斑节对虾混养池塘微生物群落生态功能初探

Ecological Functions of Microbial Communities in Tiger Shrimp Penaeus monodon Polyculture Ponds

利用宏基因组技术比较斑节对虾单独养殖、斑节对虾与海蜇混养、斑节对虾与海蜇和菲律宾蛤仔混养3种养殖模式池塘沉积物的微生物群落。试验结果显示,皮氏罗尔斯通氏菌为最主要的致病菌,斑节对虾养殖池塘沉积物中致病菌的丰度相比于对照组沉积物均明显下降。与非海水养殖池塘对照沉积物相比,斑节对虾养殖池塘沉积物的微生物群落中硝酸盐还原生成氨氮的相关基因以及硫酸盐还原产生硫化氢的相关基因含量更高,而亚硝酸盐和氨氮利用基因含量较低。3种斑节对虾养殖模式中,斑节对虾单独养殖和斑节对虾与海蜇和菲律宾蛤仔混养池塘沉积物中硝酸盐和硫酸盐还原基因丰度均高于斑节对虾与海蜇混养模式。此外,斑节对虾养殖池塘沉积物中,一些特定的生物地球化学循环过程由包括交替单胞菌、拟杆菌、着色菌、黄杆菌、脱硫杆菌和脱硫弧菌等多种微生物共同完成。探明不同斑节对虾养殖池塘微生物群落中潜在的人类致病菌情况以及氮、硫等基本元素的生物地球化学循环,对于优化养殖技术、控制疾病暴发同时提高养殖产量具有重要意义。

In this study,the microbial communities of sediments from three different types of prawn mariculture systems,including prawn,prawn+jellyfish,prawn+jellyfish+clam,and a non-mariculture in coastal area were compared by a metagenomics method.Results showed that Ralstonia pickettii was the most abundant pathogen in studied samples.The relative abundance of pathogens in the sediments of prawn mariculture ponds was significantly lower than that in the control sediments.Moreover,significantly higher abundances of genes associated with nitrate reduction to produce ammonia were presented in the prawn mariculture sediments,whereas genes related to nitrite and ammonia utilization were more abundant in the non-mariculture sediments.Meanwhile,higher abundance of genes involved in sulfate reduction to produce sulfides were also found in all types of prawn mariculture sediments compared to the non-mariculture controls.Interestingly,both genes of nitrate and sulfate reduction were more abundant in prawn monoculture and prawn+jellyfish+clam modes than those in the prawn+jellyfish system.Moreover,certain biochemical processes in prawn mariculture sediments were conducted by various microbial groups,including Alteromonadales,Bacteroidales,Chromatiales,Flavobacteriales,Desulfobac\|terales,and Desulfovibrionales.Understanding of the biogeochemical cycling of nitrogen and sulfur as well as pathogens in various prawn polyculture systems can help to improve the culture technology,restrict the outbreak of diseases,and increase the production.