Virgibacillus zhanjiangensis sp. nov., a marine bacterium isolated from sea water

Sun protection and antibacterial activities of carotenoids from the soft coral Sinularia sp. symbiotic bacteria from Panjang Island, North Java Sea

Carotenoids have shown beneficial applications in cosmetology, pharmacology, and medicine. However, environmental stress in the marine environment can trigger the production of unique secondary metabolites, such as carotenoids. These compounds can also be sustainably produced by symbiotic bacteria. We hypothesized that the soft corals in tropical regions may produce diverse biological secondary metabolites, including carotenoids, both by the host organism and their bacterial symbiont. The unique carotenoids may provide promising biological activity such as antioxidant, UV photoprotector, and antibacterial activities. To this end, we isolated and characterized the carotenoids isolated from the bacterial symbiont of Sinularia sp., a soft coral from Panjang Island, North Java Sea, strain 19. PP.Sc.13. Bacterial identification was performed using DNA barcoding of the 16S rRNA region. Identification of carotenoids was carried out using a spectrophotometer, High-Performance Liquid Chromatography (HPLC), and attenuated total reflection fourier-transformed infrared (ATR-FTIR) spectroscopy. The antioxidant activity was estimated using the diphenylpicrylhydrazyl (DPPH) method, while the Sun Protection Factor (SPF) and % transmission of erythema and pigmentation were determined based on colorimetric methods. The antibacterial activity assay was carried out using the agar diffusion method against two multidrug-resistant bacteria. The bacterial symbiont was identified as Virgibacillus sp. and the carotenoids isolated from this symbiont exhibited significant antioxidant activity and extra sun protection effect, thus categorized as UVA sunblock. Furthermore, the isolated carotenoids exhibited antibacterial activities against Methicillin Resistant-Staphylococcus aureus (MRSA) and Multidrug-resistant (MDR) Escherichia coli. This study provides evidence of the carotenoids produced by the soft coral bacterial symbiont Virgibacillus sp., which may be used as an antioxidant, sun protection, and antibacterial agent. Further investigation of the de novo biological production of carotenoids by Virgibacillus sp. is warranted.

Virgibacillus ihumii sp. nov., a new bacterium isolated from the stool of healthy African children

During a case–control study on severe acute malnutrition, strain Marseille-Q1233 was isolated. It is a Gram-positive, rod-shaped and halophilic bacillus isolated from a stool sample of Malian child under the age of 5. The fatty acid profile of the strain consisted of C15:0-anteiso and C14:0-iso as major components. Digital DNA-DNA hybridization and average nucleotide identity calculation showed 23.10% and 80.81% similarity respectively between strain Marseille-Q1233 and Virgibacillus siamensis strain Marseille-P2607, the phylogenetically closely related species with standing in nomenclature. On the basis of these results, we report the description of Virgibacillus ihumii sp. nov. strain Marseille-Q1233 as a new bacterial species.

'Gracilibacillus phocaeensis' sp. nov., 'Sediminibacillus massiliensis' sp. nov. and 'Virgibacillus ndiopensis' sp. nov., three halophilic species isolated from salty human stools by culturomics

We report the isolation of three bacterial strains that could not be identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry screening. 'Gracilibacillus phocaeensis' sp. nov., 'Sediminibacillus massiliensis' sp. nov. and 'Virgibacillus ndiopensis' sp. nov. are halophilic species isolated from salty human stools by culturomics.

Virgibacillus halotolerans sp. nov., isolated from a dairy product

A Gram-stain-positive, strictly aerobic, rod-shaped and weakly motile bacterium, designated WS 4627T, was isolated from a dairy product sample collected in southern Germany. Spherical to slightly ellipsoidal endospores were formed centrally or subterminally in sometimes slightly swollen sporangia. The isolate was able to grow at 8–35 °C, at pH 6.5–8.5 and with 0.5–16.5 % (w/v) NaCl. The diamino acid of the cell wall was meso-diaminopimelic acid (peptidoglycan type A1γ) and the genomic DNA G+C content was 39.1 mol%. The major menaquinone was MK-7, the cellular fatty acid profile contained major amounts of anteiso-C15 : 0 and anteiso-C17 : 0 and the major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. Strain WS 4627T was most closely related to ‘ Virgibacillus natachei’ FarD (96.5 % 16S rRNA gene sequence similarity) and ‘ Virgibacillus zhanjiangensis’ JSM 079157 (96.0 %). Based on the data presented, strain WS 4627T represents a novel species of the genus Virgibacillus , for which the name Virgibacillus halotolerans sp. nov. is proposed. The type strain is WS 4627T ( = DSM 25060T = LMG 26644T).

Bioflocculant production by Virgibacillus sp. Rob isolated from the bottom sediment of Algoa Bay in the Eastern Cape, South Africa

A bioflocculant-producing marine bacterium previously isolated from marine sediment of Algoa Bay was screened for flocculant production. Comparative analysis of 16S rDNA sequence identified the isolate to have 99% similarity to Virgibacillus sp. XQ-1 and it was deposited in the GenBank as Virgibacillus sp. Rob with accession number HQ537127. The bacterium produced biflocculants optimally in glucose (70.4%) and peptone (70.4%) as sole sources of carbon and nitrogen, alkaline pH (12) (74%); and the presence of Fe2+ (74%). Chemical analysis of the bioflocculant revealed it to be a polysaccharide.