• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1210-1214
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• 2010

Many bacteria are involved in the fermentation of doenjang, and Bacillus species are known to perform significant roles. Although SDS-PAGE has been frequently used to classify and identify bacteria in various samples, the microbial diversity in doenjang has not yet been investigated. This study aims to determine the identity and distribution of dominant Bacillus species in doenjang using SDS-PAGE profiles of whole-cell proteins and 16S rRNA gene sequencing. Reference Bacillus strains yielded differential SDS-PAGE banding patterns that could be considered to be highly specific fingerprints. Grouping of bacterial strains isolated from doenjang samples by whole-cell protein patterns was confirmed by analysis of their 16S rRNA gene sequences. B. subtilis was found to be the most dominant strain in most of the samples, whereas B. licheniformis and B. amyloliquefaciens were less frequently found but were also detected in several samples. The results obtained in this study show that a combined identification method using SDS-PAGE profiles of whole-cell proteins and subsequent 16S rRNA gene sequence analysis could successfully identify Bacillus species isolated from doenjang.

• KSBB Journal
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• 제19권3호
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• pp.200-205
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• 2004

반월공단의 염색폐수와 염료폐수를 균원시료로 하여 반응성 염료의 색도제거능이 나타난 13종의 균주를 분리하고, 산소농도에 따른 영향을 살펴보기 위하여 교반에 따른 색도제거율을 살펴 본 결과, 교반을 진행하지 않은 경우 효율이 더 높은 효율을 얻을 수 있었다. 또한, 5가지 반응성 염료 (reactive blue 19, reactive blue 21, reactive red 180, reactive red 195, reactive yellow 145)를 가지고 색도제거 실험을 진행한 결과 2종의 균주가 높은 효율을 보였다. 이 2종의 균주를 동정한 결과 Bacillus anthracis와 Bacillus cereus로 판명되었다. 최적 조건을 살펴보기 위하여 온도와 초기 pH 영향에 따른 색도 제거율을 알아보기 위하여 실험을 진행한 결과 35$^{\circ}C$, pH 7에서 높은 색도제거율을 보였다. 또한 탄소원과 질소원에 따른 영향을 살펴보기 위하여 Bacillus anthracis로 실험한 결과 glucose, yeast extract를 사용한 경우 89%의 높은 색도 제거율을 얻을 수 있었다. 이러한 결과로 미루어 볼 때 분리된 두 균주는 염색폐수의 색도제거에 효과적인 균주라고 사료된다.

• 한국식품영양과학회지
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• 제32권3호
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• pp.413-417
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• 2003

빵 부패미 생물에 대한 녹차추출물의 항균활성을 조사하고 녹차가루를 첨가한 찐빵의 저장 중 항균효과를 알아보고자 하였다. 사용된 세균 3종류인 Bacillus subtilis ARCC 6633, Bacillus pumilus KCTC 3348, Bacillus cereus IFO 12113과 곰팡이 Aspergillus niger KCCM l1239 모두 GTE 1% 이상에서 우수한 항균력을 가지고 있으며, 생육이 억제됨을 확인하였다. GTE의 열 안정성은 넓은 온도 범위(50~20$0^{\circ}C$)에서 열을 가하지 않았을 때와 동일하게 항균력이 유지되었고, pH 사용범위 (4~9)에 관계없이 동일한 환으로 항균력을 나타내었다. 녹차를 첨가한 찐빵을 $25^{\circ}C$에 저장하면서 총 곰팡이 수와 총 세균 수를 측정한 결과 대조군, GTP 1%, 3% 첨가군 모두 저장 3일째에 곰팡이가 나타났으나 GTP 5% 첨가군에서는 저장 3일째에 나타났다. 총 세균 수는 저장 3일 이후 $10^{7}$ CFU/g을 넘어 부패가 진행 중이었으나 GTP 3%는 5일째에, GTP 5% 첨가군은 7일째에 $10^{7}$ CFU/g을 나타났다. 그러므로 찐빵에서의 녹차의 항균 효과에 따른 저장기간 연장은 녹차가루 첨가량 5% 이상의 수준에서 가능하리라고 추측된다.

