广西主栽中高温平菇耐硒能力比较及生物富硒条件初步优化

Comparison on Se tolerance of high temperature oyster mushroom varieties in Guangxi and their Se-enriching condition optimization

【目的】筛选高耐硒平菇品种,初步优化高耐硒平菇菌丝液体富硒条件,为研发出高效安全的富硒功能食用菌产品提供科学依据。【方法】将不同比例Na2SeO3添加到培养基中,通过比较固体培养基上13株中高温平菇菌落直径大小、菌丝长势强弱并结合液体深层发酵试验,筛选出高耐硒平菇品种;通过单因子试验初步优化高耐硒平菇品种的Na2SeO3浓度、初始pH、接种量、装液量条件。【结果】供试的13株平菇菌株中以江都302对Na2SeO3的耐受系数最小,仅为0.40。单因素试验结果显示,江都302菌株在160r/min摇床转速、28℃培养7d条件下最适的Na2SeO3添加量为5～15mg/L、初始pH为5.0～7.0,接种量5%～15%、装液量80～120mL。【结论】不同平菇菌株对Na2SeO3的耐受力差异明显,以江都302号菌株的耐硒能力最强。培养基Na2SeO3浓度、初始pH、接种量、装液量对平菇菌丝生物富硒能力影响较大,在试验组合中,江都302菌株在Na2SeO3浓度10mg/L、初始pH6.0、接种量10%、装液量100mL/250mL时菌体含硒量最高。

[Objective]The present research was conducted to screen out high Se resistant oyster mushroom varieties and preliminarily optimize Se-accumulation condition of oyster mushroom mycelia in order to provide scientific references for developing efficient,safe,and high Se tolerant and edible mushroom products.[Method]Colony diameter,mycelia growth vigor of 13 high temperature oyster mushroom strains in solid medium with different ratios of Na2SeO3,were compared to select Se tolerant oyster mushroom varieties combined with submerged fermentation.The Na2SeO3 concentration,initial pH,inoculum quantity,and medium volume for high Se-tolerant oyster mushroom varieties were optimized using single factors test.[Result]With the lowest tolerance coefficient of 0.4,Jiangdu 302 displayed the strongest Se tolerance compared to that of the other 12 oyster mushroom varieties.It was found that the optimal conditions for Jiangdu 302 strain,culturing on shaking table with rotation rate of 160 r/min at 26℃ for 7 days,were as follows：Na2SeO3 concentration 5-15 mg/L,initial pH 5.0-7.0,inoculum quantity 5-15%,and medium volume 80-120 mL in the single factor experiment.[Conclusion]Obvious differences were found in Na2SeO3 tolerance of all 13 strains,yet Jiangdu 302 showed the strongest Se tolerance ability.Na2SeO3 concentration,initial pH value,inoculum quantity,and medium volume influenced the Se-enrichment of oyster mushroom mycelia tremendously.Amongst the experimental combinations,Se content in Jiangdu 302 was the highest under Na2SeO3 concentration 10mg/L,initial pH value 6.0,inoculum 10%,and medium volume 100 mL/250 mL.