Phylum Proteobacteria, Class Betaproteobacteria, Order Burkholderiales, Family Alcaligenaceae, Genus Derxia, Derxia lacustris
Chen et al. 2013.
Gram-negative rods, 1.0-1.2 x 2.0-4.0 μm, surrounded by a thick capsule. Motile. Non-
spore-forming. Poly-beta-hydroxybutyrate granules are accumulated.
After 48 h of incubation on R2A agar at 25 ºC, colonies are convex, round, smooth with
entire margins, light yellow, glistening, translucent, 0.4-1.8 mm in diameter. Become
brownish yellow and brownish red after prolonged incubation(5 days). Growth occurs
at 15-40 ºC (optimum 25-35 ºC), at pH 6.0-7.0 (optimum pH 6.0) and with 0-4 % NaCl
(optimum 0-1 %). Aerobic.
Isolated from fresh water in Heaven Lake located in Southern Cross-Island Highway, Taiwan. Nitrogen-fixing bacterium.
Sensitive to novobiocin, rifampicin, penicillin G, ampicillin, chloramphenicol, gentamicin, kanamycin, tetracycline, streptomycin, nalidixic
acid and sulfamethoxazole+ trimethoprim.
- Chen (W.M.), Huang (W.C.) and Sheu (S.Y.): Derxia lacustris sp. nov., a nitrogen-fixing bacterium isolated from a freshwater lake.
Int. J. Syst. Evol. Microbiol., 2013, 63, 965-970.
- Franca, L., Albuquerque, L., Sanchez, C., Fareleira, P. and Da Costa, M. S. 2016. Ampullimonas aquatilis gen. nov., sp. nov.
isolated from bottled mineral water. Int. J. Syst. Evol. Microbiol., 66, 1459-1465.
Positive results for acid phosphatase, alkaline phosphatase, catalase, esterase (C4), leucine arylamidase, oxidase, valine
arylamidase, naphthol-AS-BI-phosphohydrolase, beta-glucosidase & hydrolysis of Tween 60.
Can assimilate: glucose, gluconate, malate, D-fructose, succinic acid monomethyl ester, acetic acid, formic acid, beta-hydroxybutyric
acid, DL-lactic acid, quinic acid, D-saccharic acid, succinic acid, bromosuccinic acid, methyl pyruvate, D-gluconic acid,
beta-hydroxybutyric acid, DL-lactic acid, malonic acid, propionic acid, quinic acid, D-saccharic acid, succinic acid & succinamic acid.
Negative results for arginine dihydrolase, casein hydrolysis, corn oil hydrolysis, DNase, esterase lipase, esculin hydrolysis, gelatin
hydrolysis, lipase (C14), cystine arylamidase, alpha- and beta-galactosidase, beta-glucuronidase, alpha-glucosidase,
alpha-mannosidase, alpha-fucosidase, nitrate reduction, N-Acetyl-beta-glucosaminidase, indole production, starch hydrolysis,
trypsin, alpha-chymotrypsin, Tweens 20, 40 and 80 hydrolysis, urease & acid production from glucose.
No assimilation of: sucrose, D-sorbitol, arabinose, cis-aconitic acid, adipate, mannitol, mannose, N-acetylglucosamine, maltose,
caprate, citrate, phenylacetate, L-glutamic acid, L-proline, 2-aminoethanol, glycerol, D-galactose, trehalose, melibiose, lactose,
maltose, sorbitol, alpha-ketoglutarate, formate & L-serine.
(c) Costin Stoica