亚麻籽环肽混合物抑制霉菌生长繁殖活性

摘要

To evaluate antifungal activity of these flaxseed cyclolinopeptides,FCLPs,two strains,Paecilomyces varioti bainier(AS 3.776)and Aspergillus flavus(CICC 2476),were selected as test strains and inoculated on potato dextrose agar (PDA) with FCLPs of serial concentrations added before or after autoclave.IC50 of FCLPs mixtures on spores formation of P.varioti bainier were 0.53 mg/mL (autoclaved) and 0.34 mg/mL (not autoclaved),and IC50 on A.flavuswere were 0.31 mg/mL (autoclaved) and 0.24 mg/mL (not autoclaved),respectively.Most of antifungal activity of FCLPs was retained after autoclave.Residual antifungal activity against Paecilomyces varioti bainier were found as much as 76.8％ (radial growth) and 76.7％ (spores formation) of original activity,and those gainst A.flavus were as much as 61.6％ (radial growth) and 41.7％ (spores formation),respectively.Results of spores germination test indicated that the average inhibition rate against P.varioti bainier (17.8％) was higher than that against A.flavus(7.8％).After fungi culture,FCLPs were extracted from PDA and analyzed by high performance liquid chromatography (HPLC).Results indicated that the content of FCLPs in the media was decreased due to autoclave and thus led to the decrease of antifungal activity.In this study,FCLPs were found to have antifungal activity.And the activity partially remained after autoclave.It is indicated that FCLPs had the advantages over current antimicrobial peptides applied in food processing involved with heat treatment.%选取宛氏拟青霉(AS 3.776)和黄曲霉(CICC 2476)作为试验菌株,于121℃高温灭菌前、后添加一定浓度梯度的亚麻籽环肽混合物(flaxseed cyclolinopeptides,FCLPs)到马铃薯葡萄糖琼脂培养基中.FCLPs对宛氏拟青霉孢子形成的半数抑制浓度IC50分别为0.53 mg/mL(高温灭菌)和0.34 mg/mL(未经高温灭菌);对黄曲霉孢子形成的IC50值分别为0.31 mg/mL(高温灭菌)和0.24 mg/mL(未经高温灭菌).高温灭菌处理后,FCLPs保持了相当的抑菌活性,对宛氏拟青霉的抑制活性最低残留76.8％(菌落生长)和76.7％(孢子形成);对于黄曲霉的抑制活性,最低残留分别为61.6％(菌落生长)和41.7％(孢子形成).FCLPs对孢子萌发率的平均抑制率为17.8％(宛氏拟青霉)和7.8％(黄曲霉).采用高效液相色谱法分析霉菌培养后从培养基中提取的FCLPs,发现高温灭菌会降低环肽的含量,这可能是导致环肽抗菌活性下降的原因之一,但环肽中4种主要环肽的比例没有发生明显变化,且没有发现环肽霉菌代谢物产生.综上所述,FCLPs对霉菌具有一定抑制活性,对高温处理较为稳定,能耐食品的热加工,相比现有抗菌肽具有独特优势.