Distribution pattern of N-damo bacteria along an anthropogenic nitrogen input gradient from the coastal mangrove wetland to the South China sea sediments

TY - JOUR

T1 - Distribution pattern of N-damo bacteria along an anthropogenic nitrogen input gradient from the coastal mangrove wetland to the South China sea sediments

AU - Chen, Jing

AU - Zhou, Zhichao

AU - Gu, Ji-Dong

PY - 2022/11/1

Y1 - 2022/11/1

N2 - Microbial nitrite-dependent anaerobic methane oxidation (n-damo) process is important for mitigating methane emission and anthropogenic nitrogen inputs in the marine environment. However, the distribution pattern of n-damo bacteria along an anthropogenic N-input gradient from the coastal wetland to the pristine South China Sea is poorly understood. This study investigated the diversity and abundance of n-damo bacteria in samples collected along a N-input gradient from Mai Po (MP) mangrove wetland sediments of the Pearl River Estuary (PRE) to the deep ocean sediments of the South China Sea (SCS). Retrieved 16S rDNA sequences showed a shift of n-damo community composition of complex structures with both freshwater and marine n-damo lineages in MP intertidal sediments to marine dominated characteristic in SCS sediments. The observed variation of Shannon and Chao1 indexes of n-damo bacteria shared a similar trend of a decrease at first followed by an increase along the targeting gradient with previously investigated methanogens, anaerobic methanotrophic archaea, ammonia-oxidizing archaea and ammonia-oxidizing bacteria, but had a reverse pattern with anammox bacteria. The community structure of pmoA gene sequences contained freshwater lineages only in SCS continental shelf sediments closer to the PRE, and turned to group with other marine samples in deeper and pristine sediments. Results suggested that n-damo bacteria might be a major contributor to anaerobic denitrification in the SCS sediments because their abundances were much higher than previously studied anammox bacteria in the same sample set. The distribution pattern of n-damo bacterial diversity, richness and abundance along the anthropogenic N-input gradient implies that they could be used as a bio-indicator for monitoring the anthropogenic/terrestrial inputs in marine environments.

AB - Microbial nitrite-dependent anaerobic methane oxidation (n-damo) process is important for mitigating methane emission and anthropogenic nitrogen inputs in the marine environment. However, the distribution pattern of n-damo bacteria along an anthropogenic N-input gradient from the coastal wetland to the pristine South China Sea is poorly understood. This study investigated the diversity and abundance of n-damo bacteria in samples collected along a N-input gradient from Mai Po (MP) mangrove wetland sediments of the Pearl River Estuary (PRE) to the deep ocean sediments of the South China Sea (SCS). Retrieved 16S rDNA sequences showed a shift of n-damo community composition of complex structures with both freshwater and marine n-damo lineages in MP intertidal sediments to marine dominated characteristic in SCS sediments. The observed variation of Shannon and Chao1 indexes of n-damo bacteria shared a similar trend of a decrease at first followed by an increase along the targeting gradient with previously investigated methanogens, anaerobic methanotrophic archaea, ammonia-oxidizing archaea and ammonia-oxidizing bacteria, but had a reverse pattern with anammox bacteria. The community structure of pmoA gene sequences contained freshwater lineages only in SCS continental shelf sediments closer to the PRE, and turned to group with other marine samples in deeper and pristine sediments. Results suggested that n-damo bacteria might be a major contributor to anaerobic denitrification in the SCS sediments because their abundances were much higher than previously studied anammox bacteria in the same sample set. The distribution pattern of n-damo bacterial diversity, richness and abundance along the anthropogenic N-input gradient implies that they could be used as a bio-indicator for monitoring the anthropogenic/terrestrial inputs in marine environments.

KW - N-damo bacteria

KW - Community structure

KW - Anthropogenic nitrogen inputs

KW - Pearl river estuary

KW - South China Sea

U2 - 10.1016/j.marenvres.2022.105739

DO - 10.1016/j.marenvres.2022.105739

M3 - 文章

C2 - 36084374

SN - 0141-1136

JO - Marine Environmental Research

JF - Marine Environmental Research

ER -