ISOENZYMES AND ACTIVITY OF LACCASES PRODUCED BY Pleurotus ostreatus GROWN AT DIFFERENT TEMPERATURES

Heat stress on Fomes culture reduces proteases and improves laccases thermostability

“…In solid state fermentation using wheat bran as substrate, with Fomes sclerodermeus a maximum laccase activity of 270 U/g dry wheat bran was obtained after 28 days of incubation (Papinutti et al, 2003) and with Fomes fomentarius the highest laccase activity obtained was nearly 6 400 U/L extract after 13 days of cultivation (Neifar et al, 2010). In the solid state fermentation of Pleurotus ostreatus, using polyurethane foam as an inert support and glucose as carbon source, the highest value of laccase activity obtained was of 20 000 U/L extract after 400 hours of growth of the fungus (Montalvo et al, 2020). An advantage of the culture of Fomes sp.…”

Copper-induced Production of Laccases for Lignin Depolymerisation and Micropollutant Degradation by Laccase-mediator Systems

“…Laccases are produced as a pool of isozymes encoded by a complex set of genes whose regulation is still poorly understood, and their expression in fungi depends on environmental conditions such as temperature, pH, inductors, culture conditions and medium composition. [14][15][16][17][18] Several authors noticed an increase in laccase activity concomitantly to a rapid increase of glucose uptake and showed that laccase production was related to stress response elements in the promoters of genes encoding for laccases. [16,18] Our observations are in accordance with these results.…”

“…[14][15][16][17][18] Several authors noticed an increase in laccase activity concomitantly to a rapid increase of glucose uptake and showed that laccase production was related to stress response elements in the promoters of genes encoding for laccases. [16,18] Our observations are in accordance with these results. It is generally accepted that nitrogen depletion causes laccase production and that high carbon to nitrogen ratios are required for laccase production.…”

“…[16] However, results obtained with P. ostreatus are somewhat unusual, high laccase activity levels having been obtained by several authors in solid-state and submersed cultures. [17][18][19][20][21] Park et al [22] found that apple pomace, a medium rich in carbohydrates, dietary fibers, minerals and phenolic compounds, enhanced P. ostreatus laccase activity. Impact of copper supplementation on laccase expression was studied as well by Diaz et al [23] and Zhu et al [24] The reasons for low laccase activity observed in P. ostreatus could include differences in the structure, stability, activity or expression levels of the different isoforms as well as the absence of nutrients or laccase inducers in the culture medium.…”