Inducción de la degradación de lignina de paja de trigo en aromáticos por Aspergillus spp. y Penicillium chrysogenum

Wheat straw is a recalcitrant agricultural waste; incineration of this material represents an important environmental impact. Different reports have been made regarding the use of the structural components of wheat straw, i.e.cellulose, hemicellulose and lignin; however, lignin has been less exploited because it is largely considered therecalcitrant part. Residual wheat straw lignin (REWSLI) has a potential biotechnological value if depolymerization is attained to produce aromatics. Ligninolytic mitosporic fungus represent an alternative where very littleresearch has been done, even though they are capable of depolymerize REWSLI in simple nutritional conditions inrelatively short periods, when compared to basidiomycetes. The aim of this research was to study the depolymerization activity of Aspergillus spp and Penicillium spp on semipurified REWSLI as the sole carbon source toproduce aromatics. The depolymerization capacity was determined by the activity of the laccase, lignin peroxidaseand manganese peroxidase enzymes. The generated aromatics derived from the REWSLI depolymerization were identified by gas chromatography. Obtained results revealed that Penicillium chrysogenum depolymerized thelignin material by 34.8% during the 28-day experimentation period. Laccase activity showed the largest activitywith 111 U L-1in a seven-day period, this enzyme induction was detected in a smaller period than that required bybasidiomycetes to induce it. Moreover, the enzymatic activity was produced without the addition of an extracarbon source as metabolic inductor. Aspergillus spp and Penicillium spp generated guaiacol, vanillin, and hydroxybenzoic, vanillinic, syringic and ferulic acid with a maximum weekly production of 3.5, 3.3, 3.2, 3.3, 10.1and 21.9 mg mL-1, respectively.La paja de trigo es un desecho agrícola recalcitrante, su eliminación por incineración contamina el ambiente. Se hainvestigado el aprovechamiento de sus componentes estructurales: celulosa, hemicelulosa a excepción de la lignina por ser la porción recalcitrante. La lignina residual de paja de trigo (LIREPATO) tiene valor potencial biotecnológico si es degradada en aromáticos. Como alternativa, los hongos mitospóricos ligninolíticos poco se haninvestigado, a pesar de que degradan la LIREPATO en medio de cultivo mineral en un tiempo relativamentecorto comparado con lo reportado con los basidiomicetos. El objetivo de esta investigación fue analizar en Aspergillus spp y Penicillium spp en la degradación de LIREPATO como única fuente de carbono en la generación dearomáticos. La degradación de la LIREPATO en aromaticos se realizo lacasa, lignina peroxidasa y manganesoperoxidasa. Los aromáticos generados se identificaron por cromatografía de gases. Los resultados señalan quePenicillium chrysogenum degradó la LIREPATO con hasta un 34.8% en 28 días de incubación. La actividadlacasa fue la mayor con 111 U L-1 en 7 días, menor tiempo a lo reportado en basidiomicetos y sin la adición unafuente de carbono adicional para inducirla. Aspergillus ssp y Penicilium spp generaron guayacol, vainillina, ácidoshidroxibenzoico, vainillínico, siríngico, y ferúlico con producción máxima por semana de 3.5, 3.3, 3.2, 3.3, 10.1 y21.9 mg mL-1 respectivament

Wheat straw lignin degradation induction to aromatics by por Aspergillus spp. and Penicillium chrysogenum

Wheat straw is a recalcitrant agricultural waste; incineration of this material represents an important environmental impact. Different reports have been made regarding the use of the structural components of wheat straw, i.e. cellulose, hemicellulose and lignin; however, lignin has been less exploited because it is largely considered the recalcitrant part. Residual wheat straw lignin (REWSLI) has a potential biotech-nological value if depolymerization is attained to produce aromatics. Ligninolytic mitosporic fungus represent an alternative where very little research has been done, even though they are capable of depol-ymerize REWSLI in simple nutritional conditions in relatively short periods, when compared to basidio-mycetes. The aim of this research was to study the depolymerization activity of Aspergillus spp and Penicillium spp on semipurified REWSLI as the sole carbon source to produce aromatics. The depoly-merization capacity was determined by the activity of the laccase, lignin peroxidase and manganese peroxidase enzymes. The generated aromatics derived from the REWSLI depolymerization were identi-fied by gas chromatography. Obtained results revealed that Penicillium chrysogenum depolymerized the lignin material by 34.8% during the 28-day experimentation period. Laccase activity showed the largest activity with 111 U L-1 in a seven-day period, this enzyme induction was detected in a smaller period than that required by basidiomycetes to induce it. Moreover, the enzymatic activity was produced with-out the addition of an extra carbon source as metabolic inductor. Aspergillus spp and Penicillium spp generated guaiacol, vanillin, and hydroxybenzoic, vanillinic, syringic and ferulic acid with a maximum weekly production of 3.5, 3.3, 3.2, 3.3, 10.1 and 21.9 mg mL-1, respectively