Centro de Investigaciones Biológicas, CSIC, C/ Ramiro de Maeztu 9, E-28040 Madrid, Spain.
Chemosphere. 2010 Jan;78(1):72-6. doi: 10.1016/j.chemosphere.2009.09.050. Epub 2009 Oct 28.
The objective of this work was to evaluate the ability of the white rot basidiomycete Coriolopsis rigida to detoxify the water soluble fraction from "alpeorujo" (WSFA), a solid by-product produced by the olive oil extraction industry and characterized by a high concentration of phenols which limits its use as fertilizer and/or amendment. C. rigida reduced the phenol content in the liquid media supplemented with WSFA at 10 and 20% (v/v) after 15d of incubation. The analysis of WSFA toxicity after fungal treatment showed that C. rigida was responsible for a significant increase in the survival rate of Azospirillum brasiliense, a N(2) fixing soil rhizobacterium which promotes plant growth. Supplementation of culture medium with CuSO(4) (300 microM) resulted in strong laccase induction thus facilitating higher phenol reduction and detoxification of WSFA. In vitro reactions using a crude extracellular preparation from laccase-active C. rigida showed phenol removal as well as detoxification of the WSFA at 20%. These results suggest that C. rigida reduces the phenol content of the WSFA through the effect of laccase on free phenolic compounds consequently decreasing the toxic effect on A. brasiliense, which suggests that the enzyme plays an important role in the process. These findings have implications in the management and revalorization of olive-mill residues treated with laccase-producing fungi and their potential impact on integrative agricultural systems including organic residues and the co-inoculation with microorganisms which can facilitate the growth of plants of agricultural interest.
本研究旨在评估白腐菌糙皮侧耳（Coriolus rigida）对橄榄果渣水溶性部分（WSFA）的解毒能力。WSFA 是橄榄油提取工业的一种固体副产物，其特点是酚类化合物浓度高，限制了其作为肥料和/或改良剂的用途。糙皮侧耳在补充 10%和 20%（v/v）WSFA 的液体培养基中培养 15 天后，降低了液体介质中的酚含量。真菌处理后 WSFA 毒性分析表明，糙皮侧耳显著提高了固氮土壤根瘤菌巴西固氮螺菌（Azospirillum brasiliense）的存活率，巴西固氮螺菌可促进植物生长。培养基中添加 CuSO4（300 microM）可强烈诱导漆酶，从而促进更高的酚还原和 WSFA 解毒。利用漆酶活性糙皮侧耳的粗细胞外制剂进行的体外反应表明，WSFA 中的酚去除和解毒率达到 20%。这些结果表明，糙皮侧耳通过漆酶对游离酚类化合物的作用降低了 WSFA 中的酚含量，从而降低了对巴西固氮螺菌的毒性影响，表明该酶在该过程中起着重要作用。这些发现对用产漆酶真菌处理的橄榄渣的管理和再利用具有重要意义，其对包括有机残留物在内的综合农业系统以及与有利于农业有价值植物生长的微生物共同接种的潜在影响。
