Induction, expression and characterisation of laccase genes from the marine-derived fungal strains Nigrospora sp. CBMAI 1328 and Arthopyrenia sp. CBMAI 1330

Abstract

The capability of the fungi Nigrospora sp. CBMAI 1328 and Arthopyrenia sp. CBMAI 1330 isolated from marine sponge to synthesise laccases (Lcc) in the presence of the inducer copper (1–10 μM) was assessed. In a liquid culture medium supplemented with 5 μM of copper sulphate after 5 days of incubation, Nigrospora sp. presented the highest Lcc activity (25.2 U·L−1). The effect of copper on Lcc gene expression was evaluated by reverse transcriptase polymerase chain reaction. Nigrospora sp. showed the highest gene expression of Lcc under the same conditions of Lcc synthesis. The highest Lcc expression by the Arthopyrenia sp. was detected at 96 h of incubation in absence of copper. Molecular approaches allowed the detection of Lcc isozymes and suggest the presence of at least two undescribed putative genes. Additionally, Lcc sequences from the both fungal strains clustered with other Lcc sequences from other fungi that inhabit marine environments.

Production of Fungal Laccase Using Orange Peelings as Substrate by Submerged Static Fermentation

“…D'souza-Ticlo et al [27] opined that cu 2+ can have a negative coefficient with other media components on biomass accumulation. Our result is in contrast with the work of Passarini et al [22] who reported high biomass production in the presence of copper sulphate for Nigrospora sp. CBMAI 1328.…”

“…In this present study, the media containing Cu 2+ concentrations beyond 0.05% (w/v) showed a significant decrease in laccase production and fungal growth. This may be attributed to the inhibitory effect of Cu 2+ at higher concentrations as equally observed by Passarini et al [22]. Our result is in agreement with the reports of Galhaup et al [34] and Stajic et al [37] who separately reported that the addition of CuSO 4 in various concentrations (1-10 mM) stimulated laccase production in T. pubescens, P. ostreatus HA1493, P. ostreatus HA1494 and P. eryngii.…”

“…Maximum laccase production (34.6 U/ml) was obtained when 0.25 mM CuSO 4 was added into the medium for Pycnoporus cinnabarimus [52]. According to Passarini et al [22], Nigrospora sp. CBMAI 1328 produced highest level of laccase (25.2 U/L) in the presence of 5 µM CuSO 4 after 120 h of incubation.…”

“…This informed the decision to evaluate rice bran and orange peel for their potential as sole carbon source for laccase production by fungi. Fungal laccase production is highly regulated by the media composition and hence medium optimization has become one of the main methods to enhance laccase production [22]. Therefore, this present study was aimed at isolation, screening of potential laccase producing fungi and assessing the ability of selected agro-waste residues for laccase production as well as optimize the laccase production by P. ostreatus under submerged static conditions using One-Factorat-a-Time methodology.…”

“…Further increment of copper concentrations beyond 0.05% (w/v) resulted in corresponding decrease in laccase production. Passarini et al [22] and Liu et al [25] opined that cu 2+ requirements by microorganisms are usually satisfied by very low concentrations of 1-10 µM but toxic to fungal metabolism at higher concentrations. The trend of our result on effect of copper concentration on laccase production may be because of insinuation that higher concentration of copper is inhibitory to fungal growth [44].…”