剩余污泥热碱解及其用于微生物油脂生产的探索
2011-09-29徐静阳大浦宏隆刘德华梶原将
徐静阳,大浦 宏隆,刘德华,梶原将
1 清华大学化学工程系应用化学研究所,北京 100084
2 日本东京工业大学生命理工学部,横滨 226-8501
剩余污泥热碱解及其用于微生物油脂生产的探索
徐静阳1,2,大浦 宏隆2,刘德华1,梶原将2
1 清华大学化学工程系应用化学研究所,北京 100084
2 日本东京工业大学生命理工学部,横滨 226-8501
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%。
剩余污泥,热碱解,氮,产油酵母,微生物油脂
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.
Keywords:excess sludge, heat-alkaline treatment, nitrogen, oleaginous yeast, microbial lipid
随着近年来能源紧缺与环境问题的日益突出,生物柴油作为一种新型能源得到广泛重视。产油微生物可将多种可再生资源转化为油脂,即微生物油脂,且以其生产过程不占用耕地资源,可以连续产出等诸多的特点与优越性而受到关注,有望为生物柴油产业提供油脂原料。
微生物发酵产油脂大体分为菌体增殖期和油脂积累期两个阶段,前期细胞增殖需要消耗丰富的碳、氮源,保持菌体旺盛的代谢从而增加生物量,后期限制氮源从而使其积累油脂[1]。相应的,在发酵工艺上常用一步法限氮发酵或两步发酵法。……
