Phylum Firmicutes, Class Bacilli, Order Bacillales, Family Bacillaceae, Genus Bacillus, Bacillus nealsonii Venkateswaran, Kempf,
Chen, Satomi, Nicholson and Kern 2003.
Description is based upon a single isolate.
Gram-positive, motile rods, 1.0 x 4.0-5.0 µm. Produce 0.5 x 1.0 µm, ellipsoidal
endospores in unswollen sporangia; spores bear an additional extraneous layer
similar to an exosporium.
Young colonies on TSA are 3-4 mm in diameter, irregular, rough and umbonate with
undulate or lobate edges, beige.
Facultatively anaerobic. Growth temperature 25-55 ºC; pH 6-10. Grow in 0-8% NaCl
medium. NaCl, alantoin or urate are not required for growth.
Isolated from dust particles collected at a spacecraft-assembly facility. Spores are resistant to UV, gamma-radiation, dessication and
- N.A. Logan and P. De Vos, 2009. Genus I. Bacillus Cohn 1872. In: (Eds.) P.D. Vos, G. Garrity, D. Jones, N.R. Krieg, W. Ludwig, F.
A. Rainey, K.-H. Schleifer, W.B. Whitman. Bergey’s Manual of Systematic Bacteriology, Volume 3: The Firmicutes, Springer, 21-127.
- K. Venkateswaran,M. Kempf,F. Chen,M. Satomi,W. Nicholson and R. Kern, 2003. Bacillus nealsonii sp. nov., isolated from a
spacecraft-assembly facility, whose spores are gamma-radiation resistant. IJSEM 53, 165-172.
Positive results for beta-galactosidase, catalase, acid production from: L-arabinose, N-acetyl-D-glucosamine, D-arabitol, cellobiose,
D-fructose, galactose, beta-gentibiose, gluconate, glycerol, meso-inositol, 2- or 5-ketogluconate, lactose, lyxose, D-glucose,
D-mannitol, D-mannose, melezitose, melibiose, raffinose, rhamnose, sorbitol, salicin, starch, sucrose, trehalose & D-xylose.
Negative results for arginine dihydrolase, lysine decarboxylase, ornithine decarboxylase, tryptophan deaminase, hydrolysis of gelatin,
oxidase, urease, lipase, amylase, alginase, indole production, H2S production, nitrate reduction, hydrolysis of starch,
Voges-Proskauer, citrate utilization, acid production from: methyl beta-xyloside, glycogen, adonitol & ribose.
(c) Costin Stoica