The microbial community is dynamic in a mangrove ecosystem and thus controls various nutrient transformation processes in the ecosystem. In the current efforts to rehabilitate mangroves, this study focused on detecting significant variation within the bacterial community distribution in sediments, at two different depths, of an old regenerated mangrove forest stand of Avicennia marina. The regenerated mangrove forest site was artificially induced by placing wave breakers. Sediment samples were collected at 0-15 cm and 15-30 cm depth and analysed for soil properties. The bacterial community distribution was investigated using high throughput deoxyribonucleic acid (DNA) sequencing of the 16S rRNA gene. Bioinformatics analysis of the DNA sequence data showed that sediments were dominated by Proteobacteria (mostly Gammaproteobacteria and Deltaproteobacteria), followed by Firmicutes (Clostridia), Chloroflexi (Anaerolinae and Dehalococcoidetes), Actinobacteria (Acidimicrobiia, Coriobacteria), Acidobacteria (RB25 and BPC 102), Bacteroidetes (Saprospirae, Flavobacteriia, Bacteriocedes), Gemmatimonadetes and others. However, the intensity of the bacterial groups differed with respect to sampling depths and soil properties. The DNA sequencing revealed the sustenance of observed phylum in the soils of regenerated mangrove forest as compared to old mangrove stand. This highlights the positive effects of rehabilitation using wave breakers leading to microbial colonisation.

is an important tourist attraction and has been severely affected by erosion and pollution, threatening its soil biodiversity. Microbes in mangroves control various nutrient transformation processes in the ecosystem and their population differ with regards to spatial variation. In our current efforts to elucidate the relationship between soil variables and bacterial population, we analysed high-throughput metagenomic datasets from two sites of an old growth mangrove and a severely eroded intertidal mudflat in Tanjung Piai National Park. Sediment samples were collected at 5-20 cm depth for analysis. Bacterial communities were investigated by throughput sequencing of the 16S rRNA gene. Soil pH, organic carbon, organic matter and nitrogen content significantly differed at both sites. Bacterial community structure revealed that sediments from both sites were dominated by phylum Proteobacteria (32-58%), followed by Chloroflexi (6-19%) and Bacteroidetes (2-5%). Intertidal mudflats had the highest numbers of operational taxonomic unit, as well as Proteobacteria (47%), Firmicutes (1%) and Spriochaetes (4%) compared with the old growth forest, which recorded the highest Bathyarchaeota (11%) population. Results revealed the sustenance of observed phylum in the soils of contrasting sites and call for future strategies in elucidating functional analysis of bacterial population in further understanding their roles in mangrove ecosystems.