• Microbiology and Biotechnology Letters
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• v.49 no.3
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• pp.432-439
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• 2021

Microbial community plays important roles in the culture environment of mud crab Scylla serrata. One of the environmental management efforts for the cultivation of S.serrata is by stabilizing microorganisms involved in nitrogen cycle process. The availability of dissolved inorganic nitrogen in its culture environment under a recirculating system closely relates to the nitrogen cycle, which involves both anaerobic and aerobic bacterial activities. Anaerobically, there are two major nitrogen compound degradation processes, i.e., denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This study aimed to identify denitrifying and DNRA bacteria isolated from the recirculating cultivation of S. serrata. The water samples were collected from anaerobic filters called close filter system, which is anaerobically conditioned with the addition of varying physical filter materials in the recirculating mud crab cultures. The results showed that three denitrifying bacterial isolates and seven DNRA bacterial isolates were successfully identified. The phylogenetic analysis based on 16S rRNA gene of the denitrifying bacteria revealed that HIB_7a had the closest similarity to Stenotrophomonas daejeonensis strain MJ03. Meanwhile, DNRA bacterial isolate of HIB_92 showed a 100% similarity to Bacillus sonorensis strain N3, Bacillus vallismortis strain VITS-17, Bacillus tequlensis strain TY5, Geobacillus sp. strain DB24, Bacillus subtilis strain A1, and Bacillus mojavensis strain SSRAI21. This study provides basic information denitrifying and DNRA bacterial isolates identity which might have the potential to be applied as probiotics in aquaculture systems in order to maintain optimal environmental conditions.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.283-285
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• 2019

The draft genome sequencing for Pelagicola sp. DSW4-44 (= KCTC 62762 = KCCM 43261), isolated from deep seawater of East Sea in Korea, was performed using Illumina HiSeq platform. As a result, the draft genome was comprised of a total length of approximately 4.85 Mbp with G + C content of 54.3%, and included a total of 4,566 protein-coding genes, 3 rRNA genes, 48 tRNA genes, 3 non-coding RNA genes, and 67 pseudo genes. In the draft genome, the strain DSW4-44 contained genes involved in the nitrogen metabolism of dissimilatory nitrate reduction to ammonium (DNRA) and denitrification, which were not found other strains in the genus Pelagicola.