Coraliomargarita akajimensis gen. nov., sp. nov., a novel member of the phylum 'Verrucomicrobia' isolated from seawater in Japan An obligately aerobic, Gram-negative, non-spore-forming, non-motile, spherical bacterium, designated strain 04OKA010-24

An aerobic, Gram-negative, non-motile, yellow-to-orange pigmented and rod-shaped bacterium, designated strain SM1T , was isolated from seawater in Thailand and subjected to a polyphasic taxonomic study. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the novel isolate shared 93-95 % sequence similarity with species of the genus Myroides. The DNA-DNA relatedness values of strain SM1 T with Myroides odoratimimus JCM 7460 T andMyroides odoratus JCM 7458 T were below 70 %. The DNA G+C content of strain SM1 T was 33?6 mol%, the major menaquinone was MK-6 and the major fatty acids were C 15 : 0 iso, C 17 : 1 v9c iso and C 17 : 0 iso 3-OH. Based on its phenotypic and chemotaxonomic characteristics, strain SM1 T was classified as representing a novel species of the genus Myroides, for which the name Myroides pelagicus sp. nov. is proposed. The type strain is SM1 T (=IAM 15337 T =KCTC 12661 T ).The genus Myroides was established by the reclassification of Flavobacterium odoratum as Myroides odoratus, the type species, on the basis of genomic, chemotaxonomic and phenotypic studies (Vancanneyt et al., 1996). Myroides odoratimimus was also described in the report. Currently, the genus Myroides comprises only these two species, both of which originated from clinical sources (Holmes et al., 1977). Strain SM1 T was obtained during the isolation of crude oilutilizing and -emulsifying bacteria from seawater (Maneerat et al., 2005). Strain SM1T and the two species of the genus Myroides were found to produce surface-active compounds in marine broth, which were identified as cholic acid, deoxycholic acid and their conjugates with glycine. These findings led to the first report indicating that bile acids can be produced by prokaryotic cells (Maneerat et al., 2005). In the present study, we attempted to elucidate the phylogenetic position of strain SM1T using a polyphasic taxonomic approach, including 16S rRNA gene sequence analysis, fatty acid content analysis, quinone analysis and genotypic (G+C content of DNA, DNA-DNA hybridization) and physiological comparisons. Based on these data, it is proposed that strain SM1T represents a novel species in the genus Myroides.Temperature range and pH range for growth were determined by incubating in Luria-Bertani (LB) medium (Atlas, 2004). Cell morphology was observed by microscopy (BX60; Olympus). Growth under anaerobic conditions was determined after 2 weeks incubation in an AnaeroPack (Mitsubishi Gas). Catalase activity was determined by bubble formation in 3 % H 2 O 2 solution. Oxidase activity was determined by cytochrome oxidase paper (Nissui Pharmaceutical). API 20E and API ZYM strips (bioMérieux) were used to determine physiological and biochemical characteristics. API 20E and API ZYM were read after 48 h incubation at 28 u C and 4 h incubation at 37 u C, respectively. The nutritional features of strain SM1T and M. odoratimimus JCM 7460 T and M. odoratus JCM 7458 T were determined using Biolog MicroPlates. The strains were grown on BUG medium (Biolog, supplemented ...

No abstract

No abstract

Proteolytic degradation by secreted proteases into the culture medium is one of the significant problems to be solved in heterologous protein production by filamentous fungi including Aspergillus oryzae. Double (tppA, and pepE) and quintuple (tppA, pepE, nptB, dppIV, and dppV) disruption of protease genes enhanced human lysozyme (HLY) and bovine chymosin (CHY) production by A. oryzae. In this study, we used a quintuple protease gene disruptant and performed successive rounds of disruption for five additional protease genes (alpA, pepA, AopepAa, AopepAd, and cpI), which were previously investigated by DNA microarray analyses for their expression. Gene disruption was performed by pyrG marker recycling with a highly efficient gene-targeting background (∆ligD) as previously reported. As a result, the maximum yields of recombinant CHY and HLY produced by a decuple protease gene disruptant were approximately 30% and 35%, respectively, higher than those produced by a quintuple protease gene disruptant. Thus, we successfully constructed a decuple protease gene disruptant possessing highly improved capability of heterologous protein production. This is the first report on decuple protease gene disruption that improved the levels of heterologous protein production by the filamentous fungus A. oryzae.