• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.490-496
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• 2008

Symbiobacterium toebii is a commensal symbiotic thermophile that cannot grow without support from a partner bacterium. We investigated the properties of Symbiobacterium growth-supporting factors (SGSFs) produced by the partner bacterium Geobacillus toebii. SGSFs occurred in both the cell-free extract (CFE) and culture supernatant of G. toebii and might comprise multifarious materials because of their different biological properties. The heavy SGSF contained in the cytosolic component exhibited heat- and proteinase-sensitive proteinaceous properties and had a molecular mass of >50 kDa. In contrast, the light SGSF contained in the extracellular component exhibited heat-stable, proteinase-resistant, nonprotein properties and had a molecular mass of <10 kDa. Under morphological examination using light microscopy, S. toebii cultured with the culture supernatant of G. toebii was filamentous, whereas S. toebii cultured with the CFE of G. toebii was rod-shaped. These results strongly suggest that the SGSFs produced by G. toebii comprise two or more types that differ in their growth-supporting mechanisms, although all support the growth of S. toebii. Upon the examination of the distribution of SGSFs in other bacteria, both cytosolic and extracellular components of Geobacillus kaustophilus, Escherichia coli, and Bacillus subtilis had detectable growth-supporting effects for S. toebii, indicating that common SGSF materials are widely present in various bacterial strains.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2001년도 추계학술대회
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• pp.46-53
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• 2001

A commensal thermophile, Symbiobacterium toebii, isolated from hay compost (toebii) in Korea commensally interacted with a thermophilic Geobacillus toebii sp. nov., which was a new species within the genus Geobacillus on the basis of the phenotypic traits and molecular systematic data. S. toebii required the crude extracts and/or culture supernatant of the Geobacillus toebii for axenic growth and could grow on the temperature between 45 and $70^{\circ}C$ (optimum: $60^{\circ}C$; 2.4 h doubling time) and pH 6.0 and 9.0 (optimum: pH 7.5). The G+C content of the genomic DNA was $65 mol\%$, and the major quinones were MK-6 and MK-7. A phylogenetic analysis of its 16S rDNA sequence indicated that Symbiobacterium toebii was closely related with solely reported Symbiobacterium thermophilum. The presence of the commensal thermophile 16S rDNA and accumulation of indole in all the enriched cultures indicate that Symbiobacterium toebii is widely distributed in the various soils. The genome of S. toebii constituted a circular chromosome of 3,280,275 base pairs and there was not an extra-chromosomal element (ECE). It contained about 4,107 predicted coding sequences. Of these protein coding genes, about $45.6\%$ was encoded well-known proteins and annotated the functional assignment of 1,874 open reading frames (ORFs), and the rest predicted to have unknown functions. The genes encoding thermostable tyrosine phenol-lyase and tryptophan indole-lyase were cloned from the genomic DNA of S. toebii and the enzymatic production of L-tyrosine and L-tryptophan was carried out with two thermostable enzymes overexpressed in recombinant E. coli.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.611-615
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• 2008

Novel groups of uncultivable anaerobic thermophiles were isolated from compost by enrichment cultivation in medium with a cell-free extract of Geobacillus toebii. The cell-free extract of G. toebii provided the medium with growth-supporting factors (GSF) needed to cultivate the previously uncultured microorganisms. Twenty-nine GSF-requiring candidates were successfully cultivated, and 16 isolated novel bacterial strains were classified into three different groups of uncultivable bacteria. The similarity among these 16 isolates and a phylogenetic analysis using 16S rRNA gene sequences revealed that these GSF-requiring strains represented novel groups within the family Clostridiaceae.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.1008-1012
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• 2003

Symbiobacterium toebii has been reported as a thermophile exhibiting a commensal interaction with Geobacillus toebii. The distribution of the commensal thermophiles in various soils was investigated using a denaturing gradient gel electrophoresis (DGGE). Based on the DGGE analysis, the enrichment condition for the growth of Symbiobacterium sp. was found to also enrich populations of several other microbial spp. as well as Symbiobacterium sp. In the enrichment experiment, several different 16S rDNA sequences of commensal thermophiles were detected in all of the soil samples tested, indicating that commensal thermophiles are widely distributed in various soils.

• 한국미생물·생명공학회지
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• 제35권1호
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• pp.11-16
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• 2007

Pseudoalteromonas carrageenovora 유래의 arylsulfatase 유전자는 PCR로 증폭한 후 Geobacillus toebii의 D-amino acid aminotransferase(D-ATT) 유전자 유래의 구성적 발현 promoter를 함유하는 pHCE-IA vector로 subcloning 하였다. 4-Methylumbelliferyl sulfate가 포함된 LB 평판배지 상에서 자란 형질전환체 Escherichia coli BL2l (DE3)/pHCE-AST는 360 nm상에서 4-methylumbellifrrone에 의한 강한 형광을 보였고, 이는 대장균에서 arylsulfatase가 활성형으로 생산되었음을 의미하였다. E. coli BL21 (DE3)/pHCE-AST를 0.4% glycerol 또는 0.4% glucose가 포함된 LB 배지로 배양했을 때 arylsulfatase활성은 glycerol이 포함된 배지에서 활성이 더 높게 나타났다. 2% glycerol이 포함된 LB배지에서 arylsulfatase 활성은 약 15.0 unit/ml에 달했으며, 이는 1% glycerol을 첨가해서 배양했을 때보다 2.6배 이상의 높은 발현 수준이였다. 재조합 arylsulfatase 효소로 제조된 agarose와 시판용 agarose를 DNA markers를 이용해서 전기영동 성능을 비교했을 때 우수한 이동성과 분리능을 보였다. 본 연구의 결과, E. coli에서 과발현 생산된 arylsulfatase 효소를 이용하여 전기영동용 고순도 agarose생산 공정에 적용 가능함을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.940-945
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• 2001

Symbiobacterium toebii has been previously reported as a novel commensal thermophile exhibiting a commensal interaction with thermophilic Geobacillus sp. SK-1. We investigated the distribution of this commensal thermophile in various soils using molecular methods, such as quantitative PCR and terminal restriction fragment polymorphism analysis. Based on a nested competitive quantitative PCR the 16S rDNA of the commensal thermophile was only detected in compost soils at about $1.0{\times}10^4$ cpoies per gram of soil, corresponding to $0.25{\times}10^4$ cells per gram of soil. However, in an enrichment experiment at $60^{\circ}C$, about $1.0{\times}10^8$ copies of 16S rDNA molecules were detected per ml of enriched culture broth for all the soils, and more than 0.1 mM indole accumulated as the product of commensal bacterial growth. When incubated at $30^{\circ}C$, neither the 16S rDNA of the commensal bacterium nor any indole accumulation was detected. Accordingly, even though the 16S rDNA of the bacterium was only detected in the compost soils by a nested PCR, the presence of the 16S rDNA molecules of commensal thermophile and accumulation of indole in all the enriched cultures appeared to indicate that the commensal thermophile is widely distributed in various soils.