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.

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.

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.

본 연구는 Bacillus subtilis를 활용한 바이오플락 양식 기술(Biofloc technology, BFT)을 이용하여 대농갱이(Leiocassis ussuriensis) 양식의 가능성을 확인하기 위해 90일 동안 생존, 성장지수와 사육수 수질의 변화를 관찰하였다. 대농갱이를 입식하기 전 BFT 수 제조를 위해 실험수조에 사료와 당밀을 첨가한 후 B. subtilis를 접종하여 40일간 수질을 안정화시켰다. 실험결과, 대농 갱이의 생존율은 대조구 92.7±3.2%와 BFT 실험구 95.8±3.3%로 조사되었다. 증체율은 대조구 118.1±9.0%와 BFT 실험구 197.7±15.6%을 보였고, 일간 성장율은 대조구 0.87±0.5%, BFT 실험 구 1.21±0.06%로 나타났다. 사료효율은 대조구가 43.7±2.6%이었고, BFT 실험구는 70.1±4.1%로 측정되어 BFT 실험구의 사료효율이 더 높은 것으로 조사되었다. 실험기간 동안의 수질 변화를 측정한 결과, pH는 대조구와 BFT 실험구 모두 감소되었고, MLSS는 대조구에서 변화를 보이지 않았지만, BFT 실험구에서는 90일째부터 유의한 증가를 보였다. NH4 +-N와 NO2 --N는 대조구 에서 실험 30일째부터 유의한 증가를 보였으나, BFT 실험구에서는 변화를 보이지 않았다. 결론 적으로 B. subtilis를 활용한 BFT 시스템을 대농갱이 양성 과정에 적용한 결과, 수질은 안정화 되는 경향을 보였고, 성장도와 사료효율은 대조구에 비해 높은 것으로 조사되어 긍정적인 효 과가 있는 것으로 확인되었다.

This study aimed to investigate the effects of probiotic treatment with IgY and Bacillus subtilis complex on diarrhea and weight gain in Hanwoo calves. Bacillus and E. coli levels were measured in the feces of calves post probiotic administration. Subsequently, calves with diarrhea were divided into two groups. The total and daily weight gain was measured in 23 calves after three months of suckling and divided into three groups. In Test 1, Bacillus was detected of the control group constantly at 104 CFU/g; a statistically significant difference was observed between the treatment and the control groups on the 1st and 3rd day (p<0.05) but not on the 7th day, confirming that the Bacillus subtilis survived in the intestine only until the 7th day. The treatment and control groups in Test 2 did not show any significant difference in the E. coli levels. However, comparison of changes in the E. coli levels showed a decreased of 6.39×108±9.80×108 CFU/g in the control group increase by 1.54×109±2.16×109 CFU/g, and, a decrease by 1.47×109±2.20×109 CFU/g; a decrease of by 4.20×107±3.90×108 CFU/g was observed in the treated group, an increase by 7.19×108±2.04×109 CFU/g, anda a decrease by 9.22×108±1.79×109 CFU/g. The changes in, control group were more rapid than in the treatment group. Therefore we hypothesize that probiotics inhibit E. coli growth. A concurrent improvement in weight gain was observed following probiotic administration. The IgY and Bacillus subtilis probiotics complex used in this study can be effectively used for the prevention and treatment of calf diarrhea.

The present study aimed to investigate the effect of fermentation on physical properties of texturized vegetable protein (TVP) by using Bacillus subtilis. TVP was prepared by texturizing the mixture of isolated soy protein (50%), wheat gluten (40%) and corn starch (10%) with the use of twin-screw extruder at two different moisture contents (40% and 50%), 100 g min-1 feed rate, 200 rpm screw speed and 130°C die temperature. Then, TVPs were subjected to solid-state fermentation using B. subtilis at 37°C for 60 h. The texture (springiness, cohesiveness, chewiness and hardness), integrity index and color (lightness, redness and yellowness) of TVPs were determined before and after fermentation for 0, 12, 24, 36, 48 and 60 h, respectively. The springiness and cohesiveness did not change significantly after fermentation in all samples. However, chewiness and hardness decreased with increased fermentation time with the lowest values observed at 60 h after fermentation of TVPs (both 40% and 50% MC). Integrity index of fermented TVPs was significantly reduced while fermentation time was increased. Integrity index started to decrease significantly at 36 h after fermentation in TVP extruded with 40% MC. In another TVP (50% MC), the integrity decreased at 24 h after fermentation but it maintained higher integrity index than TVP (40% MC) throughout the whole fermentation period. The significant total color change was observed with increased fermentation time. During fermentation, lightness and yellowness decreased but redness increased significantly. This study pointed out that TVP fermented by B. subtilis still has good texture, and thus has the potential to become an attractive food for consumers who usually avoid fermented foods due to rotten appearance with no texture.

