• Food Industry
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• 통권216호
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• pp.73-77
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• 2010

• Journal of the Korea Academia-Industrial cooperation Society
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• 제6권4호
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• pp.342-348
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• 2005

In this study, novel strains showing better protein degradation activity were isolated for the production of effective compost from garbages. Well growing bacteria with clear zone on the skim milk agar media were isolated . The strain was identified as Bacillus subtilis PNV-1 through various biochemical tests, Bergy's manual of determinative bacteriology and 165 rDNA partial sequence. The extracellular protease of the strain PNV-1 has its activity at broad pH and the optimal temperature was $50^{\circ}C$. Also, the strain PNV-1 was highly tolerant to high concentration of salt, red/black pepper and mustard.

• The Journal of Natural Sciences
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• 제19권1호
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• pp.57-64
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• 2008

The fsrA gene in Bacillus subtilis has an analogous role of ryhB in E. coli and is controlled under fur, the iron regulator gene. At high concentration of iron the transcription of ryhB is repressed by fur and ryhB is transcribed under low concentration of iron. To spare iron produced ryhB small RNA represses the expression of sdhCDAB (succinate dehydrogenase). This study shows the growth rate of Bacillus subtilis strain of fur and fur/fsrA deletion mutants using organic acids of TCA cycle as carbon source. Mutant strain of fur does not grow well with succinate carbon source, but further deletion of fsrA regain to the growth of wild type strain. Also, nearly same results were observed with citrate and fumarate. These results are consistent to those of E. coli system. But fur and fur/fsrA deletion mutants grow well as much as the growth of wild type with malate carbon source. These results showed that upstream genes of succinate of TCA cycle are repressed by fsrA, but downstream of succinate are not repressed by fsrA.

• Microbiology and Biotechnology Letters
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• 제46권3호
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• pp.253-260
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• 2018

Beneficial microorganisms are widely used in the forestry, livestock, and, in particular, agricultural sectors to control soilborne diseases and promote plant growth. However, the industrial utilization of these microorganisms is very limited, mainly due to uncertainty concerning their ability to colonize and persist in soil. In this study, the survival of beneficial microorganisms in field soil microcosms was investigated for 13 days using quantitative PCR with B. subtilis group-specific primers. Bacterial community dynamics of the treated soils were analyzed using 16S ribosomal RNA (rRNA) gene amplicon sequencing on the Illumina MiSeq platform. The average 16S rRNA gene copy number per g dry soil of Bacillus spp. was $4.37{\times}10^6$ after treatment, which was 1,000 times higher than that of the control. The gene copy number was generally maintained for a week and was reduced thereafter, but remained 100 times higher than that of the control. Bacterial community analysis indicated that Acidobacteria ($26.3{\pm}0.9%$), Proteobacteria ($24.2{\pm}0.5%$), Chloroflexi ($11.1{\pm}0.4%$), and Actinobacteria ($9.7{\pm}2.5%$) were abundant phyla in both treated and non-treated soils. In the treated soils, the relative abundance of Actinobacteria was lower, whereas those of Bacteroidetes and Firmicutes were higher compared to the control. Differences in total relative abundances of operational taxonomic units belonging to several genera were observed between the treated and non-treated soils, suggesting that inoculation of soil with the Bacillus strains influenced the relative abundances of certain groups of bacteria and, therefore, the dynamics of resident bacterial communities. These changes in resident soil bacterial communities in response to inoculation of soil with beneficial Bacillus spp. provide important information for the use of beneficial microorganisms in soil for sustainable agriculture.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제8권3호
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• pp.627-631
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• 2007

The factors affecting on sludge sedimentation are reported as F/M ratio, ingredient, composition of influent substrate, dissolved oxygen concentration, temperature, pH, filamentous bacteria and SRT. Aeration tank applying Bacillus sp. has an important role for maintaining the dominant microorganism species to make steady progress for spore growth affecting sedimentation. This research aims to investigate the affecting factor for the sedimentation in B3 system and RABC system with aeration tank applying tapered aeration. Extracellular polymeric substances(EPS), protein and carbohydrate can be produced for the extreme condition, that is down to 0.2 mg/L of dissolved oxygen in the aeration tank. This research found out the relation between the sedimentation and the EPS production, especially the ratio of protein/carbohydrate. The spore of Bacillus sp. was formed at the low DO then microorganisms produced EPS. The results showed that the production of EPS was 109.95 mgEPS/gSS at 1.6 mg/L of DO, however it was 131.77 mgEPS/gSS at 0.5 mg/L of DO. The sedimentation was affected by protein content in EPS and the ratio of protein and carbohydrate. The settleability of sludge was not affected by the ratio of protein/carbohydrate in B3 process, meanwhile settleability was affected by the ratio of it in RABC process, respectively.

