酸浆豆腐废水中发酵假丝酵母的研究

Fermentation of Candida macedoniensis in wastewater of Suanjiang Tofu

实验室从豆腐酸浆中分离筛选出一株发酵黄浆水产蛋白较高的假丝酵母FM45菌株。采用正交试验法对该菌株的产蛋白培养基配比进行了优化,确定了最佳产蛋白方案。该菌株在黄浆水中添加6%(w/v)废糖蜜、1.2%(w/v)(NH4)2SO4、0.12%(w/v)K2HPO4,生物量和蛋白产量分别达到12.08g/L和5.97g/L。同时进行了假丝酵母FM45菌株发酵过程的研究,发现假丝酵母FM45在16～18h蛋白产量达到最高。通过对假丝酵母FM45蛋白的氨基酸分析,假丝酵母不仅所含的必需氨基酸种类齐全,而且必需氨基酸之间的比例适宜,是营养价值较高的优质蛋白资源。

Candida macedoniensis FM45, which has high protein production capacity, was screened and purified from stock cultures of 5 yeast strains in laboratory. Effects of sources of carbon, nitrogen and phosphoruse, initial pH value, inoculum concentration on production of protein by FM45 were studied and the optimum fermentation conditions were determined. Biomass and protein yield of FM45 could reach 12.08 g/L and 5.97 g/L respectively under the eondions of waste molasses： 6% （w/v）, （NI-L）2SO4： 1.2% （w/v）, K2HPO4： 0.12% （w/v）, initial pH value： 4.5, 30 ml medium in 250 ml shaker and fermented at 30℃, 220 r/min for 16-18 h. It was found that FM45 contained 18 kinds of amino acids and it was a high quality protein source.