• Animal Bioscience
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• 제36권4호
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• pp.671-678
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• 2023

Objective: Previous studies isolated the thermophilic ammonium-tolerant (TAT) bacterium Bacillus sp. TAT105 that grew in composting swine manure with the assimilation of ammonium nitrogen and reduced ammonia emissions during composting. Those studies also investigated the potential for applications of TAT105 to composting. It was observed that the concentration of TAT bacteria, phylogenetically close to TAT105, increased during composting. The objectives of this study were to identify the phylogenetic placement of these TAT bacteria and investigate their distribution in various composts. Methods: The phylogenetic placement of TAT105 was examined based on the sequence of 16S ribosomal RNA gene. The genomic DNA homology between TAT105 and the type strains of bacterial species that were phylogenetically close to TAT105 were examined by DNA-DNA hybridization. Moreover, the tolerances of these strains to NH₄Cl and NaCl were analyzed using a cultivation method. Concentrations of TAT bacteria in various composts were evaluated using an agar medium specific to TAT bacteria and polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results: TAT105 was most closely related to Bacillus thermolactis and Bacillus kokeshiiformis. Many variants of these species have been detected in various environments, including composts. The type strains of these species displayed TAT characteristics that were similar to those of TAT105. Among the composts examined in this study, TAT bacteria were detected at high concentrations (10⁵ to 10⁹ colony forming units per gram of dry matter) in most of the composts made from cattle manure, swine manure, bark, and excess sludge. Conclusion: TAT bacteria comprised B. thermolactis, B. kokeshiiformis, and their phylogenetically close relatives. They were considered to be adaptable to composting of some certain materials, and a favorable target for searching for strains with some useful function that could be applied to composting of these materials.

• 환경생물
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• 제25권3호
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• pp.260-266
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• 2007

PLLA분해활성을 가진 고온성세균을 우리나라 경작토로부터 분리하였다. 분리된 균주는 그람양성 간균으로 16S rDNA 염기서열분석 결과 Geobacillus caldoxylosilyticus로 동정되었으며, 현재까지 보고되지 않은 새로운 PLLA분해세균으로 밝혀졌다. 조절화된 퇴비화조건에서 멸균퇴비에 분리균주를 접종하고 $58^{\circ}C$에서 40일간 분해활성을 측정하였다. 이 균주는 중량평균 분자량이 5000, 11000, 34000 및 256000인 PLLA5000, PLLA11000, PLLA34000 및 PLLA256000를 각각 66%, 57%, 41%및 40%생분해하였다. PLLA256000을 기질로 하여 gelatin, yeast extract 및 ammonium sulfate를 0.1%씩 첨가하여 분해활성 변화를 조사한 결과 대조군에 비하여 분해활성이 각각 27%, 13% 및 10%증진되었으며, 접종량을 $10^9cfu\;g^{-1}$로부터 $10^{10}cfu\;g^{-1}$ 및 $10^{11}cfu\;g^{-1}$로 증가시킴에 따라 PLLA256000의 생분해도는 각각 14% 및 20% 증가하였다.

• 한국수산과학회지
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• 제47권5호
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• pp.516-521
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• 2014

A bacterium producing ${\alpha}$-galactosidase (${\alpha}$-$\small{D}$-galactoside galactohydrolase, EC 3.2.1.22) was isolated. The isolate, KM-1 was identified as Bacillus coagulans based on its 16S rRNA sequence, morphology, and biochemical properties. ${\alpha}$-Galactosidase activity was detected the culture supernatant of B. coagulans KM-1. The bacterium showed the maximum activity for hydrolyzing para-nitrophenyl-${\alpha}$-$\small{D}$-galactopyranoside (pNP-${\alpha}Gal$) at pH 6.0 and $50^{\circ}C$. It hydrolyzed oligomeric substrates such as melibiose, raffinose, and stachyose liberating a galactose residue, indicating that the B. coagulans KM-1 ${\alpha}$-galactosidase hydrolyzed ${\alpha}$-1,6 linkage. The results suggest that the decreased stachyose and raffinose contents in fermented soybean meal are due to the ${\alpha}$-galactosidase activity.

• BMB Reports
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• 제45권2호
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• pp.91-95
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• 2012

Glutamate dehydrogenase from axenic bacterial cultures of a new microorganism, called GWE1, isolated from the interior of a sterilization drying oven, was purified by anion-exchange and molecular-exclusion liquid chromatography. The apparent molecular mass of the native enzyme was 250.5 kDa and was shown to be an hexamer with similar subunits of molecular mass 40.5 kDa. For glutamate oxidation, the enzyme showed an optimal pH and temperature of 8.0 and $70^{\circ}C$, respectively. In contrast to other glutamate dehydrogenases isolated from bacteria, the enzyme isolated in this study can use both $NAD^+$ and $NADP^+$ as electron acceptors, displaying more affinity for $NADP^+$ than for $NAD^+$. No activity was detected with NADH or NADPH, 2-oxoglutarate and ammonia. The enzyme was exceptionally thermostable, maintaining more than 70% of activity after incubating at $100^{\circ}C$ for more than five hours suggesting being one of the most thermoestable enzymes reported in the family of dehydrogenases.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.680-683
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• 2000

고온성 박테리아인 Hydrogenobacter thermophilus가 생산하는 cytochrome c-552 유전자에 대한 primer를 제작하여 PCR을 통해 증폭한 후 E. coli에 cloning하였다. 또한 point mutagenesis를 통해 fusion protein을 만들기 위한 기초자료를 마련하였다. 앞으로 cytochrome c-552가 E. coli에서 mutant type으로 발현되기 위한 발현벡터의 개발과 이를 정제하는 기술을 개발하는 것이 필요할 것이다.

