Arai W

References (4)

Title : Polysaccharide hydrolase of the hadal zone amphipods Hirondellea gigas - Kobayashi_2018_Biosci.Biotechnol.Biochem_82_1123
Author(s) : Kobayashi H , Nagahama T , Arai W , Sasagawa Y , Umeda M , Hayashi T , Nikaido I , Watanabe H , Oguri K , Kitazato H , Fujioka K , Kido Y , Takami H
Ref : Biosci Biotechnol Biochem , 82 :1123 , 2018
Abstract : Hirondellea species are common inhabitants in the hadal region deeper than 7,000 m. We found that Hirondellea gigas thrived in the Challenger Deep possessed polysaccharide hydrolases as digestive enzymes. To obtain various enzymes of other H. gigas, we captured amphipods from the Japan Trench, and Izu-Ogasawara (Bonin) Trench. A phylogenetic analysis based on the cytochrome oxidase I gene showed close relationships among amphipods, despite the geographic distance between the localities. However, several differences in enzymatic properties were observed in these H. gigas specimens. We also carried out RNA sequencing of H. gigas from the Izu-Ogasawara Trench. The cellulase gene of H. gigas was highly homologous to cellobiohydrolase of Glucosyl Hydrolase family 7 (GH7). On the other hand, enzymatic properties of H. gigas's cellulase were different from those of typical GH7 cellobiohydrolase. Thus, these results indicate that hadal-zone amphipod can be good candidates as the new enzyme resource.
ESTHER : Kobayashi_2018_Biosci.Biotechnol.Biochem_82_1123
PubMedSearch : Kobayashi_2018_Biosci.Biotechnol.Biochem_82_1123
PubMedID: 29623763
Gene_locus related to this paper: 9crus-a0a2p2i2d2 , 9crus-a0a2p2ic40

Title : Complete genome sequence and expression profile of the commercial lytic enzyme producer Lysobacter enzymogenes M497-1 - Takami_2017_DNA.Res_24_169
Author(s) : Takami H , Toyoda A , Uchiyama I , Itoh T , Takaki Y , Arai W , Nishi S , Kawai M , Shin-Ya K , Ikeda H
Ref : DNA Research , 24 :169 , 2017
Abstract : Lysobacter enzymogenes M497-1 is a producer of commercialized achromopeptidase and is expected to harbour genes encoding various other antimicrobial enzymes. Here, we present the complete sequence of the genome of M497-1 and the expression profiles of the genes for various antimicrobial enzymes. Of the 117 peptidase-encoding genes found in the 6.1-Mb genome of M497-1, 15 genes (aside from the gene encoding the achromopeptidase) were expressed at a level higher than that of the average ribosomal protein genes in the 24-h culture. Thus, the strain was found more valuable than hitherto considered. In addition, M497-1 harbours 98 genes involved in the biosynthesis of various natural products, 16 of which are M497-1-specific across 4 Lysobacter species. A gene cluster starting at LEN_2603 through LEN_2673 among the 98 genes closely resembled the lysobactin biosynthesis gene cluster of Lysobacter sp. ATCC 53042. It is likely that M497-1 may produce lysobactin or related antibacterial compounds. Furthermore, comparative genomic analysis of M497-1 and four other Lysobacter species revealed that their core genome structure comprises 3,737 orthologous groups. Our findings are expected to advance further biotechnological application of Lysobacter spp. as a promising source of natural bioactive compounds.
ESTHER : Takami_2017_DNA.Res_24_169
PubMedSearch : Takami_2017_DNA.Res_24_169
PubMedID: 28065880
Gene_locus related to this paper: lysen-a0a1j1ebl3 , lysen-a0a1j1e5b0 , lysen-a0a0s2dfs0

