• Journal of Mushroom
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• v.9 no.4
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• pp.180-185
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• 2011

Spent mushroom substrates (SMS) is a by-product remaining after a crop of mushrooms. About four surfactin-producing strains were isolated from SMS (Pleurotus eryngii). Among of them, one isolate, which designated to YJ07, potentially showed the antifungal activity against Aspergillus flavus and Aspergillus ochraceous producing mycotoxin on PDA medium. The biochemical characteristics of the strain YJ07 was similar with Bacillus subtilis and Bacillus amyloliquefaciens by Bacillus ID kit and VITEK 2 system. Comparative 16S rDNA gene sequence analysis of the strain YJ07 also showed that the strain YJ07 was most closely related to Bacillus amyloliquefaciens with sequence similarity of 99.5%. On the basis of their biochemical characteristics and phylogenetic distinctiveness, the strain YJ07 was classified within the genus Bacillus as Bacillus amyloliquefaciens YJ07. The antifungal compound from B. amyloliquefaciens YJ07 was similar to lipopeptide surfactin from Bacillus subtilis by TLC and HPLC analysis.

• Journal of Life Science
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• v.19 no.12
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• pp.1724-1730
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• 2009

The mannanase-producing bacteria, designated CS47, was isolated from the fresh feces of three horses (from a farm in Jinju National University). The isolate CS47 was facultatively anaerobic and grew at temperatures ranging from $20^{\circ}C$ to $50^{\circ}C$ with an optimal temperature of $38^{\circ}C$. The DNA G+C content of the isolate CS47 was 44 mlo%. The major fatty acids were anteiso-15:0 (39.6%), 17:0 (7.6%), and iso-15:0 (37.8%). The 16S rRNA gene sequence similarity between the isolate CS47 and other Bacillus strains varied from 93% to 98%. In the phylogenetic analysis based on these sequences, the isolate CS47 and Bacillus amyloliquefaciens clustered within a group and separated from other species of Bacillus. Based on the physiological and molecular properties, the isolate CS47 was classified within the genus Bacillus as Bacillus amyloliquefaciens CS47. The optimal pH and temperature for mannanase activity of B. amyloliquefaciens CS47 were pH 6.0 and $50^{\circ}C$, respectively. The thermal stability of mannanase from B. amyloliquefaciens CS47 is valuable when using this enzyme in industrial application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5343-5350
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• 2015

This study aims to compare and analyze the antioxidant effect of Cheonggukjang's traditional fermentation strain, Bacillus subtilis NG24 which was a control of the study, in order to see the biological activity effect of the new strain, Bacillus amyloliquefaciens NBF11-1 that was first found in the surface of the bamboo stem, but hasn't been insufficiently researched. In the antioxidant activity experiment of the Cheonggukjang extract, the B.amyloliquefaciens NBF11-1 sample showed a significant increase in the total polyphenol extract content, compared to B.subtilis NG24(p=0.032). Also, compared to B.subtilis NG24, the sample containing B.amyloliquefaciens NBF11-1 showed a significant increase in SOD-like Activity, DPPH radical scavenging, and NO radical scavenging, as the concentration rose(p<.05). Additionally, $IC_{50}$ in each antioxidant activity experiment significantly decreased in the B.amyloliquefaciens NBF11-1 sample like SOD-like Activity(p=0.045), DPPH radical scavenging(p=0.041), and NO radical scavenging(p=0.019), compared to B.subtilis NG24.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.249-252
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• 2013

The Bacillus KU801 strain, due to its potential in the field of probiotics for animal use, was isolated from chicken feces. Strain KU801 was identified as Bacillus amyloliquefaciens KU801 based on the results of 16S rRNA sequencing. Vegetative and spore cells of B. amyloliquefaciens KU801 were resistant to artificial gastric juice and artificial bile acid. B. amyloliquefaciens KU801 was found to inhibit the production of nitric oxide (NO) and increase the production of Interleukin-1 alpha (IL-1${\alpha}$). DNA damage induced by N-methyl-Ntion of ninitroso-guanidine (MNNG) was significantly inhibited, in a dose dependent manner, by preincubating MNNG together with B. amyloliquefaciens KU801. These results demonstrate the potential use of B. amyloliquefaciens KU801 as a feed additive.

• Current Research on Agriculture and Life Sciences
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• v.31 no.1
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• pp.30-37
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• 2013

Bacillus subtilis and Bacillus amyloliquefaciens are closely related species that share a similar genomic background, and are both known to secrete large amounts of proteins directly into a medium. The extracellular proteomes of two strains of Bacillus subtilis and two strains of Bacillus amyloliquefaciens were compared by 2-D gel electrophoresis during the late exponential growth phase. The relative abundance of some minor protein spots varied among the four strains of Bacillus. Over 123 spots of extracellular proteins were visualized on the gel for B. subtilis CH 97, 68 spots for B. subtilis 3-5, 230 spots for B. amyloliquefaciens CH 51, and 60 spotsfor B. amyloliquefaciens 86-1. 2D gel electrophoresis images of the four Bacillus strains showed significantly different protein profiles. Consistent with the 2D gel electrophoretic analysis, most of the B. subtilis proteins differed from the proteases secreted by the B. amyloliquefaciensstrains. Among the proteins identified from B. subtilis, approximately 50% were cytoplasmic and 30% were canonically extracellular proteins. The secreted protein profiles for B. subtilis CH 97 and B. subtilis 3-5 were quite different, as were the profiles for B. amyloliquefaciens CH 51 and 86-1. The four proteomes also differed in the major protein composition. The B. subtilis CH 97 and B. amyloliquefaciens CH 51 proteomes both contained large amounts of secreted hydrolytic enzymes. Among the four strains, B. subtilis 3-5 secreted the least number of proteins. Therefore, even closely related bacteria in terms of genomic sequences can still have significant differences in their physiology and proteome layout.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.98-105
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• 2016

