Allorhizobium sonneratiae sp. nov., an endophytic bacterium isolated from the root of Sonneratia apetala.

A novel endophytic bacterium, designated strain BGMRC 0089T, was isolated from a surface-sterilized root of Sonneratia apetala. Cells were observed to be Gram-negative, rod-shaped and motile with polar flagella. Strain BGMRC 0089T was found to grow optimally at 28-30 °C, pH 7.0-8.0 and in the presence of 1 % (w/v) NaCl. Strain BGMRC 0089T contained ubiquinone Q-10 and the predominant fatty acid was summed feature 8. The polar lipid profile of strain BGMRC 0089T was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidylethanolamine. Based on the results of 16S rRNA gene analysis, this isolate has the closest phylogenetic relationships with Rhizobium lemnae L6-16T (96.5 %) and Allorhizobium oryziradicis N19T (96.4 %). Average nucleotide identity, amino acid identity and digital DNA-DNA hybridization values of the isolate with the type strains of the genera Rhizobium and Allorhizobium were below 84.6, 73.9 and 22.1  %, respectively. Analysis the 4.55 Mb draft genome of strain BGMRC 0089T revealed several plant-associated genes, which may play important roles for the plant in the adaptation to the mangrove habitat. Based on its distinct phylogenetic, phenotypic and chemotaxonomic characteristics, strain BGMRC 0089T is proposed to represent a novel Allorhizobium species, for which the name Allorhizobium sonneratiae sp. nov. is proposed (type strain BGMRC 0089T=DSM 100171T=MCCC 1K04805T).

Parvularcula maris sp. nov., an algicidal bacterium isolated from seawater.

A taxonomic study was carried out on strain BGMRC 0090T, which was isolated from seawater. The isolate was a Gram-negative, aerobic, flagellated, rod-shaped bacterium with algicidal activity. Optimal growth was observed at 30 °C, pH 6.0 and with 2 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain BGMRC 0090T belonged to the genus Parvularcula, with highest sequence similarity to Parvularcula lutaonensis CC-MMS-1T (98.4 %). Average nucleotide identity, amino acid identity and digital DNA-DNA hybridization values between strain BGMRC 0090T and five strains of the genus Parvularcula with publicly available genomes were below 84.0, 69.2 and 21.4 %, respectively. The genome of strain BGMRC 0090T was 3.2 Mb with 64.8 mol% DNA G+C content and encoded 2905 predicted proteins, three rRNA, 42 tRNA and four ncRNA genes. Some algicidal biosynthesis-associated genes were detected in the genome. Strain BGMRC 0090T contained Q-10 as the major quinone. The predominant fatty acids were identified as summed feature 8 (C18 : 1ω7c/ω6c) and C16 : 0. Based on the polyphasic evidence presented in this paper, strain BGMRC 0090T is concluded to represent a novel species of the genus Parvularcula, for which the name Parvularcula maris sp. nov. is proposed. The type strain is BGMRC 0090T (= KCTC 92591T=MCCC 1K08100T).