• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.147-153
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• 2011

Bacillus species have been involved in metal association as biosorbents, but there is not a clear understanding of this chelating property. In order to evaluate this metal chelating capacity, cultures and spores from Grampositive bacteria of species either able or unable to produce surface layer proteins (S-layers) were analyzed for their capacity of copper biosorption. Only those endowed of S-layers, like Bacillus sphaericus and B. thuringiensis, showed a significant biosorption capacity. This capacity (nearly 50%) was retained after heating of cultures, thus supporting that structural elements of the envelopes are responsible for such activity. Purified S-layers from two Bacillus sphaericus strains had the ability to biosorb copper. Copper biosorption parameters were determined for strain B. sphaericus 2362, and after analyses by means of the Langmuir model, the affinity and capacity were shown to be comparable to other bacterial biosorbents. A competitive effect of $Ca^{2+}$ and $Zn^{2+}$, but not of $Cd^{2+}$, was also observed, thus indicating that other cations may be biosorbed by this protein. Spores that have been shown to be proficient for copper biosorption were further analyzed for the presence of S-layer content. The retention of S-layers by these spores was clearly observed, and after extensive treatment to eliminate the S-layers, the biosorption capacity of these spores was significantly reduced. For the first time, a direct correlation between S-layer protein content and metal biosorption capacity is shown. This capacity is linked to the retention of S-layer proteins attached to Bacillus spores and cells.

• The Plant Pathology Journal
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• 제31권2호
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• pp.152-164
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• 2015

Biological control of major rice diseases has been attempted in several rice-growing countries in Asia during the last few decades and its application using antagonistic bacteria has proved to be somewhat successful for controlling various fungal diseases in field trials. Two novel endophytic Bacillus species, designated strains YC7007 and $YC7010^T$, with antimicrobial, plant growth-promoting, and systemic resistance-inducing activities were isolated from the roots of rice in paddy fields at Jinju, Korea, and their multifunctional activities were analyzed. Strain YC7007 inhibited mycelial growth of major rice fungal pathogens strongly in vitro. Bacterial blight and panicle blight caused by Xanthomonas oryzae pv. oryzae (KACC 10208) and Burkholderia glumae (KACC 44022), respectively, were also suppressed effectively by drenching a bacterial suspension ($10^7cfu/ml$) of strain YC7007 on the rhizosphere of rice. Additionally, strain YC7007 promoted the growth of rice seedlings with higher germination rates and more tillers than the untreated control. The taxonomic position of the strains was also investigated. Phylogenetic analyses based on 16S rRNA gene sequences indicated that both strains belong to the genus Bacillus, with high similarity to the closely related strains, Bacillus siamensis KACC $15859^T$ (99.67%), Bacillus methylotrophicus KACC $13105^T$ (99.65%), Bacillus amyloliquefaciens subsp. plantarum KACC $17177^T$ (99.60%), and Bacillus tequilensis KACC $15944^T$ (99.45%). The DNA-DNA relatedness value between strain $YC7010^T$ and the most closely related strain, B. siamensis KACC $15859^T$ was $50.4{\pm}3.5%$, but it was $91.5{\pm}11.0%$ between two strains YC7007 and $YC7010^T$, indicating the same species. The major fatty acids of two strains were anteiso-$C_{15:0}$ and iso $C_{15:0}$. Both strains contained MK-7 as a major respiratory quinone system. The G+C contents of the genomic DNA of two strains were 50.5 mol% and 51.2 mol%, respectively. Based on these polyphasic studies, the two strains YC7007 and $YC7010^T$ represent novel species of the genus Bacillus, for which the name Bacillus oryzicola sp. nov. is proposed. The type strain is $YC7010^T$ (= KACC $18228^T$). Taken together, our findings suggest that novel endophytic Bacillus strains can be used for the biological control of rice diseases.

• Journal of Biosystems Engineering
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• 제43권4호
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• pp.394-400
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• 2018

Purpose: This research evaluated five types of nanoparticles to develop a surface-enhanced Raman spectroscopy (SERS) method for the rapid detection of two Bacillus species (Bacillus cereus and Bacillus thuringiensis) that are commonly found on fresh produce, which can cause food poisoning. Methods: Bacterial concentrations were adjusted to a constant turbidity, and a total of $30{\mu}L$ of each Bacillus cell suspension was prepared for each nanoparticle. A point-scan Raman system with laser light source of wavelength 785 nm was used to obtain SERS data. Results: There was no qualitative difference in the SERS data of B. cereus and B. thuringiensis for any of the five nanoparticles. Three gold nanoparticles, stabilized in either citrate buffer or ethanol, showed subtle differences in Raman intensities of two Bacillus species at $877.7cm^{-1}$. Conclusions: Among the three types of nanoparticles, the gold nanoparticles stabilized in citrate buffer showed the lowest standard deviation, followed by gold nanoparticles stabilized in ethanol. This result supports the potential application of gold nanoparticles for SERS-based detection of B. cereus and B. thuringiensis.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.498-508
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• 2019

