본 연구는 2020년 10월 중 충청남도내 단체 급식소에서 발생한 대규모 집단 식중독 원인에 대하여 분석하였다. 전 체 급식원 135명 중 21명(15.6%)에서 음식을 섭취한 후 1 시간 이내에 주로 매스꺼움과 구토 증상을 보였다. 유증 상자 21명 중 11명과, 조리종사자 1명, 조리기구 2건과 보 존식 8건에서 B. cereus가 검출됨에 따라 B. cereus에 의 한 집단 식중독으로 판단하였다. 분리된 21개의 균주를 PFGE 분석한 결과, 19개의 균주가 동일한 것으로 판단되 었고, 이들 균주가 가지고 있는 독소 유전자는 CER, nheA, entFM이었다. 실험결과, CER을 포함하고, 증상 발현 시간 이 1시간 이내로 매우 짧아 B. cereus의 구토형 식중독으 로 판단하였다. 집단식중독 원인으로 안전하지 않은 급식 환경과 제대로 관리되지 않은 음식에 의한 것이라 조사되 었다. 이러한 결과는 단체급식에서의 급식환경과 제공되 는 음식이 철저하게 관리되어야 한다는 것을 보여준다. 이 와 더불어 보존식에서 원인 병원체를 찾아내는 것은 식중 독의 원인을 추정하는데 매우 중요하므로, 집단급식소에 서 규정에 맞는 보존식 용기를 이용하여 이를 적정온도에 잘 보관해야한다. 또한 정밀한 식중독 역학조사를 기반으 로 사례를 분석하고 결과를 전파함으로써 유사한 식중독 이 재발하지 않도록 해야 한다.

Bacillus thuringiensis (Bt) is widely used as an environmentally friendly insecticide compared to chemical insecticides. However, challenges such as difficulty in direct practical application, limited efficacy duration, and stability have been identified. To solve these issues, formulation-based research is being extensively conducted. In this study, the high insecticidal activity strain Bt IMBL-B9, identified in previous research, was subjected to large-scale cultivation using a fermentor. Subsequently, various formulations were developed through formulation processes. and characteristics such as their wettability, suspensibility and particle size were assessed to select the optimized formulation.

Although insects lack the adaptive immunity characteristic of vertebrates, certain species exhibit enhanced subsequent immune responses upon re-encountering a pathogen, a phenomenon known as immune priming. The underlying mechanism of this phenomenon is still elusive. This study evaluated the immune priming of the diamondback moth, Plutella xylostella, induced by a nonpathogenic and commensal bacterium, Bacillus subtilis. Prior exposure of P. xylostella to B. subtilis significantly increased survival against a pathogenic bacterium, Bacillus thuringiensis, compared to larvae without pre-exposure. To extend the effect of the microbial commensals, two antibiotics, ampicillin and kanamycin, were treated to suppress their populations. In the axenic-like condition in the gut, cellular and humoral immune responses were significantly suppressed. An addition of B. subtilis to the diet of P. xylostella significantly enhanced the immune responses. Apolipoprotein D, known as a lipid carrier, acts like a vertebrate lipocalin in the immune priming of the other insect, Spodoptera exigua. The ortholog of this gene has been identified in P. xylostella, and its expression was induced upon B. subtilis treatment. This study sheds light on the potential role of commensal gut microbes, including B. subtilis, in the immune priming of these insects.

This study investigated the physicochemical properties of protein-fortified rice flour by mixing rice flour (RF) with untreated and fermented plant proteins. Fermented faba bean protein concentrate (FMFP) and chickpea flour (FMCF) were prepared by solid-state fermentation of faba bean protein concentrate (UTFP) and chickpea flour (UTCF) using Bacillus subtilis. FMFP and FMCF exhibited higher crude protein, reducing sugar and starch contents more than their counterparts. The increased rate of essential and branched-chain amino acids in FMFP and FMCF exceeded that of crude protein. Adding plant proteins to RF decreased swelling power (SP) and increased solubility in RF-UTFP and RF-FMFP mixtures, while SP and solubility increased in RF-UTCF and RF-FMCF mixtures. All RF-plant protein mixtures showed higher gelatinization temperature and lower gelatinization enthalpy than RF. Thermal gelation was found in all RF-plant protein mixtures, but the RF-FMCF mixture may form weak and unstable gel structures. The increase in pasting viscosity was minimal for the RF-UTFP and RF-FMFP mixtures but more pronounced for the RF-UTCF and RF-FMCF mixtures. Overall, FMFP may be a potential protein source to supplement the protein deficiency in RF with minimal changes in RF-based foods’ rheological and textural properties.

