微生物油脂花生四烯酸产生菌离子束诱变和发酵调控

某些微生物是高质量油脂的生产者.微生物油脂不仅有益健康,而且是生物柴油潜在的油脂来源.中国是个油脂资源缺乏的国家,开发微生物源油脂具有重要的意义.本文以产油微生物——高山被孢霉菌为出发菌,以单细胞油脂多不饱和脂肪酸产率为筛选目标,采用二步离子束诱变-筛选的策略,获得了高产菌株.研究了高产菌株的营养需求,创建了重复利用提油后的残体(菌粕)合成微生物油脂的技术.针对丝状真菌高密度发酵的传能和传质问题,研制了6×50和4×200m3大容量专用反应器组,单位发酵容积生物量达38.2g/L(发酵液)、油脂20.67g/L.其中具有重要生理活性的花生四烯酸产率最高达9.89g/L,平均为8.97g/L.花生四烯酸提取和精炼后的残油转化为生物柴油,主要指标达到国家生物柴油标准.

Ion-beam-mutation breeding of an arachidonic acid biosynthesis microorganism and its industrial fermentation control

Some microorganisms in nature produce high-quality oils.These oils provide nutritional benefits to human health,and can be potential sources of biodiesel.Developing microorganism-derived oils,also known as single-cell oils,is particularly important for China because of the shortage of oil resources.We have bred a high-yielding,polyunsaturated fatty acids(PUFCs)-producing strain from the fungi Mortierella alpine by using a two-step strategy of ion-beam-mutation breeding and PUFCs productivity screening.We further studied the nutritional requirements of this new strain,and developed a technique that recycles the fungi residues,after oil extraction,into fermentation substrates.A biomass of 38.2 g/L,20.67 g/L of which were oils,was reached in the 6×50 m3 and 4×200 m3 high-capacity reactors,designed for mycelial fungus fermentation at high-density,with optimized energy and mass transmission efficiency.Among the oils,the content of the physiologically active arachidonic acid reached 9.89 g/L at the highest level and 8.97 g/L on average.Residual oils,after arachidonic acid extraction and refinement,were processed into biodiesel,the main indexes of which attained the national standards.