RESUMEN
Trichoderma reesei is a mesophilic, filamentous fungus, and it is a major industrial source of cellulases, but its lignocellulolytic protein expressions on lignocellulosic biomass are poorly explored at present. The extracellular proteins secreted by T. reesei QM6a wild-type and hypercellulolytic mutant Rut C30 grown on natural lignocellulosic biomasses were explored using a quantitative proteomic approach with 8-plex high throughput isobaric tags for relative and absolute quantification (iTRAQ) and analyzed by liquid chromatography tandem mass spectrometry. We quantified 230 extracellular proteins, including cellulases, hemicellulases, lignin-degrading enzymes, proteases, protein-translocating transporter, and hypothetical proteins. Quantitative iTRAQ results suggested that the expressions and regulations of these lignocellulolytic proteins in the secretome of T. reesei wild-type and mutant Rut C30 were dependent on both nature and complexity of different lignocellulosic carbon sources. Therefore, we discuss here the essential lignocellulolytic proteins for designing an enzyme mixture for optimal lignocellulosic biomass hydrolysis.
Asunto(s)
Celulasas/metabolismo , Proteínas Fúngicas/metabolismo , Lignina/metabolismo , Proteómica/métodos , Trichoderma/enzimología , Biomasa , Proteínas Portadoras/biosíntesis , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Celulasas/biosíntesis , Celulasas/genética , Cromatografía Liquida , Proteínas Fúngicas/biosíntesis , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica , Hidrólisis , Familia de Multigenes , Mutación , Péptido Hidrolasas/biosíntesis , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Espectrometría de Masas en Tándem , Trichoderma/genéticaRESUMEN
Bioenergy, particularly biofuel, from lignocellulosic biomass has been considered as one of the most promising renewable and sustainable energies. The industrial productivity and efficiency of microbial lignocellulolytic enzymes for cellulosic biofuel applications are significantly affected by pH of culture condition. This study established and compared hydrolytic protein expression profiles of Trichoderma reesei QM6a, QM9414, RUT C30 and QM9414MG5 strains at different pH in cellulosic culture media. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of secretome of T. reesei cultured from pH 3.0-9.0 revealed significantly higher hydrolytic protein expressions at acidic pH. The Bray-Curtis similarity indices, clustering, and Shannon diversity index elucidated differences in protein secretion at different pHs in individuals and among the strains. This study demonstrated a comparative lignocellulolytic enzyme secretion profile of T. reesei and its mutants at different pHs and provides pH sensitive and resistance enzyme targets for industrial lignocellulose hydrolysis.