共培养条件下绿木霉对褐环乳牛肝菌产酶的诱导效应

为了探讨绿木霉与褐环乳牛肝菌的互作机理,在体外共培养条件下,采用光学显微镜和扫描电镜对二者生长重叠部分进行体外观察,发现二者生长无相互影响,在营养生长方面几乎不存在竞争关系。为进一步揭示绿木霉与褐环乳牛肝菌的互作机制,采用体外诱导和生物化学等方法,向褐环乳牛肝菌发酵液中加入灭活绿木霉菌丝诱导物,每天对发酵液中的多酚氧化酶、几丁质酶、漆酶和中性蛋白酶等酶活性进行检测。试验结果表明,绿木霉诱导褐环乳牛肝菌产漆酶能力最强;在整个共培养过程中,多酚氧化酶和漆酶活力始终处于较高水平,在诱导培养第6天,这两种酶活性升至最高,分别达到25.2U/mL和1 580U/mL;灭活绿木霉菌丝对褐环乳牛肝菌几丁质酶的诱导具有“瞬时性”,在诱导培养第2天即检测到较高的几丁质酶活性;中性蛋白酶的活性变化基本上呈先上升后下降的规律,且能增大褐环乳牛肝菌中性蛋白酶的固有产量,形成“叠加效果”。综上所述,绿木霉对褐环乳牛肝菌几乎不存在营养竞争关系,但其灭活菌丝体对褐环乳牛肝菌发酵液的多种酶活性存在诱导增效作用。

The enzyme production of Suillus luteus induced by co-culturing with Trichoderma virens

The investigation of overlapping sections of co-culturing Trichoderma virens and Suillus luteus under light microscope and scanning electron microscope (SEM) in vitro showed that the two species were not significantly affected in growth by each other. It seems that there was no mutual nutrient competition. For further revealing the interaction between T. virens and S. luteus, in vitro induction and biochemical methods were applied to detect the activities of polyphenol oxidase, chitinase, laccase and neutral protease of fermentation broth of S. luteus every day. It was showed that the addition of sterilized mycelia of T. virens to the fermentation broth of S. luteus resulted in evident increase of the laccase production of S. luteus, and the activities of polyphenol oxidase and laccase were kept at high levels during the whole investigating process. After six days, the activities of the two enzymes reached to the highest level, being 25.2U/mL and 1 580U/mL respectively. The activity of chitinase induced by sterilized T. virens mycelia was found to be instantaneous in S. luteus fermentation broth. Higher chitinase activity was detected on the second day in the co-culturing solution. The activity of neutral protease first increased but soon decreased. It is concluded that T. virens contributes the enhancement of enzyme activities of S. luteus, assisting in the establishment of mycorrhizal relationship between S. luteus and roots of Pinus sylvestris var. mongolica.