九龙江口肥水-缢蛏养殖塘厌氧氨氧化微生物活性研究

STUDY ON THE ACTIVITY OF ANAEROBIC AMMONIA OXIDIZING BACTERIA IN COMBINATION CULTURE SYSTEM OF FERTILIZER POOL AND SINONOVACULA CONSTRICTA CULTURE POND IN JIULONG RIVER ESTUARY

缢蛏串联养殖经由饵料藻类养殖塘(俗称肥水塘)投放适量含氮化合物以提高生产效率,了解此过程中的沉积物氮转化对调控和管理河口养殖塘氮的收支具有重要意义。以福建九龙江口肥水-缢蛏养殖塘为研究对象,运用同位素示踪技术和高通量测序技术探究缢蛏塘和肥水塘沉积物厌氧氨氧化速率及微生物群落结构,并分析其环境调控机制。结果表明,肥水塘沉积物厌氧氨氧化速率为(1.76±0.11) nmol/(g·h),相对贡献为9.16%±0.40%,显著高于缢蛏塘(P<0.05)。缢蛏塘和肥水塘厌氧氨氧化微生物主要由Candidatus Scalindua、Ca.Kuenenia、Ca.Brocadia和Ca.Anammoximicrobium属组成。其中,Ca.Kuenenia属为养殖塘的优势菌属。沉积物厌氧氨氧化微生物多样性和丰富度呈显著的空间分布特征,肥水塘中生物多样性更高(P<0.05)。厌氧氨氧化微生物活性和群落结构差异主要受养殖土地利用方式、溶解氧(DO)、NH_(4)^(+)和NO_(3)^(-)含量等环境因子的调控。该研究在一定程度上揭示了养殖环境中厌氧氨氧化过程的重要性,填补了河口养殖湿地氮回归大气的认知空白。

A tandem culture system was designed to produce razor clam Sinonovacula constricta in pond with an upstream culture pond that was used to cultivate algae as bait for the razor clam in Jiulong River estuarine area,Fujian,SE China.A certain amount of nitrogen compounds was put into the algae pond for nurturing alga.The nitrogen(N)budget in water and sediment of the tandem system was studied to for best practice.The rates and microbial community structure of anaerobic ammoxidation(anammox),and their response to the ambience factor were studied using 15N isotope-tracing technology and high-throughput sequencing methods.Results show that the potential rate of anammox in sediment of the algae ponds was(1.76±0.11)nmol/(g·h),and the relative contribution rate to anaerobic ammoxidation was 9.16%±0.40%,which was significantly higher than of the S.constricta pond.Anammox bacteria in the S.constricta pond and the algae pond were dominated by Ca.Scalindua,Ca.Kuenenia,Ca.Brocadia,and Ca.Anammoximicrobium.The diversity and richness of anammox bacteria in sediment of the algae pond were significantly higher than those of the S.constricta pond(P<0.05).Environmental factors including DO,NH_(4)^(+),and NO_(3)^(-)contents controlled the anammox microbial community structure of the system.This study revealed the N utilization and removal processes of anammox,and filled the gap in the knowledge of N return into the atmosphere in estuarine aquaculture wetland.