• Mycobiology
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• 제41권4호
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• 한국식품저장유통학회지
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• 제17권3호
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• pp.365-369
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• 2010

본 연구에서는 야생에서 분리한 눈꽃동충하초균의 배양적 특성을 알아보기 위해 배양특성 시험을 수행하였다. $25^{\circ}C$, 습도 60%에서 눈꽃동충하초균을 고체배양한 결과 초기 균사의 직경 12 mm에서 4일차에 균사체 직경이 36 mm 이었으며, 배양 5일차부터 급격한 균사신장이 일어나다가 8일차 이후부터는 생육속도가 서서히 감소되는 경향을 보였다. PDB 액체배지에서 종균배양의 상태와 생육도를 검토한 결과, PMV가 배양일차에 따라 1일차에 1%, 3일차에 4%로 증가하다가 7일차 이후부터는 11%로서 최대의 생육을 나타내었다. 따라서, 균의 질(quality)과 양(quantity)적인 측면에서 7일차 생육이 가장 양호함을 알 수 있었다. GPA, PDA, YM, MCM, Czapek 총 5가지 배지를 사용하여 고체배양을 실시한 결과 균사체 생육이 가장 양호한 배지는 PDA로 나타났다. pH에 따른 눈꽃동충하초 버섯의 생육정도를 알아보기 위해 배지의 pH를 5.0, 5.5, 6.0, 6.5, 7.0으로 달리하여 10일간 배양한 결과 균사체의 직경이 pH 6.0에서 85.0 mm/10일로 가장 양호하였으며, 중성영역보다는 산성영역인 pH 6.0 이하에서는 균사생장과 밀도가 감소하는 경향을 보였다. 동충하초버섯균의 균사생장에 미치는 온도의 영향을 조사한 결과, $25^{\circ}C$에서 균사생장과 밀도가 가장 양호하였다. 접종량에 따른 종균배양의 상태와 생육도를 검토한 결과 접종량 10% 사용시 가장 양호한 결과를 나타내었다. 비이드 첨가에 따른 균사체의 생육 및 형태를 알아보기 위하여 비이드의 크기를 직경 3 mm와 5 mm로 다르게 하여 PDB 배지에서 액체배양한 결과, 3 mm의 비드로 실험한 결과 비이드 첨가 개수가 0개에서 50개로 증가할수록 SED (%)가 31%에서 56%로 증가하여 균체의 생육이 양호한 것으로 나타났다. 비이드 크기는 3 mm보다 큰 5 mm를 첨가하여 배양하였을 때 SED와 PMV 값이 모두 높은 결과를 나타내었다.

• KSBB Journal
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• 제21권2호
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• pp.96-102
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• 2006

H. erinaceum은 식용은 물론 각종 약리효과를 나타내어 현재 산업적으로 매우 주목되고 있는 기능성 소재들 중의 하나이다. 본 연구에서는 H. erinaceum의 기능성 소재화 연구의 일환으로, 지금까지 체계적으로 연구된 바 없는 H. erinaceum의 액체배양을 시도하고. 이 버섯 액체배양의 최적화를 수행하였다. 16종 버섯 배지의 플라스크 배양을 통해 우수 기본 배지를 선발하였고, 이의 반응표면분석에 의해 배지 및 배양조건의 최적화를 수행한 결과, 최적 배지 조성은 glucose 3%, yeast extract/peptone(1:1) 0.2%, $KH_2PO_4/MgSO_4$(1:1) 0.2%이었으며, 최적 배양조건은 $22.28^{\circ}C$, pH 5.67, 접종량 13.42%에서 얻어졌다. 이러한 최적 배지 및 배양조건하에서 얻어진 균사체량은 약 9 g/L 이었으며, 이는 기본배지에서 배양 8일 후 얻어진 최대값인 5.40 g/L에 비하면 약 1.7배 향상된 결과이었다. 하지만 H. erinaceum의 액체배양시 낮은 균체량과 비교적 느린 생육이 관찰되어 보다 높은 생산성의 향상을 위해서는 이에 적합한 새로운 형태의 fermenter의 선정 및 새로운 배양 system의 적용이 필요한 것으로 나타났다.

