Chitinophaga solisilvae sp. nov., isolated from forest soil

Abstract

A Gram-stain-negative, strictly aerobic, non-motile and rod-shaped bacterial strain, O9T, was isolated from a forest soil sample collected at Dai, Xishuangbanna, Yunnan Province, PR China. Strain O9T grew optimally at pH 7.0, at 28‒30 °C and in the absence of NaCl. 16S rRNA gene sequence analysis placed strain O9T within the genus Chitinophaga of the family Chitinophagaceae, with Chitinophaga terrae KP01T (97.8 %), Chitinophaga jiangningensis JN53T (97.7 %), Chitinophaga niastensis JS16-4T (97.4 %), Chitinophaga qingshengii JN246T (97.3 %) and Chitinophaga dinghuensis DHOC24T (97.3 %) as its closest relatives. Strain O9T hydrolysed casein, gelatin and Tween 80. It could not assimilate l-arabinose, l-rhamnose, sucrose, melibiose, gentiobiose or d-fructose as a carbon source. It was negative for esterase lipase (C8) and β-glucosidase. Phosphatidylethanolamine was the predominant polar lipid. The major respiratory quinone of strain O9T was MK-7. Its major fatty acids were iso-C15:0 (34.2 %), C16:1 ω5c (20.9 %) and iso-C17:0 3-OH (12.6 %). The genomic DNA G+C content of strain O9T was 49.0 mol% based on total genome calculations. The average nucleotide identity score between the genomic sequence of strain O9T and that of Chitinophaga terrae KP01T was 72.9%. The Genome-to-Genome Distance Calculator showed that DNA‒DNA hybridization values for strain O9T and Chitinophaga terrae KP01T were 13.6, 21.1 and 14.4%, respectively. Based on the polyphasic taxonomic data, strain O9T represents a novel species of the genus Chitinophaga , for which the name Chitinophaga solisilvae sp. nov. is proposed. The type strain is O9T (=CGMCC 1.12462T=KCTC 32404T).

Chitinophaga silvatica sp. nov., isolated from forest soil, and reclassification of Chitinophaga extrema as a later heterotypic synonym of Chitinophaga solisilvae

“…These results also supported that strain K2CV101002-2 T represented a novel species within the genus Chtinophaga. According to the species descriptions [2,3], both C. extrema Mgbs1 T and C. solisilvae O9 T took iso-C 15 : 0 , C 16 : 1 ω5c and iso-C 17 : 0 3-OH as the major fatty acids with a relatively high content (7.2 and 7.8 %) of summed feature 3 (C 16 : 1 ω7c and/or C 16 : 1 ω6c) and MK-7 as the predominant respiratory quinone, which supported the conclusion of genomic and phenotypic comparisons.…”

“…These results also supported that strain K2CV101002-2 T represented a novel species within the genus Chtinophaga . According to the species descriptions [2, 3], both C. extrema Mgbs1 T and C.…”

“…Now, it belongs to the family Chitinophagaceae in the phylum Bacteroidetes while myxobacteria only refer to the group of Myxococcales in Proteobacteria. More than 41 species in the genus Chitinophaga had been validly published, including the recently described Chitinophaga extrema [2], Chitinophaga solisilvae [3], Chitinophaga fulva [4], etc., and most of them were obtained from soil, especially forest soil, such as Chitinophaga tropicalis , Chitinophaga varians , Chitinophaga silvisoli , Chitinophaga caseinilytica , Chitinophaga flava and Chitinophaga dinghuensis [5–10]. This is probably due to their roles in such environments and some Chitinophaga species have shown plant growth promoting (PGP) abilities by altering the carbon source use of their fungal hosts as endosymbiotic bacteria and decomposing both dead fungal and plants in substance recycling [11, 12].…”

“…This is probably due to their roles in such environments and some Chitinophaga species have shown plant growth promoting (PGP) abilities by altering the carbon source use of their fungal hosts as endosymbiotic bacteria and decomposing both dead fungal and plants in substance recycling [11, 12]. Members of the genus Chitinophaga are characterized by cells that are Gram-stain-negative, filamentous or rod-shaped, aerobic and taking iso-C 15:0 , C 16:1 ω 5 c and iso-C 17:0 3-OH as the major fatty acids and MK-7 as the predominant respiratory quinone [3]. Here we present another novel strain, designated K2CV101002-2 T , which was also isolated from forest soil, by using a polyphasic approach.…”

“…The phenotypic characterization results supported that strain K2CV101002-2 T represented a novel distinct species of the genus Chtinophaga. Moreover, we also compared C. extrema Mgbs1 T and C. solisilvae O9 T according to the original species descriptions [2,3] and the two strains showed the same results in most phenotypic characteristics including growth media (R2A agar, NA, TSA and MacConkey agar), production of flexirubin-type pigments, enzyme activities (oxidase, catalase, acid phosphatase, alkaline phosphatase, trypsin, naphthol-AS-BI-hosphohydrolase, βgalactosidase, α-glucosidase, N-acetyl-β-glucosaminidase, leucine arylamidase, valine arylamidase and cystine arylamidase), hydrolysis of gelatin and chitin, and substrates assimilation (d-glucose, d-mannose, maltose, lactose, l-arabinose, raffinose and trehalose), which suggested that they should belong to the same species.…”