• Journal of Life Science
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• v.33 no.6
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• pp.506-511
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• 2023

The purposes of this study were to isolate and characterize lactic acid bacteria with antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) from fermented food and to confirm the antibacterial activities of fermented rice products using the isolated lactic acid bacterium. Three bacteria, namely, Weissella sp. ISF-1, ISF-2, and ISF-3, were selected from fermented squid based on the 16S rRNA gene sequence. All three strains grew well in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activity against Bacillus cereus, Staphylococcus aureus, and MRSA. Their growth was excellent at 0% ~ 5% (w/v) NaCl and relatively good up to 7% (w/v) NaCl. The initial pH of 8 was optimal for their growth, and good growth was also observed at pH 6, 7, and 9. The lyophilisates of the fermented rice using Weissella sp. ISF-1 showed antibacterial activities against B. cereus, S. aureus, and MRSA. We inferred that isolated lactic acid bacteria could be useful in the development of probiotics and biopreservatives for foods and in the treatment of MRSA and may increase the value of rice products.

• Korean Journal of Environmental Agriculture
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• v.21 no.3
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• pp.216-222
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• 2002

In order to evaluate the antifungal activity of bacteria against plant pathogenic fungi, 8 bacteria were isolated from mushroom compost hot spring, seaweed, and forest soil and mutants from them were induced by $LD_{95}$ gamma radiation($^{60}Co$). Bacillus circulans K1, Burkholderia gladioli K4 and Bacillus subtilis YS1 showed wide antifungal spectrum against 12 kinds of plant pathogenic fungi. From the radiation sensitivity test, B. gladioli K4 was very sensitive to gamma radiation and its $D_{10}$ value was 0.11 kGy. Antifungal activities of B. circulans Kl-1004 and B. subtilis YS1-1009, which were induced by the radiation of $^{60}Co$ increased against Botryosphaeria dothidea. The mutant strains, B. subtilis YS1-1006 and B. subtilis YS1-1009 were resistant to tebuconazole and copper hydroxide. SAR535, SAR5108, and SAR5118 mutated from Streptomyces sp. SAR01 were antifungal activity deficient mutants against 5 kinds of plant pathogenic fungi compared to wild strain, so that they could be supposed to be model strains far studying antifungal mechanism. It is suggested that various functional types of mutants could be induced by gamma radiation and applied usefully.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.185-192
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• 2009

Chungkookjang fermenting Bacillus subtilis 028-1 strain suppressed the growth of Staphylococcus sp. LS2, Saccharomyces cerevisiae, and Candida albicans. B. subtilis 028-1 strain produced antibiotic effectively in the medium of 2% soybean meal and 1% maltose as a disaccharide, when the shaking was continued 15~18 h and the pH of culture medium was maintained under 6.5. The antibiotic activity was optimized when the initial pH of the culture medium of test strain was adjusted with weak alkali, was remained after 20 min of boiling and for more than 1 month in room temperature, and was weakened slowly by the digestion of chymotrypsin and papain. The molecular weight of the antibiotic was identified between 500 and 1,000 dalton by dialysis, and antibiotic substance was considered as not surfactin but a member of iturin family because of the absence of fibrinolytic activity.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.96-103
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• 2009

For the control of pathogenic microorganisms, Bacillus spp. were isolated from diseased pepper fruits in Korea. Among them, Bacillus sp. IUB158-03 showed high inhibitory effect on mycelial growth and spore germination of C. gloeosporioides and Botrytis cinerea. The strain was identified as B. amyloliquefaciens IUB158-03 based on its physiological, biochemical characteristics and Microlog analysis. The highest level of antifungal substances by B. amyloliquefaciens IUB158-03 were obtained when the bacterium was cultured in medium containing 2% soluble starch, 3% yeast extract, 0.5% tryptone, 0.5% $NH_4H_2PO_4$, and 1% NaCl (pH 6.0) at $25^{\circ}C$ for 72 hrs. The antifungal substances were purified by butanol extraction, silica gel column chromatography, preparative thin layer chromatography, and high performance liquid chromatography. The purified antifungal substance was confirmed $R_f$ 0.27 by TLC. This substance exhibited antifungal activity against Fusarium solani, Rhizoctonia solani, Botrytis cineria, Alternata alternaria of plant pathogenic fungi and Trichophyton mentagrophytes, Epidermophyton floccosum, Cryptococcus neoformans of human pathogenic fungi.

