Flavitalea antarctica sp. nov., isolated from Fildes Peninsula, Antarctica

Identification of chlorpyrifos-degrading microorganisms in farmland soils via cultivation-independent and -dependent approaches

Microorganisms have important roles in the bioremediation of organophosphorus pesticides (OPs) in farmland soils. However, the majority of functional microorganisms (>99%) are yet to be cultivated. In this study, magnetic nanoparticle-mediated isolation (MMI) coupled with high-throughput sequencing was applied to identify the microorganisms responsible for chlorpyrifos (CPF) degradation in farmland soils. Various microorganisms have been identified as CPF degraders via MMI, in which the roles of genera Citrobacter, Exiguobacterium, Azoarcus, Azohydromonas and Massilia have not previously been related to CPF degradation. Two organophosphorus hydrolase genes (ophB and ophC) were involved in CPF metabolism in MMI enrichments, compared to only ophB found in the cultivable CPF degrader Alcaligenes L1. Also, a more thorough degradation of CPF was found in MMI enrichments, where 3,5,6-trichloro-2-pyridinol (TCP), O,O-diethyl thiophosphate (DETP), 2,3,5-trichloro-6-methoxypyridine (TMP) and O,O,S-trimethyl phosphorothioate were identified as the biodegradation products. This work suggests that MMI is a promising technology for separating functional microorganisms from complex microbiota, with deeper insight into their ecological functions, providing fundamental knowledge on soil bioremediation strategies.

Hanamia caeni gen. nov., sp. nov., a Member of the Family Chitinophagaceae Isolated from Activated Sludge in Korea

A novel Gram-stain-negative, aerobic, yellowish-pigmented, non-motile, rod-shaped bacterial strain, designated strain BO-59^T, was isolated from the activated sludge of a wastewater treatment plant in Hanam City, South Korea. Phylogenetic study based on the 16S rRNA gene sequence positioned BO-59^T in a distinct lineage in the family Chitinophagaceae, sharing less than 92.8% sequence similarity with members of the closely related genera Ferruginibacter, Flavitalea, Pseudoflavitalea, Flavisolibacter, Niastella, and Terrimonas. Phylogenomic- and genomic relatedness analyses revealed that strain BO-59^T is clearly distinguished from other genera in the family Chitinophagaceae by average nucleotide identity < 66.9%) and the genome-to-genome distance (< 29.5%) values. The strain BO-59^T contained MK-7 as the predominant quinone, and iso-C_15:0, iso-C_17:0 3OH, and iso-C_15:1 G as major fatty acids (> 10%). The DNA G + C content was 39.1 mol% based on genome sequence analysis. The polar lipids of strain BO-59^T were phosphatidylethanolamine, an unidentified aminophospholipid and three unidentified polar lipids. 16S rRNA gene sequence similarity, physiological, and biochemical characteristics indicated that strain BO-59^T represents a novel species of a new genus, for which the name Hanamia caeni gen. nov., sp. nov. is proposed. The type strain is BO-59^T (= KACC 19646^T = LMG 30865 ^T).

Pinibacter aurantiacus gen. nov., sp. nov., isolated from rhizospheric soil of a pine tree

A Gram-stain-negative, aerobic and rod-shaped novel bacterial strain, designated MAH-26^T, was isolated from rhizospheric soil of a pine tree. The colonies were orange coloured, smooth, spherical and 0.7-1.8 mm in diameter when grown on Reasoner's 2A (R2A) agar for 2 days. Strain MAH-26^T was able to grow at 10-40 °C, at pH 6.0-9.0 and with 0-1.0 % NaCl. Cell growth occurred on nutrient agar, R2A agar, tryptone soya agar and Luria-Bertani agar. The strain gave positive results in oxidase and catalase tests. Strain MAH-26^T was closely related to Flavihumibacter sediminis CJ663^T and Parasegetibacter terrae SGM2-10^T with a low 16S rRNA gene sequence similarity (92.8 and 92.9 %, respectively) and phylogenetic analysis indicated that the strain formed a distinct phylogenetic lineage from the members of the closely related genera of the family Chitinophagaceae. Strain MAH-26^T has a draft genome size of 6 857 405 bp, annotated with 5173 protein-coding genes, 50 tRNA and two rRNA genes. The genomic DNA G+C content was 41.5 mol%. The predominant isoprenoid quinone was menaquinone 7. The major fatty acids were identified as iso-C_15:0, iso-C_15:1 G and iso-C_17:0 3OH. On the basis of phylogenetic inference and phenotypic, chemotaxonomic and molecular properties, strain MAH-26^T represents a novel species of a novel genus of the family Chitinophagaceae, for which the name Pinibacter aurantiacus gen. nov., sp. nov. is proposed. The type strain of Pinibacter aurantiacus is MAH-26^T (=KACC 19749^T=CGMCC 1.13701^T).

Flavitalea flava sp. nov., a bacterium isolated from a soil sample, and emended description of the genus Flavitalea

A Gram-stain negative strain, designated AN120636^T, was isolated from a soil sample collected from Goesan-gun, Chungbuk, South Korea. The strain was strictly aerobic, with golden yellow-pigmented colonies on R2A agar. Cells were non-motile, long or short rods and some were observed to be coccal. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain AN120636^T belongs to the genus Flavitalea in the family of Chitinophagacea, with Flavitalea populi (95.4%), Pseudoflavitalea soli (95.0%), Flavitalea gansuensis (94.7%) and Pseudoflavitalea rhizosphaerae (94.7%) as its close relatives. Growth was observed at 15-32 °C, pH 5.0-7.0 and in the absence of NaCl. The strain contained iso-C_17:0 3-OH, iso-C_15:1 G and iso-C_15:0 as its major cellular fatty acids; phosphatidylethanolamine as the major polar lipid; MK-7 as its respiratory quinone; and the polyamine was homospermidine. The genomic DNA G+C content was 44.8 mol%. On the basis of the polyphasic evidence, strain AN120636^T is considered to represent a novel species, for which the name Flavitalea flava sp. nov. is proposed. The type strain is AN120636^T (=KCTC 52346^T=CCTCC AB 2017174^T).