Melanoidin-containing wastewaters induce selective laccase gene expression in the white-rot fungus Trametes sp. I-62.
Wastewaters generated from the production of ethanol from sugar cane molasses may have detrimental effects on the environment due to their high chemical oxygen demand and dark brown color. The color is mainly associated with the presence of melanoidins, which are highly recalcitrant to biodegradation. We report here the induction of laccases by molasses wastewaters and molasses melanoidins in the basidiomycetous fungus Trametes sp. I-62. The time course of effluent decolorization and laccase activity in the culture supernatant of the fungus were correlated. The expression of laccase genes lcc1 and lcc2 increased as a result of the addition of complete molasses wastewater and its high molecular weight fraction to fungal cultures. This is the first time differential laccase gene expression has been reported to occur upon exposure of fungal cultures to molasses wastewaters and their melanoidins.
González
Tania
T
Department of Molecular Microbiology, Centro de Investigaciones Biológicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain.
Terrón
María Carmen
MC
Yagüe
Susana
S
Junca
Howard
H
Carbajo
José María
JM
Zapico
Ernesto Javier
EJ
Silva
Ricardo
R
Arana-Cuenca
Ainhoa
A
Téllez
Alejandro
A
González
Aldo Enrique
AE
D001673:Biodegradation, Environmental; D015966:Gene Expression Regulation, Fungal; D042845:Laccase / Q000235:genetics* / Q000378:metabolism*; D008965:Molasses / Q000032:analysis; D011108:Polymers / Q000378:metabolism*; D020072:Polyporales / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014865:Waste Disposal, Fluid
D011108:Polymers; C011908:melanoidin polymers; D042845:Laccase