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Kim S.-Y.,Sangji University | Lee B.-M.,National Institute of Agricultural Biotechnology | Cho J.-Y.,Sangji University
Biotechnology Letters | Year: 2010

Two genes involved in central carbon metabolism were inactivated to modulate intracellular glucose 6-phosphate and to evaluate its effects on xanthan production in wild-type Xanthomonas oryzae pv. oryzae. Upon the inactivation of the phosphogluconate dehydratase gene (edd), intracellular glucose 6-phosphate increased from 0.05 to 1.17 mmol/g (dry cell wt). This was accompanied by increased xanthan production of up to 2.55 g/l (culture medium). In contrast, inactivation of 6-phosphogluconate dehydrogenase gene (gndA) did not influence intracellular glucose 6-phosphate nor xanthan production. The intracellular availability of glucose 6-phosphate is proposed as a rate-limiting factor in xanthan production, and it may be possible to increases production of xanthan by modulating the activities of enzymes in central carbon metabolism. © Springer Science+Business Media B.V. 2009. Source

Shin K.-S.,National Institute of Agricultural Biotechnology | Park S.-Y.,Chungbuk National University | Paek K.-Y.,Chungbuk National University
In Vitro Cellular and Developmental Biology - Plant | Year: 2013

Suboptimal environmental conditions inside closed culture vessels can be detrimental to in vitro growth and survival of plantlets during the acclimatization process. In this study, the environmental factors that affected Doritaenopsis plantlet growth and the relationship between growth and sugar metabolism were investigated. Cultures were maintained under heterotrophic, photoautotrophic, or photomixotrophic conditions under different light intensities and CO2 concentrations. Photoautotrophic growth of Doritaenopsis hybrid plantlets could be promoted significantly by increasing the light intensity and CO2 concentration in the culture vessel. The concentration of different sugars in the leaves of in vitro-grown plantlets varied with different cultural treatments through a 10-wk culture period. Starch, reducing sugars, and nonreducing sugar contents were higher in plantlets grown under photoautotrophic and photomixotrophic conditions than in heterotrophically grown plantlets. Net photosynthesis rates were also higher in photoautotrophically and photomixotrophically grown plantlets. These results support the hypothesis that pyruvate, produced by the decarboxylation of malate, is required for optimal photoautotrophy under high photosynthetic photon flux density. Growth was greatest in plantlets grown under CO2-enriched photoautotrophic and photomixotrophic conditions with high photosynthetic photon flux density. The physiological status of in vitro-grown Crassulacean acid metabolism (CAM)-type Doritaenopsis showed a transition from C3 to CAM prior to acclimatization. © 2013 The Society for In Vitro Biology. Source

Madhaiyan M.,Chungbuk National University | Madhaiyan M.,National University of Singapore | Poonguzhali S.,Chungbuk National University | Kwon S.-W.,National Institute of Agricultural Biotechnology | Sa T.-M.,Chungbuk National University
International Journal of Systematic and Evolutionary Microbiology | Year: 2010

A Gram-positive bacterium, designated strain CBMB205 T, was isolated from the rhizosphere soil of traditionally cultivated, field-grown rice. Cells were strictly aerobic, motile, rod-shaped and formed endospores. The best growth was achieved at 30 °C and pH 7.0 in ammonium mineral salts (AMS) medium containing 600 mM methanol. A comparative 16S rRNA gene sequence-based phylogenetic analysis placed strain CBMB205 T in a clade with the species Bacillus amyloliquefaciens, Bacillus vallismortis, Bacillus subtilis, Bacillus atrophaeus, Bacillus mojavensis and Bacillus licheniformis and revealed pairwise similarities ranging from 98.2 to 99.2 %. DNA-DNA hybridization experiments revealed a low level (<36 %) of DNA-DNA relatedness between strain CBMB205 T and its closest relatives. The major components of the fatty acid profile were C 15 : 0 anteiso, C 15 : 0 iso, C 16 : 0 iso and C 17 : 0 anteiso. The diagnostic diamino acid of the cell wall was meso-diaminopimelic acid. The G+C content of the genomic DNA was 45.0 mol%. The lipids present in strain CBMB205 T were diphosphatidylglycerol, phosphatidylglycerol, a minor amount of phosphatidylcholine and two unknown phospholipids. The predominant respiratory quinone was MK-7. Studies of DNA-DNA relatedness, morphological, physiological and chemotaxonomic analyses and phylogenetic data based on 16S rRNA gene sequencing enabled strain CBMB205 T to be described as representing a novel species of the genus Bacillus, for which the name Bacillus methylotrophicus sp. nov. is proposed. The type strain is CBMB205 T (=KACC 13105 T=NCCB 100236 T). © 2010 IUMS. Source

Verma N.,National Bureau of Plant Genetic Resources | Rana M.K.,National Bureau of Plant Genetic Resources | Negi K.S.,National Bureau of Plant Genetic Resources | Kumar G.,National Bureau of Plant Genetic Resources | And 3 more authors.
Indian Journal of Biotechnology | Year: 2010

Inter-population diversity in 54 Indian Perilla landraces and 18 accessions of exotic origin was investigated using sequence tagged microsatallite (STMS) markers. The STMS markers clearly distinguished the Indian accessions from the exotic ones. Neighborhood-joining (NJ) clustering pattern revealed association of geographical diversity and genetic diversity for Indian Perilla germplasm. Population genetic parameters studied for 14 Indian Perilla populations from two distinct regions (North-eastern region and North-western Himalayas, Uttarakhand State) revealed greater diversity for accessions from the later region. Analysis of molecular variance, revealed that bulk of the variations existed between populations within groups, followed by variations within populations and between groups. The summary of group-wise F-statistics and gene flow revealed greater population differentiation for Uttarakhand populations as compared to accessions from North-eastern region of India. Source

Dixit A.,Kongju National University | Dixit A.,Rice University | Chung J.W.,Kongju National University | Zhao W.G.,Kongju National University | And 8 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2010

Thirty microsatellite loci for further genetic analysis of Citrus species were developed by constructing a microsatelliteenriched library using capture with streptavidin-coated magnetic beads and used to assess genetic diversity in 40 Citrus accessions. In total, 150 alleles were detected, with an average of five alleles per locus. The average gene diversity and polymorphism information content values were 0.58 and 0.52, and ranged from 0.35 - 0.74 and from 0.32 - 0.70, respectively. Values for the observed and expected heterozygosities ranged from 0.13 - 1.00 and from 0.36 - 0.75, respectively. Fifteen loci deviated from the Hardy-Weinberg equilibrium (P < 0.05). The mean similarity coefficient among accessions was 0.5906. Based on the UPGMA algorithm, two main groups were successfully identified. These new microsatellite markers can be used to further investigate the genetics of, and phylogenic relationships in Citrus spp. Source

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