• The Plant Pathology Journal
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• 제27권3호
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• pp.257-265
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• 2011

During 2002-2008 in Korea, 455 extracts from myxobacteria consisting of 318 cellulolytic and 137 bacteriolytic myxobacteria were isolated, which were then screened for antifungal activity against the phytopathogens Botrytis cinerea, Colletotrichum acutatum, Penicillium sp., Pyricularia grisea, and Phytophthora capsici. 204 isolates had antifungal activity, causing both a clear zone due to blocked spore germination and inhibition of mycelial growth; most (199) were from cellulolytic (Sorangium cellulosum) and only five were from bacteriolytic myxobacteria. B. cinerea, the best controlled among the five tested pathogens, had a unique group of antifungal isolates of myxobacterial extracts compared to the other pathogens' groups. Among seventy-nine bioactive myxobacteria, four isolates, KYC 3130, KYC 3247, KYC 3248 and KYC 3270, were selected and all were cellulolytic. Liquid culture filtrates of these four myxobacteria were applied to tomato, cherry tomato, strawberry, and kiwi fruits 5 h before inoculation with gray mold conidia; then the treated fruits were placed in an airtight container and the experiment was repeated six to eight times. Incidence (%) of gray mold on fruit of the infected control treatment was 84-98%, whereas it was only 5-21% after the KYC 3270 treatment. After KYC 3270 treatment of the four fruits, mold control was 79-95%, which was highest among the filtrates and statistically the same as treatment with fludioxonil, a registered chemical against gray mold of stored fruits.

• The Plant Pathology Journal
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• 제18권3호
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• pp.142-146
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• 2002

The effect of potassium phosphonate ($KH_2PO_3 or $K_2 HPO_3$) on the control of Phytophthora root rot of lettuce was evaluated in a liquid hydroponic culture. Phosphonate 100 ppm strongly inhibited mycelial growth of Phytophthora species in vitro but did not affect normal growth of lettuce in a greenhouse test. Application of the chemical before infection showed over 94% control value, while it was less than 35% when applied after infection. In a field trial, phosphonate 100 ppm, which was directly supplemented into the nutrient solution, satisfactorily controlled the disease as it did not develop until 28 days after transplanting and remained at less than 2% infection rate at the end of cultivation. Meanwhile, in the control plot, the disease initiated at 7 days after transplanting and developed rapidly reaching over 70% infection rate at 28 days. Population density of the causal pathogen, R drechsleri, in a heavily infested farm was 22.0-25.0 cfu/100 ml of nutrient solution. However, it decreased to 1.3-2.0 cfu/100 ml at 7 days after treatment with phosphonate 200 ppm.

• The Plant Pathology Journal
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• 제27권2호
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• pp.156-163
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• 2011

Antifungal activity of three Myxococcus spp., KYC 1126, 1136, and 2001, was tested in vitro against three phytopathogenic fungi (Botrytis cinerea, Colletotrichum acutatum, and Pyricularia grisea). Spore germination and mycelial growth of the three pathogenic fungi were completely inhibited by bioactive substances from a myxobacterium KYC 1126. In addition, the activity of KYC 1126 was fungicidal, but liquid culture filtrate of KYC 1126 did not affect protoplast reversion in C. acutatum. A bioassay of KYC 1126 filtrate against anthracnose in hot pepper was conducted in the greenhouse and field at 2009 and 2010. The incidence of anthracnose in control seedlings was 74%, but was reduced to 29% after KYC 1126 treatment. The control value with KYC 1126 was 60% while that with the fungicide dithianon was 42%. In the greenhouse, disease incidence with KYC 1126 was consistentely 10-35% lower than with fungicide as a positive control. The control value with KYC 1126 was 13.4% and 41.0%, whereas that with the fungicide was 52.3% and 63% in 2009 and 2010, respectively. Although anti-anthracnose activity of KYC 1126 was not maintained for long time in the field, the bacteriolytic myxobacterium KYC 1126 could be a prospective biocontrol agent.

