罗非鱼-鱼腥草共生养殖池塘沉积物菌群结构与功能特征

为探究鱼腥草浮床对罗非鱼池塘沉积物中细菌群落的影响,采用Biolog-Eco和PCR-DGGE技术,对比分析了2013年9—11月鱼腥草浮床(试验塘)和常规养殖(对照塘)2种模式下,罗非鱼养殖池塘沉积物中菌群的结构和功能多样性特征。Biolog-Eco结果显示:9月份试验塘沉积物微生物代谢强度和菌群多样性指数均低于对照塘;但10—11月份则明显高于对照塘,且不同月份丰富度指数与对照塘相比均差异显著(P0.05),说明鱼腥草浮床在养殖中、后期能有效增加细菌生物量和提高种群丰富度。主成分分析(PCA)显示:试验塘和对照塘不同月份沉积物中菌群对羧酸类碳源的相对利用率差异较大,且不同月份利用碳源的差异程度为10月11月9月;DGGE结果显示:试验塘和对照塘沉积物主要的菌群结构组成相似,分属于6个门,包括变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)、蓝细菌门(Cyanobacteria)和梭杆菌门(Fusobacteria),其中变形菌门(54.17%)均为优势菌群,但同一月份试验塘菌群多样性均明显多于对照塘。结果表明,鱼腥草浮床具有增加罗非鱼池塘沉积物菌群功能多样性和优化菌群结构的作用。

Effect of Houttuynia cordata Floating-bed on the Structure and Function of Bacterial Community in the Sediments of Tilapia Aquacultural System

To explore the effect of Houttuynia cordata floating-bed on bacterial community of sediment in tilapia pond, Biolog-Eco and PCR-DGGE were used to evaluate structure and function of the bacterial community in the sediments in Houttuynia-Tilapia symbiotic system from September to November in 2013. The Biolog-Eco results showed that microbial metabolic activity and bacterial diversity index in the treatment ponds were lower than those of the control ponds in September, while the status of the treatment and control ponds were just opposite from October to November. The richness indexes of the treatment ponds of different months were significantly different compared with that of the control ponds(P<0.05), therefore Houttuynia cordata floating-bed could effectively increase the bacterial biomass and species richness in the mid and late period. Principal component analysis (PCA) results showed that relative utilization ratios of carboxylic acids were significantly different in different months, and the different degrees appeared in the order of October>November>September. The DGGE results indicated that the composition of microbial community in the sediments of treatment and control ponds were similar. The bacteria belonged to six bacterial phyla, including Proteobacteria, Bacteroidetes, Acidobacteria, Chloroflexi, Cyanobacteria and Fusobacteria. Proteobacteria (54.17%) was the dominant bacterial community. However, the bacterial community diversity of the treatment ponds was obviously higher than that of the control ponds in the same month. As a result, Houttuynia cordata floating bed had a positive effect on optimizing the structure of microbial community, and increasing the diversity of microbial community.