Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Streptococcaceae, Genus Streptococcus, Streptococcus castoreus
Lawson et al. 2005. Lancefield group A.
Gram-positive cocci that occur in pairs or short chains.
Colonies are 0.5 mm in diameter after 24 hours of incubation on horse blood agar.
Beta-hemolytic. Facultatively anaerobic, but grows best under anaerobic conditions.
Growth is stimulated by rich medium and CO2. No growth on MRS at 37 ºC in air, but
there is growth on MRS in CO2 and in a microaerophilic atmosphere. Growth on
chocolate medium is superior to growth on blood agar.
Isolated from a dead European beaver (Castor fiber).
- Lawson P.A., Foster G., Falsen E., Markopoulos S.J. & Collins M.D.: Streptococcus castoreus sp. nov., isolated from a beaver
(Castor fiber). Int. J. Syst. Evol. Microbiol., 2005, 55, 843-846.
Positive for esculin hydrolysis, arginine dihydrolase, acid phosphatase, alkaline
phosphatase, alanine phenylalanine proline arylamidase, leucine arylamidase,
phosphoamidase, beta-glucosidase, beta-glucuronidase, acid production from:
starch, maltose, methyl beta-D-glucopyranoside, pullulan & sucrose.
Negative for hippurate hydrolysis, esterase C4, ester lipase C8, lipase C14, chymotrypsin, cystine arylamidase, alpha-fucosidase,
alpha-galactosidase, beta-galactosidase, alpha-glucosidase, glycyl tryptophan arylamidase, alpha-mannosidase, pyroglutamic acid
arylamidase, N-acetyl-b-glucosaminidase, trypsin, valine arylamidase, urease, Voges–Proskauer test, acid production from: L-
arabinose, D-arabitol, cyclodextrin, glycogen, inulin, lactose, mannitol, melezitose, melibiose, raffinose, sorbitol, tagatose & trehalose.
Variable for beta-mannosidase.
(c) Costin Stoica