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Ethidium bromide stimulated hyper laccase production from bird's nest fungus Cyathus bulleri
Author(s) -
Dhawan S.,
Lal R.,
Kuhad R.C.
Publication year - 2003
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1046/j.1472-765x.2003.01267.x
Subject(s) - laccase , ethidium bromide , food science , biology , chemistry , botany , biochemistry , enzyme , dna
Aims: Effect of ethidium bromide, a DNA intercalating agent, on laccase production from Cyathus bulleri was studied. Methods and Results: The bird's nest fungus, Cyathus bulleri was grown on 2% (w/v) malt extract agar (MEA) supplemented with 1·5 µg ml −1 of the phenanthridine dye ethidium bromide (EtBr) for 7 d and when grown subsequently in malt extract broth (MEB), produced a 4·2‐fold increase in laccase production as compared to the untreated fungus. The fungal cultures following a single EtBr treatment, when regrown on MEA devoid of EtBr, produced a sixfold increase in laccase in MEB. However, on subsequent culturing on MEA in the absence of EtBr, only a 2·5‐fold increase in laccase production could be maintained. In another attempt, the initial EtBr‐treated cultures, when subjected to a second EtBr treatment (1·5 µg ml −1 ) on MEA for 7 d, produced a 1·4‐fold increase in laccase production in MEB. Conclusions: The white‐rot fungus Cyathus bulleri , when treated with EtBr at a concentration of 1·5 µg ml −1 and regrown on MEA devoid of EtBr, produced a sixfold increase in laccase production in MEB. Significance and Impact of the Study: The variable form of C. bulleri capable of hyper laccase production can improve the economic feasibility of environmentally benign processes involving use of fungal laccases in cosmetics (including hair dyes), food and beverages, clinical diagnostics, pulp and paper industry, industrial effluent treatment, animal biotechnology and biotransformations.