본 연구에서는 강한 내열성을 가지는 비병원성 Bacillus atrophaeus, Bacillus subtilis, Geobacillus stearothermophilus 포자의 열 저항성을 분석하여 레토르트 식품 제조 시 직 접적인 멸균 여부 판정에 사용 가능성을 평가하고자 하였 다. B. subtilis 포자의 D121-value는 2.9±0.1분이었으며, Zvalue는 43.0±1.4oC로 나타났다. G. stearothermophilus 포 자의 D121-value는 4.3±0.1분이었으며, Z-value는 25.0±1.6oC 로 나타났다. B. atrophaeus 포자의 D121-value는 3.7±0.1분 이었으며, Z-value는 35.8±1.4oC로 나타났다. B. subtilis, G stearothermophilus와 B. atrophaeus 포자의 D121-value는 모 두 레토르트 식품 멸균 확인에 사용되는 C. botulinum 포 자의 D121-value 보다 높은 값을 나타내었다. 이러한 결과 를 종합하여 볼 때 레토르트 식품 멸균 시 병원성 포자형 성균인 C. botulinum 대신 B. subtilis, G. stearothermophilus, B. atrophaeus 포자를 사용할 수 있을 것으로 판단된다. 또 한 기존 세균발육 실험에 소요되는 13일보다 단시간인 2- 3일에 멸균 여부를 확인할 수 있을 것으로 판단된다.

In this study, Bacillus velesensis TJS119, isolated from freshwater, demonstrated growth inhibition against insect pathogenic fungi. The culture medium of the B. velezensis TJS119 strain underwent sequential fractionation with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Notably, the n-butanol fraction exhibited significant antifungal activity against Metarhizium anisopliae and Beauveria bassiana. LC/MS analysis of antifungal peaks identified the production of various lipopeptides by B. velezensis TJS119, including two types of iturin A (C14, C15), four types of fengycin A (C14, C15, C16, C17), and two types of fengycin B (C16, C17). The antifungal efficacy of Iturin A and Fengycin against insect pathogenic fungi was further validated using the paper disc diffusion method. These findings underscore the potential of B. velezensis TJS119 as a promising candidate for future research and applications in the realm of agricultural biological controls against fungal diseases.

Protaetia brevitarsis seulensis larvae from industrial insects are traditionally recognized as functional health foods in South Korea. We evaluated the immuno-modulatory effects of feeding beneficial microorganism (Bacillus velezensis TJS119) to P. brevitarsis larvae as a dietary source. In this study, we investigated the immune-enhancing activities of P. brevitarsis larvae hot-water extract (PLW) and PLW after treatment with B. velezensis TJS119 (PLWB) using the RAW 264.7 macrophage cell line. We examined the effects of PLWB on cell proliferation, cytokine production, and nitric oxide production in RAW264.7 cells. PLWB showed no cytotoxicity at concentrations ranging from 7.8 to 1,000 μg/mL in RAW264.7 cells. Treatment with PLWB increased the production of nitric oxide and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β)] at doses of 62.5 to 1,000 μ g/mL in RAW264.7 cells. As a result, PLWB exhibited a stronger immune-enhancing effect compared to PLW. In conclusion, the results of this study offer experimental evidence to support the potential utilization of PLWB as an immunity-enhancing nutraceutical ingredient.

Bacillus velezensis TJS119 was isolated from the freshwater, and antagonistic activity against of pathogenic fungi. Strain TJS119 showed a broad spectrum of antagonistic activities many fungal pathogens, including the green muscardine fungus Metarhizium anisopliae. The whole-genome sequence of B. velzensis TJS119 was analyzed using the illumina platform. The genome comprises a 3,809,913 bp chromosome with a G + C content of 46.43%, 3,834 total genes, 10 rRNA and 73 tRNA genes. The genome contained a total of 8 candidate gene clusters (difficidin, fengycin, bacillaene, macrolactin, bacillibactin, bacilysin, surfactin and butirosin) to synthesize secondary metabolite biosynthesis. Overall, our data will aid future studies of the biocontrol mechanisms of B. velezensis TJS119 and promote its application in insect disease control.

