• Journal of Food Hygiene and Safety
• /
• v.14 no.2
• /
• pp.167-171
• /
• 1999

In order to screen the antagonistic bacteria which inhibit the growth of the apple pathogen, Penicillum expansum, we isolated an effective bacterial strain and investigated into the antifungal activity of the antagonist and it's identification. The eleven strains of bacteria which strongly inhibited P. expansum were isolated from the nature, and the best antagonistic bacterial strain designated as CH142, was selected. The antagonistic strain CH142 was identified to be the genus Bacillus subtilis based on morphological and biochemical characterization. The CH142 showed 55.9% of antifungal activity against the growth of P. expansum. By the treatment of the culture broth and the heat treated culture filtrate of it, the B. subtilis CH142 showed 90% and 15% of antifungal activity, respectively.

• Preventive Nutrition and Food Science
• /
• v.14 no.3
• /
• pp.252-259
• /
• 2009

We previously isolated Bacillus strains with high fibrinolytic activities (FAs) from cheonggukjang prepared by traditional ways. To test their potential as starters for cheonggukjang, soybean was fermented for 72 hr at $37^{\circ}C$ with each isolate and a control lab strain: B. subtilis CH3-25 (BS3-25), B. amyloliquefaciens CH51 (BA51), B. amyloliquefaciens CH86-1 (BA86-1), and B. subtilis 168 (BS168, control, lab strain). Viable cell numbers of all cheonggukjang samples rapidly increased and reached about $10^9$ CFU/g after 6 hr. During 72 hr, the initial pH of 6.3 rapidly increased to 8.1$\sim$8.2 for cheonggukjang fermented with BS3-25 or BA86-1, and 7.3 for those with BA51 or BS168. FAs and protease activities (acid, neutral, and alkaline) rapidly increased in cheonggukjang fermented with BS3-25, BA51, or BA86-1 during the first 12 hr. On the other hand, those of cheonggukjang fermented with BS168 slightly increased during the first 36 hr. There were significant changes in acid and neutral protease activities in cheonggukjang fermented with BA51 or BA86-1 during the 24 hr. Rapid increases of $\beta$-glucosidase activity corresponded well with rapid increases of $\alpha$-amylase and $\alpha$-galactosidase activities in addition to increases in antioxidant activities and the TPCs (total phenolic contents). The highest increase in the TPCs was observed in cheonggukjang fermented with BA86-1 while the least was that fermented with BS168.

• Food Science and Preservation
• /
• v.14 no.2
• /
• pp.194-200
• /
• 2007

In order to enhance the functionality and storage period of traditional fermented foods, the strain CH-14, which To enhance the quality of traditional fermented foods, and to lengthen acceptable storage periods, a bacterial strain, CH-14, showing potent enzyme activities and antibacterial capabilities, was isolated and characterize4 The bacterium wn Gram-positive, catalase-positive, oxidase-negative, formed endospores, expressed flagella, was rod-shaped, and had dimensions of 0.5 0.7m and 3.5 4.2m. The bacterium CH-14 was identified as Bacillus subtilis using Bergey's Manual of Systematic Bacteriology, Bergey's Manual of Determinative Bacteriology, and an API 50 CHL Carbohydrate Test Kit. An optimum growth medium contained 2% (w/v) cellobiose as a carbon source, a mixture of 0.5% (w/v) yeast extract and 0.5% (w/v) peptone as nitrogen sources, and 0.05% (w/v) $MgSO_4{\cdot}7H_2O$. The optimal culture temperature and the optimal initial pH were in the ranges of 30 $45^{\circ}C$ and 4.5 10.0, respectively. Maximum production of the antibacterial substance occurred after 24h of culture. The minimum inhibitory concentrations of the antibacterial substance were 5mg bacterial dry weight/mL against E. coli and P. mirabilis, and 10 mg/mL against S. aureus, S. enteritidis and V. parahaemolyticus.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.1
• /
• pp.23-30
• /
• 2014

The present study investigated the effects of dietary Edwardsiella tarda (E. tarda) specific bacteriophage (phage) and Bacillus subtilis (B. subtilis) mixture on innate immune responses and antibacterial activity of Nile tilapia, Oreochromis niloticus. In a dietary experiment, tilapia were fed the control diet (C), a phage-only supplemented diet (P), a B. subtilis only supplemented diet (B), or a B. subtilis and phage mixed diet (B+P). A respiratory burst and significant increase in lysozyme activity (P<0.05) were noted in the B+P group, as compared to other groups after 4 days of feeding. The B group showed a significant (P<0.05) increase in respiratory burst and lysozyme activity versus the C and P groups, whereas no significant increases (P<0.05) were observed in the P and C groups. $ACH_{50}$ was significantly up-regulated in the B+P group versus other groups after 8 days of feeding (P<0.05). In vivo antibacterial activity was significantly enhanced in the B+P fed group, as compared to other groups (P<0.05) after 7 days of E. tarda challenge. A significant (P<0.05) increase in antibacterial activity was seen in the B group, as compared to C or P groups after 14 days of feeding. These results suggest that a B. subtilis and phage mixture could be utilized as an alternative to antibiotics in the control of fish diseases caused by E. tarda.