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Cutinase is a very versatile enzyme due to the wide range of substrates that it can use. It has application in several biotechnological areas, acting as biocatalysts in the food industry, in detergents as well as in biodegradation of polymers and other toxic substances. In this research, glucose consumption, protein content, biomass and cutinase production by Fusarium culmorum were evaluated. Cutinolitic activity was observed using gel zymography. This fungus was grown on culture media containing glucose and different concentrations of apple cutin (0, 1, 3 and 10 g/L) in solid-state fermentation. F. culmorum showed the highest production of biomass, protein and cutinase in medium supplemented with 10 g of cutin/L. Glucose uptake was inversely proportional to the cutin concentration. Medium lacking cutin showed the fastest glucose consumption. Heavily stained bands were observed in the gel with increasing concentrations of cutin after 72 h, showing a molecular weight of 50 kDa. These results shown that apple cutin induced cutinase production and was also used as carbon source. It was also observed that glucose did not act as a repressor of cutinase production. Keywords: cutinase, Fusarium culmorum, solid-state fermentation. RESUMENLa versatilidad de la cutinasa es debida a los diversos sustratos que puede emplear. Estas enzimas tienen aplicación en distintas áreas biotecnológicas, lo que las convierte en atractivos biocatalizadores para la industria alimentaria, de detergentes, así como en la degradación de polímeros y sustancias tóxicas. En este trabajo se evaluó el consumo de glucosa, contenido de proteína, la producción de biomasa y cutinasas por el hongo Fusarium culmorum crecido en medios conteniendo glucosa y diferentes concentraciones de cutina de manzana (0, 1, 3 y 10 g/L) en fermentación sólida. La actividad cutinolítica fue observada empleando zimografia. F. culmorum mostró la mayor producción de biomasa, proteína y cutinasas en el medio adicionado con 10 g de cutina/L. El consumo de glucosa fue inversamente proporcional a la concentración de cutina. La glucosa se consumió más rápido en el medio sin adición de cutina. El aumento en la concentración de cutina de manzana incremento la intensidad en la banda mostrada en el zimograma a partir de las 72 h, cuyo peso molecular fue de 50 kDa. Estos resultados muestran que la cutina de manzana indujo la producción de cutinasa y que fue usada como fuente de carbono. La glucosa no actúa como un represor de la producción de cutinasas.Palabras clave: cutinasa, fermentación sólida, Fusarium culmorum.

This study aimed to evaluate the growth, respiratory activity, and biodegradation of chlorpyrifos in cultures of Azotobacter vinelandii ATCC 12837. A strategy based on the modification of culture media and aeration conditions was carried out to increase the cell concentration of A. vinelandii, in order to favor and determine its tolerance to chlorpyrifos and its degradation ability. The culture in shaken flasks, using sucrose as a carbon source, significantly improved the growth compared to media with mannitol. When the strain was cultivated under oxygen-limited (5.5, 11.25 mmol L−1 h−1) and no-oxygen-limited conditions (22 mmol L−1 h−1), the growth parameters were not affected. In cultures in a liquid medium with chlorpyrifos, the bacteria tolerated a high pesticide concentration (500 ppm) and the growth parameters were improved even under conditions with a reduced carbon source (sucrose 2 g L−1). The strain degraded 99.6% of chlorpyrifos at 60 h of cultivation, in co-metabolism with sucrose; notably, A. vinelandii ATCC 12837 reduced by 50% the initial pesticide concentration in only 6 h (DT50). Graphical Abstract

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