본 연구는 수확 후 감귤의 부패과 발생 억제를 위하여 grapefruit seed extract과 oregano oil이 혼입된 carnauba 코팅 과 calcium oxide이 혼입된 chitosan 코팅을 감귤에 적용하여 Penicillium italicium 저해 효과에 대하여 연구하였다. carnauba 수용액(18%(w/w))에 grapefruit seed extract 또는 oregano oil을 단독으로 각각 0.3-1%(w/w) 첨가하였고, grapefruit seed extract과 oregano oil을 0.75:0.25, 0.5:0.5,그리고 0.25:0.75(w/w)의 비율로 혼합하여 첨가하였다. 또한 1% chitosan 수용 액의 경우 0.3-3%(w/w)의 calcium oxide을 첨가하여 코팅제를 개발하였다. 감귤 과피에 접종된 P. italicium에 대한 각 코팅제의 저해 효과는 부패과 발생률(%)로 표현하였다. carnauba wax 코팅의 경우, grapefruit seed extract을 단독으로 1% (w/w) 첨가, grapefruit seed extract과 oregano oil을 혼합하여 0.5:0.5%(w/w) 비율로 첨가하였을 때 부패과 발생률은 각각 23.6%와 25%로 유의적으로 가장 낮았고(P<0.05), calcium oxide을 첨가한 chitosan 코팅의 경우 calcium oxide의 농도와 관계없이 모든 조건에서 부패과 발생률이 유의적 차이를 보이지 않았다(P>0.05). 따라서 grapefruit seed extract 과 oregano oil이 혼입된 carnauba wax 코팅은 감귤의 저장 중 부패에 관여하는 P. italicium를 저해하여 저장성을 향상 시킬 수 있는 것으로 사료되었다.
Green mold of Phellinus baumii caused by Penicillium was observed in Daegu on August, 2000. The causal fungus was identified as Penicillium citrinum based on their cultural and morphological characteristics. Conidiophores one-stage branched, terminating in a whorl of 3~5 metulae. Metulae mostly 5.2~7.8㎛. Phialides were flask-shaped, 5.7~7.5×2.2~2.7㎛. Conidia were subglobose, 1.8~2.3㎛ in size. Colonies on Czapek agar were mostly attaining a diameter of 23 ㎜ within 8 days at 25 . The optimum temperature for growth of the fungus was about 20~30℃. On the basis of mycological characteristics and pathogenecity test on host mushrooms, the fungus was identified as Penicillium citrinum. This is the first report on the green mold of Phellinus baumii caused by Penicillium citrinum in Korea. The present study was carried out to investigate the preventive effect of Penicillium citrinum by backfill (sand, granite soil, and smash rock). The result showed that the use of granite was 3~10% infection rate and sand was 2~10% infection of P. citrinum. However, the smash rocks showed no infection of this fungus. The chemical properties of smash rocks was pH 8.4, showing alkalinity. The sand and granite soil were pH 6.1 and pH 7.5, respectively. These did not have heavy metals such as Mn, Fe, Pb and As.
Green mold of Phellinus baumii caused by Penicillium was observed in Daegu on August, 2000. The causal fungus was identified as Penicillium citrinum based on their cultural and morphological characteristics. Conidiophores one-stage branched, terminating in a whorl of 3~5 metulae. Metulae mostly 5.2~7.8㎛. Phialides were flask-shaped, 5.7~7.5×2.2~2.7㎛. Conidia were subglobose, 1.8~2.3㎛ in size. Colonies on Czapek agar were mostly attaining a diameter of 23㎜ within 8 days at 25℃. The optimum temperature for growth of the fungus was about 20~30℃. On the basis of mycological characteristics and pathogenecity test on host mushrooms, the fungus was identified as Penicillium citrinum. This is the first report on the green mold of Phellinus baumii caused by Penicillium citrinum in Korea. The present study was carried out to investigate the preventive effect of Penicillium citrinum by backfill (sand, granite soil, and smash rock). The result showed that the use of granite was 3~10% infection rate and sand was 2~10% infection of P. citrinum. However, the smash rocks showed no infection of this fungus. The chemical properties of smash rocks was pH 8.4, showing alkalinity. The sand and granite soil were pH 6.1 and pH 7.5, respectively. These did not have heavy metals such as Mn, Fe, Pb and As.
본 연구에서는 상황버섯 (P. baumii)의 자실체에 발생하는 Penicillium sp.균을 동정하기 위하여, 분리균의 배양적·형태적 특징을 조사하였다. 분리된 Penicillium sp.의 형태적 특성을 조사한 결과, 분생포자의 모양은 타원형이고 직경이 1.8∼2.3 ㎛ 크기로 분생포자를 많이 형성하였다. 분생포자경은 균사로부터 one-stage branch 모양을 형성하였고, matulae는 3∼5개로 길이가 5.2∼7.8 ㎛이며, phialide는 플라스크상이고 크기가 5.7∼7.5×2.2∼2.7 ㎛이였다. Czapek's agar 배지에서 생육시 25℃에서 8일간 균체가 23 ㎜ 생장하였다. PDA 배지 상에서 균총의 형태는 처음에는 조밀한 솜털모양의 백색을 띄었으며 차츰 기중균사가 형성되었고, 점차 회녹색으로 변하였다. 이상과 같은 형태 및 배양적 특징으로 이 균을 P. rubrum으로 동정하였다. 상황버섯 (P. baumii)에서 P. rubrum에 의한 병은 아직 국내에 보고된바 없어, P. rubrum에 의한 상황버섯 (P. baumii) 푸른곰팡이병을 최초로 보고한다.
This experiment was conducted to investigate the effects of mixed culture with mycotoxigenic and non-mycotoxigenic fungi on mycotoxin production. For this work, Aspergillus flavus (aflatoxin producing strain), Aspergillus niger (non-mycotoxigenic strain) and Penicilhum griseofulvum (patulin producing strainvere cultured in 5 ml SLS medium for 15 days under single or mixed culture. Affatoxin was determined by direct competitive ELISA, whereas, patulin was measured by HPLC. The mycelial growth, pH and total acidity were also observed by general methods. The mycelial growth was slightly decreased in the mixed culture, meanwhile total acidity was increased and pH was shown lower than that in single culture. Aspergillus flavus produced 145 ㎍/ml of aflatoxin for 12 days single culture, but in mixed culture, aflatoxin was decreased to 93%, and was shown as 10.16 ㎍/ml level. Patulin production in mixed culture was also decreased to 69.3% and was shown only 23.72 ㎍/ml level as compared with in single culture.
P. verruculosum의 xylanase는 iodine, NBS, DEP, 그리고 2, 3-butanedione에 의해 실활되는 것으로 보아 활성중심에 tyrosine, histidine, tryptophan 및 arginine 잔기가 존재함으로서 효소활성에 직접적으로 또는 간접적으로 관여하는 것으로 생각된다. 금속이온들 중 Hg^2+와 Mn^2+에 의해서 현저히 활성이 저해되었으나 Cu^2+에 의해서는 반대로 활성이 크게 증가되었으며 Hg^2+에 의한 활성의 저해효과는 β-mercaptoethanol의 첨가에 의해 보호되었다. P. verruculosum으로부터 분리한 β-xylosidase는 NBS와 SDS에 의해 효소활성이 크게 저해되는 반면 실험에 사용된 다른 수식제들에 의해서는 별 영향을 받지 않았으며 금속이온들 중 Hg^2+에 의해서 크게 활성이 저해됨으로써 효소활성에 tryptophan잔기가 관여할 것으로 생각된다.