温度对银耳胞外酶活力及营养品质特性的影响

摘要

In order to provide a theoretical basis for growth regulation and efficient cultivation of Tremella fuciformis,the effects of different cultivation temperatures on seven extracellular enzyme activities at various growth and development stages and nutritional quality characteristics of Tremella fuciformis were studied. Meanwhile, the relative importance of seven extracellular enzymes for the nutritional quality of Tremella fuciformis was discussed by correlation analysis and path analysis. The results showed that the changes in the activity of extracellular enzymes of the same type were similar and the changes in all enzyme activities tested were stepwise in the appropriate temperature range. Comparative study revealed that the dry biological efficiency,polysaccharide content and protein content of mature Tremella fuciformis were the highest at (23.0 ± 0.5)℃ among seven cultivation temperatures, which were 35.67%, 21.51% and 8.53%, respectively. Correlation analysis showed that the average activity of all extracellular enzymes except carboxymethyl cellulase was positively correlated with dry biological efficiency and polysaccharide content, and protein content was positively correlated with the average activity of all seven extracellular enzymes. Further, path analysis showed that protease was a key factor for the nutritional quality of Tremella fuciformis.Collectively,these results indicated at(23.0±0.5)℃,the activity of key extracellular enzymes was higher and the nutritional quality of Tremella fuciformis was the best.Therefore,(23.0 ± 0.5)℃can be recommended for industrial cultivation of Tremella fuciformis.%研究不同温度对银耳栽培过程中生长发育各阶段的7 种胞外酶活力和银耳品质特性的影响;采用相关性分析和通径分析2 种数据分析方法,探讨各胞外酶平均酶活力与银耳品质的关系,揭示各胞外酶对银耳品质的相对重要性,为银耳工厂化高质、高产栽培提供可靠理论依据.结果表明,在适宜的温度范围内,同种胞外酶活力变化规律相似,不同胞外酶活力变化具有明显的阶段性;对比研究发现,在栽培温度(23.0±0.5)℃时,成熟银耳的干生物学效率、多糖含量和蛋白质含量在7 个温度组中最高,分别为35.67%、21.51%和8.53%.相关性分析表明,所测胞外酶的平均酶活力(除羧甲基纤维素酶外)与干生物学效率和多糖含量呈正相关性,蛋白质含量与7 种胞外酶平均酶活力均呈正相关性;进一步通径分析发现,蛋白酶是影响银耳营养品质的关键胞外酶.综上所述,在栽培温度(23.0±0.5)℃时,基质中主要胞外酶具有高活力,银耳的营养品质最高,可将此温度作为银耳工厂化栽培的指导温度.