Bacillus species were isolated from iru, a traditional fermented condiment in Nigeria. Polyphasic approach was used to evaluate the phylogenetic relationship and strain sub-type of the isolated species. Additionally, the phylogenetic profiles of the species isolated from iru were compared with those of bacilli isolated from different continents. The phylogenetic diversity analysis was performed using the combination of 16S rRNA gene sequencing, ITS-PCR, ITS-PCR-RFLP, and M13 RAPD-PCR. The analysis revealed that Bacillus subtilis U170B and B. subtilis U146A isolated from iru were the closest relatives of strains belonging to the phylogeny of B. subtilis sensu stricto and were related to other bacilli isolated from different continents that had functional benefits. The two isolated species exhibited resistance to acidic pH (pH 2.0). The survival rates of B. subtilis U170B, B. subtilis U146A, and B. clausii UBBC-07 (commercial probiotic strain) cultured at pH 2.0 for 3 h were 33.45, 12.44, and 9.53%, respectively. The strains were highly tolerant to bile salts [0.3% (w/v)]. B. subtilis U170B exhibited the highest cell viability (43.45%) when cultured for 3 h in the presence of bile salts, followed by B. subtilis U146A (25%) and B. clausii UBBC-07 (18.94%). B. subtilis U170B and B. subtilis U146A did not exhibit haemolytic activity and were susceptible to different antibiotics. Additionally, these two strains exhibited weak antagonistic activity against B. cereus. The diverse wild strains of B. subtilis can be used as a safe multifunctional starter culture for the industrial production of condiments with health benefits.

• 산업기술연구
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• 제37권1호
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• pp.16-20
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• 2017

A new putative laccase gene (soncotA) which show 78% homology with that from Bacillus licheniformis (liccotA) was isolated from draft genome sequence of Bacillus sonorensis KCTC 13918. A 1,545 bp of PCR product corresponding 514 amino acids was cloned into NdeI-NotI site of pET21c and expressed as soluble form in E. coli. About 59 kDa size of recombinant laccase was purified into homogenity by Ni-NTA column and laccase activity was confirmed by zymography. The enzymatic properties of recombinant laccase were characterized. The specific activity of B. sonorensis laccase was 0.033 fold lower than that of Bacillus licheniformis laccase. The finding of new laccase gene broadened the enzymatic diversity of Bacillus species laccases.

• 대한미생물학회지
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• 제35권1호
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• pp.31-40
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• 2000

Bacillus anthracis, the etiological agent of anthrax has been classified into the Bacillus subgroup I with B. cereus, B. mycoides and B. thuringiensis based on morphological and DNA similarity. DNA studies have further indicated that these species have very AT-rich genomes and high homology, indeed it has been proposed that these four sub-species be recognized as members of the one species. Several methods have been developed to obtain good differentiation between these species. However, none of these methods provides the means for an absolutely correct differntiation. The analysis of fatty acid methyl esters (FAMEs) was employed as a quick, simple and reliable method for the identification of 21 B. anthracis strains and closley related strains. The most significant differences were found between B. anthracis and B. anthracis closely related strains in FAMEs profiles. All tested strains of B. anthracis had a branched fatty acid C17:1 Anteiso A, whereas the fraction of unsaturated fatty acid Iso C17:1 w10c was found in B. anthracis closely related strains. By UPGMA clustering analysis of FAMEs profiles, all of the tested strains were classified into two clusters defined at Euclidian distance value of 24.5. The tested strains of B. anthracis were clustered together including Bacillus sp. Kyungjoo 3. However, the isolates of B. anthracis closely related spp. Rho, S10A, 11R1, CAU9910, CAU9911, CAU9912 and CAU9913 were clustered with the other group. On the basis of these results, isolates of B. anthracis Bongchon, Kyungjoo 1, 2 and Bacillus sp. Kyungjoo 3 were reclassified as a B. anthracis. It is concluded that FAMEs analysis provides a sensitive and reliable method for the identification of B. anthracis from closely related taxa.

• Food Science and Biotechnology
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• 제18권4호
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• pp.1046-1050
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• 2009

Our previous study showed that isoflavone profile of soybean undergoes a significant change during cheonggukjang preparation. In particular, the content of metabolite(s) with similar retention time to glycitein under the high performance liquid chromatography (HPLC) condition was significantly increased while the levels of genistein and its derivatives were notably lowered. Therefore, we hypothesized that genistein and its derivatives might be converted to genistein glucosides with similar elution time to glycitein. Our current data suggest that genistein and its derivatives are extensively metabolized into various compounds including genistein glycosides, but not glycitein or its derivatives, by Bacillus species isolated from traditional cheonggukjang. Some of daidzein was also converted into a derivative with shorter retention time by Bacillus amyloliquefaciens 51 and 86-1 but not by Bacillus subtilis 3-5 and 3-17. As metabolism of soy isoflavones, major health-promoting components in soy products, is widely variable depending upon Bacillus species, it is essential to select microorganism that minimizes the breakdown or modification of soy isoflavones in the process of fermented soy product manufacture.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.437-443
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• 2013

