养殖中后期高位池对虾水体微生物群落结构及水体理化因子

Microbial community structure and physicochemical factors in the water of upland pond of Litopenaeus vannamei during the middle and late stage of culture

针对凡纳滨对虾(Litopenaeus vannamei)高位池越冬棚养殖模式,采集养殖中后期水样,分析水体微生物群落结构、优势菌种类和水体理化因子的动态变化。结果表明:越冬棚保温效果良好,池塘水温由搭棚前最低的20.6℃上升并维持稳定于26.5℃左右,可满足对虾正常生长需求;养殖中后期水体异养细菌数量在5.10×104~2.95×105cfu·m L^(-1)波动,菌群结构相对稳定,优势菌数量在养殖后期略有增加;嗜冷杆菌(Psychrobacter)、亚硫酸杆菌(Sulfitobacter)等在养殖中后期均为优势种,搭棚后黄杆菌(Flavobacteria)、生丝微菌(Hyphomicrobium)等形成优势;亚硝氮、硝氮和水温是影响养殖中后期水体微生物群落分布的主要理化因子。研究表明,搭建越冬棚有利于保持养殖池塘水环境的相对稳定,养殖中后期水体氮素水平的控制尤为重要。因此,为促进水中有益菌的生态优势,调控水体菌群结构和生态功能,建议在养殖中后期,尤其是搭建越冬棚前后合理使用益生菌制剂,净化水质,稳定生态环境。

For the culture mode of over-winter sheds （OWS）, water samples were collected fromLitopenaeus vannamei culture ponds aiming to investigate the variation of microbial community structure, dominant bacterial species and environmental factors in the pond water in the middle and late stage of culture. The results showed that the water temperature increased from 20.6 ℃ to 26.5 ℃ after building OWS, which was suitable for the growth of shrimp. The amount of heterotrophic bacteria in the water was between 5.1×104 and 2.95×105 cfu·mL-1 in the middle and late stage of culture. The structure of microbial community was relatively stable, and the number of dominant bacteria increased.Psychrobacter andSulfitobacter were the dominant bacteria, whileFlavobacteria andHyphomicrobium appeared after building OWS. Additionally, the RDA analysis showed that nitrite nitrogen, nitrate nitrogen and temperature were the major physical and chemical factors influencing the abundance and distribution of microbial communities. The results indicate that aquaculture environment could be kept relatively stable after OWS building, and the regulation of nitrogen concentration is very important in the middle and late stage of culture. Therefore, we suggested that probiotics should be used before and after building OWS in order to promote and stabilize ecological advantage of beneficial bacteria, and regulate bacterial community structure and ecological function.