Characteristics and dyes biodegradation potential of crude lignolytic enzymes from white-rot fungus crepidotus variabilis isolated in coastal Tanzania

Abstract

Lignocellulosic enzymes from Crepidotus variabilis collected from mangrove forests of coastal Tanzania were investigated by using standard methods, and their ability to degrade aromatic compounds were elucidated. The fungal crude enzyme filtrates had maximum laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP) activities of 70 U/mL, 16 U/mL and 8, U/mL respectively. The crude enzyme extracts were able to oxidize rhemazol brilliant blue-R (RBB-R) dye, phenol, "-naphthol and pyrogallol. Also, they could remove up to 58% and 92% color from raw textile effluent and aromatic dyes, respectively, after 14 days of incubation at 30ºC and pH 4.5. Desalted and size-separated enzyme filtrates, resolved by sodium docecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing (IEF), showed laccases and peroxidases from C. variabilis to have molecular weights of 67 kDa and 47 kDa, respectively, while the isoelectric points (pI) of laccases and peroxidases were found to lie in a range of 3.0 to 4.1. The study provided basic information on the characteristics of crude lignolytic enzymes from C. variabilis and confirmed it to be one of the potential biodegraders of aromatic compounds that could be applied in bioremediation of polluted ecosystems.

Biodeterioration of low-density polyethylene by mangrove-associated endolichenic fungi and their enzymatic regimes

“…After incubation at 28 ± 2°C, for 7 days, the production of laccase was observed using 0·1 mol l −1 α‐naphthol drop test (Okino et al . 2000; Mtui 2007).…”

“…The production of peroxidases was observed using 1% pyrogallol drop test (Okino et al . 2000; Mtui 2007).…”

“…As described in Kannangara et al (2009), to qualitatively assess laccase production, ELF were inoculated in malt extract agar (MEA; Oxoid Ltd., pH 7Á0 AE 0Á2). After incubation at 28 AE 2°C, for 7 days, the production of laccase was observed using 0Á1 mol l −1 α-naphthol drop test (Okino et al 2000;Mtui 2007). Endolichenic fungi species were subjected to laccase quantification with slight modifications to the methods described in Nicolcioiu et al (2018) and Senthivelan et al (2019).…”

“…Peroxidase production was qualitatively assessed by inoculating ELF in MEA (Oxoid Ltd., pH 7Á0 AE 0Á2) and incubating at 28 AE 2°C, for 7 days (Kannangara et al 2009). The production of peroxidases was observed using 1% pyrogallol drop test (Okino et al 2000;Mtui 2007).…”

Archives of Environmental Protection

“…The process of biodegradation reduced the values within recommended values which confi rmed the signifi cance of this process. High BOD and COD made aquatic life diffi cult while reduction in these values made water suitable for aquatic life (Elkassas and Mohamed 2014, Mtui andNakamura 2008, Porwal et al 2015). Luczkiewicz et al in 2011, reported the reduction in COD, BOD and Total Suspended Solid (TSS) of wastewater treated with various physical techniques but the ratio of reduction (a difference between initial value and fi nal value) was low compared to our results during current study.…”