Bacillus thuringiensis (Bt) is currently the most commonly used microbial pesticide. In the previous study, Bt IMBL-B9 known for its high toxicity against Spodoptera exigua, S. frugiperda and Plutella xylostella was characterized. To develop novel biopesticide, optimization of culture medium is required for the cost-effective mass production for toxin production of IMBL-B9. Through experimental design by Plackett-Burman design, ingredients that significantly influenced the production of IMBL-B9's toxin were selected. Using these results, the novel culture medium for IMBL-B9 was developed and the toxin yield of IMBL-B9 was significantly increased than conventional media by using this medium. These results could be useful for the development of biopesticides.

The objective of this study was to achieve biological control of green mold disease in Pyogo mushrooms using antagonistic microorganisms. Bacillus subtilis BSM320 cells inhibited mycelial growth by 48–60% against three Trichodermaisolates including T. hazianumisolated from the substrates of Lentinula edodes, showing their antifungal activity.The bacteria were cultured to a high density of 4.2 x 109±113.7 cfu/mlin aqueous extract of composted spent mushroom substrates of L. edodes containing 1% glucose and showed a higher growth rate than that observed when using the commercial medium, Luria-Bertani broth. The bacterial culture showed a 75% protective effect without damaging the mushroom fruiting bodies. These results suggest that B. subtilis BSM320culture is suitable for biological control of green mold disease during mushroom cultivation.

본 연구에서는 MnSO4이 B. thuringiensis의 곤충독소 형 성에 미치는 영향을 분석하여 신속 검출배지 개발의 기초 자료를 제안하고자 하였다. 본 실험에 사용한 균주는 순 천대학교 식품위생안전실험실에 보관되어 있던 B. thuringiensis reference 1주(KCTC 1511)와 식품에서 분리 된 wild type strain 9주를 사용하였다. B. thuriengiensis의 곤충독소 생성 확인은 식품의약품안전처의 곤충독소 확인 시험법에 따라 실험하였다. 0.005%-MnSO4이 첨가된 Nutrient agar는 배양 48시간에 3개 평판 중 2개 평판 (66.6%)에서 곤충독소가 관찰되었고, 120시간에 3개 평판 (100%) 모두에서 곤충독소가 관찰되었다. AK agar는 48 시간 배양 후 3개 평판 중 1개 평판(33.3%)에서 곤충독소 가 관찰되었으며, 배양 120시간에 3개 평판(100%) 모두에 서 곤충독소가 관찰되었다. 이러한 결과는 포자형성에 사 용되는 AK agar보다 식품공전에서 제시하고 있는 포자형 성 배지인 0.005%-MnSO4 Nutrient agar가 B. thuringiensis 의 곤충독소를 신속하게 생성시키는 것으로 나타났다. B. thuringiensis 10개 균주를 24시간 배양하여 관찰한 결과, 0.000%-MnSO4 배지에서 10개 평판 중 1개 평판(10%), 0.001%-MnSO4이 첨가된 배지의 10개 평판 중 2개 평판 (20%)에서 곤충독소가 관찰되었다. 0.002%-MnSO4이 첨가 된 배지는 10개 평판 중 3개 평판(30%)에서 곤충독소가 관찰되었다. 0.003%-0.009%-MnSO4이 첨가된 배지에서는 곤충독소가 관찰되지 않았다. 이러한 결과로 보아 24시간 배양 시까지는 0.002%-MnSO4이 첨가된 Nutrient agar가 B. thuringiensis의 곤충독소를 가장 신속하게 생성시키는 것으로 나타났다. B. thuringiensis의 곤충독소는 포자형성 과 동시에 생성된다는 보고와 MnSO4이 포자형성에 기여 한다는 보고를 종합하여 보면, MnSO4이 B. thuringiensis 의 포자형성을 가속화하고 이로 인해 곤충독소도 신속하 게 생성된 것으로 판단된다. 따라서 B. thuringiensis의 곤 충독소를 신속하게 생성하기 위해 기존 식품공전에서 제 시하고 있는 Nutrient agar보다 0.002%-MnSO4이 첨가된 Nutrient agar를 사용하는 것이 효율적일 것으로 판단된다. 그러나 Nutrient agar와 0.002%-MnSO4 Nutrient agar의 24 시간 배양 후 곤충독소 생성율의 차이는 작게 나타나 다 수의 wild type B. thuringiensis를 대상으로 추가적인 연구 가 필요할 것으로 판단된다.

