混合菌群发酵马尾藻作为海藻肥料的研究

Studies on fermentation of Sargassum by mixed microorganism utilized as seaweed fertilizer

从马尾藻原位分离发酵菌群,采用分子生物学手段分析鉴定菌种组成,获得发酵菌株4株分别为巨大芽孢杆菌(Bacillus megaterium),非脱羧勒克氏菌(Leclerciaadecarboxylata),鞘氨醇单胞菌(Sphingomonasleidyi)以及赖氨酸芽孢杆菌(Lysinibacillusmacroides);控制4菌株接种比例进行马尾藻发酵,监测发酵过程中菌种生物量、褐藻酸含量及褐藻寡糖含量变化规律,结果表明,马尾藻经发酵36 h生成聚合度2-5的褐藻寡糖,并伴随菌种二次生长及pH下降等易于观察检测的参数变化;含褐藻寡糖的发酵原液稀释600倍后,能够明显促进小麦种子萌发及根生长,与清水对照相比萌发率提高26%,根系长度增长37%。本研究为微生物发酵法生产海藻肥料提供了可行案例,证实该方法简单有效,可操作性强,有广阔的应用前景,为将来实现海藻发酵肥工业化生产提供理论支持和数据支撑。

Fermentative microorganisms present on the surface of seaweed were screened and then identified by16S rDNA sequence analysis.We obtained the following four fermentative strains:Bacillus megaterium,Leclerciaadecarboxylata,Lysinibacillusmacroides,and Sphingomonasleidyi.Using controlled inoculation proportion of these four strains,we obtained a stable fermentation product.We studiedthe changes and mechanisms of seaweed fermentation processto provide theoretical and data support for industrialization production of seaweed fermentation fertilizer.At36h in the fermentation process,alginate oligosaccharides with polymerization degrees of2-5were generated and accompanied by secondary growth of fermentative strains and a decreased pH,which were the parameters that could be easily observed and monitored.Fermentation broth diluted600times could significantly promote the germination and root growth of wheat seeds.Germination rate was26%higher and root growth was37%longer than those in the control group,respectively.These results provided a feasible strategy for the production of seaweed fertilizer by microbial fermentation.This simple and effective fermentation method has strong operability and broad application prospects.