• Title/Summary/Keyword: Microbial Properties

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Microbiological Control of Insect Pests (해충의 미생물학적 방제)

  • Kawase Shigemi
    • Korean journal of applied entomology
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    • v.22 no.2 s.55
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    • pp.67-73
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    • 1983
  • Despite the great importance of chemical insecticides, with the ever increasing resistance of pest insects to chemical insecticides and the growing concern over environmental pollution, it becomes evident that the problem of pest attack on crops cannot be solved by anyone system. Under these circumstances, main pathogens of insects, i.e., viruses, bacteria, fungi and protozoa, have been studied to control many insect pests. Some of these pathogens are now being produced as microbial insecticides at the rate of hundreds of tons per year in the world. Some microbial insecticides are very effective against numerous or target insects under suitable environmental condition, and microbial control has been played an important role in integrated control program. They have many unique properties such as selectivity, multiplication and harmless to higher animals. However, we must be aware also that there are many problems to be solved, such as safety, persistence and difficulty of efficacy, etc_ on the microbial insecticides.

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Potential for Efficient Synthesis of GSH Utilizing GCS1 and GLR1 Mutant Strains of Candida albicans

  • Jaeyoung SON;Min-Kyu KWAK
    • The Korean Journal of Food & Health Convergence
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    • v.10 no.2
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    • pp.7-11
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    • 2024
  • Glutathione (GSH) is a vital compound composed of glutamic acid, cysteine, and glycine, crucial for cellular functions including oxidative stress defense and detoxification. It has widespread applications in pharmaceuticals, cosmetics, and food industries due to its antioxidant properties and immune system support. Two primary methods for GSH synthesis are enzymatic and microbial fermentation. Enzymatic synthesis is efficient but costly, while microbial fermentation, particularly using yeast strains like Candida albicans, offers a cost-effective alternative. This study focuses on genetically modifying C. albicans mutants, specifically targeting glutathione reductase (GLR1) and gamma-glutamylcysteine synthetase (GCS1) genes, integral to GSH synthesis. By optimizing these mutants, the research aims to develop a model for efficient GSH production, potentially expanding its applications in the food industry.

Effects of Composts and Soil Amendments on Physicochemical Properties of Soils in Relation to Phytophthora Root and Crown Rot of Bell Pepper

  • Kim, Ki-Deok;Nemec, Stan;Musson, George
    • The Plant Pathology Journal
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    • v.16 no.5
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    • pp.283-285
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    • 2000
  • Two field tests were conducted in 1995 to examine the effects of composts and soil amendments on physicochemical properties of soil in relation to Phytophthora root and crown rot of bell pepper. Chitosan, crab shell waste, humate, sewage sludge-yard trimmings, and wood chips were applied to test plots, some of which affected the levels of P, K, Mg, pH, and H. Physicochemical properties were not related with disease incidence, but percent organic matter, estimated nitrogen release, K, and Mg were correlated with total microbial activity. The elements K and Mg were especially responsible for the increased soil microbial activity that could affect development of root and crown rot of pepper.

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Effects of Ozone Treatment and Gamma Irradiation on the Microbial Decontamination and Physicochemical Properties of Red Pepper Powder (고춧가루의 오염미생물 제거 및 이화확적 특성에 관한 오존처리와 감마선 조사의 영향)

  • 이성희;이현자;변명우
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.3
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    • pp.465-467
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    • 1997
  • The comparative effects of ozone treatment and gamma irradiation on the sterilization, physicochemical properties and sensory quality of red pepper powder were investigated. As for the sterilization of microorganisms, 7.5~10 KGy of gamma irradiation completely eliminated the coliforms, yeast and molds, and total aerobic bacteria. On the other hand, ozone treatment failed to eliminate the highly contaminated microbial load, especially total aerobic bacteria. The physicochemical properties including capsaicin, capsanthin, browning, fatty acid compositions and sensory quality were not significantly changed by gamma irradiation up to 10 kGy, whereas ozone treatment caused significant changes in fatty acid compositions and destruction of natural pigments (p<0.05). The above results led us to conclude that gamma irradiation was more effective than ozone treatment for the sterilization and maintenance of physicochemical and sensory qualities of red pepper powders.

