Virgibacillus

Genus created for Bacillus pantothenticus. Cells are motile, Gram-positive rods (0·3€“0·7x2€“6 microns) that occur singly, in pairs or short chains or filaments. They bear oval to ellipsoidal endospores that lie in swollen sporangia. Colonies are small, circular, low-convex and slightly transparent to opaque. Members of the genus are catalase-positive. In the API 20E strip and in conventional tests, the Voges€“Proskauer reaction is negative, indole is not produced, citrate is usually not used and nitrate reduction to nitrite is variable. Urease and hydrogen sulphide are usually not produced. Gelatin, aesculin and casein are usually hydrolysed. Growth is stimulated by 4€“10 % NaCl. Growth may occur between 5 and 50 degrees C, with an optimum of about 28 or 37 degrees C. D-Raffinose and D-melibiose can be used as sole carbon sources; no growth on D-arabinose, D-fructose or D-xylose. The different members of the genus show a wide range of activities in routine phenotypic tests, and this may reflect undiscovered requirements for growth factors and/or special environmental conditions. The major fatty acid is anteiso-C15 : 0. The major polar lipids are diphosphatidyl glycerol and phosphatidyl glycerol. Five phospholipids and one polar lipid of unknown structure are present in all species of the genus. Presence of phosphatidyl ethanolamine and other lipids is variable. The main menaquinone type is MK-7, with minor to trace amounts of MK-6 and MK-8. In the species tested, the cell wall contains peptidoglycan of the meso-diaminopimelic acid type. The G+C content is in the range 36€“43 mol%. The type species is Virgibacillus pantothenticus. Taxa related to this genus have been islolated from Permian sediments that are over 250,000,000 years old. Heyndrickx M, Lebbe L, Kersters K, De Vos P, Forsyth G, Logan NA (1998) Virgibacillus: a new genus to accommodate Bacillus pantothenticus(Proom and Knight 1950). Emended description of Virgibacillus pantothenticus. Int J Syst Bacteriol 48:99€“106.

Virgibacillus is a genus of Gram-positive, rod-shaped (bacillus) bacteria and a member of the phylum Bacillota. Virgibacillus species can be obligate aerobes (oxygen reliant), or facultative anaerobes and catalase enzyme positive. Under stressful environmental conditions, the bacteria can produce oval or ellipsoidal endospores in terminal, or sometimes subterminal, swollen sporangia. The genus was recently reclassified from the genus Bacillus in 1998 following an analysis of the species V. pantothenticus. Subsequently, a number of new species have been discovered or reclassified as Virgibacillus species.