Enzymatic mechanisms and detoxification of dry olive-mill residue by Cyclocybe aegerita, Mycetinis alliaceus and Chondrostereum purpureum. (February 2017)

• Record Type: Journal Article
• Authors: Reina, Rocío; Liers, Christiane; García-Romera, Inmaculada; Aranda, Elisabet
• Is Part Of: International biodeterioration & biodegradation. Volume 117(2017)
• Page Start: 89
• Page End: 96
• Publication Date: 2017-02
• Subjects: Class II peroxidases -- Laccase -- Olive-mill residues -- Unspecific peroxygenase -- CYPs -- Phytotoxicity; Biodegradation -- Periodicals; Bioremediation -- Periodicals; Biodegradation -- Periodicals; Biodégradation -- Périodiques; Biorestauration -- Périodiques; Electronic journals; 620.11223
• DOI: 10.1016/j.ibiod.2016.11.029
• Languages: English
• ISSNs: 0964-8305

Abstract

Abstract: The detoxification of dry olive-mill residue (DOR), a lignocellulosic by-product, was investigated using three agaric fungi: Cyclocybe aegerita, Mycetinis alliaceus and Chondrostereum purpureum . The lignin-modifying enzymes (LME) secretion pattern of the above-mentioned fungi such as DyP-type peroxidase (DyP), laccase (Lac), unspecific peroxygenase (UPO), and manganese peroxidase (MnP) was determined in presence and absence of DOR. In C . aegerita, a laccase (Lac) and unspecific peroxygenase (UPO) induction was found when DOR was present in the medium. Thus, these enzymes appeared to be responsible for DOR detoxification and, indirectly, its plant-growth-promoting effect. In the experiment performed with M . alliaceus, no differences were found in DyP-type peroxidase (DyP) secretion when the basal barley medium was supplemented with DOR. However, MnP and Lac activities in DOR-barley reached a maximum after 5 weeks of incubation with a concomitant decline in DOR phytotoxicity. C . purpureum completely eliminated DOR phytotoxicity but no significant production of LME was detected in soy or barley fungal media. Other enzymatic mechanisms were also investigated, in relation to hydrolytic enzymes and the intracellular system cytochrome P450 monooxygenase (CYPs). Our results suggest the participation of a complex enzymatic system (intra and extracellular) in C . purpureum for the biotransformation of DOR. Graphical abstract: Highlights: Conditions for SSF with DOR have been set up using dung- and wood-dwelling fungi. DOR stimulates the secretion of UPO in Cyclocybe aegerita . The exhausted bio-remediated by-product is able to enhance tomato plant growth. Chondrostereum purpureum removes the phytotoxicity of DOR.