Identification and characterization of potential useful bacteria from marine environment

Marine environment remained as largely unexplored source for researchers to discover novel properties from marine organisms which can benefits human kind. The study aims to isolate marine bacterium from various source of marine environment. Six bacterial strains were successfully isolated from marine samples from seashore of the Desaru, Malaysia and identified by 16S rRNA sequencing. The characterizations of bacterial strains were also performed based morphological tests, Gram staining, biochemical tests and antibiotic sensitivity against several antibiotics by disc diffusion method. The 16S rRNA sequence of D-2, D-4, D-7, D-15, D-31 and D-33 revealed a high identity of 97 to 99% with 16S rRNA sequence belong to genera Pseudomonas, Marinomonas, Exiquobacterium,Micrococcus, Pseudoalteromonasand Shewanella respectively. Strain D-31 exhibited higher tolerance towards antibiotic with resistance to Kanamycin, Ampicillin and Erythromycin. However, the growth of other strains was retarded by at least two of the antibiotics on their normal growth. The isolation of marine bacterial strain belongs to Marinomonas sp. and Pseudoalteromonassp. create of interest for further biological characterization as the strains from these two genera have been proven for the discovery of new antimicrobial substances, enzymes for industry application and unique secondary metabolites

Isolation and characterization of bacteria from the skins of guava and apple

In recent years, cut fruit products get a warmest hit among current community. A rapid lifestyle changes among most civilizations leads them to choose a convenient way to get balanced meal and nutrients. The control of microbial growth in cut fruits is an important aspect. This study aimed to isolate and characterize the bacteria from apple and guava fruit skins. Moreover, this study also aimed to investigate the effect of temperature and antimicrobial agent in controlling the growth of bacteria from fruit skins. Six bacteria from guava and seven bacteria from apple fruit skins were successfully isolated. These bacteria were then characterized using biochemical tests. Based on Bergey’s manual, the bacteria were classified as Staphylococcus spp., Proteus spp., Micrococcus spp., Bacillus spp., Pseudomonas spp., Erwinia spp. and Enterobacter spp.. Two parameters, which were antimicrobial agent (XY-12) concentration and temperature, were optimized to control the growth of bacteria in the fruit skins. Results revealed that the optimum XY-12 concentration and temperature in retarding the growth of bacteria were 0.6 mL/L and 4°C respectively. A total of 99.4% of bacterial growth reduction was achieved when guava skins were treated with 0.6 mL/L of XY-12 and incubated at 4°C for 4 days in comparison with the control. In addition, a 100% of bacterial growth inhibition was observed when apple skins were treated under the same conditions. The antimicrobial assays (disc diffusion method) were also performed individually on the 13 isolated bacteria. At 0.6 mL/L of XY-12, largest zone of inhibition (2.70 cm) was observed in strain SA 4 after 24 hours of incubation followed by 2.60 cm (strain SG 5) and 2.46 cm (strain SA 2 and SA 3). Negative control (disc with distilled water) did not show any zone of inhibition

Draft genome sequence of Vitellibacter aquimaris D-24(T) isolated from seawater

Vitellibacter aquimaris D-24T (=KCTC 42708T = DSM 101732T), a halophilic marine bacterium, was isolated from seawater collected from Desaru beach, Malaysia. Here, we present the draft genome sequence of D-24T with a genome size of approximately 3.1 Mbp and G + C content of 39.93%. The genome of D-24T contains genes involved in reducing a potent greenhouse gas (N2O) in the environment and the degradation of proteinaceous compounds. Genome availability will provide insights into potential biotechnological and environmental applications of this bacterium

Genomic analyses of five Roseivirga species: Insights into marine adaptation

To date, the genus Roseivirga consists of six species with one subspecies and is one of the least-studied genera among the family Flammeovirgaceae. In order to further explore this genus, the genome sequences of five Roseivirga spp. were compared and described in this study. The Roseivirga genomes have similar sizes in the range of 4.08–4.47 Mb with an average of 4.22 Mb. Several key proteins related to osmotic stress adaptation were identified in Roseivirga spp. including betaine transporter, choline dehydrogenase, and glutamate synthases. Significant amount of proteins associated with amino acid transport and metabolism were also present in Roseivirga genome. All five Roseivirga spp. were able to grow in medium contained casamino acids (mixture of amino acids) as sole carbon or nitrogen sources. Taken together, these findings suggested the potential role of Roseivirga in decomposing organic nitrogen matter in marine environment

Draft genome sequence of Vitellibacter vladivostokensis KMM 3516T: a protease-producing bacterium

Type strain Vitellibacter vladivostokensis KMM 3516T (= NBRC 16718T) belongs to the phylum Cytophaga–Flavobacterium–Bacteroides. To date, no genomes of the Vitellibacter spp. have been reported, and their metabolic pathways are unknown. This study reports the draft genome sequence of V. vladivostokensis. Moreover, mining of genes associated with proteolytic enzymes was performed to provide insights for further enzyme characterization

Characterization of detergent compatible protease from halophilic Virgibacillus sp CD6

A halophilic bacterium, Virgibacillus sp. strain CD6, was isolated from salted fish and its extracellular protease was characterized. Protease production was found to be highest when yeast extract was used as nitrogen source for growth. The protease exhibited stability at wide range of salt concentration (0–12.5%, w/v), temperatures (20–60 °C), and pH (4–10) with maximum activity at 10.0% (w/v) NaCl, 60 °C, pH 7 and 10, indicating its polyextremophilicity. The protease activity was enhanced in the presence of Mg2+, Mn2+, Cd2+, and Al3+ (107–122% relative activity), and with retention of activity > 80% for all of other metal ions examined (K+, Ca2+, Cu2+, Co2+, Ni2+, Zn2+, and Fe3+). Both PMSF and EDTA inhibited protease activity, denoting serine protease and metalloprotease properties, respectively. High stability (> 70%) was demonstrated in the presence of organic solvents and detergent constituents, and the extracellular protease from strain CD6 was also found to be compatible in commercial detergents. Proteinaceous stain removal efficacy revealed that crude protease of strain CD6 could significantly enhance the performance of commercial detergent. The protease from Virgibacillus sp. strain CD6 could serve as a promising alternative for various applications, especially in detergent industry