• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.545-555
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• 2011

The diversity elucidation by amplified ribosomal DNA restriction analysis and 16S rDNA sequencing of 96 associative diazotrophs, isolated from the feeder roots of tea on enriched nitrogen-free semisolid media, revealed the predominance of Gram-positive over Gram-negative bacteria within the Kangra valley in Himachal Pradesh, India. The Gram-positive bacteria observed belong to two taxonomic groupings; Firmicutes, including the genera Bacillus and Paenibacillus; and Actinobacteria, represented by the genus Microbacterium. The Gram-negative bacteria included ${\alpha}$-Proteobacteria genera Brevundimonas, Rhizobium, and Mesorhizobium; ${\gamma}$-Proteobacteria genera Pseudomonas and Stenotrophomonas; and ${\beta}$-Proteobacteria genera Azospira, Burkholderia, Delftia, Herbaspirillum and Ralstonia. The low level of similarity of two isolates, with the type strains Paenibacillus xinjiangensis and Mesorhizobium albiziae, suggests the possibility of raising species novum. The bacterial strains of different phylogenetic groups exhibited distinct carbon-source utilization patterns and fatty acid methyl ester profiles. The strains differed in their nitrogenase activities with relatively high activity seen in the Gramnegative strains exhibiting the highest similarity to Azospira oryzae, Delftia lacustris and Herbaspirillum huttiense.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.125-134
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• 2017

Enhanced disease susceptibility1 (EDS1) is a regulator of basal defense responses required for resistance mediated by TIR-NBS-LRR containing R proteins. We identified three transcripts of EDS1-like genes encompassing diverse/separate expression patterns, based on the transcriptome analysis by Next Generation Sequencing (NGS) of V. flexuosa inoculated with Elsinoe ampelina. These genes were designated VfEDL1 (Vitis flexuosa Enhanced Disease Susceptibility1-like1), VfEDL2 and VfEDL3, and contained 2464, 1719 and 1599 bp, with 1791, 1227 and 1599 bp open reading frames (ORFs), encoding proteins of 596, 408 and 532 amino acids, respectively. The predicted amino acid sequences of all three genes showed the L-family lipase-like domain (class 3 lipase domain), and exhibited a potential lipase catalytic triad, aspartic acid, histidine and serine in the conserved G-X-S-X-G. All three VfEDL genes were upregulated at 1 hpi against the bacterial and fungal pathogens Rizhobiumvitis and E. ampelina, respectively, except VfEDL1, which was downregulated against E. ampelina at all time points. Against E. ampelina, VfEDL2 and VfEDL3 showed downregulated expression at later time points. When evaluated against R. vitis, VfEDL1 showed downregulated expression at all time points after 1 hpi, while VfEDL3 showed upregulation up to 24 hpi. Based on the expression response, all three genes may be involved in plant resistant responses against R. vitis, and VfEDL2 and VfEDL3 show additional resistant responses against E. ampelina infection.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1790-1797
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• 2017

In the present study, we demonstrate that the growth of salt-stressed pepper plants is improved by inoculation with plant growth-promoting rhizobacteria (PGPR). Three PGPR strains (Microbacterium oleivorans KNUC7074, Brevibacterium iodinum KNUC7183, and Rhizobium massiliae KNUC7586) were isolated from the rhizosphere of pepper plants growing in saline soil, and pepper plants inoculated with these PGPR strains exhibited significantly greater plant height, fresh weight, dry weight, and total chlorophyll content than non-inoculated plants. In addition, salt-stressed pepper plants that were inoculated with B. iodinum KNUC7183 and R. massiliae KNUC7586 possessed significantly different total soluble sugar and proline contents from non-inoculated controls, and the activity of several antioxidant enzymes (ascorbate peroxidase, guaiacol peroxidase, and catalase) was also elevated in PGPR-treated plants under salt stress. Overall, these results suggest that the inoculation of pepper plants with M. oleivorans KNUC7074, B. iodinum KNUC7183, and R. massiliae KNUC7586 can alleviate the harmful effects of salt stress on plant growth.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.146-151
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• 1990

