• Journal of Microbiology and Biotechnology
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• 제13권1호
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• pp.125-133
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• 2003

Chemical properties and physiological activities of the freeze-dried synnemata of Beauveria bassiana were examined. A proximate analysis showed that the synnemata consisted mainly of carbohydrate (49.86%), protein 11.36%), and a moisture content of 30.64%. It contained a low amount of crude ash (4.76%) and fat (3.38%). The carbohydrate was composed mainly of mannose (52.3%), galactose (31.5%), glucose (13.2%), and rhamnose (3%). Trace amounts of arabinose, xylose, and fructose were present. Major amino acids In the synnemata were glutamic acid, glycine, aspartic acid, arginine, threonine, alanine, valine, leucine, lysine, and aspartic acid with the amounts of 30.42, 25.22, 17.17, 15.12, 12.65, 15.23, 12.47, 11.47, 14.24, and 17.17 mg/g, respectively. Among extracts from the synnemata, the hot-water extract showed 67% of anticomplementary activity compared to that of the positive control, followed by ethyl acetate extract (17%) and methanol extract (15%). The hot-water extract also had anticoagulant activity with 55 sec of coagulating time and this fraction exhibited the most potent Intestinal immune system modulating activity. The methanol extract showed the highest inhibitory activity (25%) on the 12-O-tetradecanoyl phorbol-13-acetate-induced superoxide ($O_2^-$) generation, followed by hot-water extract (18%) and ethyl acetate extract (10%). The data in the present study indicate that the extract of Beauveria bassiana synnemata contains some healthful chemical ingredients and it could provide beneficial physiological activities. These features of the synnemata should be of interest to the food industry as well as other industrial fields.

• 한국버섯학회지
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• 제9권2호
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• pp.87-89
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• 2011

뽕나무병원성세균에 대한 Beaveria bassiana 6균주의 항균활성을 paper disc법으로 조사하였고 최소성장저해농도(MIC)를 액체배지희석법으로 조사하였다. 항균활성은 B. bassiana J200에서만 나타났으며, Erwinia rhapontici KACC 10407에서는 13mm, Pseudomonas syringae KACC 10390와 Xanthomonas campestris KACC 12134에서는 각각 17 mm의 항균활성이 나타났다. MIC 측정 결과 E. rhapontici KACC 10407, P. syringae KACC 10390 및 X. campestris KACC 12134 모두 4.0%에서 MIC를 보였다. 이상의 결과로 B. bassiana의 뽕나무병원성세균에 대한 생물학적 방재제로서의 이용 가능성을 확인하였다.

• 미생물학회지
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• 제38권1호
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• pp.50-53
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• 2002

백강균(Beauveria bassiana DGUM 34001)은 $24^{\circ}C$의 온도와pH 7.0의 초기 pH에서 최적의 균사체 생육을나타내었다. 사용한 복합배지 중 mushroom complex배지(MCM)에서 가장 우수한 균사생육을 나타내었다. Czapek-Dox 한천배지를 최소배지로 각각 탄소원, 질소원 및 인산원의 영향을 조사한 결과, glucose, soytone 및 sodium phosphate ($NaH_2$$PO_4$)에서 가장 우수한 균사 생육을 보여주었다. MCM액체배지에서 균사 배양 후 세포외 효소 활성을 측정한 결과,$\alpha$-amylase, lipase, chitinase, CMCase및 pretense의 비효소활성은 각각 297.0, 0.058, 0.33, 0.21 및 22.8 units/mg protein이었다. Casein과 soluble chitosan을 첨가할 경우 세포외 분비 pretense와 chitinase의 효소 활성 이 증가되었다.

• 한국균학회지
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• 제39권3호
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• pp.256-258
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• 2011

곤충병원성 곰팡이 B. bassiana KK5균의 포자 발아 촉진제를 조사하기 위한 연구가 수행되었다. 탄수화물을 포함한 18 화합물을 B. bassiana 포자와 혼합하여 12시간 동안 water agar에서 배양하였다. 18종의 화합물 중 fructose, mannose 그리고 skim milk와 혼합된 포자의 발아율은 배양 12시간 후 무처리와 비교하여 촉진되는 것으로 조사되었다. 발아 촉진 효과가 확인된 1% fructose, mannose 또는 skim milk와 포자 혼합액을 진딧물에 살포 하였을 때, skim milk와 포자 혼합액의 처리에서 복숭아혹진딧물 3령 약충에 대한 살충증진 효과를 보였다.

• Applied Biological Chemistry
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• 제40권5호
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• pp.388-394
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• 1997

곤충 병원성 곰팡이 Beauveria bassiana ATC7159의 배양여액으로부터 균체외 protease (basiasin I)를 Ammonium sulfate 침전, DEAE-Sephadex A-50, CM-cellulose 및 Hydroxyapatite column chromatography를 수행하여 완전히 정제하였다. 이 과정으로 41배 정제되었으며 정제수율은 13.6%였다. 정제된 bassiasin I의 분자량은 SDS-PAGE 상에서 약 32,000 Da이며 pI값은 9.5로 확인되었다. $NH_2$ 말단 아미노산 서열은 다른 곤충 병원성 곰팡이가 생산하는 pretense들과 높은 상동성을 보였다. Protease 활성의 최적 pH는 10.5 부근이며, pH 5.0-11.0범위에서 안정하였다. 최대 활성온도는 $60-65^{\circ}C$이며, $60^{\circ}C$에서 120분후에 약 20%의 잔존활성을 보였다. 이 pretense는 phenylmethylsulfonyl fluoride (PMSF) 및 diisopropyl fluorophosphate (DFP)에 의해 저해된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.189-194
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• 2002

