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