The viability of rhizobia according to various kinds of carrier materials, inoculum size, storage temperature and sterilization methods was investigated for the development of legume inoculat. The results were followings. 1. Peat and perlite were favorable as a carrier material. 2. Rhizobia counts were reached to $5{\times}10^8cells/g$ carrier 1-2 weeks after inoculation with inoculum size below $10^4cells/g$ carrier. 3. $10^9cells/g$ carrier was maintained 12 weeks after storage at room temperature. 4. Steam heat sterilization was the best method for carrier sterilization among methods used in this study. Dry heat and ${\gamma}$-ray sterilization were also applicable.

• Journal of Microbiology and Biotechnology
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• v.16 no.1
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• pp.118-125
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• 2006

The region responsible for replication of the megaplasmid pAtC58 in the nopaline-type Agrobacterium tumefaciens strain C58 was determined. A derivative ofa Co1E1 vector, pBluscript SK-, incapable of autonomous replication in Agrobacterium spp, was cloned with a 7.6-kb Bg1II-HindIII fragment from a cosmid clone of pAtC58, which contains a region adjacent to the operon for the utilization of deoxyfructosyl glutamine (DFG). The resulting plasmid conferred resistance to carbenicillin on the A. tumefaciens strain UIA5 that is a plasmidfree derivative of C58. The plasmid was stably maintained in the strain even after consecutive cultures for generations. Analysis of nested deletions of the 7.6-kb fragment showed that a 4.3-kb BglII-XhoI region sufficiently confers replication of the derivative of the ColE1 vector on UIA5. The region comprises three ORFs, which have high homologies with repA, repB, and repC of plasm ids in virulent Agrobacterium spp. including pTiC58, pTiB6S3, pTi-SAKURA, and pRiA4b as well as those of symbiotic plasmids from Rhizobium spp. Phylogenie analysis showed that rep genes in pAtC58 are more closely related to those in pRiA4 than to pTi plasmids including pTiC58, suggesting that the two inborn plasmids, pTiC58 and pAtC58, harbored in C58 evolved from distinct origins.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1141-1147
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• 2012

Polyhydroxyalkanoate (PHA) is a class of biodegradable plastics that have great potential applications in the near future. In this study, the micro-biodiversity and productivity of PHA-accumulating bacteria in activated sludge from a domestic wastewater treatment plant were investigated. A previously reported primer set and a self-designed primer set (phaCF1BO/phaCR2BO) were both used to amplify the PHA synthase (phaC) gene of isolated colonies. The new primers demonstrated higher sensitivity for phaC, and combining the PCR results of the two primer sets was able to widen the range of detected genera and raise the sensitivity to nearly 90%. Results showed that 85.3% of the identified bacteria were Gram-negative, with Ralstonia as the dominant genus, and 14.7% were Gram-positive. In addition, Zoogloea and Rhizobium contained the highest amounts of intracellular PHA. It is apparent that glucose was a better carbon source than pentone or tryptone for promoting PHA production in Micrococcus. Two different classes, class I and class II, of phaC were detected from alphaproteobacteria, betaproteobacteria, and gammaproteobacteria, indicating the wide diversity of PHA-accumulating bacteria in this particular sampling site. Simultaneous wastewater treatment and PHA production is promising by adopting the high PHA-accumulating bacteria isolated from activated sludge.

• Biomedical Science Letters
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• v.6 no.1
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• pp.1-9
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• 2000

To identity the genes responsible for the biosynthesis of exopolysaccharide, recombinant plasmids pUEX10 and pLEX10 were constructed from plasmid pLEX3 which was isolated from the recombinant cosmid library of Zoogloea ramigera 115. The complete nucleotide sequence of the 1.7 kb genomic DNA insert in plasmid pUEX10 was determined. Its analysis identified two open reading frames (ORF3 & ORF4) which could encode two proteins. The amino acid sequence derived from ORF3 showed the homology with gumC protein in Xanthomonas campestris as well as exoP protein in Rhizobium melizoti. The partial amino acid sequence of ORF4 showed the homology with polysaccharide export protein in Thermotoga maritima. Z. ramigera 115SLR and Z. ramigera 115SLR/pLEX10 showed the similar pattern for EPS production. Yield of exopolysaccharides produced by Z. ramigera 115SLR and Z. ramigera 115SLR/pLEX10 was 0.26% (w/v) and 0.16% (w/v), respectively.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.246-251
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• 1992

