Iron Or Zinc Bioaccumulated In Mycelial Biomass Of Edible Basidiomycetes

Abstract Iron and zinc bioaccumulation in mycelial biomass of different medicinal basidiomycetes was evaluated in order to produce metal-enriched mycelial biomass as an alternative functional food from non-animal sources and based on biotechnology processes. Pleurotus ostreatus strain U2-9, U2-11, U6-8, and U6-9, Pleurotus eryngii strain U8-11, Schizophyllum commune strain U6-7, and Lentinula edodes strain U6-11 and U6-12 were grown in malt extract agar with or without addition of 50 mg/L iron or 7.5 mg/L zinc. The mycelial biomass was separated and iron and zinc concentrations were determined in a flame atomic absorption spectrophotometer. Basidiomycete strains presented different growth rates with the presence of iron and zinc; there was no dependence between the metal bioaccumulation and the fungal growth. The fungi presented greater capacity to bioaccumulate iron than zinc. P. ostreatus (U2-9) has greater iron bioaccumulation (3197.7 mg/kg) while P. ostreatus (U6-8) greater zinc bioaccumulation (440.4 mg/kg) in mycelial biomass. P. ostreatus (U2-9), P. ostreatus (U2-11), and S. commune (U6-7) had the highest metal translocation rates from the culture medium to mycelial biomass. The mycelial biomass enriched with iron or zinc is an alternative to a new functional food from non-animal sources.

摘要：本研究评估了不同药用担子菌（Basidiomycetes）菌丝体生物量对铁、锌的生物富集特性，旨在依托生物技术流程制备富金属菌丝体，以此作为非动物源的功能食品替代方案。试验采用麦芽提取物琼脂培养基，设置添加50 mg/L铁、7.5 mg/L锌及无金属添加的三组培养条件，对平菇（Pleurotus ostreatus）菌株U2-9、U2-11、U6-8、U6-9，杏鲍菇（Pleurotus eryngii）菌株U8-11，裂褶菌（Schizophyllum commune）菌株U6-7以及香菇（Lentinula edodes）菌株U6-11、U6-12进行培养。收集分离菌丝体后，采用火焰原子吸收分光光度计测定其中铁与锌的浓度。结果显示，供试担子菌菌株在铁、锌存在下的生长速率存在差异；金属生物富集量与真菌生长速率之间无相关性。供试真菌对铁的生物富集能力整体强于锌。其中，平菇U2-9的菌丝体铁富集量最高，达3197.7 mg/kg；平菇U6-8的菌丝体锌富集量最高，为440.4 mg/kg。平菇U2-9、平菇U2-11以及裂褶菌U6-7的金属从培养基向菌丝体的转运效率最高。综上，富铁或富锌菌丝体可作为非动物源新型功能食品的替代选择。