Overproduction of laccase by a monokaryotic strain of Pycnoporus cinnabarinus using ethanol as inducer.
OBJECTIVE
Laccase production by the monokaryotic strain Pycnoporus cinnabarinus ss3 was studied using ethanol as inducer in the culture medium.


RESULTS
The effect of ethanol was tested at 10, 20, 30, 35 and 45 g l-1 and compared with that of ferulic acid, known until now as the most efficient inducer for laccase expression by P. cinnabarinus ss3. In the presence of 35 g l-1 ethanol, laccase activity (266 600 U l-1) and productivity (19 000 U l-1 day-1) were nine and fivefold higher compared with ferulic acid-induced cultures, and 155- and 65-fold higher compared with non-induced cultures, respectively. In vivo, ethanol added to the culture medium of P. cinnabarinus ss3 favoured a continuous and high expression of laccase gene. Under these conditions, P. cinnabarinus ss3 produced preferentially the isoenzyme LAC I. Ethanol added in vitro to the purified P. cinnabarinus ss3 laccase typically inhibited the enzymatic activity.


CONCLUSIONS
In spite of an initial inhibitory effect on mycelial growth, ethanol was shown to be a very strong inducer for laccase expression by P. cinnabarinus ss3 allowing an average yield of 1-1.5 g l-1 laccase.


CONCLUSIONS
This study identified P. cinnabarinus ss3 as an outstanding producer of laccase in the presence of ethanol as inducer. Ethanol is an inexpensive agricultural by-product and the process is simple to scale-up for industrial production.
Lomascolo
A
A
Unité Mixte de Recherche 1163 INRA/Universités de Provence et de la Méditerranée de Biotechnologie des Champignons Filamenteux, IFR 86 de Biotechnologie Agro-Industrielle de Marseille, France. lomascolo@esil.univ-mrs.fr
Record
E
E
Herpoël-Gimbert
I
I
Delattre
M
M
Robert
J L
JL
Georis
J
J
Dauvrin
T
T
Sigoillot
J-C
JC
Asther
M
M
D001487:Basidiomycota / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D003373:Coumaric Acids / Q000494:pharmacology; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D000431:Ethanol / Q000494:pharmacology*; D042845:Laccase; D010088:Oxidoreductases / Q000096:biosynthesis* / Q000302:isolation & purification
D003373:Coumaric Acids; D003470:Culture Media; D000431:Ethanol; C004999:ferulic acid; D010088:Oxidoreductases; D042845:Laccase