改变培养基碳源复壮草菇退化菌种

碳源是草菇重要的营养源之一,草菇菌种在添加葡萄糖的传统PDA上长期继代会导致菌种退化。本研究用蔗糖、果糖、甘露醇、海藻糖代替PDA中的葡萄糖,对草菇原种（D0）和退化菌株（D1-D3）进行复壮。结果表明：改变碳源对D0影响不显著。蔗糖、果糖、甘露醇、海藻糖均可提高D1-D3的气生菌丝密度、菌丝生长速度和生物量,诱导厚垣孢子产生,并增加菌丝多糖和蛋白质含量;有效抑制了活性氧O₂ ^-·、H₂O₂的积累;提升了超氧化物歧化酶（SOD）和过氧化物酶（POD）活性,但过氧化氢酶（CAT）活性变化不显著;且菌种退化程度越高,复壮效果越好,海藻糖的效果最佳。与对照组相比,海藻糖处理组使退化最严重的D3的菌丝生长速度和生物量分别提高了75.00%和66.67%,多糖和蛋白质含量分别增加了22.49%和16.58%;O₂ ^-·和H₂O₂分别降低了12.50%、12.83%;POD和SOD分别提高了33.33%和255.56%。本研究通过改变培养基的碳源,有效复壮了草菇退化菌种的菌丝特性;也为延缓食用菌菌种退化研究提供参考。

Rejuvenation of Volvariella volvacea degeneration strains by changing medium carbon source

Long-term subculture on the traditional glucose potato integrated medium (PDA) lead to degeneration of cultivated Volvariella volvacea. Sucrose, fructose, mannitol and trehalose were used to replace glucose carbon source in PDA to study the rejuvenation of V. volvacea original strain (D0) and degraded strains (D1-D3). The results showed that the change of carbon source hadn’t significant effect on D0. Sucrose, fructose, mannitol and trehalose could effectively increased aerial mycelium density, mycelium growth rate and mycelium biomass of V. volvacea degenerated strains, induced sporulation of chlamydospores, and increased the content of mycelial polysaccharide and protein, and effectively inhibited the accumulation of O₂ ^-· and H₂O₂. At the same time, the activity of mycelium superoxide dismutase (SOD) and peroxidase (POD) increased, but the change of catalase activity was not significant. The higher the degradation degree, the better the strains rejuvenated. Trehalose proved to be highly effective to rejuvenation. Compared with the experimental control, trehalose increased the mycelium growth rate and biomass by 75.00% and 66.67% respectively of the seriously degraded D3. The content of polysaccharides and proteins increased by 22.49% and 16.58%. O₂ ^-· and H₂O₂ decreased by 12.50% and 12.83%, and POD and SOD increased by 33.33% and 255.56%, respectively. These results indicated that by changing the carbon source of the medium, the V. volvacea degenerated strains were effectively rejuvenated.