Genome sequence of an uncharted halophilic bacterium Robertkochia marina with deciphering its phosphate-solubilizing ability.

The wide use of whole-genome sequencing approach in the modern genomic era has opened a great opportunity to reveal the prospective applications of halophilic bacteria. Robertkochia marina CC-AMO-30DT is one of the halophilic bacteria that was previously taxonomically identified without any inspection on its biotechnological potential from a genomic aspect. In this study, we present the whole-genome sequence of R. marina and demonstrated the ability of this bacterium in solubilizing phosphate by producing phosphatase. The genome of R. marina has 3.57 Mbp and contains 3107 predicted genes, from which 3044 are protein coding, 52 are non-coding RNAs, and 11 are pseudogenes. Several phosphatases such as alkaline phosphatases and pyrophosphatases were mined from the genome. Further genomic study (phylogenetics, sequence analysis, and functional mechanism) and experimental data suggested that the alkaline phosphatase produced by R. marina could potentially be utilized in promoting plant growth, particularly for plants on saline-based agricultural land.

Draft genome sequence of Parvularcula flava strain NH6-79 T, revealing its role as a cellulolytic enzymes producer.

To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 ß-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and ß-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and ß-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.

Genome sequence data of Mangrovimonas sp. strain CR14 isolated from mangrove forest at Tanjung Piai National Park, Malaysia.

Mangrovimonas sp. strain CR14 is a halophilic bacterium affiliated with family Flavobacteriaceae which was successfully isolated from mangrove soil samples obtained from Tanjung Piai National Park, Johor. The whole genome of strain CR14 was sequenced on an Illumina HiSeq 2500 platform (2 × 150 bp paired end). Herein, we report the genome sequence of Mangrovimonas sp. strain CR14 in which its assembled genome consisted 20 contigs with a total size of 3,590,195 bp, 3209 coding sequences, and an average 36.08% G + C content. Genome annotation and gene mining revealed that this bacterium demonstrated proteolytic activity which could be potentially applied in detergent industry. This whole-genome shotgun data of Mangrovimonas sp. strain CR14 has been deposited at DDBJ/ENA/GenBank under the accession JAAFZY000000000. The version described in this paper is version JAAFZY010000000.

Genome analysis of cellulose and hemicellulose degrading Micromonospora sp. CP22.

In this study, a bacterial strain CP22 with ability to produce cellulase, xylanase and mannanase was isolated from the oil palm compost. Based on the 16S rRNA gene analysis, the strain was affiliated to genus Micromonospora. To further investigate genes that are related to cellulose and hemicellulose degradation, the genome of strain CP22 was sequenced, annotated and analyzed. The de novo assembled genome of strain CP22 featured a size of 5,856,203 bp with G + C content of 70.84%. Detailed genome analysis on lignocellulose degradation revealed a total of 60 genes consisting of 47 glycoside hydrolase domains and 16 carbohydrate esterase domains predicted to be involved in cellulolytic and hemicellulolytic deconstruction. Particularly, 20 genes encode for cellulases (8 endoglucanases, 3 exoglucanases and 9 ß-glucosidases) and 40 genes encode for hemicellulases (15 endo-1,4-ß-xylanase, 3 ß-xylosidase, 3 α-arabinofuranosidase, 10 acetyl xylan esterase, 6 polysaccharide deacetylase, 1 ß-mannanase, 1 ß-mannosidase and 1 α-galactosidase). Thirty-two genes encoding carbohydrate-binding modules (CBM) from six different families (CBM2, CBM4, CBM6, CBM9, CBM13 and CBM22) were present in the genome of strain CP22. These CBMs were found in 27 cellulolytic and hemicellulolytic genes, indicating their potential role in enhancing the substrate-binding capability of the enzymes. CBM2 and CBM13 are the major CBMs present in cellulases and hemicellulases (xylanases and mannanases), respectively. Moreover, a GH10 xylanase was found to contain 3 CBMs (1 CBM9 and 2 CBM22) and these CBMs were reported to bind specifically to xylan. This genome-based analysis could facilitate the exploration of this strain for lignocellulosic biomass degradation.

Robertkochia solimangrovi sp. nov., isolated from mangrove soil, and emended description of the genus Robertkochia.

To date, there is sparse information for the genus Robertkochia with Robertkochia marina CC-AMO-30DT as the only described member. We report here a new species isolated from mangrove soil collected at Malaysia Tanjung Piai National Park and perform polyphasic characterization to determine its taxonomic position. Strain CL23T is a Gram-negative, yellow-pigmented, strictly aerobic, catalase-positive and oxidase-positive bacterium. The optimal growth conditions were determined to be at pH 7.0, 30-37 °C and in 1-2 % (w/v) NaCl. The major respiratory quinone was menaquinone-6 (MK-6) and the highly abundant polar lipids were four unidentified lipids, a phosphatidylethanolamine and two unidentified aminolipids. The 16S rRNA gene similarity between strain CL23T and R. marina CC-AMO-30DT is 96.67 %. Strain CL23T and R. marina CC-AMO-30DT clustered together and were distinguished from taxa of closely related genera in 16S rRNA gene phylogenetic analysis. Genome sequencing revealed that strain CL23T has a genome size of 4.4 Mbp and a G+C content of 40.72 mol%. Overall genome related indexes including digital DNA-DNA hybridization value and average nucleotide identity are 17.70 % and approximately 70%, below the cutoffs of 70 and 95%, respectively, indicated that strain CL23T is a distinct species from R. marina CC-AMO-30DT. Collectively, based on the phenotypic, chemotaxonomic, phylogenetic and genomic evidences presented here, strain CL23T is proposed to represent a new species with the name Robertkochia solimangrovi sp. nov. (KCTC 72252T=LMG 31418T). An emended description of the genus Robertkochia is also proposed.

Characterization of detergent compatible protease from halophilic Virgibacillus sp. CD6.

A halophilic bacterium, Virgibacillus sp. strain CD6, was isolated from salted fish and its extracellular protease was characterized. Protease production was found to be highest when yeast extract was used as nitrogen source for growth. The protease exhibited stability at wide range of salt concentration (0-12.5%, w/v), temperatures (20-60 °C), and pH (4-10) with maximum activity at 10.0% (w/v) NaCl, 60 °C, pH 7 and 10, indicating its polyextremophilicity. The protease activity was enhanced in the presence of Mg2+, Mn2+, Cd2+, and Al3+ (107-122% relative activity), and with retention of activity > 80% for all of other metal ions examined (K+, Ca2+, Cu2+, Co2+, Ni2+, Zn2+, and Fe3+). Both PMSF and EDTA inhibited protease activity, denoting serine protease and metalloprotease properties, respectively. High stability (> 70%) was demonstrated in the presence of organic solvents and detergent constituents, and the extracellular protease from strain CD6 was also found to be compatible in commercial detergents. Proteinaceous stain removal efficacy revealed that crude protease of strain CD6 could significantly enhance the performance of commercial detergent. The protease from Virgibacillus sp. strain CD6 could serve as a promising alternative for various applications, especially in detergent industry.