Diversity Of Marine Bacteria Research Articles

Evaluating the contingency treatment performance of advanced electro-catalysis oxidation processes for marine bacteria in ballast water.

Effects of ballast water treatment by advanced electro-catalysis oxidation processes (AEOP) on abundance, activity, and diversity of marine bacteria were examined in a full-scale ballast water management system (BWMS) at Yangshan Port, Shanghai, China. Water samples were collected immediately after treatment and at discharge to evaluate the contingency treatment performance of the BWMS for bacteria. After treatment, the total viable count reduced to 0.7 × 104 CFU·mL-1, and both Escherichia coli and enterococci decreased to 10 CFU·100 mL-1, which satisfied the D-2 Standard of the International Maritime Organization. AEOP can be as an effective contingency reception facility. Sequencing of 16S rRNA gene amplicons demonstrated the declining trend in bacterial diversity, and while the treatment did not completely eliminate the risk of bacterial dispersal, potentially pathogenic bacteria survived in treated and discharged samples. Bacterial diversity is of greater concern when evaluating effects of ballast water treatment on microorganisms because the bacteria which can develop adaptive mechanisms to environmental change will have a greater potential for invasion in the new environment.

Evaluation of the correlation of Sargassum fusiforme cultivation and biodiversity and network structure of marine bacteria in the coastal waters of Dongtou Island of China

Sargassum fusiforme is widely cultivated in the temperate coastal areas, and is particularly abundant in China, Korea, and Japan. However, information about if large-scale seaweed cultivation can affect the bacterial community in the coastal sea area is limited. This study explores the effects of large-scale cultivation of Sargassum fusiforme on the biodiversity and network structure of marine bacteria in the coastal water of Dongtou Island, China. The diversity of marine bacteria in the surface waters was significantly higher than that in the bottom waters in the cultivation area and adjacent area. The α-diversity metrics showed no significant difference between surface waters and bottom waters in the open sea area. Additionally, permutational multivariate analysis of variances suggested a significant difference in the microbial community structure between location, which were sampled relative to the cultivation area. At the phylum level, the dominant phyla in all groups were Proteobacteria, Cyanobacteria, Actinobacteria and Bacteroidetes. Proteobacteria was the most abundant phylum, accounting for more than 65% in all groups. The redundancy analysis showed that environmental factors affected the bacterial communities, and the results of an aggregated boosted tree analysis indicated that dissolved oxygen was a critical factor in controlling the bacterial communities in the surface waters, NO3−-N and NH4+-N were identified as primary factors associated with the change in bacterial community composition in the bottom waters. Network analysis revealed that the negative interactions between species pairs were the major relationship in the microbial ecosystem. Bacterial communities at S. fusiforme location were associated with larger sub-modules and a larger number of keystone species. Alphaproteobacteria and Gammaproteobacteria were identified as the keystone species in all locations. The results of the present study suggested that the differences in biodiversity and network structure of marine bacteria might be associated with the S. fusiforme cultivation.

Industrial enzymes-producing marine bacteria from marine resources

Industrial enzymes are important for various biotechnological applications. Currently, the diversity of industrial enzymes-producing marine bacteria from Malaysia remains mostly unknown. This study investigated the diversity of industrial enzyme-producing marine bacteria from culture collections at the Institute of Marine Biotechnology, Universiti Malaysia Terengganu. Out of 200 bacterial isolates revived, 163 bacteria isolate were successfully growth. Marine bacteria produced enzymes with total scoring higher than four were selected for molecular identification using 16S rDNA. About 161 bacteria isolate secreted amylase (68.7 %), lipase (88.3 %) and protease (68.7 %). The phylogenetic analysis led to the identification of three major phyla, namely Proteobacteria, Firmicutes and Bacteroidetes. These phyla were differentiated into nine genera consisted of Bacillus, Chryseomicrobium, Photobacterium, Pseudoalteromonas, Ruegeria, Shewanella, Solibacillus, Tenacibaculum and Vibrio. Genetic variation was more likely to occur within similar marine bacteria species. The microbial community was found to affect the production of industrial enzymes and the diversity of marine bacteria.

Marine bacterial communities in the upper gulf of Thailand assessed by Illumina next-generation sequencing platform

BackgroundThe total bacterial community plays an important role in aquatic ecosystems. In this study, bacterial communities and diversity along the shores of the Upper Gulf of Thailand were first characterized. The association between bacterial communities and types of land use was also evaluated.ResultsThe bacterial communities and diversity of seawater in the Upper Gulf of Thailand, with regard to types of land use, were first revealed by using Illumina next-generation sequencing. A total of 4953 OTUs were observed from all samples in which 554 OTUs were common. The bacterial communities in sampling sites were significantly different from each other. The run-off water from three types of land use significantly affected the community richness and diversity of marine bacteria. Aquaculture sites contained the highest levels of community richness and diversity, followed by mangrove forests and tourist sites. Seawater physicochemical parameters including salinity, turbidity, TSS, total N, and BOD5, were significantly different when grouped by land use. The bacterial communities were mainly determined by salinity, total N, and total P. The species richness estimators and OTUs were positively correlated with turbidity. The top ten most abundant phyla and genera as well as the distribution of bacterial classes were characterized. The Proteobacteria constituted the largest proportions in all sampling sites, ranging between 67.31 and 78.80%. The numbers of the Marinobacterium, Neptuniibacter, Synechococcus, Candidatus Thiobios, hgcI clade (Actinobacteria), and Candidatus Pelagibacter were significantly different when grouped by land use.ConclusionsType of land use significantly affected bacterial communities and diversity along the Upper Gulf of Thailand. Turbidity was the most influential parameter affecting the variation in bacterial community composition. Salinity, total N, and P were the ones of the important factors that shaped the bacterial communities. In addition, the variations of bacterial communities from site-to-site were greater than within-site. The Proteobacteria, Bacteroidetes, Actinobacteria, Cyanobacteria, Verrucomicrobia, Euryarchaeota, Planctomycetes, Firmicutes, Deep Sea DHVEG-6, and Marinimicrobia were the most and common phyla distributed across the Upper Gulf of Thailand.

Phylogenetic Analysis and Diversity of Marine Bacteria Isolated from Rhizosphere Soils of Halophyte in Suncheon Bay

Phylogenetic Analysis and Diversity of Marine Bacteria Isolated from Rhizosphere Soils of Halophyte in Suncheon Bay