• Korean Journal of Soil Science and Fertilizer
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• 제43권6호
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• pp.995-1001
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• 2010

Biogeography is the study of the distribution of biodiversity over space and time. We report the development of a prototype database that maps of microbial diversity in the context of the geochemical and geological environment and geographic location. It aims to reveal where organisms live, and at what abundance in nation wide. Microbial data collected from agricultural land during 1999 to 2007 were categorized for mapping with ArcGIS program. Distribution maps of bacteria, fungi, Bacillus and gram negative bacteria of agricultural land showed different patterns from each other. Microbial biomass content investigated in year of 2007 was higher than in 1999.

• Journal of Food Hygiene and Safety
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• 제35권4호
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• pp.319-325
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• 2020

Widespread consumption of fresh-cut vegetables without cooking results in ingestion of major foodborne pathogens including Bacillus cereus. In this study, we aimed to develop a method to rapidly detect B. cereus in fresh-cut vegetables by combining commercial PCR analysis with enrichment of the pathogenic levels. A mixture of B. cereus strains (KCTC1013, KCTC1014, KCTC1092, KCTC1094, and KCTC3624) was inoculated on the surface of fresh-cut cabbage lettuce (20 g) and baby leafy vegetables (10 g) to concentration 1, 2, 3, 4, and 5 log CFU/g. Eighty milliliters of TSB with 0.15% polymyxin B was used for cabbage lettuce, and 90 mL of medium was used for baby leafy vegetables and incubated at 42℃ for 0, 2, 3, 4, 5, 6, and 7 h. One milliliter of the enriched media was plated on mannitol-egg yolk-polymyxin agar for quantification, and another 1 mL was used for DNA extraction for PCR analysis. Additionally, the minimum number of sub-samples to be tested from a pack of fresh-cut vegetable samples was determined using 5 sub-samples. The results from this study showed that for detecting B. cereus in fresh-cut cabbage lettuce, 3, 4, 5, 6, and 7 h enrichment were required to at least detect 5, 4, 3, 2, and 1 log CFU/g of B. cereus, respectively. B. cereus in fresh-cut baby leafy vegetables could be detected after 2, 3, 4, 5, and 6 h of enrichment at 5, 4, 3, 2, and 1 log CFU/g, respectively, using a combination of enrichment and PCR analysis. To determine if a pack of fresh-cut vegetable is positive, the minimum number of sub-samples should be 3. These results can be used to develop a rapid detection method to semi-quantify B. cereus in fresh-cut vegetable samples combining enrichment and PCR.

• 농업기술회보
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• 제51권5호
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• pp.17-18
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• 2014

최근 들어 식물의 뿌리 주변에는 사는 근권미생물과 식물과의 상호작용연구가 새롭게 조명되고 있다. 바실러스, 슈도모나스 등의 근권미생물은 식물의 면역기능을 활성화시켜 작물의 건강을 지키는 것으로 밝혀지고 있으며 이러한 기술을 도입할 경우 농작물의 안전 관리에 중요한 역할을 한다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 한국환경과학회 2006년도 추계 학술발표회 발표논문집
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• pp.357-361
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• 2006

• Korean Journal of Soil Science and Fertilizer
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• 제44권5호
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• pp.819-823
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• 2011

The present study evaluated the seasonal changes of the soil microbial population by selected media in an organic farming system (OFS) with rye rotation cropping management compared to those in a conventional farming system (CFS) with chemical fertilizers, pesticide and herbicide from May 2009 to October 2010 in an upland field. With the exception of fungi, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. were higher in the OFS soil during soybean-growing stages. In addition, populations of aerobic bacteria, Gram-negative bacteria, and Bacillus spp. in the OFS soil were nearly two times more than those in the CFS soil on reproductive growth stages. Our findings suggested that Bacillus spp. should be considered as responsible factor for microbial population differentiation observed between the OFS and the CFS in upland fields.