤维素糖转化为三酰甘油以生产生物柴油和其他有价值的油脂化学品的合适培养基。
Microbial oil is a potential alternative to food/plant-derived biodiesel fuel. Our previous screening studies identified a wide range of oleaginous yeast species, using a defined laboratory medium known to stimulate lipid accumulation. In this study, the ability of these yeasts to grow and accumulate lipids was further investigated in synthetic hydrolysate (SynH) and authentic ammonia fiber expansion (AFEX™)-pretreated corn stover hydrolysate (ACSH). Most yeast strains tested were able to accumulate lipids in SynH, but only a few were able to grow and accumulate lipids in ACSH medium. Cryptococcus humicola UCDFST 10-1004 was able to accumulate as high as 15.5 g/L lipids, out of a total of 36 g/L cellular biomass when grown in ACSH, with a cellular lipid content of 40% of cell dry weight. This lipid production is among the highest reported values for oleaginous yeasts grown in authentic hydrolysate. Pre-culturing in SynH media with xylose as sole carbon source enabled yeasts to assimilate both glucose and xylose more efficiently in the subsequent hydrolysate medium. This study demonstrates that ACSH is a suitable medium for certain oleaginous yeasts to convert lignocellullosic sugars to triacylglycerols for production of biodiesel and other valuable oleochemicals.