The presence of bacterial strains showing antagonistic activity to common pathogens found in a variety of fermented foods in Korea was explored. A bacterium inhibiting the growth of pathogens such as Aspergillus terreus (KCTC6178), A. flavus (KCTC6984), Staphylococcus aureus (KCCM12214), Escherichia coli O157:H7 (KCCM40406), Bacillus cereus (KCTC1012), Cryptococcus neoformans (ATCC208821), Salmonella typhimurium (ATCC19430), and Listeria monocytogenes (KCTC3569) was isolated from Makgeolli, a Korean traditional rice wine. The strain showing high antipathogenic activity was identified as B. amyloliquefaciens based on the nucleotide sequence of the 16S ribosomal RNA gene. Compared with B. amyloliquefaciens KCTC1660, whose genome has been sequenced, the isolate exhibited significantly low activities of starch-degrading enzymes and high resistance to high temperature and low pH.

• Journal of Dairy Science and Biotechnology
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• v.39 no.3
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• pp.87-93
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• 2021

This study analyzed and compared growth characteristics under large-scale fermentation at 35℃ of three microorganisms with the ability to reduce odor-producing substances in livestock. The three microorganisms (Bacillus subtilis FWC1, Bacillus amyloliquefaciens NAAS1, and Pichia farinosa NAAS2) evaluated in this study have been proven effective in reducing odor-inducing substances. Bacillus subtilis FWC1 exhibited the highest viable cell count when using 2% maltodextrin as carbon source, 0.05% soy-peptone as nitrogen source, and 0.3% yeast extract. The optimum media composition for B. amyloliquefaciens NAAS1 was 1.2% modified-starch with 0.8% yeast extract. The spore formation rate in the mass production of the Bacillus strains was over 90%, indicating that optimal growth medium compositions have been identified. In the case of P. farinosa NAAS2, our optimized growth medium [2% (w/v) glucose and 1% (w/v) yeast extract] improved biomass production.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.27-34
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• 2016

Sclerotium rolfsii is a well known broad host range soil borne plant pathogenic fungus and caused serious damage to various vegetable crops. To develop an effective biological control agent for S. rolfsii, an isolate which showed strong inhibitory effect on the mycelial growth of S. rolfsii was selected among the antagonistic bacterial isolates collected from vinyl-house soil. The bacterial isolate was identified as Bacillus amyloliquefaciens KBC1009 based on the morphological, physiological characteristics and by 16S rRNA sequence analysis. The growth conditions for B. amyloliquefaciens KBC1009 were optimized in LB media(pH7) by culturing at 30℃ for 72 hrs. Glucose and yeast extract were confirmed as the best carbon and nitrogen sources, respectively. In order to test the inhibitory effect of B. amyloliquefaciens KBC1009 to stem rot of pepper, green house experiment was conducted. Drench of 1/500 diluted bacterial suspension of B. amyloliquefaciens KBC1009(5×108 cfu/ml) to each pepper plant 3 times with 10 days interval showed 66.7% control effectiveness. These results suggest that B. amyloliquefaciens KBC1009 is one of promising biocontrol agent to control stem rot caused by Sclerotium rolfsii.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.44-55
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• 2016

Bacillus cereus is a gram-positive, rod-shaped, spore-forming bacterium that has been isolated from contaminated fermented soybean food products and from the environment. B. cereus produces diarrheal and emetic toxins and has caused many outbreaks of foodborne diseases. In this study, we investigated whether B. amyloliquefaciens RD7-7, isolated from rice doenjang (Korean fermented soybean paste), a traditional Korean fermented soybean food, shows antimicrobial activity against B. cereus and regulates its toxin gene expression. B. amyloliquefaciens RD7-7 exhibited strong antibacterial activity against B. cereus and inhibited the expression of B. cereus toxin-related genes (groEL, nheA, nheC, and entFM). We also found that addition of water extracts of soybean and buckwheat soksungjang (Korean fermented soybean paste made in a short time) fermented with B. amyloliquefaciens RD7-7 significantly reduced the growth and toxin expression of B. cereus. These results indicate that B. amyloliquefaciens RD7-7 could be used to control B. cereus growth and toxin production in the fermented soybean food industry. Our findings also provide a basis for the development of candidate biological control agents against B. cereus to improve the safety of fermented soybean food products.

• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.161-168
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• 1986

A 1.95Kb Sau3Al fragment coding for $\alpha$-amylase from Bacillus amyloliquefaciens was isolated by the shotgun method using Escherichia coli as a host. The genome of Bacillus amyloliquefaciens was partially digested with the restriction endonuclease Sau3Al and joined to plasmid YRp7 cleaved with the restriction endonuclease BamHI. The $\alpha$-amylase gene present in a 1.95Kb insert was stably maintained and expressed in Escherichia coli. The amount of $\alpha$-amylase activity produced by Escherichia coli containing the hybrid plasmid pEA24 was about 65% of the activity produced by the donor Bacillus amyloliquefaciens strain. The properties of $\alpha$-amylase produced by Escherichia coli were very similar to those produced by Bacillus amyloliquefaciens as based on optimum temperature, pH, and effect of CaCl$_2$ concentration. About 70% of the $\alpha$-amylase produced by Escherichia coli was localized in the periplasmic space, whereas the remaining enzyme was localized in the inner part of the cell.