• Asian Journal of Turfgrass Science
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• v.11 no.3
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• pp.173-183
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• 1997

This study was conducted to develop an integrated disease management system against large patch disease. Attempts were made to estimate the effect of calcium hydroxide, silicate fertilizer and urea on the mycelial growth of Rhizoctonia sotani AG2-2 and the development of large patch in vitro and in vivo and to establish the most promising combination of fertilizer, fungicide and antagonistic microbes. 1.The mycelial growth of Rhizoctonia sotani AG2-2 were completely inhibited at 2,000, 1,000 and 3,000ppm concentration by calcium hydroxide, silicate fertilizer and urea, respectively. Inhibition effect of silicate fertilizer was the highest, but that of urea was the lowest compared with other treatments. 2.Treatment of calcium hydroxide at rate of l00g /$m^2$ was the most effective, and control effect appeared from 30 days after treatment in spring, which was better in autumn than in spring. Silicate fertilizer treated at rate of l00g /$m^2$, 200g /m$^2$, in spring and 50g /$m^2$ in autumn were very effective. Urea at rate of 30g /$m^2$ was more effective than 60g /m$^2$ and 120g /m$^2$. 3.The efficacies of mepronil and toclofos-methyl, applied twice in spring and once in autumn, were 83.8% in spring, which persisted to 70% in autumn compared with untreated plot. 4.The efficacies of Trichoderma harzianum were the highest by 55% in spring, but those of Bacillus amyloliquefaciens BL-3 and Peudomonas putida were the highest by 80% in autumn among other antagonists tested, when two organisms were applied twice in spring and once in autumn.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.9-18
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• 2017

Nine bacilli with fibrinolytic activities were isolated from doenjang, a traditional Korean fermented soy food. Among them, RSB34 showed the strongest activity and was identified as Bacillus amyloliquefaciens by 16S rRNA and recA gene sequencing. During growth on LB up to 96 h, RSB34 showed the highest fibrinolytic activity ($83.23mU/{\mu}l$) at 48 h. Three bands of 23, 27, and 42 kDa in size were observed when the culture supernatant was analyzed by SDS-PAGE and 27 and 42 kDa bands by fibrin zymography. The gene encoding the 27 kDa fibrinolytic enzyme AprE34 was cloned by PCR. BLAST analyses confirmed that the gene was a homolog to genes encoding AprE-type proteases. aprE34 was overexpressed in Escherichia coli BL21(DE3) using pET26b(+). Recombinant AprE34 was purified and examined for its properties. The $K_m$ and $V_{max}$ values of recombinant AprE34 were $0.131{\pm}0.026mM$ and $16.551{\pm}0.316{\mu}M/l/min$, respectively, when measured using an artificial substrate, N-succinyl-ala-ala-pro-phe-p-nitroanilide. aprE34 was overexpressed in B. subtilis WB600 using pHY300PLK. B. subtilis transformants harboring pHYRSB34 (pHY300PLK with aprE34) showed higher fibrinolytic activity than B. amyloliquefaciens RSB34.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.141-148
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• 2001

Postharvest decay of onion bulbs was examined by inspecting the commercial packages in the market or in storage. Bulb rot incidence was unexpectedly high, and onion bulbs with 1st quality grade were rotten most severely by 51%, followed by 32% for 2nd and 21% for 3rd grades. This indicates that larger bulbs had higher incidences of bulb rots. Major pathogens associated with basal and neck rots were Fusarium oxysporum and Aspergillus sp. or Botrytis allii, respectively, of which basal rot was most prevalent and damaging during storage. Among the epiphytic microorgani는 from onion plants, several Bacillus and Paenibacillus spp. and previously selected Pseudomonas putida and Trichoderma harzianum had inhibitory efficacy against bulb rot pathogens. Among these B. amyloliquefaciens BL-3, Paenibacillus polymyxa BL-4, and P. putida Cha 94 were highly inhibitory to conidial germination of F. oxysporum and B. allii. P. putida Cha 94, B. amyloliquefaciens BL-3, P. polymyxa BL-4, and T. harzianum TM were applied in the rhizoplane of onion at transplanting. Initially antagonist populations decreased rapidly during the first one month. However, among these antagonists, rhizoplane population densities of BL-3, Cha 94, and TM were consistently high thereafter, maintaining about 10$^4$-10$^{5}$ cells or spores per gram of onion root up to harvest time. The other bacterial antagonist BL-4 survived only for two months. TM was the most effective biocontrol agent against basal rot, with the number of rotten bulbs recorded at 4%, while that of the control was 16%. Cha 94 was effective for the first 20 days, but basal rot increased thereafter and had about the same control efficacy as that of BL-3 and BL-4. When the antagonists were applied to the topping areas of onion bulbs at harvest, TM was the most effective in protecting the stored onion bulbs from neck rotting. The second effective antagonist was BL-3. TM and BL-3 completely suppressed the neck rot in another test, suggesting that biocontrol of postharvest decay of onion using these microorganisms either at the time of transplanting or at harvesting may be promising.