Silkworm diseases are major constraint in silk cocoon production. Among silkworm diseases, white muscar-dine is highly contagious and most common in winter and rainy seasons. It is suggested that hemocytes involve in defense against invasion of Beauveria bassi-ana and systemic fungicide/chemicals prevent the proliferation of fungi in the hemolymph or preventing the growth of the fungi in the body cavity through enhancing the hemocyte mediated defense response. In the present study the influence of systemic fungicide on hematological changes in silkworms infected with Beauveria bassiana was reported. It is observed that the total hemocyte counts increased in the hemolymph up to 5 days post inoculation in systemic fungicide treated batches while in the inoculated control the increase was up to 3 days indicating the positive hemocyte mediated response in silkworm treated with systemic fungicide. After 2 days in the inoculated control as the multiplication and growth of mycelia increased, defense capacity of the silkworm was decreased. The biochemical changes were also observed in the hemolymph of silkworm infected with B. bassiana. In silkworm infected with Beauveria bassi-ana, the total protein content increased whereas total carbohydrate and total lipids decreased as the infection progresses. In the case of systemic fungicide treated batches the increase in total protein content was comparatively higher and decrease in total carbohydrate and lipids were comparatively lower than the inoculated control.

• Mycobiology
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• 제40권2호
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• pp.111-116
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• 2012

Ten strains of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana were evaluated to find the most effective strain for optimization studies. The first criterion tested for strain selection was the mortality (> 50%) of Spodoptera litura larvae after inoculation of the fungus for 4 days. Results on several bioassays revealed that B. bassiana BNBCRC showed the most virulence on mortality S. litura larvae (80% mortality). B. bassiana BNBCRC also showed the highest germination rate (72.22%). However, its conidia yield ($7.2{\times}10^8$ conidia/mL) was lower than those of B. bassiana B 14841 ($8.3{\times}10^8$ conidia/mL) and M. anisopliae M6 ($8.2{\times}10^8$ conidia/mL). The highest accumulative radial growth was obtained from the strain B14841 (37.10 mm/day) while the strain BNBCRC showed moderate radial growth (24.40 mm/day). M. anisopliae M6 possessed the highest protease activity (145.00 mU/mL) while M. anisopliae M8 possessed the highest chitinase activity (20.00 mU/mL) during 96~144 hr cultivation. Amongst these criteria, selection based on virulence and germination rate lead to the selection of B. bassiana BNBCRC. B. bassiana B14841 would be selected if based on growth rate while M. anisopliae M6 and M8 possessed the highest enzyme activities.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.604-612
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• 2011

Beauveria bassiana SFB-205 supernatant can effectively control cotton aphid populations, which is closely associated with its chitinase activity. The present work extends to optimizing a culture medium to produce more efficacious supernatant in flask conditions, followed by scale-up in 7 L, 300 L and 1.2 KL fermentors with the parameter of chitinase. In flask conditions, a combination of soluble starch and yeast extract produced the greatest amount of chitinase (5.1 units/ml) and its supernatant had the highest aphicidal activity. An optimal quantitative combination of the two substrates, estimated by a response surface method, enabled the supernatant to have 15.7 units/ml of chitinase activity and 3.7 ml/l of median lethal concentration ($LC_{50}$) of toxicity against cotton aphid adults in laboratory conditions. In the scale-up conditions, overall supernatant had 25-28 units/ml of chitinase activity. Decrease in pH and limitation of dissolved oxygen (DO) during cultures were significantly related to the yield of chitinase. These results suggest that the substrate-dependent chitinase production can be background information for optimizing a culture medium, and pH and DO are critical factors in maximizing the production in scale-up conditions.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.211-215
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• 2008

To select entomopathogenic fungi controlling aphids effectively, several isolates were screened against second instars of Myzus persicae nymphs in the glasshouse using conidia suspension at $1.0{\times}10^5$ conidia/ml. Among these isolates, SFB-205 conidia showed the highest insecticidal activity about 32.7% efficacy to M. persicae at 4 days after application in the glasshouse. The attachment of SFB-205 conidia on the surface of M. persicae nymphs, and germination and penetration were observed using scanning electron microscopy. SFB-205 was identified as Beauveria bassiana species through the comparison of 5.8 s rRNA genes. There were 24 polymorphisms between SFB-205 and the previously reported isolate, B. bassiana ATCC74040 using six kinds of primer combinations in amplified fragment length polymorphism (AFLP) analysis. The B. bassiana SFB-205 might be used as a practical biological control agent for the green peach aphid, M. persicae in the field.

• Mycobiology
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• 제37권3호
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• pp.218-224
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• 2009

The principal objective of this study was to determine the optimal liquid culture conditions in shake flasks for maximal sporulation of Beauveria bassiana. The optimal initial pH for the spore production of B. bassiana using Potato Dextrose Broth was 5.2. The screening in shake flasks of carbon and nitrogen sources resulted in the identification of an optimal medium based on 3% sucrose and 1% casamino acid, with a C : N ratio of 22 : 4. Using this medium, a production level of $5.65{\times}10^7$ spores per ml was obtained after 5 days of culture. Using 3% corn meal, 2% corn steep powder, and 2% rice bran, the maximum spore concentration of $8.54{\times}10^8$/ml was achieved 8 days after inoculation at $25^{\circ}C$ in a rotary shaking incubator operated at 200 rpm. This represents a yield gain of approximately 2.89 times that of pre-optimization.