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Effect of Pineapple Protease on the Characteristics of Protein Fibers

  • Koh Joon-Seok;Kang Sang-Mo;Kim Soo-Jin;Cha Min-Kyung;Kwon Yoon-Jung
    • Fibers and Polymers
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    • v.7 no.2
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    • pp.180-185
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    • 2006
  • A pineapple protease, bromelain, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the pineapple protease was about $60^{\circ}C$ at pH 7. The wool and silk were treated with the protease extracted from a pineapple and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The protease treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of protease-treated fibers were observed by microscopy.

Effects of Packaging Materials on the Physicochemical Characteristics of Seasoned Anchovies During Storage (포장재가 멸치조미가공품의 저장 중 이화학적 품질 특성에 미치는 영향)

  • Lee, Eui-Seok;Lee, Hyong-Ju;Bae, Jae-Seok;Kim, Yong-Kuk;Lee, Jong-Hyeouk;Hong, Soon-Taek
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.4
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    • pp.461-469
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    • 2013
  • This research is performed to investigate the changes in the physicochemical properties and microbial growths of seasoned anchovies with various packaging materials (PET/CPP : polyethylene terephthalate/cast polypropylene, PET/EVOH : polyethylene terephthalate/ethylene-vinyl alcohol, PET/AL/LDPE: polyethylene terephthalate/aluminum/low density polyethylene), which are stored at various temperatures (25, 35, $45^{\circ}C$) for 60 days. Generally, it is being observed that changes in physicochemical properties (i.e., moisture content, color, brown intensity, TBA value, TMA, VBN etc) of seasoned anchovies are significant when stored at higher temperatures. Particularly, the packaging materials are found to influence substantially on the physicochemical properties of seasoned anchovies. With packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e., PET/CPP), the changes in physicochemical properties of seasoned anchovies are significant, while being low with low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). In addition, results of microbial growths in seasoned anchovies show that significant increases in total aerobic bacteria counts (about 100-fold after 60 day of storage) are observed in samples with packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e, PET/CPP), while with only small increases for samples of low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). Based on the changes in the physicochemical properties and results of microbial growths, it is being concluded that PET/EVOH film is suitable for the packaging of seasoned anchovies.

Microbial Transglutaminase Modifies Gel Properties of Porcine Collagen

  • Erwanto, Y.;Kawahara, S.;Katayama, K.;Takenoyama, S.;Fujino, H.;Yamauchi, K.;Morishita, T.;Kai, Y.;Watanabe, S.;Muguruma, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.2
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    • pp.269-276
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    • 2003
  • We studied the gel properties of porcine collagen with microbial transglutaminase (MTGase) as a catalyst. A creep meter was used to measure the mechanical properties of gel. The results showed samples with high concentration of MTGase gelled faster than those with a low concentration of MTGase. The gel strength increased with incubation time and the peaks of breaking strength for 0.1, 0.2 and 0.5% MTGase were obtained at 40, 20 and 10 min incubation time, respectively. According to SDS-PAGE, the MTGase was successfully created a collagen polymer with an increase in molecular weight, whereas no change in formation was shown without MTGase. The sample with 0.5% MTGase began to polymerize after 10 or 20 min incubation at $50^{\circ}C$, and complete polymerization occurred after 40-60 min incubation. Scanning electron microscopic analysis revealed that the gel of porcine collagen in the presence of MTGase produced an extremely well cross-linked network. The differential scanning calorimetric analysis showed the peak thermal transition of porcine collagen gel was at $36^{\circ}C$, and that with MTGase no peak was detected during heating from 20 to $120^{\circ}C$. The melting point of porcine collagen gel could be controlled by MTGase concentration, incubation temperature and protein concentration. Knowledge of the structural and physicochemical properties of porcine collagen gel catalyzed with MTGase could facilitate their use in food products.

Effects of Soil Microbial Agent with Red Ginseng Marc on Growth of Watermelon -A Field Study- (홍삼박을 활용한 토양미생물제제가 수박의 생육에 미치는 영향 -현장연구를 중심으로-)

