剩余污泥热碱解及其用于微生物油脂生产的探索

Heat-alkaline treatment of excess sludge and the potential use of hydrolysate as nitrogen source for microbial lipid production

摘要:

为了将剩余污泥中的蛋白质成分进行资源化利用，采用热碱解法进行处理，并尝试将处理后得到的上清液作为氮源培养圆红冬孢酵母用于微生物油脂的合成。结果表明，pH 13下处理5 h的条件对于污泥减量以及含氮物质析出最为有效，而污泥在pH 10处理5 h时得到的上清液则相对更适于酵母培养。在剩余污泥中添加NaOH调节初始pH为10，在60 ℃下处理5 h后中和体系pH值至7，得到的上清液经微孔膜过滤后用于配制限氮培养基可以使菌体生长良好，并且细胞内油脂含量达35％。

Abstract:

To recover and use protein resources in excess sludge and decrease the cost of microbial lipid production, heat-alkaline was used to treat the sludge, and the hydrolysate was preliminarily used as nitrogen source to cultivate Rhodosporidium toruloides AS 2.1389 for lipid accumulation. Firstly, we treated the excess sludge under different alkaline conditions (pH 10, pH 12, pH 13) within the reaction time of 5–10 h to investigate the effect of nitrogen source release. Secondly, we used the sludge hydolysate to culture R. toruloides AS, and test the effect on cell growth. Results showed that treatment of excess sludge at pH 13 for 5 h was the most effective for nitrogen release. However, the hydrolysate obtained at pH 10 (5 h) was the most suitable for culturing R. toruloides AS, and under this condition, the inner-cellular lipid content could reach 35% of the total biomass weight.