• 한국식품과학회지
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• 제24권5호
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• pp.477-481
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• 1992

품질이 좋은 된장을 제조하기 위한 연구의 일환으로 재래식 된장과 Aspergillus oryzae와 Bacillus natto를 혼합한 된장을 제조해서 발효기간에 따른 대두조직의 변화를 조사한 결과 가압, 가열처리에 의하여 세포벽이 붕괴되거나 ghost 상태를 보였고 표피부와 내부의 세포질은 원형질 분리가 현저한 차이가 있으며 protease에 의한 당단백 구상체의 융합과 amylase에 의하여 전분이 분해되어 작은 공포를 보였으며 발효에 의한 균침투 과정이 시일이 경과함에 따라 표피부에서 내부로 이행되어지며 Aspergillus oryzae와 Bacillus natto 혼합 된장의 표피부와 유세포에서 점질물이 보인다. 또한 발효시간이 경과함에 따라 염색성이 나빠지고 세포벽이 다각형으로 되는데 재래식 보다는 Aspergillus oryzae와 Bacillus natto 혼합구가 현저하였다.

• 한국잠사곤충학회지
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• 제34권1호
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• pp.41-48
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• 1992

해충의 미생물적 방제를 위하여 Bacillus thuringiensis 살충제(BT제) 개발에 관한 기초자료를 얻고자 3균주의 공시균주인 B. thuringiensis var. kurstaki, B. thuringiensis var. dendrolimus, B. thuringiensis var. aizawai와 3종의 공시충으로 누에, 흰불나방, 배추흰나비의 유충을 이용하고 B. thuringiensis 내독소단백질을 alkalidyddor 또는 공시된 3종의 곤충소화액으로 처리하여 전기영동을 비교하여 아래와 같은 결과를 얻었다. 1. 3균주의 B. thuringiensis에서 생산된 내독소단백질은 alkali 또는 곤충의 소화액 처리에 따라서 변화되는 뚜렷한 차이가 없는 것으로 나타났다. 2. 각 균주의 내독소단백질의 분자량은 B. thuringiensis var. aizawai가 130kDa, B. thuringiensis var. kurstaki가 140kDa, 130kDa, 그리고 B. thuringiensis var. dendrolimus가 140kDa의 부분에 2band로 나타났으며, 이들 내독소단백질은 alkali 용액이나 숙주곤충의 소화액으로 처리시 활성화되어 40-65kDa의 저분자 단백질로 전환되었다. 또한 숙주곤충소화액에 따라 내독소단백질의 활성화 속도에 약간의 차이가 있는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.290-295
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• 1994

30 monoclonal antibodies (mAbs) were produced against Bacillus thuringiensis subsp. canadensis. Out of the these, 6 mAbs were selected for further studies. SDS-PAGE analyses of sonicated antigens of 10 8. thuringiensis strains showed that they generally had both predominant protein antigens of molecular weights of 45 kilodalton (kd) except for shandogiensis and konkukian, and 37kd except for israelensis, tochigiensis, and shandogiensis, respectively. These results indicate that 4kd and 37kd may be important for demonstrating common antigens except for a few strains of B. thuringiensis. In comparing the result of the westem blot using mAbs with that of using polyclonal antibodies to canadensis, we found that immunoreactive proteins of 99 and 39 kd were identified as common antigens, which might act as antigenic determinants, and might be surface or flagella antigens. Reactivities of mAbs with 41 strains of 8. thuringiensis demonstrated that mAbs of C-1, C-3, C-4, C-S and C-6 except C-2 did not recognize epitopes of thuringiensis, but that all of the mAbs recognized epitopes of galleriae, kurstaki, dakota, tolrJokuensis, silo, toguchini, and leesis. The potential applications of the mAbs we produced would be useful tools for the clarification of taxonomy, investigation of antigenic relationship between B. thuringiensis strains, and localization of specific surface and flagella antigens.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.457-460
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• 2002