  • Ryu, Hyo-Seung;Lee, Jong-Wha;Kim, Chang-Man;Choi, In-Hag
    • Journal of Environmental Science International
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    • v.24 no.12
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    • pp.1705-1710
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    • 2015
  • The aim of the present study was to determine the effects of soil microbial agent with red ginseng marc on growth of watermelon during 5 months. The three treatments were distributed in a completely randomized design with four replicates per plot. After 1 week in planting dates, the growth of watermelon (full length, stem thichness, leaf length and lead width) showed no significant difference in all treatments. During elongation stage (20 days), soil microbial agent with red ginseng marc was increased by 5% in leaf thickness (May 23) and 7~14% in leaf length (May 16 and 23) when compared to other treatments. For changes in fruit bearing thickness, there were no differences among treatments. Characteristics of watermelon in harvest season have an effect on harvest and length, stalk length, naval length, weight, sugar content and yield, except for harvest and width. In particular, yields increased with treatments with two soil microbial agent (7~12%), indicating that soil microbial agent with red ginseng marc showed higher yield than the other treatments. In conclusion, red ginseng marc-treated soil microbial agents have a positive effect on the harvest season of watermelon and can provide useful information for the selection of the functional microbial properties and the registration of microbial fertilizer.

Effects of microbial enzymes on starch and hemicellulose degradation in total mixed ration silages

  • Ning, Tingting;Wang, Huili;Zheng, Mingli;Niu, Dongze;Zuo, Sasa;Xu, Chuncheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.2
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    • pp.171-180
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    • 2017
  • Objective: This study investigated the association of enzyme-producing microbes and their enzymes with starch and hemicellulose degradation during fermentation of total mixed ration (TMR) silage. Methods: The TMRs were prepared with soybean curd residue, alfalfa hay (ATMR) or Leymus chinensis hay (LTMR), corn meal, soybean meal, vitamin-mineral supplements, and salt at a ratio of 25:40:30:4:0.5:0.5 on a dry matter basis. Laboratory-scale bag silos were randomly opened after 1, 3, 7, 14, 28, and 56 days of ensiling and subjected to analyses of fermentation quality, carbohydrates loss, microbial amylase and hemicellulase activities, succession of dominant amylolytic or hemicellulolytic microbes, and their microbial and enzymatic properties. Results: Both ATMR and LTMR silages were well preserved, with low pH and high lactic acid concentrations. In addition to the substantial loss of water soluble carbohydrates, loss of starch and hemicellulose was also observed in both TMR silages with prolonged ensiling. The microbial amylase activity remained detectable throughout the ensiling in both TMR silages, whereas the microbial hemicellulase activity progressively decreased until it was inactive at day 14 post-ensiling in both TMR silages. During the early stage of fermentation, the main amylase-producing microbes were Bacillus amyloliquefaciens (B. amyloliquefaciens), B. cereus, B. licheniformis, and B. subtilis in ATMR silage and B. flexus, B. licheniformis, and Paenibacillus xylanexedens (P. xylanexedens) in LTMR silage, whereas Enterococcus faecium was closely associated with starch hydrolysis at the later stage of fermentation in both TMR silages. B. amyloliquefaciens, B. licheniformis, and B. subtilis and B. licheniformis, B. pumilus, and P. xylanexedens were the main source of microbial hemicellulase during the early stage of fermentation in ATMR and LTMR silages, respectively. Conclusion: The microbial amylase contributes to starch hydrolysis during the ensiling process in both TMR silages, whereas the microbial hemicellulase participates in the hemicellulose degradation only at the early stage of ensiling.

Analysis of Soil Microbial Communities Formed by Different Upland Fields in Gyeongnam Province

  • Kim, Min Keun;Ok, Yong Sik;Heo, Jae-Young;Choi, Si-Lim;Lee, Sang-Dae;Shin, Hyun-Yul;Kim, Je-Hong;Kim, Hye Ran;Lee, Young Han
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.2
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    • pp.100-106
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    • 2014
  • The present study investigated variations in soil microbial communities by fatty acid methyl ester (FAME) and the chemical properties at 24 sites of upland soils in Gyeongnam Province. The electrical conductivity of the soil under potato cultivation was significantly higher than those of the red pepper and soybean soils (p < 0.05). The gram-negative bacteria community in potato soil was significantly lower than those in the garlic and soybean soils (p < 0.05). The communities of actinomycetes and arbuscular mycorrhizal fungi in the red pepper soil were significantly higher than those in the potato soil (p < 0.05). In addition, the cy17:0 to 16:$1{\omega}7c$ ratio was significantly lower in red pepper, soybean, and garlic soils compared with potato soil, indicating that microbial stress decreased. Consequently, differences in soil microbial community were highly associated with cultivated crop species, and this might be resulted from the difference in soil chemical properties.