优化鸡粪微生态分解及添加降解液促进微藻过量合成生物油脂

摘要

以小球藻(Chlorella protothecoides)为出发菌株,优化鸡粪微生态分解及添加降解液促进微藻细胞生长和胞内油脂合成.通过控制溶解氧(DO)优化鸡粪微生态分解,获得高氮和低氮两种降解液.微藻培养过程分为细胞生长(0～120 h)和油脂合成(120～200 h)两个阶段,前期添加高氮降解液促进细胞生长,后期添加低氮降解液和葡萄糖补充氮源及能量过量合成油脂,实现细胞浓度和生物油脂产率最大化.C.protothecoides培养期间,0～120 h恒速流加(15 mL/(L·D))高氮降解液,120～200 h流加(15 mL/(L·D))低氮降解液和葡萄糖(1.5 g/(L·D)),培养结束(200h)时,油脂质量浓度高达5.28 g/L,分别比对照及不添加葡萄糖时油脂质量浓度增加74.8％和21.1％.结果表明,两阶段鸡粪降解液添加与葡萄糖再生ATP结合策略促进油脂合成是有效的.%The degradation of chicken manure was optimized and digested chicken manure filtrate (DCMF) was added to promote cells growth and lipid production in heterotrophic culture Chlorella protothecoides.Higher and low nitrogen DCMF were obtained by controlling dissolved oxygen (DO) level.Based on the fact that higher nitrogen DCMF favored cells growth but retarded lipid accumulation and vice versa for lower nitrogen DCMF,a two-step DCMF supplementation of feeding higher nitrogen DCMF (15 ml/L/D) at the cell growth phase (0～120 h) and lower one (15 ml/L/D) at the stationary phase (120～200 h) was adopted to enhance lipid production.Moreover,the strategies of DCMF supplementation coupled with adenosine triphosphate (ATP) regeneration from glucose feeding (1.5 g/L/D) were developed.Experimental results showed that lipid yield of 5.28 g/L was achieved after 200 h cultivation,increased by 74.8％ and 21.1％ respectively,compared to the control and the one without glucose addition.It was suggested that application of DCMF combined with glucose feeding as being feasible for lipid overproduction.