高产油脂菌株的筛选及其利用柠檬酸废水发酵的工艺优化

Screening for high-throughput,high-content oleaginous microorganisms and the fermentation process optimization by using citric acid wastewater as culture medium

文中采用了高效的常压室温等离子体(ARTP)诱变技术,结合流式细胞仪对经过尼罗红染色后的细胞进行了高通量筛选,获得了一株高产油脂的粘红酵母菌株,油脂含量较出发菌株提高了69.4%。将分选得到的菌株利用柠檬酸废水进行微生物油脂的生产。研究了废水稀释比例、初始pH值、初始补糖浓度对粘红酵母生长、油脂积累和COD降解率的影响。结果表明,最适的发酵条件为使用废水原液,pH值为5.5,初始补糖浓度为20g/L。此时,粘红酵母的生物量、油脂含量、油脂产量和COD降解率分别达到9.18g/L、37.66%、3.27g/L和63.3%。并且利用气相色谱-质谱分析了脂肪酸的组成。所产菌体的油脂成分中,不含和脂肪酸的含量较基础培养基提高了10.5%,可达88.32%,主要成分是油酸和亚油酸。表明柠檬酸废水适于粘红酵母进行微生物油脂的生产,并进一步用于生物柴油的制备。

Efficient Atmospheric and Room Temperature Plasma(ARTP) was employed to generate Rhodotorula glutinis mutation,and then using flow cytometry for high-throughput,high-content screening of cells which were dyed by Nile red.As a result,a high-yield mutant with change in lipid content was obtained,which increased 69.4%.Then citric acid wastewater as a medium was treated by Rhodotorula glutinis mutation to produce microbial lipid in this study.The effect of related factors,such as dilution rate of wastewater,pH,initial glucose addition concentration on biomass,lipid content,lipid production and COD degradation rate were discussed,respectively.The result indicated that the optimal fermentation conditions were:addition of 20g/L glucose,pH 5.5 and wastewater without dilution.Under this condition,the biomass production,lipid content,lipid production and COD degradation rate were 9.18g/L,37.66%,3.27g/L and 63.3%,respectively.The main composition of fatty acid in the resultant lipid was analyzed by gaschromatography-mass spectrometry which showed:The content of unsaturated fatty acids was 10.5% higher than synthetic medium,up to 88.32%.The main composition was oleic acid and linoleic acid.The result showed that citric acid wastewater was suitable for Rhodotorula glutinis to product microbial oil,and further used for the preparation of biodiesel.