title: Faunal Burrows Alter the Diversity, Abundance, and Structure of AOA, AOB, Anammox and n-Damo Communities in Coastal Mangrove Sediments.
abstract: In the present work, the diversity, community structures, and abundances of aerobic ammonia-oxidizing archaea (AOA) and bacteria (AOB), anaerobic ammonium-oxidizing (anammox) bacteria, and denitrifying anaerobic methane oxidization (n-damo) bacteria were unraveled in the bioturbated areas of the coastal Mai Po mangrove sediments. Results indicated that the bioturbation by burrowing in mangrove sediments was associated with higher concentration of NH4+but lower concentrations of both NO2-and NO3-, and increase in diversity and richness of both AOA and AOB, but relatively lower diversity and richness of n-damo bacteria. The phylotypes of anammox bacterial community were significantly increased while their phylogenetic lineages observed in the less bioturbated areas were also maintained. Infauna also showed a great impact on the composition of n-damo bacterial phylotypes and burrowing activity altered the n-damo community structure profoundly in the sampled areas. The communities of n-damo bacteria in the surrounding bulk sediments showed similar structures to marine n-damo communities, but those on the burrow wall and in the ambient surface layer had a freshwater pattern, which was different from previous findings in Mai Po wetland. On the other hand, the abundances of AOA, AOB, and n-damo bacteria were greatly stimulated on burrow walls while the abundance of anammox bacteria remained unchanged. Infaunal burrows and mangrove roots affected the relative abundance of AOA and AOB. The benthic infauna stimulated the abundances of AOA, AOB, anammox, and n-damo bacteria. Furthermore, NH4+and NO2-were important environmental factors changing the structure of each group. The communities of anammox and n-damo bacteria in bioturbated areas showed a competitive relationship.
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China.|School of Life Sciences, The University of Warwick, Coventry, UK.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, Faculty of Science, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, People's Republic of China. jdgu@hku.hk.|State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, SAR, People's Republic of China. jdgu@hku.hk.
authors.forename: Ji-Dong
authors.identifier: 0000-0002-7082-9784
authors.initials: JD
authors.lastname: Gu
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D064751:Ammonium Compounds / Q000378:metabolism; D000818:Animals; D001105:Archaea / Q000145:classification*; D001419:Bacteria / Q000145:classification*; D003386:Brachyura; D019015:Geologic Sediments / Q000382:microbiology*; D006723:Hong Kong; D010084:Oxidation-Reduction; D010802:Phylogeny
chemical_list: D064751:Ammonium Compounds; D000641:Ammonia
keywords: Ammonia-oxidizing archaea; Ammonia-oxidizing bacteria; Anammox; Bioturbation; Coastal sediment; n-Damo