Effect of Nutritional Factors and Copper on the Regulation of Laccase Enzyme Production in Pleurotus ostreatus

Abstract

This research aimed to establish the relationship between carbon–nitrogen nutritional factors and copper sulfate on laccase activity (LA) by Pleurotus ostreatus. Culture media composition was tested to choose the nitrogen source. Yeast extract (YE) was selected as a better nitrogen source than ammonium sulfate. Then, the effect of glucose and YE concentrations on biomass production and LA as response variables was evaluated using central composite experimental designs with and without copper. The results showed that the best culture medium composition was glucose 45 gL−1 and YE 15 gL−1, simultaneously optimizing these two response variables. The fungal transcriptome was obtained in this medium with or without copper, and the differentially expressed genes were found. The main upregulated transcripts included three laccase genes (lacc2, lacc6, and lacc10) regulated by copper, whereas the principal downregulated transcripts included a copper transporter (ctr1) and a regulator of nitrogen metabolism (nmr1). These results suggest that Ctr1, which facilitates the entry of copper into the cell, is regulated by nutrient-sufficiency conditions. Once inside, copper induces transcription of laccase genes. This finding could explain why a 10–20-fold increase in LA occurs with copper compared to cultures without copper when using the optimal concentration of YE as nitrogen sources.

Single-cell protein production by Pleurotus ostreatus in submerged fermentation

“…P. ostreatus cultivation has led to a maximum biomass production of 18 g L −1 at a combination of 45 g L −1 glucose and 15 g L −1 yeast extract. 46 In another study using a lower range of yeast extract concentrations (1.0 to 5.0 g L −1 ) in the culture medium for P. ostreatus growth, a low value (1.72 g L −1 ) of biomass production was achieved at 40 g L −1 glucose and 3.0 g L −1 yeast extract. 47 Concerning the submerged cultivation of Tuber sinense , the maximum biomass production (24.8 g L −1 ) was found when glucose and yeast extract concentrations were 60 g L −1 and 30 g L −1 , respectively.…”

Fungi as a source of eumelanin: current understanding and prospects

“…( 2017 ) demonstrated that fungal extracellular laccase production is sensitive to the presence of other fungi, providing a potential link between the upregulation of laccase and melanogenesis, but their complete regulatory mechanisms are yet unclear. Much work has been done exploring the characterization of and possible means of regulating extracellular laccases in fungi (Durán-Sequeda et al., 2022 ; Eggert et al., 1996 ; Flores et al., 2009 ; Janusz et al., 2020 ; Lonergan & Baker, 1995 ; Minussi et al., 2007 ; Palmieri et al., 2000 ; Peña et al., 2021 ), but few studies have explored the capabilities of these laccases to participate in melanogenesis. Independent work by both Jia et al.…”

Improvement of Laccase Production by Thielavia terrestris Co3Bag1. Enhancing the Bio-Catalytic Performance of the Native Thermophilic TtLacA via Immobilization in Copper Alginate Gel Beads

“…An increase of 10-fold and 1.4-fold in laccase activity has been registered at 1 mM CuSO 4 in Pleurotus ostreatus [ 42 ] and white rot fungus WR-1 [ 43 ], respectively. Variations in terms of the effect of copper addition on laccase activity and isoenzymatic patterns from Pleurotus sajor-caju , as laccase activity increased 2.3 and 1.3-fold in cultures supplemented with 0.5 and 1 mM CuSO 4 , respectively, and correlation with two isoenzymes of 65 kDa and 35 kDa shown by zymogram analysis has been reported [ 44 ].…”