• The Plant Pathology Journal
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• 제30권3호
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• pp.279-287
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• 2014

KYC 3262 was selected as a biocontrol agent against anthracnose on hot pepper from 813 extracts of myxobacterial isolates. Dual culture with Colletotrichum acutatum and 813 myxobacterial extracts was conducted, and 19 extracts were selected that inhibited germination and mycelial growth of C. acutatum. All selections were Sorangium cellulosum, which are cellulolytic myxobacteria from soil. With the infection bioassay on detached fruits in airtight containers, KYC 3262, KYC 3512, KYC 3279, and KYC 3584 were selected. The listed four myxobacteria were cultured in CSG/1 liquid media, and harvested filtrates were sprayed on the infected fruits. KYC 3262 was selected from the studies of attached fruit in a greenhouse study. KYC 3262 filtrate was applied for 3 years (from 2011 to 2013) in a field study in Asan, Republic of Korea. Control values of the KYC 3262 in the field were 31%, 89%, and 82% in 2011, 2012, and 2013, whereas values of the fungicide spray treatment were 19%, 97%, and 91%, respectively. Yields (kg/20 plants) of the KYC 3262 were 2.66 kg and 18.6 kg in 2011 and 2013, respectively, and those of the fungicide treatment were 2.0 kg and 20.2 kg, in 2011 and 2013, respectively.

• Mycobiology
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• 제28권1호
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• pp.33-38
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• 2000

Mycelium of Hericium erinaceum isolate KU-1 was cultured in liquid medium (HL medium) and solid medium (Ko medium) at pH 4.0 in $28^{\circ}C$. 1.0% glucose or fructose was the most favorable carbon source, and 0.2% amonium acetate or $NaNO_3$ was an exellent nitrogen source for mycelial growth as well as production of antimicrobial substances. The mixture of saw dust 70% with rice bran 30% (SR medium) was the substrate for formation of sporophores. The active substrates in extracts from mycelium, culture filtrate and fruiting body were separated by TLC. The solvent for TLC was EtOAc: Chloroform: MeOH (10 : 5 : 10). Phenol-like substances appeared at Rf $0.5{\sim}0.9$, and fatty acid-like substances appeared at Rf $0.1{\sim}0.2$. The purified materials from the extracts showed antimicrobial effects to Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Aspergillus niger, Candida albicans and Microsporum gypseum. The S. aureus was the most inhibited. Minimal inhibitory concentration (MIC) of purified white powder and the Hercenone derivatives against S. aureus were $5.65\;{\mu}g/ml$ and $1.85\;{\mu}g/ml$, respectively.

• 한국버섯학회지
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• 제5권2호
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• pp.81-85
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• 2007

본 연구는 번데기동충하초를 곡물배지를 이용하여 자실체를 형성하는 실험으로 액체종균제조에 적합한 조건은 맥아추출배지를 농도 0.7%, pH 5~5.5,으로 조정하였을 때 균사의 건중량은 $3.9{\sim}4.1mg/m{\ell}$로 양호 하였다. 자실체 발생 최적 환경조건은 습도 95%, 온도 $17^{\circ}C$, 조도 600 lx, 이산화탄소농도 500ppm하였을 때, 곡물배지 일반현미와 흑미에서 24.3g/병, 20.5g/병의 자실체가 형성되었다.

• 한국균학회지
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• 제34권2호
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• pp.92-97
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• 2006

구름버섯 균사체를 12% 감귤 추출액에서 7일간 배양한 배양액을 열탕 추출한 후 균사체 잔사를 여과하여 제거하고, 동량의 ethyl acetate(1 : 1, v/v)로 재차 추출하였다. EA 추출물은 복합내성을 갖는 MRSA 균주인 S. aureus CCARM3230와 P. aeruginosa CCARM2171에 대해 현저한 생육저지 활성을 확인하였다. 본 추출물을 silica gel chromatography로 분획하였을 때 dichloromethane : methanol(9 : 1, v/v)의 용매조건으로 용출한 분획물의 항균활성이 가장 높았으며, 활성물질이 높은 순도의 단일 물질로 정제되었음을 HPLC 분석으로 확인하였다. 다제 내성 균주들에 대해 현저한 항균 활성을 보이고, 특히, 그람음성균인 P. aeruginosa CCARM2171과 그람양성균인 S. asures CCARM3230 균주 모두에서 현저한 항균활성을 나타낸 것은 본 추출물의 활성물질이 광범위 항균 스펙트럼을 갖는 신규의 항생물질로 개발될 수 있는 가능성을 보여주는 것으로 사료되었다.