蓝藻是一类进化历史悠久、革兰氏阴性、无鞭毛、含叶绿素a、不形成叶绿体、能 进行产氧性光合作用的原核生物。近年来，太湖蓝藻爆发频繁，大量蓝藻被打捞上来， 处置较困难。本文通过多途径研究蓝藻资源化利用的可行性，试图寻找出一种有效的蓝 藻利用方式，从而使其变废为宝，化害为利。 对太湖蓝藻组分分析表明其蛋白质含量较高，达到40.45%，微囊藻毒素浓度为2 mg/g。采用1%浓度的蓝藻培养酿酒酵母，培养26 h时酵母生物量最高只达到1.5 g/L，对 蓝藻的转化率只有16%，且发酵后微囊藻毒素未发生降解，所得酵母胞内毒素含量达到 390 μg/kg，该途径利用蓝藻资源不具可行性。 以无锡市太湖底泥为菌株来源，筛选获得一株具有显著降解微囊藻毒素能力的菌株 L3，鉴定发现其属肠杆菌属（Enterobacter）。L3在较适生长条件下，72h内对初始浓度 为50 mgL -1 的MC-RR和MC-LR的降解率分别达73.5%，72.8%，且L3对微囊藻毒素的 降解发生在胞外。采用紫外-亚硝基胍的两步诱变方法处理L3，获得一株高产突变株 L3-s8，其对毒素降解率达到91.5%，较出发菌株提高了24.5%，对其传代10次未发现自 发的回复突变现象。 以蓝藻和稻草秸秆为固态发酵原料，经无灭菌的自然发酵发现物料中两株主要霉菌 M-1，M-2，分属毛霉属（Mucor）及木霉属（Trichoderma）。采用 L3-s8 及 M-1﹑M-2 混和发酵，使物料中粗纤维降解率达到 40.30%，MC 降解率达到 75.24%。发酵后物料 主要指标均达到有机肥标准，但仍残留少量毒素，该途径实现蓝藻资源化利用的可行性 较为明朗。 关键词，蓝藻；微囊藻毒素；酿酒酵母；毒素降解；固态发酵Abstract Cyanobacteria is a kind of prokaryote with a long history of evolution, Gram-negative, non-flagellar, including chlorophyll a, no chloroplast, it can photosynthesis with the production of oxygen. In recent years, the blue algae frequently outbreaks in Taihu Lake, a large number of cyanobacteria had been raised, but it’s difficult to dispose them. In this paper, multi-channel was carried to study the feasibility of the use of it, trying to find an effective way to make them helpful. Component analysis of the algae showed its high protein content, reaching 40.45 percent, the microcystin concentration is 2 mg/g. Using 1% algae to cultivate Saccharomyces cerevisiae, the biomass was only 1.5g/L after 26h, the conversion rate of cyanobacteria was only 16%, the microcystin didn’t degradated, the microcystin concentration of yeast is 390 μg/kg, it showed non-feasibility to use the cyanobacteria this way. We screened a strain of L3 with significant ability to degrade microcystin from the sediment of Taihu Lake, identification showed it belongs to Enterobacter. Under suitable condition, after 72h fermentation, it can degradate MC-RR and MC-LR with the initial concentration of 50 mgoL -1 to the rate of 73.5%, 72.8% respectively, and the degradation occurred extracellularly. UV-nitrosoguanidine mutagenesis was carried to L3, we gained a high-degradating mutant L3-s8, its degradation rate of microcystin reached to 91.5%, increased 24.5%, and spontaneous reverse mutation hadn’t be found after 10 run of propagation. Taking cyanobacteria and rice straw as materials of solid fermentation, we found fungal M-1, M-2 after non-sterilized natural fermentation，they belonged to Mucor and Trichoderma respectively. We inoculated L3-s8 with M-1, M-2，the degradation rate of microcystin reached to 40.5%, the fermented materials meet the criteria of organic fertilizer well, but trace microcystin still residued, it showed feasibility to use cyanobacteria this way. Keywords: Blue algae , Microcystin , Saccharomyces cerevisiae , Microcystin degradation , Solid fermentation目 录 第一章 引言..............................................................................................................................1 1.1 概述................................................................................................................................. 1 1.2 目前国内外对蓝藻的研究利用..................................................................................... 1 1.2.1 提取有用物质 ......................................................................................................... 1 1.2.2 制作有机肥料 ......................................................................................................... 2 1.2.3 生产沼气 ................................................................................................................. 3 1.2.4 制作生物柴油 ......................................................................................................... 3 1.3MC 概况........................................................................................................................... 3 1.3.1 微囊藻毒素结构 ..................................................................................................... 3 1.3.2 微囊藻毒素毒性 ..................................................................................................... 4 1.4 微囊藻毒素降解研究进展............................................................................................. 4 1.4.1 物理吸附法 ............................................................................................................. 4 1.4.2 化学降解法 ............................................................................................................. 4 1.4.3 生物降解法 ............................................................................................................. 6 1.5 本课题研究意义及内容................................................................................................. 6 1.5.1 研究意义 ................................................................................................................. 6 1.5.2 研究内容 ................................................................................................................. 6 第二章 材料与方法..................................................................................................................9 2.1 实验材料......................................................................................................................... 9 2.1.1 主要材料及菌种 ..................................................................................................... 9 2.1.2 主要仪器 ................................................................................................................. 9 2.1.3 主要试剂 ................................................................................................................. 9 2.1.4 培养基 ..................................................................................................................... 9 2.2 实验方法....................................................................................................................... 10 2.2.1 蓝藻组分测定 ....................................................................................................... 10 2.2.2MC 测定 ................................................................................................................. 10 2.2.3 酿酒酵母培养 ....................................................................................................... 112.2.4 酿酒酵母生物量测定 ........................................................................................... 11 2.2.5 诱变处理条件与步骤 ........................................................................................... 11 2.2.6 固态培养方法 ....................................................................................................... 12 2.2.7 粗纤维测定 ........................................................................................................... 12 2.2.8 氨基态氮测定 ....................................................................................................... 12 第三章 结果与讨论................................................................................................................13 3.1 太湖蓝藻组分分析....................................................................................................... 13 3.1.1 太湖蓝藻组分分析 ............................................................................................... 13 3.1.2 微囊藻毒素含量的分析 ....................................................................................