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 1996년도 정기총회 및 학술발표회
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• pp.30-30
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• 1996

A suproxide dismutase gene of Aquifex pyroprolus, a novel marine hypenhermophilic bacterium, was cloned, expressed, and characterized. The SOD of A pyrophilus (ApSOD) is an iron-containing homo-oligomeric protein with a monomeric molecular weight of 24.2 kDa. the amino acid sequence is similar to those of known Mn- and Fe-SODs from thermophilic archaea, and metal binding residues in all SOD sequences from different species are also conserved in A. pyrophilus SOD. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제26권11호
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• pp.1651-1658
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• 2013

Nitrate contamination in ground and surface water is an increasingly serious environmental problem and only a few bacterial strains have been identified that have the ability to remove nitrogen pollutants from wastewater under thermophilic conditions. We therefore isolated thermophilic facultative bacterial strains from wood chips that had been composted with swine manure under aerated high temperature conditions so as to identify strains with denitrifying ability. Nine different colonies were screened and 3 long rod-shaped bacterial strains designated as SG-01, SG-02, and SG-03 were selected. The strain SG-01 could be differentiated from SG-02 and SG-03 on the basis of the method that it used for sugar utilization. The 16S rRNA genes of this strain also had high sequence similarity with Geobacillus thermodenitrificans $465^T$ (99.6%). The optimal growth temperatures ($55^{\circ}C$), pH values (pH 7.0), and NaCl concentrations (1%) required for the growth of strain SG-01 were established. This strain reduced 1.18 mM nitrate and 1.45 mM nitrite in LB broth after 48 h of incubation. These results suggest that the G. thermodenitrificans SG-01 strain may be useful in the removal of nitrates and nitrites from wastewater generated as a result of livestock farming.

• BMB Reports
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• 제32권5호
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• pp.480-485
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• 1999

Tyrosine phenol-lyase of thermophilic Symbiobacterium sp. SC-1, which is obligately and symbiotically dependent on thermophilic Bacillus sp. SK-1, was purified and characterized. The enzyme is composed of four identical subunits and contains approximately 1 mol of pyridoxal 5'-phosphate (PLP) per mol subunit as a cofactor. The enzyme showed absorption maxima at 330 and 420 nm, and lost this absorption profile by treatment with phenylhydrazine. The apparent dissociation constsnt, $K'_D$, for PLP was determined with the apoenzyme to be about $1.2\;{\mu}M$. The isoelectric point was 4.9. The optimal temperature and pH for the $\alpha,\beta$-elimination of L-tyrosine were found to be $80^{\circ}C$ and pH 8.0, respectively. The substrate specificity of the enzyme was very broad: L-amino acids including L-tyrosine, 3,4-dihydroxyphenyl-L-alanine (L-DOPA), L-cysteine, L-serine, S-methyl-L-cysteine, $\beta$-chloro-L-alanine, and S-(o-nitrophenyl)-L-cysteine all served as substrates. D-Tyrosine and D-serine were also decomposed into pyruvic acid and ammonia at rates of 7% and 31% relative to their corresponding L-enantiomers, respectively. D-Alanine, which was inert as a substrate in a, $\beta$-elimination, was the only D-amino acid racemized by the enzyme. The $K_m$ values for L-tyrosine, L-DOPA, S-(o-nitrophenyl)-L-cysteine, $\beta$-chloro-L-alanine, and S-methyl-L-cysteine were 0.19, 9.9, 0.36, 12, and 5.5 mM, respectively.

• KSBB Journal
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• 제28권5호
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• pp.332-337
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• 2013

호열성 진정세균인 Thermotoga maritima의 xylose isomerase 유전자를 대장균을 이용하여 클로닝하고 재조합 발현시켰다. 재조합 효소의 최적활성은 $90^{\circ}C$와 pH 8.0에서 관찰되었다. 사포닌을 재조합효소로 처리한 후 사람의 위암 세포주 (AGS)와 대장암 세포주 (HT-29)에 처리한 결과, 효소 무처리 사포닌에 비해 우수한 암세포 생육저해 활성을 나타냈다. 한편, 푸코이단을 재조합효소로 처리한 후 동일 세포주들에 처리한 결과, 효소 무처리 푸코이단과 비슷한 암세포 생육저해 활성을 보였다. 1 ${\mu}g/ml$ 농도의 효소 처리 사포닌은 100 ${\mu}g/ml$ 농도의 효소 무처리 사포닌과 유사하거나 우수한 암세포 생육저해 활성을 보였다. 본 연구결과는 기능성 식품이나 의약품의 개발에 참고가 될 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제22권5호
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• pp.637-641
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• 2012

TPDex, a putative dextranase from Thermoanaerobacter pseudethanolicus, was purified as a single 70 kDa band of 7.37 U/mg. Its optimum pH was 5.2 and the enzyme was stable between pH 3.1 and 8.5 at $70^{\circ}C$. A half-life comparison showed that TPDex was stable for 7.4 h at $70^{\circ}C$, whereas Chaetominum dextranase (CEDex), currently used as a dextranase for sugar milling, was stable at $55^{\circ}C$. TPDex showed broad dextranase activity regardless of dextran types, including dextran T2000, 742CB dextran, and alternan. TPDex showed the highest thermostability among the characterized dextranases, and may be a suitable enzyme for use in sugar manufacture without decreased temperature.