Title : High frequency of phylogenetically diverse reductive dehalogenase-homologous genes in deep subseafloor sedimentary metagenomes - Kawai_2014_Front.Microbiol_5_80
Author(s) : Kawai M , Futagami T , Toyoda A , Takaki Y , Nishi S , Hori S , Arai W , Tsubouchi T , Morono Y , Uchiyama I , Ito T , Fujiyama A , Inagaki F , Takami H
Ref : Front Microbiol , 5 :80 , 2014
Abstract : Marine subsurface sediments on the Pacific margin harbor diverse microbial communities even at depths of several hundreds meters below the seafloor (mbsf) or more. Previous PCR-based molecular analysis showed the presence of diverse reductive dehalogenase gene (rdhA) homologs in marine subsurface sediment, suggesting that anaerobic respiration of organohalides is one of the possible energy-yielding pathways in the organic-rich sedimentary habitat. However, primer-independent molecular characterization of rdhA has remained to be demonstrated. Here, we studied the diversity and frequency of rdhA homologs by metagenomic analysis of five different depth horizons (0.8, 5.1, 18.6, 48.5, and 107.0 mbsf) at Site C9001 off the Shimokita Peninsula of Japan. From all metagenomic pools, remarkably diverse rdhA-homologous sequences, some of which are affiliated with novel clusters, were observed with high frequency. As a comparison, we also examined frequency of dissimilatory sulfite reductase genes (dsrAB), key functional genes for microbial sulfate reduction. The dsrAB were also widely observed in the metagenomic pools whereas the frequency of dsrAB genes was generally smaller than that of rdhA-homologous genes. The phylogenetic composition of rdhA-homologous genes was similar among the five depth horizons. Our metagenomic data revealed that subseafloor rdhA homologs are more diverse than previously identified from PCR-based molecular studies. Spatial distribution of similar rdhA homologs across wide depositional ages indicates that the heterotrophic metabolic processes mediated by the genes can be ecologically important, functioning in the organic-rich subseafloor sedimentary biosphere.
ESTHER : Kawai_2014_Front.Microbiol_5_80
PubMedSearch : Kawai_2014_Front.Microbiol_5_80
PubMedID: 24624126
Gene_locus related to this paper: 9zzzz-x0wci8 , 9zzzz-x1k9j7 , 9zzzz-x0se68 , 9zzzz-x0tpm6 , 9zzzz-x0tv89 , 9zzzz-x0ws69 , 9zzzz-x1tg33 , 9zzzz-x1anx0 , 9zzzz-x1m8t8 , 9zzzz-x1a5i7 , 9zzzz-x1k2t2 , 9zzzz-x0uzq5

Title : A deeply branching thermophilic bacterium with an ancient acetyl-CoA pathway dominates a subsurface ecosystem - Takami_2012_PLoS.One_7_e30559
Author(s) : Takami H , Noguchi H , Takaki Y , Uchiyama I , Toyoda A , Nishi S , Chee GJ , Arai W , Nunoura T , Itoh T , Hattori M , Takai K
Ref : PLoS ONE , 7 :e30559 , 2012
Abstract : A nearly complete genome sequence of Candidatus 'Acetothermum autotrophicum', a presently uncultivated bacterium in candidate division OP1, was revealed by metagenomic analysis of a subsurface thermophilic microbial mat community. Phylogenetic analysis based on the concatenated sequences of proteins common among 367 prokaryotes suggests that Ca. 'A. autotrophicum' is one of the earliest diverging bacterial lineages. It possesses a folate-dependent Wood-Ljungdahl (acetyl-CoA) pathway of CO(2) fixation, is predicted to have an acetogenic lifestyle, and possesses the newly discovered archaeal-autotrophic type of bifunctional fructose 1,6-bisphosphate aldolase/phosphatase. A phylogenetic analysis of the core gene cluster of the acethyl-CoA pathway, shared by acetogens, methanogens, some sulfur- and iron-reducers and dechlorinators, supports the hypothesis that the core gene cluster of Ca. 'A. autotrophicum' is a particularly ancient bacterial pathway. The habitat, physiology and phylogenetic position of Ca. 'A. autotrophicum' support the view that the first bacterial and archaeal lineages were H(2)-dependent acetogens and methanogenes living in hydrothermal environments.
ESTHER : Takami_2012_PLoS.One_7_e30559
PubMedSearch : Takami_2012_PLoS.One_7_e30559
PubMedID: 22303444
Gene_locus related to this paper: 9bact-h5srl9 , 9chlr-h5sfm8