ABSTRACT
A Gram-negative bacterium, designated as strain YIM 690229T, was isolated from the roots of Limonium otolepis. The strain was able to grow at 10-40 °C (optimum, 28-37 °C), pH 6.0-8.0 (optimum, 7.0) and in the presence of up to 7% NaCl (w/v) (optimum, up to 2.5%). Comparative 16S rRNA gene sequence analysis revealed that strain YIM 690229T shared less than 93.9% sequence similarities with members within the order Rhizobiales, and was remotely related to members of the family Hyphomicrobiaceae. Strain YIM 690229T was characterized by the presence of Q-10 as the predominant respiratory lipoquinone. The major fatty acids (> 10%) detected were C18:1 ω7c, C16:0, anteiso-C15:0 and summed feature 4 (iso-C17:1 I and/or anteiso-C17:1 B). The polar lipids consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanoamine and two unidentified lipids. The genomic DNA G + C content was 57.2 mol%. Data from this polyphasic taxonomy study suggested that strain YIM 690229T should be classified as a new species of a new genus within the family Hyphomicrobiaceae for which the name Limoniibacter endophyticus gen. nov., sp. nov., is proposed. The type species of the genus Limoniibacter gen. nov. is Limoniibacter endophyticus. The type strain of the species Limoniibacter endophyticus sp. nov. is YIM 690229T (= KCTC 42097T = JCM 30141T = CCTCC AB 2014130T = CGMCC 1.12906T).
Subject(s)
Hyphomicrobiaceae/isolation & purification , Plant Roots/microbiology , Plumbaginaceae/microbiology , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Hyphomicrobiaceae/genetics , Hyphomicrobiaceae/growth & development , Molecular Typing , Phosphatidylethanolamines/chemistry , Phospholipids/chemistry , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
As a natural attribute of clean and healthy soil, fungistasis is an important indicator of soil quality, and has positive ecological significance to the inhibition of plant disease eruption caused by soil-borne fungal pathogens. In this study, soil samples (0-15 cm) were collected from the abandoned land at Shenyang Experimental Station of Ecology, Chinese Academy of Sciences, to which pesticides and fertilizers have never been applied for nearly 10 years. A series of soil samples with gradient fungistasis was obtained by heating (CK, 100 degrees C, 110 degrees C, and 121 degrees C for 4 min, respectively), and bacterial community structure was analyzed by Polymerase Chain Reaction coupled with Denaturing Gradient Gel Electrophoresis method (PCR-GGGE). The results showed that there was a significant correlation between soil fungistasis and bacterial community composition. Treatment CK showed the strongest capacity to control the growth of target soil-borne pathogenic fungi. The further the bacterial community structure of treated soil deviated from that of CK, the lower the soil fungistasis was. Sequencing and the following phylogenetic analysis of special bands in DGGE indicated that Sphingomonas asaccharolytica, Nitrospira sp., Hyphomicrobiaceae sp., Bacillus megaterium, and Micrococcus sp. could be involved in soil fungistasis.
