Effect of Cu2+, Mn2+ and aromatic compounds on the production of laccase isoforms by Coprinus comatus

Abstract

Six different extracellular laccase isoforms were identified in submerged cultures of the commercially important edible mushroom, Coprinus comatus. Although laccase activity (*55 IU/L) was readily detectable in unsupplemented control cultures containing 1.6 lM Cu 2? after 22-day incubation, mean enzyme levels (*150-185 IU/L) were 2.7-3.4-fold higher in cultures supplemented with 0.5-3.0 mM Cu 2? . Laccase production was also stimulated by Mn supplementation over the range 0.05-0.8 mM Mn 2? , and the peak value of *225 IU/L recorded after 22 days in cultures containing 0.8 mM added Mn 2? was 4.5-fold higher compared with unsupplemented controls. Of 12 aromatic compounds tested for their effect on laccase isozyme production by C. comatus, highest laccase levels (*188 IU/L), equivalent to a 4.4-fold increase compared with unsupplemented controls (*43 IU/L), were recorded after 22 days in cultures supplemented with 3.0 mM caffeic acid. Other aromatic compounds tested all stimulated laccase production, with peak enzyme levels 1.3-3.3-fold higher compared with unsupplemented controls. Extracellular laccase levels in cultures supplemented with optimal concentrations of Mn 2? and caffeic acid together were 38% and 15% lower, respectively, compared with cultures containing the separate supplements. Lac1 was the most abundant laccase isoform produced under all the conditions tested, but marked differences were observed in the production patterns of Lac2-Lac6.

Cytotoxicity of Blended Versus Single Medicinal Mushroom Extracts on Human Cancer Cell Lines: Contribution of Polyphenol and Polysaccharide Content

“…Although Song and van Griensven 21 determined a high correlation among the polyphenols and polysaccharides of different medicinal mushroom extracts (R=0.82), our study revealed no connection between these compounds ( Table 2). According to Lu and Ding, 25 naturally derived antioxidant compounds of Coprinus comatus include total phenols, flavonoids, tocopherols, and polysaccharides. The results of our study revealed no correlation between the content of polysaccharides and antioxidant capacity of mushroom blends.…”

Production of lignocellulolytic enzymes from floriculture residues using Pleurotus ostreatus

“…Other authors have reported the effect of the inductors, copper and manganese, in improving laccase activity depending on the substrate, organism, crop, and the concentrations of these metals (Giardina et al 2000, Baldrian et al 2005, Stajić et al 2006, Lu & Ding 2010. For example, Baldrian et al (2005) reported that average laccase activity increases 79 % with Cu addition in cultures of P. ostreatus on wheat straw.…”

Affect on biosynthesis of laccase from Pleurotus sp. by some metal ions

“…Trong khi ở một số loài nấm khác, thí dụ như hoạt tính laccase tăng 180,5% ở P. ostreatus Em-1 khi bổ sung 10 mM ion Mn 2+ [12], tăng 4,5 lần trong môi trường có nồng độ Mn 2+ 0,8 mM đối với Coprinus comatus [10].…”