酵母菌发酵啤酒生产废水产微生物油脂和菌体蛋白的研究

Production of microbial oil and bacterial protein from beer production wastewater fermented by yeast

为探索啤酒生产废水综合利用的方法和途径,采用液体发酵的方法,从7个酵母菌株中筛选出既能产微生物油脂和菌体蛋白,又能有效降解COD的菌株。考察了优良酵母菌株的发酵周期,并对其所产油脂的脂肪酸组成和菌体蛋白的氨基酸组成进行分析。结果表明:6#菌株——Trichosporon porosum D02、1#菌株——斯达油脂酵母Lipomyces starkeyi 1809对废水的资源化利用程度最高,6#和1#2个优良酵母菌株在发酵120 h时的油脂产量、菌体粗蛋白产量、COD降解率分别达到8.93 g/L、6.1 g/L、89.09%和4.62 g/L、4.42 g/L、81.47%。2个优良酵母菌株所产油脂的脂肪酸组成均以C_(16)和C_(18)系为主,含量最高的为油酸(C_(18∶1))和棕榈酸(C_(16∶0)),不饱和脂肪酸指数(IUFA)分别达到80.33%和61.57%。除脯氨酸未检出外,2个优良酵母菌株菌体蛋白均含有17种氨基酸,其中8种必需氨基酸占氨基酸总量的比例分别为44.14%和44.23%,可完全充当动物蛋白饲料。

For exploring the comprehensive utilization method and way of beer production wastewater, using the liquid fermentation to select high - yield strains which could product microbial oil, bacterial protein and could effectively degrade COD from seven yeast strains were studied. The fermentation period was examined and the fatty acid composition of microbial oil and amino acid composition of bacterial protein of the screened yeast strains were analyzed. The results showed that the resource utilization degrees highest. When two ty, crude bacterial porosum DO2） and 1# strain （Lipomyces starkeyi 1809 ） on wastewater were the screened strains 6# strain and 1# strain were fermented for 120 h, the oil productiviprotein productivity and degradation rate of COD were 8.93 g/L, 6.1 g/L, 89. 09% and 4. 62 g/L, 4. 42 g/L, 81.47% respectively. C18 and C16 fatty acids were the main components in the fatty acid composition of microbial oil of two screened strains. The contents of oleic acid and palmitic acid were the highest. The indexes of unsaturated fatty acid （IUFA） were 80.33% and 61.57% respectively. Except proline was not detected, the bacterial protein of two screened strains contained 17 kinds of amino acids and the contents of eight kinds of essential amino acids were 44.14% and 44.23% respectively. Bacterial protein could be used as a new source of animal protein feed.