Alberts J F, Gelderblom W C A, Botha A, van Zyl W H
Department of Microbiology, University of Stellenbosch, Matieland, 7602, South Africa.
Int J Food Microbiol. 2009 Sep 30;135(1):47-52. doi: 10.1016/j.ijfoodmicro.2009.07.022. Epub 2009 Jul 28.
The enzymatic degradation of aflatoxin B(1) (AFB(1)) by white rot fungi through laccase production was investigated in different liquid media. A significant (P<0.0001) correlation was observed between laccase activity and AFB(1) degradation exhibited by representatives of Peniophora and Pleurotus ostreatus cultivated in minimal salts (MSM) (r=0.93) and mineral salts - malt extract (MSB-MEB) (r=0.77) liquid media. Peniophora sp. SCC0152 cultured in MSB-MEB liquid medium supplemented with veratryl alcohol and sugarcane bagasse showed high laccase activity (496U/L), as well as 40.45% AFB(1) degradation as monitored using high performance liquid chromatography. P.ostreatus St2-3 cultivated in MSM liquid medium supplemented with veratryl alcohol resulted in laccase activity of 416.39U/L and 35.90% degradation of AFB(1). Aflatoxin B(1) was significantly (P<0.0001) degraded when treated with pure laccase enzyme from Trametes versicolor (1U/ml, 87.34%) and recombinant laccase produced by Aspergillus niger D15-Lcc2#3 (118U/L, 55%). Aflatoxin B(1) degradation by laccase enzyme from T. versicolor and recombinant laccase enzyme produced by A. niger D15-Lcc2#3 coincided with significant (P<0.001) loss of mutagenicity of AFB(1), as evaluated in the Salmonella typhimurium mutagenicity assay. The degradation of AFB(1) by white rot fungi could be an important bio-control measure to reduce the level of this mycotoxin in food commodities.
在不同液体培养基中研究了白腐真菌通过产漆酶对黄曲霉毒素B(1)（AFB(1)）的酶促降解作用。在以最低盐类（MSM）（r=0.93）和矿质盐-麦芽提取物（MSB-MEB）（r=0.77）为液体培养基培养的亚侧耳属和糙皮侧耳属真菌中，观察到漆酶活性与AFB(1)降解之间存在显著（P<0.0001）相关性。在添加藜芦醇和甘蔗渣的MSB-MEB液体培养基中培养的亚侧耳属菌株SCC0152表现出较高的漆酶活性（496U/L），并且通过高效液相色谱监测发现AFB(1)降解率为40.45%。在添加藜芦醇的MSM液体培养基中培养的糙皮侧耳菌株St2-3漆酶活性为416.39U/L，AFB(1)降解率为35.90%。用云芝纯漆酶（1U/ml，87.34%）和黑曲霉D15-Lcc2#3产生的重组漆酶（118U/L，55%）处理时，黄曲霉毒素B(1)被显著（P<0.0001）降解。在鼠伤寒沙门氏菌致突变性试验中评估发现，云芝漆酶和黑曲霉D15-Lcc2#3产生的重组漆酶对黄曲霉毒素B(1)的降解与AFB(1)致突变性的显著（P<0.001）丧失相吻合。白腐真菌对AFB(1)的降解可能是降低食品中这种霉菌毒素水平的一项重要生物防治措施。
