Aquihabitans daechungensis gen. nov., sp. nov., an actinobacterium isolated from reservoir water

Abstract

A novel Gram-reaction-positive bacterium, strain CH22-21 T , was isolated from a water sample taken from Daechung Reservoir, Republic of Korea, during the late-blooming period of cyanobacteria. Cells of strain CH22-21 T were non-motile, ciliated short rods that formed creamywhite colonies on half-strength modified R2A agar. Chemotaxonomic results showed menaquinone MK-9(H 6 ) as the predominant respiratory menaquinone, diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannoside as major polar lipids, 16 : 1v5c, 16 : 0, 17 : 1v8c and 18 : 1v9c as major fatty acids, and a DNA G+C content of 71.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the strain formed a separate lineage within the order Acidimicrobiales, showing similarity values of ,92.3 % with its closest phylogenetic neighbours. The combined genotypic and phenotypic data showed that strain CH22-21 T could be distinguished from all genera within the order Acidimicrobiales and represented a novel species of a new genus in the family Iamiaceae, for which the name Aquihabitans dachungensis gen. nov., sp. nov. is proposed. The type strain of Aquihabitans dachungensis is CH22-21 T (5KCTC 19849 T 5JCM 17787 T ).Cyanobacterial blooms are a frequent summer occurrence in Daechung Reservoir, central South Korea (Oh et al., 2007), and have a negative impact on water quality and water utilization. Serious blooms of cyanobacteria produce a distinctive taste and odour to the water, and create a health hazard. While studying the interaction between cyanobacteria and heterotrophic bacteria thriving among the cyanobacteria, a Gram-positive bacterium, strain CH22-21 T , forming a lineage in the order Acidimicrobiales was isolated. At the time of writing, the class Actinobacteria comprises five subclasses: Acidimicrobidae, Actinobacteridae, Coriobacteridae, Nitriliruptoridae and Rubrobacteridae. However, most of the genera and species are located in the subclass Actinobacteridae, with very few in the other four subclasses. In addition, there are two recognized families, Acidimicrobiaceae and Iamiaceae. In this study, the morphological, physiological, biochemical, chemotaxonomic and phylogenetic properties of strain CH22-21 T are examined to reveal its taxonomic position.A novel bacterium, strain CH22-21 T , with a high genomic DNA G+C content was isolated. Water samples were initially diluted serially in a 0.85 % saline solution, then aliquots of each serial dilution were spread on half-strength modified R2A agar (Difco) and incubated at room temperature (25 u C) for 1 month. One creamy-white colony, designated strain CH22-21 T , was isolated and subcultivated on half-strength modified R2A agar at 30 uC for 4 weeks. Based on phylogenetic, phenotypic and chemotaxonomic analyses, the isolate was found to represent a novel species in a new genus in the order Acidimicrobiales. For further classification, the isolate was subjected to a polyphasic investigation.The Gram reaction was determined using a Gram stain kit (Becton Dickin...

Comparison of Prokaryotic and Eukaryotic Communities in Soil Samples with and without Tomato Bacterial Wilt Collected from Different Fields

“…Bacteria involved in soil nitrogen cycling affect the suppression of plant diseases, and their release of nitrogen influences the microbial community structure ( 8 , 16 ). An Aquihabitans species was recently isolated from a freshwater environment, and its ecology has yet to be examined in detail ( 21 ). An OTU in Gemmatimonas was detected in the lower layer in all three fields.…”

Rhabdothermincola salaria sp. nov., a novel actinobacterium isolated from a saline lake sediment

“…majanohamensis and R. sediminis [5, 7–14]. To date, only a few studies have briefly described the potential ecological functions of the acidimicrobial species by metagenomic analysis [15].…”

Rhabdothermincola sediminis gen. nov., sp. nov., a new actinobacterium isolated from hot spring sediment, and emended description of the family Iamiaceae

“…[1], and the type strain Iamia majanohamensis F12 T was isolated from a sea cucumber in Japan. At the time of writing, three genera were included in the family Iamiaceae , Iamia [1], Aquihabitans [2] and Actinomarinicola [3], and they were isolated from sea cucumber, reservoir water and oceanic sediment, respectively. Members of the family Iamiaceae share the same short rod-shape and MK-9 (H 6 ) and MK-9 (H 8 ) as their major respiratory quinones.…”

“…Phenotypic characteristics that differentiate strain SYSU G02662 T from closely related type strains of the family Iamiaceae Strain: 1, SYSU G02662 T ; 2, Actinomarinicola tropica SCSIO 58843 T ; 3, Iamia majanohamensis DSM 19957 T[1]; 4, Aquihabitans daechungensis DSM 27986 T[2].…”