Strain-dependent response to Cu2+ in the expression of laccase in Pycnoporus coccineus

Abstract

The effects of Cu(2+) on the activity and expression of laccase were investigated in seven different strains of Pycnoporus coccineus collected from different regions in Korea. Cu(2+) was toxic to mycelial growth at concentrations greater than 0.5 mM CuSO4 and showed complete growth inhibition at 1 mM in the liquid culture. However, Cu(2+) significantly upregulated the extracellular laccase activity at 0.2 mM in five strains of P. coccineus, IUM4209, IUM0032, IUM0450, IUM0470, and IUM4093, whereas two strains, IUM0253 and IUM0049, did not respond to Cu(2+), despite being closely related to the other five strains. Subsequent RT-PCR analysis also showed that the laccase mRNA was highly expressed only in the former five strains in the presence of Cu(2+). Taken together, these results indicate that Cu(2+) regulates expression of the laccase gene in a strain-dependent manner. The five strains commonly produced a single predominant laccase protein with a molecular weight of 68 kDa. Peptide sequencing revealed that the laccase was a homolog of Lcc1 of P. coccineus, which was isolated in China. The Cu(2+)-induced culture supernatants exhibited high degradation of polycyclic aromatic hydrocarbons, indicating that the 68-kDa laccase is the primary extracellular degradative enzyme in P. coccineus.

Use of sugarcane molasses by Pycnoporus sanguineus for the production of laccase for dye decolorization

“…Fonseca et al (2010) reported an increase in laccase production by P. sanguineus in the presence of 500 µM copper. Park et al (2015) verified that the addition of up to 200 µM copper affected laccase production in five of seven strains of Pycnoporus coccineus. These authors also verified that even though all strains had at least one laccase gene (lcc1) two strains did not respond to copper stimulation, maintaining constitutive enzymatic production without an increase in the transcription rate.…”

“…These authors also verified that even though all strains had at least one laccase gene (lcc1) two strains did not respond to copper stimulation, maintaining constitutive enzymatic production without an increase in the transcription rate. This suggests that the inducing role of copper in the laccase activity of P. sanguineus is directly related to the ability of different strains to adapt to environmental conditions (Park et al, 2015), and an evaluation of potential inducers is necessary for each specific situation and strain.…”

Isolation and Physicochemical Characterization of Laccase fromGanoderma lucidum-CDBT1 Isolated from Its Native Habitat in Nepal

“…Cu 2+ ions are thus crucial for the synthesis of catalytically active laccase protein. Further, Cu 2+ ions also induce the expression of certain genes including laccase gene [44]. The promoter region of the genes encoding for laccase contains various recognition sites specific for xenobiotics and heavy metals [3, 45].…”

PRODUÇÃO DE LACASE DE Pycnoporus sanguineus EM MEIO DE CULTIVO À BASE DE MELAÇO SOJA

“…Não há até o momento, dados sobre a regulação gênica de lacase em P. sanguineus, porém, observações feitas para outras espécies do gênero Pycnoporus sugerem que a regulação da expressão difere ente linhagens. Para P. coccineus a adição de cobre (200 µM) aumentou a produção de lacase de cinco dentre sete linhagens analisadas (PARK et al, 2015). Todavia, os autores verificaram que, mesmo todas as linhagens apresentando ao menos um gene de lacase (lcc1), duas linhagens não responderam à indução com cobre.…”

“…Todavia, os autores verificaram que, mesmo todas as linhagens apresentando ao menos um gene de lacase (lcc1), duas linhagens não responderam à indução com cobre. Isso permite sugerir que a resposta de P. sanguineus ao cobre também possa estar relacionada com a capacidade de diferentes linhagens adaptarem-se às condições ambientais exigindo que possí-veis indutores sejam avaliados em cada situação específica de cultivo e para cada linhagem (PARK et al, 2015;MARIM et al, 2016).…”