Kuang Chunyi, Hong Yiguo, Sun Wei, Wu Jiapeng, Chen Ruixi, Wei Mingken, Chen Lizhao, Zhu Zhidong
Guangdong Provincial Key Laboratory for Green Agricultural Production and Intelligent Equipment, College of Biological and Food Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, China.
Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China.
BMC Microbiol. 2025 Jul 2;25(1):396. doi: 10.1186/s12866-025-04122-0.
The nitrate reductase S (nirS) type denitrifying bacteria is important for nitrate removal, and suspended particulate matter (SPM) in coastal aquaculture water provides a microenvironment for denitrification to occur. However, it is currently unclear about the denitrification mechanism for nitrate removal occurred on SPM in coastal aquaculture water. SPM with different particle sizes (0.22, 1 and 5 μm) were collected from coastal cage aquaculture ponds water in Maoming City, China. Gene abundance, community structure, diversity and environmental influences of nirS-type denitrifying bacteria on SPM were investigated by fluorescence quantitative PCR (qPCR), high-throughput sequencing and statistical analysis. Roseobacter was widely distributed on SPM with three kinds of particle sizes, especially SPM with 0.22 μm particle size. Pelomonas and Pseudomonas were mainly present on SPM with 1 and 0.22 μm particle sizes, while Acidithiobacillales was mainly present on SPM with 5 μm particle size. The nirS gene abundance and community diversity of denitrifying bacteria was higher on SPM with 5 μm particle size than that with 1 and 0.22 μm particle sizes. The nirS-type denitrifying bacteria communities clustered evidently according to SPM particle sizes in cage aquaculture ponds water. NO-N, NO-N, particle size, and pH were identified as significant factors affecting the community structure and diversity of nirS-type denitrifying keystone genera on SPM. The present study provided new insights into denitrification in the microenvironment on SPM in aquaculture systems, which may contribute to the biological management of cage aquaculture ponds.
硝酸盐还原酶S（nirS）型反硝化细菌对硝酸盐去除具有重要作用，而沿海养殖水体中的悬浮颗粒物（SPM）为反硝化作用的发生提供了微环境。然而，目前尚不清楚沿海养殖水体中SPM上发生的硝酸盐去除反硝化机制。从中国茂名市沿海网箱养殖池塘水体中采集了不同粒径（0.22、1和5μm）的SPM。通过荧光定量PCR（qPCR）、高通量测序和统计分析，研究了nirS型反硝化细菌在SPM上的基因丰度、群落结构、多样性及环境影响。玫瑰杆菌广泛分布于三种粒径的SPM上，尤其是粒径为0.22μm的SPM。Pelomonas和假单胞菌主要存在于粒径为1和0.22μm的SPM上，而嗜酸硫杆菌目主要存在于粒径为5μm的SPM上。粒径为5μm的SPM上反硝化细菌的nirS基因丰度和群落多样性高于粒径为1和0.22μm的SPM。在网箱养殖池塘水体中，nirS型反硝化细菌群落根据SPM粒径明显聚类。NO-N、NO-N、粒径和pH被确定为影响SPM上nirS型反硝化关键属群落结构和多样性的重要因素。本研究为养殖系统中SPM微环境中的反硝化作用提供了新的见解，这可能有助于网箱养殖池塘的生物管理。