• Journal of Life Science
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• v.14 no.2
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• pp.229-234
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• 2004

Feathers, which are almost pure keratin protein, are produced in large amounts as a waste by-product at poultry-processing plants. Keratinolytic enzymes may have important uses in biotechnological processes involving keratin-containing wastes from poultry and leather processes. In this study, screening and identification of keratin-degrading bacteria were investigated. Five keratin-degrading bacterial strains (F3-1, F3-4, F7-1, C1-1, C1-2) were isolated from compost and decayed chicken feather. On the basis of morphological, physiological studies, and Biolog system, all isolates were identified as the genus Bacillus. Among them, the strain F7-1 had the highest feather-degrading activity and was selected for further taxonomical study. Phylogenetic analysis of strain F7-1 based on comparison of 165 rDNA sequences revealed that this strain is closely related to Bacillus megaterium.

• Microbiology and Biotechnology Letters
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• v.29 no.3
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• pp.142-148
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• 2001

An indigenous antagonistic bacterium Bacillus sp. 7079 was isolated from a local soil sampled at Kyongju area in Korea . The strain has strong antagonistic ability which was originated from multifunctional mechanisms of chitinase and antibiotic and is a powerful antagonistic biocontrol agent against red-pepper rotting fungus Phytophthora capsici and Wilt fungus Fusarium oxysporum. The chitinase might degrade the cell wasll for Fusarium species. The selected Bacilus sp. 7079 was identified as a Bacillus amyloliquefaciens 7079. The maximal production of the chitinase from B, amyloliquefaciens 7079 were obtained in chitin-yeast extract medium containing 0.7%, $K_2$$HPO_4$, $0.2KH_2$$PO_4$, 0.1% ($NH_4$)$_2$$SO_4$, 0.05% sodium cirate, 0.01% $MgSO_4$$7H_2$O, 0.1% yeast extract and 0.1% colloidal chitin after cultivation of 3 days at pH 7.0 and $30^{\circ}C$. The best carbon and nitrogen sources for the production of the chitinase from B amyloliquefaciens 7079 were determined to be 0.1% colloi- dal chitin and 0.15% proteose peptone NO 3 respectively, The antagonistic activity of B amyloliquefaciens 7079 was confirmed using P. capsici by in vivo pot test with red-pepper plant.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1054-1059
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• 2005

An extracellular protease was identified from Bacillus subtilis KCCM 10257 by N-terminal sequencing and mass spectral analysis. The molecular mass of the extracellular protease was estimated to be 28 kDa by SDS-PAGE. Sequencing of the N-terminal of the protease revealed the sequence of A(G,S,R)QXVPYG(A)V(P,L)SQ. The N-terminal sequence exhibited close similarity to the sequence of other proteases from Bacillus sp. A mass list of the monoisotopic peaks in the MALDI-TOF spectrum was searched after peptide fragmentation of the protease. Six peptide sequences exhibiting monoisotopic masses of 1,276.61, 1,513.67, 1,652.81, 1,661.83, 1,252.61, and 1,033.46 were observed from the fragmented protease. These monisotopic masses corresponded to the lytic enzyme L27 from Bacillus subtilis 168, and the Mowse score was found to be 75. A doubly charged Top product (MS) at a m/z of 517.3 exhibiting a molecular mass of 1034.6 was further analyzed by de novo sequencing using a PE Sciex QSTAR Hybrid Quadropole-TOF (MS/MS) mass spectrometer. MS/MS spectra of the Top product (MS) at a m/z of 517.3 obtained from the fragmented peptide mixture of protease with Q-star contained the b-ion series of 114.2, 171.2, 286.2, 357.2, 504.2, 667.4, 830.1, and 887.1 and y-ion series of 147.5, 204.2, 367.2, 530.3, 677.4, 748.4, 863.4, and 920.5. The sequence of analyzed peptide ion was identified as LGDAFYYG from the b- and y-ion series by de novo sequencing and corresponded to the results from the MALDI-TOF spectrum. From these results the extracellular protease from Bacillus subtilis KCCM 10257 was successfully identified with the lytic enzyme L27 from Bacillus subtilis 168.

