溶藻菌短短芽孢杆菌B15的发酵条件优化
毕业论文关键词：蓝藻水华；短短芽孢杆菌；铜绿微囊藻；发酵优化
Optimization of fermentation conditions of Brevibacillus brevis B15 Abstract：Brevibacillus brevis has been widely used in biological control. B. brevis B15 was isolated from soil and could produce algae-inhibition substance. The aim of this study was to improve the inhibitory activity of B15 by optimizing the culture medium and improving the fermentation conditions. The best carbon source was sucrose and the best nitrogen source was soybean determined by single factor test.According to the orthogonal test of medium components and the single factor test of fermentation parameters, the optimal culture conditions were determined. The optimized culture medium contained 15 g •L-1, 20 g•L-1soybean and 5 g•L-1NaCl at initial pH 7.0. 4% of the seed culture was inoculated to 70 mL of medium in 250 mL shaking flask, and fermented at 25℃ with shaking at 250 rpm for 48 h. The maximum inhibitory rate reached a high level of 94.80%, which was 1.20 times of that under the original conditions.
Key words: Cyanobacterial bloom ； Brevibacillus brevis ； Microcystis aeruginosa ； Fermentation optimization
摘要1
关键词1
Abstract1
Key words1
引言1
1材料与方法2
1.1实验材料2
1.2实验方法3
1.2.1铜绿微囊藻的培养3
1.2.2铜绿微囊藻的计数及其生长曲线的测定.3
1.2.3细菌的培养及细菌无菌滤液的制备3
1.2.4抑藻菌株对铜绿微囊藻生长的影响.3
1.2.5测定不同碳源对 B15 溶藻效果的影响3
1.2.6测定不同氮源对菌株B15溶藻效果的影响3
1.2.7培养基优化正交试验.3
1.2.8培养条件的单因子试验.4
1.2.8.1培养温度.4
1.2.8.2培养基初始 pH 值.4
1.2.8.3摇床转速.4
1.2.8.4接种量.4
1.2.8.5装液量.4
2结果与分析 .4
2．1铜绿微囊藻的培养及计数4
2．2培养基的成分及浓度测定5
2.2.1不同碳源对B15溶藻效果的影响5
2.2.1.1最佳碳源的筛选.5
2.2.1.2最佳质量浓度的确定.5
2.2.2不同氮源对B15溶藻效果的影响6
2.2.2.1最佳氮源的筛选.6
2.2.2.2最佳质量浓度的确定.6
2.2.2.3培养基优化正交试验.7
2.2.3培养条件的单因子试验.8
3讨论9
致谢.11
参考文献.11
引言 如今，富营养化是水体最严重的污染之一[1~6]
。随着水体富营养化现象的日益
加剧，蓝藻水华已成为我国面临的重大的环境问题，淡水中呈现富营养化后，水华会频
繁出现，面积也会逐年扩散，持续的时间也随之逐年延长。淡水中铜绿微囊藻（M.
aeruginosa）是形成水华的主要藻类之一，其产生的微囊藻毒素的主要靶器官是肝脏,具
有极高的细胞选择性和专一生物活性,可以从血液中转移到肝脏[7]
。 并且这些毒素会通过
食物链在原生动物、贝类、虾、鱼等体内积累严重威胁水产养殖业及人类生命安全[8]
。
藻类的过量繁殖会漂浮在水面上从而降低水体得透明度，严重阻碍了阳光进入水体，导