This study was conducted to examine the effect of a diet supplemented with dried Bacillus subtilis culture on broilers' productivity and blood characteristics. Broiler feeding experiments were conducted twice. The diet fed to the control group was supplemented with 0.2% Palm MateⓇ commercially available probiotics (B. subtilis), and the diet fed to the experimental group was supplemented with ThekerⓇ 0.05% dried B. subtilis culture (DBC) in experiment 1, and 0.1% DBC in experiment 2. Treatment was administered for four weeks in both groups. A higher average daily gain was observed in the group treated with 0.05% DBC in experiment 1 compared with the control group, which was significantly higher in the group that received 0.1% DBC in experiment 2 compared with the control group. A higher production index was observed in the groups that received treatment than in the control group and was higher in the 0.1% DBC group than in the 0.05% DBC group. Significantly lower serum triglyceride (TG) was observed with increased DBC content. Although the findings showed no statistical significance, lower total cholesterol (T-C) was observed in the treated group than in the control group. HDL-cholesterol (HDL-C) content showed a significant increase in the DBC-treated groups. A significantly opposite outcome was observed for LDL-cholesterol (LDL-C) content. These findings demonstrated that the atherogenic index (AI) and cardiac risk factor (CRF) decreased in the DBC-treated groups. Significantly lower serum levels of glutamic-oxaloacetic transaminase (GOT: aspartate aminotransferase, AST) and glutamate pyruvic transaminase (GPT: alanine transaminase, ALT) were detected with an increase in DBC content in the treated groups compared with the control groups. To summarize the findings described above, adding ThekerⓇ dried B. subtilis culture to broiler feeds positively improved productivity through weight gain of broilers and the production of healthier functional broilers through the improvement of blood lipids and liver function. It is expected that the findings of this study will be helpful in the effort to increase the profitability of broiler chicken farming and promote human health.

프로바이오틱스는 다양한 환경에서 분리되어 왔으며, Bacillus 균주는 유산균과 같은 일반적인 프로바이오틱스의 한계를 보완할 수 있는 내생포자 형성 능력으로 인해 프로바이오틱스 균주 중에서 유리하다. 본 연구의 목적은 한국에서 오염되지 않은 환경으로 알려진 울릉도 토양에서 분리된 Bacillus 균주의 프로바이오틱스 잠재성을 조사하는 것이다. 토양 시료는 울릉도 각지에 서 채취하였으며, 항생제 내성과 효소 활성을 평가하였다. 항생제에 내성을 나타내지 않는 6개 의 Bacillus 균주를 확보하였고 이후에 효소 활성을 검사하였다. 인체에 악영향을 미칠 수 있 는 β-glucuronidase 효소는 활성이 나타나지 않았으며, 시중에서 판매되고 있는 Bacillus 프로바 이오틱스와 유사한 효소의 활성과, 추가적으로 펩타이드 가수분해효소인 Leucine arylamidase 의 활성이 나타난 NB-1 균주가 확인되었다. 이에, 추가적인 효능 연구 및 안정성 실험을 통해 프로바이오틱스 균주로서의 가능성을 모색해야 할 필요가 있다고 판단된다.

Screening of Bacillus subtilis strains capable of producing extracellular hydrolases, including lipolytic enzyme was carried out. Within the scope of this study, total 61 strains were isolated from various domestic specific environmental samples such as seawater, soil, Jeju ranch, hot spring, salt farm, and fermented food and identified as Bacillus subtilis based on 16S rRNA sequences. Among the isolates, 4 strains had extracellular lipase activity. The growth profile of the strains revealed that 4 strains showed well growth at 50℃, 3 strains at 55℃, and pH 7.0. All strains could tolerate salinity up to 5%(w/v), 3 strains up to 10%(w/v), and only one strain showed growth at 15%(w/v). Additionally, amylolytic and proteolytic activities were detected in these strains. The highest lipolytic, amylolytic, and proteolytic activity was detected in Bacillus subtilis YS-YR 5A. These results demonstrate the potential application of extracellular hydrolase-producing Bacillus subtilis strains, especially strain YS-YR 5A, as fermentation starter to enhance the functionality and multiplication of functional natural products in the food/medicine/cosmetics/bio industries.