Colonies are cream, convex and circular with irregular, curled margins. Colony size is
approximately 0.7-1.2 mm in diameter on R2A agar after 48 h of incubation at 30 ºC.
Facultatively anaerobic. Growth occurs at 10-37 ºC (optimum, 30-35 ºC), at pH 6.0-8.0
(optimum, pH 6.0-7.0) and with 0-1.0% NaCl (optimum, 0%).
Phylum Proteobacteria, Class Betaproteobacteria, Order Neisseriales, Family Neisseriaceae, Genus Rivicola, Rivicola pingtungensis
Sheu et al. 2014 - type species of the genus.
Gram-negative straight rods, 0.3-0.6 μm in diameter and 1.4-3.2 μm in length after 48
h of incubation on R2A agar at 30 ºC. Nonmotile. Endospores are not formed.
Isolated from a freshwater sample collected from the Jin-Shih Lake, Kaoshiung County, Taiwan.
Sensitive to penicillin G (10 U/disk), ampicillin (10 μg), chloramphenicol (30 μg), gentamicin (10 μg), rifampicin (5 μg), kanamycin (30
μg), tetracycline (30 μg), novobiocin (30 μg), streptomycin (10 μg), sulfamethoxazole + trimethoprim (23.75+1.25 μg) and nalidixic acid
- Sheu, S.-Y., Chen, J.-C., Young, C.-C. and Chen, W.-M. 2014. Rivicola pingtungensis gen. nov., sp. nov., a new member of the
family Neisseriaceae isolated from a freshwater river. Int. J. Syst. Evol. Microbiol., 64, 2009-2016.
Description is based on API 20 NE, API ZYM kits and GN2 microplate results.
Positive results for acid phosphatase, catalase, esterase C4 & C8, nitrate reduction, naphthol-AS-BI-phosphohydrolase, oxidase,
Tween 20 & 60, urease, assimilation of: adipate, arabinose, caprate, glucose, gluconate, malate, mannose, mannitol,
N-acetylglucosamine & maltose.
Can utilize as sole carbon source: alpha-lactose, lactulose, D-mannitol, pyruvic acid methyl ester, acetic acid, cis-aconitic acid, citric
acid, formic acid, phydroxyphenylacetic acid, itaconic acid, DL-lactic acid, propionic acid, succinic acid, bromosuccinic acid,
succinamic acid, D-alanine, L-alanine, L-alanyl glycine, L-asparagine, L-glutamic acid, L-proline, L-serine & urocanic acid.
Negative results for alkaline phosphatase, arginine dihydrolase, casein hydrolysis, chitin hydrolysis, corn oil hydrolysis, DNase,
esculin hydrolysis, alpha-fucosidase, alpha- & beta-galactosidase, beta-glucuronidase, alpha- & beta-glucosidase,
N-acetyl-beta-glucosaminidase, gelatin hydrolysis, indole production, lipase C14, leucine arylamidase, cystine arylamidase,
alpha-mannosidase, starch hydrolysis, Tween 40 & 80, trypsin, alpha-chymotrypsin, valine arylamidase, acid production from
glucose, assimilation of citrate & phenylacetate.
(c) Costin Stoica