Journal of Microbiology

Influence of Culture Conditions and Medium Composition on the Production of Antibacterial Compounds by Marine Serratia sp. WPRA3: Mahtab Jafarzade , Nur Ain Yahya , Fatemeh Shayesteh , Gires Usup , Asmat Ahmad; J. Microbiol. 2013;51(3):373-379. Published online June 28, 2013; DOI: https://doi.org/10.1007/s12275-013-2440-2

Abstract: This study was undertaken to investigate the influence of culture conditions and medium components on production of antibacterial compounds by Serratia sp. WPRA3 (JX020764) which was isolated from marine water of Port Dickson, Malaysia. Biochemical, morphological, and molecular characteristics suggested that the isolate is a new candidate of the Serratia sp. The isolate showed strong antimicrobial activity against fungi, Gram-negative and Gram-positive bacteria. This bacterium exhibited optimum antibacterial compounds production at 28°C, pH 7 and 200 rev/min aeration during 72 h of incubation period. Highest antibacterial activity was obtained when sodium chloride (2%), yeast extract (0.5%), and glucose concentration (0.75%) were used as salt, nitrogen, and carbon sources respectively. Different active fractions were obtained by Thin-Layer Chromatography (TLC) and Flash Column Chromatography (FCC) from ethyl acetate crude extracts namely OCE and RCE in different culture conditions, OCE (pH 5, 200 rev/min) and RCE (pH 7/without aeration). In conclusion, the results suggested different culture conditions have a significant impact on the types of secondary metabolites produced by the bacterium.

NOTE] Grimontia marina sp. nov., a Marine Bacterium Isolated from the Yellow Sea: Ahyoung Choi , Kyung-Mi Kim , Ilnam Kang , Seok-Hyun Youn , Young-Sang Suh , Yoon Lee , Jang-Cheon Cho; J. Microbiol. 2012;50(1):170-174. Published online February 27, 2012; DOI: https://doi.org/10.1007/s12275-012-1615-6

Abstract: A novel species belonging to the genus Grimontia is described in this study. A Gram-negative, chemoheterotrophic, obligately aerobic, catalase- and oxidase-positive, motile by a single polar flagellum, and rod-shaped bacterium, designated IMCC5001T, was isolated from surface seawater of the Yellow Sea. Strain IMCC5001T grew optimally at 30°C in the presence of 3.5% NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate was related most closely to Grimontia hollisae with a sequence similarity of 95.8%, and formed a robust phyletic lineage with Grimontia hollisae. Differential physiological characteristics between the new strain and Grimontia hollisae KCCM 41680T and chemotaxonomic characterization including determination of DNA G+C content, fatty acid methyl esters, quinone composition, and polar lipid profiles justified the assignment of strain IMCC5001T to the genus Grimontia as a novel species. In conclusion, strain IMCC5001T represents a new species, for which the name Grimontia marina sp. nov. is proposed, with the type strain IMCC5001T (=KCTC 22666T =NBRC 105794T).

Marine Bacteria Associated with the Korean Brown Alga, Undaria pinnatifida: Yoo Kyung Lee , Hyun Jung Jung , Hong Kum Lee; J. Microbiol. 2006;44(6):694-698.; DOI: https://doi.org/2453 [pii]

Abstract: Several marine bacterial strains were isolated from Undaria pinnatifida (Miyok in Korean). Sixty-six strains were isolated on R2A agar media at 10°C and identified by a phylogenetic analysis of the 16S rRNA gene sequences. They were grouped into 10 different sequence types based on the initial sequence analysis of the 5'''' domain of the gene (approximately 500 bp). Full sequences of 16S rRNA gene were obtained from one strain in each sequence type and the species-affiliation was determined using phylogenetic and sequence similarity analyses. The results of the analyses indicated that they were closely related to Psychrobacter aquimaris, P. celer, P. nivimaris, P. pulmonis, Psychromonas arctica or Bacillus psychrodurans.These bacteria are marine or psychrotrophic bacteria. Because the sporophytes of U.pinnatifida are cultured on the costal area during winter, the U. pinnatifida-associated bacteria appeared to grow at low temperatures. U. pinnatifida sporophytes can be a good source for the isolation of psychrotrophic bacteria.

Preservation of Marine Heterotrophic Bacteria by Using a Deep-freezing Method: Shin Hye Park , Hyun Sang Lee , Hong Kum Lee; J. Microbiol. 2001;39(3):240-243.

Abstract: The effect of cryoprotectants and suspending solutions on the preservation of marine heterotophic bacteria was investigated. Six halotolerant and four halophilic bacterial isolates suspended in either distilled water or artificial seawater were preserved in glycerol and dimethylsulfoxide at -70 C, respectively. After one year of preservation, the recovery rates on the appropriate agar plates were estimated. The survival rate was found to be dependent on the strain tested, regardless of the preservation conditions tested.

Isolation and Identification of Biofilm-Forming Marine Bacteria on Glass Surfaces in Dae-Ho Dike, Korea: Kae Kyoung Kwon , Hyun Sang Lee , Sung-Young Jung , Joung-Han Yim , Jung-Hyun Lee , Hong Kum Lee; J. Microbiol. 2002;40(4):260-266.

Abstract: Bacterial strains were isolated from biofilms formed on glass slides submerged in seawater in Dae-Ho Dike. Eight strains showing fast attaching ability were selected and identified. Their exopolysaccharide(EPS)-producing ability and EPS properties were characterized. Based on Microlog System, 4 among the 8 strains were identified as Micrococcus luteus and the rest were Bacillus thuringiensis, Bacillus megaterium, Staphylococcus saprophyticus and Agrobacterium vitis. A. vitis was reidentified as Sulfitobacter pontiacus based on 16S rDNA sequence data. The amount of water-soluble EPS produced by the 8 strains ranged from 0.114 to 1.329 g·l^-1 and the productivity was negatively correlated with the cell biomass. The molecular weight of the produced EPS ranged from 0.38 to 25.19x 10^4 Da. Glucose and galactose were ubiquitous sugar components. Mannose, ribose, and xylose were also major sugar components. The molecular weight and composition of the EPS showed strain-specific variation.

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