Molccular cloning of nod genes from Bradvrhizobium sp. SNU001, a nitrogen-fixing symbiont isolated from thc root nodules of soybean (Clycine trim) . was carried out. nod genes were found to be located on thc genome of the symbiont by gcnomic hybridization with 4.5 kb EcoRI/HndIII fragment (nod DABC) of Rhizohium meliloti as probe. Genomic library of this symbiont was constructed using h phage EMBL3-BanlHI vector. from which five nod positive clones were sclectcd by primary and secondary screening methods. The partial restriction map of inserted genomic DNA of h CNS-l(c1one 2) was constructed. and 3.9 kh Bun7HI fragment. which showed strong hybridization signal to the probe, was subcloned into pBS KS(+) plasmid vector. Partial restriction inap ot' a selected subclone (pBjCNS-I) was constructed and nod DABC was found to be located on the 1.8 kb KpnI/Sacl fragment of this subclone.

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1491-1499
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• 2010

Rhizosphere microorganisms possessing phytase activity are considered important for rendering phytate-phosphorus (P) available to plants. In the present study, the Citrobacter braakii phytase gene (appA) was overexpressed in rhizobacteria possessing plant growth promoting (PGP) traits, for increasing their potential as bioinoculants. AppA was cloned under the lac promoter in the broadhost-range expression vector pBBR1MCS-2. Transformation of the recombinant construct pCBappA resulted in high constitutive phytase activity in all of the eight rhizobacterial strains belonging to genera Pantoea, Citrobacter, Enterobacter, Pseudomonas (two strains), Rhizobium (two strains), and Ensifer that were studied. Transgenic rhizobacterial strains were found to display varying levels of phytase activity, ranging from 10-folds to 538-folds higher than the corresponding control strains. The transgenic derivative of Pseudomonas fluorescens CHA0, a well-characterized plant growth promoting rhizobacterium, showed the highest expression of phytase (~8 U/mg) activity in crude extracts. Although all transformants showed high phytase activity, rhizobacteria having the ability to secrete organic acid showed significantly higher release of P from Ca-phytate in buffered minimal media. AppA overexpressing rhizobacteria showed increased P content, and dry weight (shoot) or shoot/ root ratio of mung bean (Vigna radiata) plants, to different extents, when grown in semisolid agar (SSA) medium containing Na-phytate or Ca-phytate as the P sources. This is the first report of the overexpression of phytase in rhizobacterial strains and its exploitation for plant growth enhancement.

• Journal of Embryo Transfer
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• v.28 no.1
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• pp.49-55
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• 2013

The objective of this study was to evaluate several types of uterine bacteria in Hanwoo. uterine bacteria from randomly selected 5 uterus was collected by flushing methods into a sterilized 1.5 ml centrifuge tube and was inoculated onto MacConkey agar and blood agar, respectively. After being incubated for 5% $CO_2$, aerobic or anaerobic condition at $37^{\circ}C$ during 48h, bacterial colonies were selected and re-inoculated onto blood agar plates. Re-cultured colonies were identified by Gram staining and finally identified using Vitek system. The identified bacteria were Staphylococcus lentus, Staphylococcus sciuri, Staphylococcus vitulinus, Staphylococcus warneri of Gram (+) and Rhizobium radiobacter, Sphingomonas paucimobilis of Gram (-) bacteria. Although, pathogenicity of identified bacteria was unclear, the bacteria can have an effect on the uterine microenvironment. Therefore, repetitive research will be required to determine the effects of bacteria in cattle exposed to a various environment.