• Journal of Life Science
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• v.27 no.9
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• pp.1031-1039
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• 2017

The aim of this study was to investigate the potential effects of extracts from silkworm Bombyx mori L. fermented with Bacillus subtilis KACC 91157 at levels of 5%(v/w) and 10%(v/w) in Sprague-Dawley rats intoxicated with 1%(w/w) orotic acid (OA) for 10 days. The rats were divided into a normal group (N), a control group (C: OA), and treatment groups (SP10: OA + 10% extracts from B. mori L.; BSP5: OA + 5% extracts from B. mori L. fermented with B. subtilis KACC 91157; BSP10: OA + 10% extracts from B. mori L. fermented with B. subtilis KACC 91157). Serum activities of aspartate aminotransferase (AST), alanine transferase (ALT), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) increased following OA feeding, but the rise was slightly reduced by administration of BSP10. The total lipid, free fatty acid, phospholipid, total cholesterol, and triglyceride contents in serum were significantly lower in the OA treatment groups than in the N group. However, the contents slightly increased following the administration of BSP10. Glutathione concentrations in liver and serum were reduced in the OA-induced fatty liver, but they increased following the administration of BSP10. Hepatocytes in the OA-induced fatty liver contained numerous large droplets. However, SP10, BSP5, and BSP10 feeding prevented OA-induced lipid droplet accumulation in hepatocytes. Accordingly, extracts from silkworm powder fermented with B. subtilis could be an ideal material as a dietary supplement in healthy functional foods to improve the effects of fatty liver.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.118-126
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• 2013

The experiment was carried out to analyze the inhibition effect of plant pathogenic fungi and growth promotion activity induced by the bacterial strains isolated from peatmoss. Among the isolated bacterial strains, B10-2, B10-4, B10-5 and B10-6 which showed more than 30% inhibition rate against Botrytis cinerea and Rhizoctonia solani in vitro, were further analyzed in the greenhouse for the growth promotion activity on lettuce (Lactuca sativa), pak-choi (Brassica compestris L. ssp. chinensis) and Chinese cabbage (Brassica campestris L. ssp. pekinensis). The results showed the treatment of B10-4 on lettuce showed the highest growth promotion activity with the leaf area ($169.17cm^2$), fresh weight (leaf: 40.29 g, root: 8.80 g)and dry weight (leaf: 11.24 g, root: 4.17 g), which was about two folds as compared to control. On pak-choi, the growth promotion rate was the highest with the leaf area of $112.87cm^2$, leaf fresh weight of 60.70 g, root fresh weight of 3.37 g, leaf dry weight of 14.34 g, and root dry weight of 1.90 g. As a result of treatment of B10-13 on chinese cabbage, the growth promotion rate was the highest with the leaf area ($293.56cm^2$), fresh weight (leaf: 113.67 g, root: 2.40 g) and dry weight (leaf: 6.03 g, root: 0.53 g). The production of Indole Acetic Acid (IAA) and Indole-3-Butylic Acid (IBA) were also analyzed in these bacterial isolates. The IAA and IBA analyses were carried out in all bacterial isolates each day within the 5 days of incubation period. The highest production of IAA was observed with $112.57{\mu}g/mg$ protein in B10-4 after 3 days of incubation and IBA production was the highest in B10-2 with $58.71{\mu}g/mg$ protein after 2 days of incubation. Also, phosphate solubilizing activity was expressed significantly in B10-13 in comparison to that of other bacterial isolates. Bacterial identification showed that B10-2 was Bacillaceae bacterium and B10-5 was Bacillus cereus, B10-4 and B10-6 were Bacillus sp. and B-13 was Staphylococcus sp. by ITS sequence.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.184-190
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• 1999

To acquire an industrially useful biocatalyst for the enzymatic synthesis and production of various D-amino acid aminotransferase (D-AAT) activity. The enzyme activity was found from 110 strains of isolated thermophiles revealing its wide occurrence in thermophiles. Enzyme activity and thermal stability of the D-AAT producers were compared. Finally we have selected four thermophiles as producers of potent biocatalysts for the D-amino acid production; two thermophiles, Bacillus sp. Lk-1 and LK-2, having higher specific activity and two thermophiles, B. stearothermophilus KL-01 and Bacillus sp. KLS-01, having higher thermal stability than the D-AAT producers. Taxonomic and physiological characteristics of the four isolated thermophiles were described herein.