• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.105-115
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• 2019

Saline or alkaline condition in soil inhibits growth of most crop plants and limits crop yields in many parts of the world. Augmenting an alkaline soil with alkali-tolerant bacteria capable of promoting plant growth can be a promising approach in expanding fertile agricultural land. Near-shore environments of Dokdo Island, a remote island located in the middle of the East Sea, appear to have patches of seawater-influenced haloalkaline soil that is unsupportive for growth of conventional plants. To exploit metabolic capacities of alkali-tolerant bacteria for promoting plant growth in saline or alkaline soils, we isolated of alkali-tolerant bacteria from near-shore soil samples in Dokdo and investigated properties of the isolates. Alkali-tolerant bacteria were selectively cultivated by inoculating suspended and diluted soil samples on a plate medium adjusted to pH 10. Fifty colonies were identified based on their $GTG_5$-PCR genomic fingerprints and 16S rRNA gene sequences. Most isolates were affiliated to alkali-tolerant and/or halotolerant genera or species of the phyla Firmicutes (68%), Proteobacteria (30%) and Actinobacteria (2%). Unlike the typical soil bacterial flora in the island, alkali-tolerant isolates belonged to only certain taxa of terrestrial origin under the three phyla, which have traits of plant growth promoting activities including detoxification, phytohormone production, disease/pest control, nitrogen-fixation, phosphate solubilization or siderophore production. However, Firmicutes of marine origin generally dominated the alkali-tolerant community. Results of this study suggest that haloalkaline environments like Dokdo shore soils are important sources for plant growth promoting bacteria that can be employed in bio-augmentation of vegetation-poor alkaline soils.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.188-192
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• 1989

The promoters from akali-tolerant Bacillus sp. YA-14 chromosomal DMA cloned in B. subtilis using pPL703 were stably transferred to the donor strain. In alkali-tolerant Bacillus sp., the promoters revealed similiar properties with in B. subtilis but were preyed to be more efficient than in B. subtilis comparing with pPL708. Alkali-tolerant Bacillus sp. harboring the recombinant plasmid, p-l2Bl, was abnormally more inducible with chloramphenicol than B. subtilis haying the plasmid. Therefore the host-vector system using this recombinant plasmid and alkali-tolerant Bacillus sp. was expected to be more available.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.429-432
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• 1990

The promoter isolated from chromosomal DNA of an alkali-tolerant Bacillus sp. YA-14 was subcloned and biochemically characterized. Also the relationships between the promoter activity and sporulation were investigated. In alkali-tolerant Bacillus sp. and Bacillus subtilis, the activity of promoter began to increase at the onset of sporulation with the same mode, and repressed in the presence of 1.0% (wtv) glucose. Among five spoO genes, three epoO genes (spoOB, spoH, spoOJ) were required for promoter expression.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.126-130
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• 1988

Promoters of an alkali-tolerant Bacillus sp. isolated from soil have been cloned in Bacillus subtilis using promoter probe vector pPL703. The CAT specific activity of a clone harboring the strongest promoter activity among these transformants was 8.01. This activity was 2.5 times higher than that of Bacillus subtilis harboring expression vector pPL708 and was increased after the end of the logarithmic growth phase. In the 2.8kb of inserted DNA fragment, BamHI and Sal I recognition sites were located.

• Journal of Industrial Technology
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• v.20 no.A
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• pp.39-44
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• 2000

Highly viscous biopolymer from alkali-tolerant Bacillus sp. was purified and its solution properties were investigated. The intrinsic viscosities for crude biopolymer and biopolymers purified by dialysis or CPC(cetylpyridinium chloride) treatment were 58.24, 73.60 and 42.18 dL/g, respectively. The intrinsic viscosity of biopolymer showed the maximum value at the neutral pH but it was decreased remarkably at the alkaline or acidic pH. Biopolymer exhibited the property of polyelectrolyte, showing the sharp decrease of intrinsic viscosity by the addition of NaCl. Intrinsic viscosity of dilute solution at the low NaCl concentration was exponentially dependent on temperature and its temperature dependency was increased with NaCl concentrations. The chain stiffness, coil overlap parameter, and critical concentration were 0.09, 5.25 and 0.07g/dL, respectively. Temperature dependency on intrinsic viscosity of biopolymer solution was different each other at $45^{\circ}C$. Flow activation energies at temperatures above $45^{\circ}C$ were constant, while those at temperatures below $45^{\circ}C$ increased with increase of added NaCl concentration.

