ABSTRACT

The aim of this work was to study the phospholipase A (PLA) enzyme activity of extracts from Trichoderma harzianum 1A and Trichoderma atroviride αCp8 culture media. Fermentation on submerged culture was performed and PLA activity of extracts was evaluated as a function of culture time. A turbidimetric method for continuous analysis of phospholipase activity was applied. By this, vesicles rather than soluble substrates are used resembling the in vivo environment. In Trichoderma’s culture experiments, lecithin phospholipids as inductors promoted a PLA expression level of the same order to the corresponding strain control assay. T. harzianum developed the highest PLA activity and was considered as the most potent strain. Furthermore, the activity level was clearly greater when the culture medium included the plant pathogenic fungus Sclerotium rolfsii. The T. harzianum strain showed the highest PLA potential. Besides, both T. harzianum and T. atroviride, developed higher PLA activity at the first days of culture. In the present work, T. harzianum 1A and T. atroviride αCp8 at a lower level, showed an important PLA potential for S. rolfsii control. On the other side, a lower relative response was observed when both Trichoderma strains were assayed against other pathogens such as Macrophomina phaseolina and Rhizoctonia solani. The present work contributes to the scientific knowledge about PLA activity in Trichoderma and could be useful for technological purposes to prepare formulations for the biological control of S. rolfsii in agriculture.

摘要

这项工作的目的是研究来自哈茨木霉1A 和木霉 atroviride αCp8 培养基提取物的磷脂酶 A (PLA) 酶活性。对浸没培养进行发酵，并评估提取物的 PLA 活性作为培养时间的函数。应用比浊法连续分析磷脂酶活性。通过这种方式，使用类似于体内环境的囊泡而不是可溶性底物。在木霉的培养实验中，卵磷脂磷脂作为诱导物促进了相同数量级的 PLA 表达水平到相应的菌株控制试验。哈茨木霉PLA 活性最高，被认为是最有效的菌株。此外，当培养基包含植物病原真菌Sclerotium rolfsii时，活性水平明显更高。该Ť。harzianum菌株显示出最高的 PLA 潜力。此外，两个T。harzianum和T. atroviride在培养的第一天发展出更高的 PLA 活性。在目前的工作中，T. harzianum 1A 和T. atroviride αCp8 处于较低水平，显示了对S. rolfsii控制的重要 PLA 潜力。另一方面，当木霉属菌株针对其他病原体进行了检测，如Macrophomina phaseolina和Rhizoctonia solani。目前的工作有助于了解关于木霉中PLA 活性的科学知识，并可用于制备用于农业中S. rolfsii生物防治的制剂的技术目的。