건강 식품인 병아리콩을 화장품의 원료로 활용하기 위하여 Bacillus subtilis Natto 균주로 병아리콩을 발효한 낫토를 마스크 팩에 적용하여 피부개선 효과를 연구하였다. 병아리콩 낫토를 동결건조하여 얻은 분말을 paste 제형으로 얼굴 마사지 팩에 적용하였다. 50~60대 여성을 대상으로 낫토 팩의 피부개선 효과를 조사하였다. 낫토 팩의 처치 횟수가 증가함에 따라 피부가 개선되며 4회 처치 후 개선 효과가 두드러졌다. 4회 처치 후 수분 함량과 피지 분비량이 각각 8.4±3.6%p와 4.0±2.3%p 증가하였고, 피부 모공과 주름도 각각 1.8±0.3%p와 1.8±0.9%p 감소하였다. 피부 색소침착은 1.3±0.2%p 감소 되었고, 피부 톤은 55.2%에서 55.9%로 0.7±0.2%p 밝아졌다. 병아리콩을 발효하여 얻은 낫토 발효물이 보습, 모공, 주름, 색소침착, 피지분비, 피부톤 등의 피부개선 효과가 있으며, 다양한 기능성 화장품의 원료로 활용 가능성을 확인하였다.

This study was conducted to screen for superior strains for preparation of Cheonggukjang and identify the optimal fermentation time based on fermentation of lentils by various Bacillus subtilis strains. Bacillus count was significantly high at 48 hrs of fermentation (9.22-9.51 log CFU/g). In addition, the pH was significantly high in the range of 7.60-7.92 at 48 hrs fermentation, and the reducing sugar content was significantly high (0.89-1.45). The amino-type nitrogen content and ammonia-type nitrogen content were significantly increased with fermentation time. Additionally, the amylase activity was significantly high (3.05-4.22) at 48 hrs of fermentation, as was the protease activity (4.80-5.63). Bacillus subtilis S3 (5.63), S4 (5.60) were higher than S1 (4.80), S2 (4.92). The viscous substances and DPPH radical scavenging activity increased at 48 hrs, then decreased. Sensory evaluation revealed that lentil Cheonggukjang fermented by S3 showed the highest scores in color, smell, savory taste, sweet taste, viscous substance and overall acceptability. Therefore, 48 hrs of fermentation should be suitable for lentil Cheonggukjang fermented by Bacillus subtilis S3.

Twelve strains of bacteria with cellulase and xylanase activities were isolated from spent mushroom substrates collected from button mushroom cultivation farm, Buye, Chungcheongnam-do in Korea. Among them, one strain, designated NO12, with higher cellulase and xylanase activities was selected by agar diffusion method. The strain NO12 was identified to be a Bacillus sp. by biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA gene sequence analysis showed that strain NO12 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus subtilis with 16S rDNA gene sequence similarity of 99.2%. Based on its physiological properties, biochemical characteristics, and phylogenetic distinctiveness, strain NO12 was classified within the genus Bacillus, for which the name Bacillus subtilis NO12 was proposed. The cellulase and xylanase activities of B. subtilis NO12 were slightly increased according to bacterial population from exponential phase to stationary phase in the growth curve for B. subtilis NO12. The xylanase activity continuously increased from the beginning of the exponential phase and exhibited maximum activity in the middle of the exponential phase.