• Journal of Microbiology and Biotechnology
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• v.4 no.1
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• pp.41-48
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• 1994

The xylanase from alkali-tolerant Bacillus sp. YA-14 was purified to homogeneity by CM-cellulose, Sephadex G-50, and hydroxyapatite column chromatographies. The molecular weight of the purified enzyme was estimated to be 20, 000 Da by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme slightly hydrolyzed carboxymethyl cellulose and Avicel, but did not hydrolyze soluble starch, dextran, pullulan, and ${\rho}-nitrophenyl-{\beta}$-D-xylopyranoside. The maximum degree of hydrolysis by enzyme for birchwood xylan and oat spelts xylan were 47 and 40%, respectively. The Michaelis constants for birchwood xylan and oat spelts xylan were calculated to be 3.03 mg/ml and 5.0 mg/ml, respectively. The activity of the xylanase was inhibited reversibly by $HgCl_2$, and showed competitive inhibition by N-bromosuccinimide, which probably indicates the involvement of tryptophan residue in the active center of the enzyme. The Xylanase was identified to be xylose-producing endo-type xylanase and did not show the enzymatic activities which cleave the branch point of the xylan structure.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.139-145
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• 1993

The nucleotide sequence of the xylanase gene (xynS) from alkali-tolerant Bacillus sp. YA.14 was determined and analyzed. A 639 base pairs open reading frame for xynS gene was observed and encoded for a protein of 213 amino acids with a molecular weight of 23, 339. S1 nuclease mapping showed that the transcription initiation site of the xynS gene did not exist in the cloned DNA. Ribosome binding site sequence with the free energy of -18.8 Kcal/mol was observed 8 base pairs upstream from the initiation codon, ATG. The proposed signal sequence consisted of 28 amino acids, of which 3 were basic amino acid residues and 21 were hydrophobic amino acid residues. When the amino acid sequences of xylanases were compared, Bacillus sp. YA-14 xylanase showed 48% homology with Bacillus sp. YC-335 xylanase and 96% homology with xylanases from B. subtilis and B. circulans.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.316-319
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• 1988

Pectate Lyase (PL) was cloned from alkali-tolerant Bacillus sp. YA-14 into Escherichia coli MB1000 by inserting HindIII-generated DNA fragment into the HindIII site of pBR322 and then screening recombinant transformant for the ability to hydrolyze sodium polypectate on agar plate, The recombinant plasmid, called pYPC29, was isolated, and the size of the cloned HindIII fragment was found to be 1.6 kb. The PL gene was stablely maintained and expressed efficiently in Escherichia coli. The Pt accumulated largely in the periplasmic space of Escherichia coli clones.

• Korean Journal of Food Science and Technology
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• v.23 no.2
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• pp.161-166
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• 1991

For the production of useful products from microorganism, a bacterial strain producing the biopolymer was isolated from soil. The bacteriological characteristics of the strain were examined and some chemical properties of the biopolymer produced were investigated. The bacterial strain was identified as an alkali-tolerant Bacillus sp. The results of chemical composition, various color reactions and I.R. spectrum revealed that the biopolymer contained high protein content, low amino sugar and no uronic acid. However, the biopolymer was precipitated by treating with cetylpiridinium chloride and was found to be acidic.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.21-24
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• 1991

The promoter isolated from an alkali-tolerant Hwillus sp. chromosomal DNA was subcluned. The activity of promoter in B, subtilis and alkali-tolerant Bacillus sp. began to increase at the early stage. of spore formation. In the presence of 1% glucose, the promotcr activity repressed and was recovered by ;tddition of c-GMP in the medium.