添加物对木耳液体菌种老化的影响

以黑木耳品种‘黑威15’为试验材料,研究营养物质对木耳液体菌种生长及老化的影响,筛选抗老化及易老化培养基,研究其抗氧化酶活性、底物降解酶活性、抗氧化物质及膜质过氧化程度变化规律。结果表明,①与对照组相比,添加磷酸二氢钾及VB1可延缓菌丝老化,且促进菌丝生长。添加硫酸镁对菌丝老化有缓解作用,但抑制菌丝生长。添加过量氮源可促进菌丝生长且加速菌丝老化。②与对照及易老化培养基相比,抗老化培养基中菌丝总蛋白含量、过氧化物酶、超氧化物歧化酶、抗坏血酸过氧化物酶、淀粉酶活性显著提高。表明活性氧自由基清除系统相关酶活性的提高对延缓菌丝老化具有重要作用。③SOD活性随菌龄增加而逐渐减小,与菌龄呈显著负相关。在抗老化培养基中,丙二醛含量随菌龄增加而降低,两者间呈显著负相关。在对照及易老化培养基中,MDA含量随菌龄增加呈上升趋势,两者间呈显著正相关。研究对分析木耳菌丝老化机制及解决液体菌种老化问题具有理论价值。

Effect of additives on aging of liquid spawn of Auricularia auricula

In this study, effects of nutrients on growth and aging for liquid spawn of Auricularia auricula( Heiwei 15) were explored and anti-aging and aging medium were screened. The activities of antioxidant enzymes, substrate degradation enzymes, antioxidant substances and the changes of membrane peroxidation were investigated. The results showed that, ① Addition of potassium dihydrogen phosphate and VB1 significantly delayed hyphal aging and enhanced mycelium growth compared with the control. Addition of magnesium sulfate also significantly delayed hyphal aging, but had an inhibitory effect on mycelial growth. However addition of excessive nitrogen source accelerated hyphal aging in spite of promoting mycelial growth. ② Compared with the aging medium of control, the content of mycelial total protein, peroxidase(POD), superoxide dismutase(SOD), ascorbate peroxidase(APX), and amylase activities were significantly higher in the anti-aging medium, indicating that the increase of enzyme activity related to reactive oxygen species(ROS) scavenging system played an important role in delaying hyphal aging. ③ SOD activity decreased with growth of mycelium with a significantly negative correlation. In the anti-aging medium, MDA content decreased with growth of mycelium with a significantly negative correlation. In the control and ageing medium, MDA content increased with growth of mycelium with a significantly positive correlation. The findings revealed better understanding of aging mechanism of Auricularia auricula hyphae and were of significance for solution of aging problem of liquid spawn.