In an effort to isolate novel strains expressing a thermostable esterase that hydrolyzed the rac-ketoprofen ethyl ester to ketoprofen in the stereospecific manner, we screened various soils and composts from broad ecological niches in which the activity was expected to be found. Three hundreds of microbial strains were tested to determine their ester-hydrolyzing activity by using an agar plate containing insoluble tributyrin as an indicative substrate, and then further screened by activity on the (R,S)-ketoprofen ethyl ester. Twenty-six strains were screened primarily at high growth and incubation temperature and further compared the ability to ethyl ester-hydrolyzing activity in terms of conversion yield and chiral specificity. Consequently, a strain JYl44 was isolated as a novel strain that produced a (R)-stereospecific esterase with high stability and systematically identified as a Bacillus stearothermophilus JY144. The enzyme indeed stables at a broad range of temperature, upto 65 $^{\circ}C$, and pH ranging from 6.0 to 10.0. The optimal temperature and pH for enzymatic conversion were 50 $^{\circ}C$ and 9.0, respectively. Based on the observations that resulted a poor cell growth, and enzyme expression in wild type strain, we further attempted the gene cloning into a general host Escherichia coli and determined its primary structure, concomitantly resulting a high level expression of the enzyme. The cloned gene had an open reading frame (250 amino acids) with a calculated molecular mass of 27.4 kDa, and its primary structure showed a relative high homology (45-52 %) to the esterases from Streptomyces and Bacillus strains. The recombinant whole cell enzyme could efficiently convert the rac-ketoprofen ethyl ester to (R)-ketoprofen, with optical purity of 99 % and yield of 49 %.

• 한국축산식품학회지
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• 제31권2호
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• pp.311-315
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• 2011

The objective of this study was to evaluate the antimicrobial effects of various natural flavonoids against growth of psychotropic Bacillus cereus strains, which cause dairy food outbreaks. Flavonoids were first screened for their ability to inhibit growth of B. cereus strains using the paper-disc diffusion test. Second, the growth inhibitory effect of selected flavonoids was evaluated in tryptic soy broth supplemented with 0.6% yeast extract, and the bactericidal effect of the flavonoids was measured in 0.8% (w/v) NaCl solution. Based on the paper-disc diffusion test, kaempferol was effectively active against B. cereus P14 and B. cereus KCCM 40935. Kaempferol had an antimicrobial effect at concentrations greater than 100 ${\mu}M$, and the numbers of B. cereus P14 and B. cereus KCCM 40935 decreased by 3.55 and 1.5 log cycles, respectively. The cell numbers of B. cereus P14 and B. cereus KCCM 40935 treated with 50 ${\mu}M$ kaempferol were reduced by 4.18 and 2.84 log cycles during a 24 h incubation to test the bactericidal effect of kaempferol (p<0.05). The results indicate that kaempferol had the greatest antimicrobial effect among the psychotropic B. cereus strains and the natural flavonoids tested.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.125-131
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• 2019

We have isolated and identified 72 bacterial strains from four bentonite samples collected at the mining areas located in Gyeongsangbuk-do, Republic of Korea, and measured their hydrolytic enzyme (${\alpha}$-amylase, protease, and cellulase) activities to identify the isolates with industrial-use potential. Most of the isolates belonged to the Bacillaceae, with minor portions being from the Paenibacillaceae, Micrococcaceae, and Bacillales Family XII at the family level. Of the strains isolated, 33 had extracellular ${\alpha}$-amylase activity, 30 strains produced cellulase, and 35 strains produced protease. Strain MBLB1268, having the highest ${\alpha}$-amylase activity, was identified as Bacillus siamensis ($0.38{\pm}0.06U/ml$). Bacillus tequilensis MBLB1223, isolated from Byi33-b, showed the highest cellulase activity ($0.26{\pm} 0.04U/ml$), whereas Bacillus wiedmannii MBLB1197, isolated from Zdb130-b, exhibited the highest protease activity ($54.99{\pm}0.78U/ml$). These findings show that diverse bacteria of the Bacillaceae family adhere to and exist in bentonite and are potential sources of industrially useful hydrolytic enzymes.

• 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.