• The Plant Pathology Journal
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• v.15 no.3
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• pp.162-167
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• 1999

Integration of microbial antagonists with fungicides was tried to control the gray mold caused by Botrytis cinerea on pepper in greenhouse conditions and to reduce fungicide uses. All of the selected bacterial antagonists, Bacillus amyloliquefaciens BL3, Paenibacillus polymyxa BL4, and Pseudomonas putida Cha94, completely inhibited the conidial germination of B. cinerea until 30 days after treatment. However, bacterial colonization of pepper phylloplane was poor in BL4, while the other bacterial isolates and the fungal antagonist Trichoderma harzianum TM colonized well on the phylloplane, maintaining the population density of 104-105 cfu/g until 15 days after microbial treatments. Out of 13 kinds of selected fungicides used for gray mold diseases, polyoxin B and BKF 1995 showed the most discriminatory activity on the fungal growth between B. cinerea and TM. TM grew readily on the media containing those fungicides, while B. cinerea showed poor or no mycelial growth on them. The selected fungicides and antagonists alone reduced incidence of gray mold on pepper, showing disease indices of about 2.4 to 3.0, while its was increased up to 4.2 in the untreated control. Alternate treatments with the antagonists and 2-fold diluted fungicides inhibited the disease incidence as much as the antagonists or fungicides alone, and reduced the secondary inoculum more than the single treatments. This suggests that integration of antagonists and fungicides may be an efficient way to reduce fungicide sprays with reliable control efficacy of the disease. However, there was not much difference in the early and mid-term disease progress among the treatments and the untreated control, probably due to extremely favorable environmental conditions for the disease development in this experiment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.279-288
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• 2017

This study investigated the manufacturing of fermented soybean oil using a fermenting strain commonly processed for soybeans [Bacillus amyloliquefaciens (BA), Bacillus subtilis (BS), Lactobacillus acidophilus (LBA), and B. subtilis+L. acidophilus (BLO)] and evaluated its anti-obesity activities. Cytotoxicity of four kinds of fermented soybean oils was not observed in 3T3-L1 preadipocytes at 10 and $50{\mu}g/mL$. Triglyceride content was reduced by 20.6% in the BLO group at a treatment concentration of $50{\mu}g/mL$. The simultaneous treatment of fermented soybean oil and differentiation induction medium decreased $PPAR{\gamma}$ and $C/EBP{\alpha}$ gene expression at a concentration of $50{\mu}g/mL$ and blocked adipocyte differentiation by increasing adiponectin gene expression. The inhibitory effect of adipocyte differentiation was greatest in the BLO group. C57BL/6J mice were examined for 4 weeks after being separated into seven groups [normal diet group (N), high fat diet group (C), group fed high fat diet combined with regular soybean oil (SO), group fed non-fermented soybean oil (NF), and groups fed high fat diet combined with 5% fermented soybean oil (BA, BS, LBA, and BLO)] to identify the effects of soybean oil on body weight, serum lipid, adiponectin, insulin, and leptin levels in mice with high fat diet-induced obesity. The body weight and serum lipid level of the C group increased drastically compared to those of the N group. In contrast, the group fed a diet combined with fermented soybean oil showed decreases in weight, serum total cholesterol, LDL-cholesterol, and triglyceride levels compared to those of the C group. Moreover, soybean oil was found to be effective in the BLO group. In conclusion, fermented soybean oil has positive effects in prohibiting adipocyte differentiation increased by high fat diet and improving serum lipid composition. Therefore, fermented soybean oil can be used as a functional food material with anti-obesity activity.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1070-1083
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• 2015

A gene (GT-SM3B) encoding a thermostable secreted oligoendopeptidase (GT-SM3B) was cloned from the thermophile Geobacillus thermoleovorans DSM 15325. GT-SM3B is 1,857 bp in length and encodes a single-domain protein of 618 amino acids with a 23-residue signal peptide having a calculated mass of 67.7 kDa after signal cleavage. The deduced amino acid sequence of GT-SM3B contains a conservative zinc metallopeptidase motif (His⁴⁰⁰-Glu⁴⁰¹-X-XHis⁴⁰⁴). The described oligopeptidase belongs to the M3B subfamily of metallopeptidases and displays the highest amino acid sequence identity (40.3%) to the oligopeptidase PepF_Ba from mesophilic Bacillus amyloliquefaciens 23-7A among the characterized oligopeptidases. Secretory production of GT-SM3B was used, exploiting successful oligopeptidase signal peptide recognition by Escherichia coli BL21 (DE3). The recombinant enzyme was purified from the culture fluid. Homodimerization of GT-SM3B was determined by SDS-PAGE. Both the homodimer and monomer were catalytically active within a pH range of 5.0–8.0, at pH 7.3 and 40℃, showing the K_m, V_max, and k_cat values for carbobenzoxy-Gly-Pro-Gly-Gly-Pro-Ala-OH peptidolysis to be 2.17 ± 0.04 × 10^-6 M, 2.65 ± 0.03 × 10^-3 µM/min, and 5.99 ± 0.07 s^-1, respectively. Peptidase remained stable at a broad pH range of 5.0–8.0. GT-SM3B was thermoactive, demonstrating 84% and 64% of maximum activity at 50℃ and 60℃, respectively. The recombinant oligopeptidase is one of the most thermostable M3B peptidase, retaining 71% residual activity after incubation at 60℃ for 1 h. GT-SM3B was shown to hydrolyze a collagenous peptide mixture derived from various types of collagen, but less preferentially than synthetic hexapeptide. This study is the first report on an extracellular thermostable metallo-oligopeptidase.