The diversity of culturable non-actinobacterial (NA) bacteria associated with four species of South China Sea gorgonians was investigated using culture-dependent methods followed by analysis of the bacterial 16S rDNA sequence. A total of 76 bacterial isolates were recovered and identified, which belonged to 21 species of 7 genera, and Bacillus was the most diverse genus. Fifty-one percent of the 76 isolates displayed antibacterial activities, and most of them belonged to the Bacillus genus. From the culture broth of gorgonian-associated Bacillus methylotrophicus SCSGAB0092 isolated from gorgonian Melitodes squamata, 11 antimicrobial lipopeptides including seven surfactins and four iturins were obtained. These results imply that Bacillus strains associated with gorgonians play roles in coral defense mechanisms through producing antimicrobial substances. This study, for the first time, compares the diversity of culturable NA bacterial communities among four species of South China Sea gorgonians and investigates the secondary metabolites of gorgonian-associated B. methylotrophicus SCSGAB0092.

• The Korean Journal of Ecology
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• 제22권1호
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• pp.51-58
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• 1999

자생식물과 귀화식물을 대상으로 allelochemicals를 분석하고 그 항균효과를 조사하였다. 자생식물과 귀화식물 추출액 간의 가용성 고형물 함량에는 차이를 보이지 않았고 자생식물인 까마중의 가용성 고형물 함량이 90 mg/ml로 가장 높게 나타났다. 자생식물의 에탄을 추출액에 의한 Aspergillus phoenicis KCTC 1228의 항균력은 까마중에서만 나타났으며 clear zone이 18 mm였고 포자형성은 억제되었다. 귀화식물 중 돼지풀과 망초에서 포자형성이 억제되면서 clear zone이 24 mm와 22 mm로 형성되었고 미국자리공과 원추천인국은 포자가 형성되면서 clear zone이 22 mm와 19 mm로 나타났다. 자생식물인 까마중과 귀화식물인 미국자리공과 돼지풀에서 토양미생물인 Bacillus sphiaericus 2362와 Bacillus sphiaericus 2291, Bacillus thuringiensis var. subtilis와 Bacillus thuringiensis var. cereus에서 항균력이 나타났는데 돼지풀이 각 균주에서 항균활성이 가장 크게 나타났다. 특히 Bacillus thuringiensis var. subtilis에서 clear zone이 32 mm로 활성이 강하게 조사되었다. 일반적으로 추출액내의 가용성 고형물 함량이 높을수록 항균 활성이 크게 나타남을 알 수 있다. 자생식물인 까마중과 귀화식물인 미국자리공과 돼지풀의 추출액을 HPLC로 성분분석한 결과 까마중은 hydroquinone외 3종이, 미국자리공은 cinnamic acid외 5종이, 돼지풀은 benzoic acid외 7종이 분석되었다. Phenolic compound 각각에 대한 Aspergillus phoenicis KCTC 1228에 대한 항균력은 coumaric acid와 benzoic acid에서 조사되었다.

• 한국식품과학회지
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• 제23권2호
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• pp.200-204
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• 1991

31종의 식물에서 필요 부위를 선정하여 75% 에탄올이나 물로 추출하여 얻은 추출물로서, 일반적으로 식품의 부패 혹은 변질에 관여한다고 알려진 Bacillus subtilis, Lactobacillus plantarum, Leuconostoc mesenteroides, Pseudomonas fluorescens, Bacillus cereus 등 5종의 세균과 Saccharomyces cerevisiae 등 1종의 효모를 대상으로 항균성을 시험하였다. 실험대상 6종의 모든 미생물에 대하여 항균성을 나타낸 것은 황백의 에탄올 추출물이었으며 산초, 참깨묵, 지치, 졸참나무는 효모를 제외한 5종에 대하여 댓잎, 오동나무, 리기다는 B. subtilis 및 S. cerevisiae 혹은 L. mesenteroides 및 S. cerevisiae 또는 L. mesenteroides 및 P. fluorescens, B. cereus를 각각 제외한 4종에 대하여 항균성을 나타냈고, 균종에 따라 약간의 차이는 있었지만 황백이 가장 높은 항균성을 보였다. B subtilis, L. plantarum 및 L. mesenteroides에는 황백이, P. fluorescens에는 황백과 오배자가 disc diffusion method에서 가장 높은 항균성을 보였다. 에탄올 추출물과 물 추출물을 비교한 결과 거의 대부분 에탄올 추출물의 항균성이 높았으나, 균종에 따라서는 일부 물 추출물에서 항균성을 따로 보이거나 더 높은 경향이 있기도 하였다. 이상과 같이 천연물 중에도 상당한 항균성물질이 존재한다는 것이 확인되었다.