RESUMO
In this study, 16S high-throughput and metagenomic sequencing analyses were employed to explore the changes in microbial community and function with the succession of mangroves (Sonneratia alba, Rhizophora apiculata, and Bruguiera parviflora) along the Merbok river estuary in Malaysia. The sediments of the three mangroves harbored their own unique dominant microbial taxa, whereas R. apiculata exhibited the highest microbial diversity. In general, Gammaproteobacteria, Actinobacteria, Alphaproteobacteria, Deltaproteobacteria, and Anaerolineae were the dominant microbial classes, but their abundances varied significantly among the three mangroves. Principal coordinates and redundancy analyses revealed that the specificity of the microbial community was highly correlated with mangrove populations and environmental factors. The results further showed that R. apiculata exhibited the highest carbon-related metabolism, coinciding with the highest organic carbon and microbial diversity. In addition, specific microbial taxa, such as Desulfobacterales and Rhizobiales, contributed the highest functional activities related to carbon metabolism, prokaryote carbon fixation, and methane metabolism. The present results provide a comprehensive understanding of the adaptations and functions of microbes in relation to environmental transition and mangrove succession in intertidal regions. High microbial diversity and carbon metabolism in R. apiculata might in turn facilitate and maintain the formation of climax mangroves in the middle region of the Merbok river estuary.
RESUMO
To date, the genus Mangrovimonas consists of only one species, Mangrovimonas yunxiaonensis strain LY01 that is known to have algicidal effects against harmful algal blooms (HABs) of Alexandrium tamarense. In this study, the whole genome sequence of three Mangrovimonas-like strains, TPBH4(T)(=LMG 28913(T),=JCM 30882(T)), ST2L12(T)(=LMG 28914(T),=JCM 30880(T)) and ST2L15(T)(=LMG 28915(T),=JCM 30881(T)) isolated from estuarine mangrove sediments in Perak, Malaysia were described. The sequenced genomes had a range of assembly size ranging from 3.56 Mb to 4.15 Mb which are significantly larger than that of M. yunxiaonensis LY01 (2.67 Mb). Xylan, xylose, L-arabinan and L-arabinose utilization genes were found in the genome sequences of the three Mangrovimonas-like strains described in this study. In contrast, these carbohydrate metabolism genes were not found in the genome sequence of LY01. In addition, TPBH4(T) and ST2L12(T) show capability to degrade xylan using qualitative plate assay method.
