The high demand for food and energy imposed by the increased life expectancy of the population has driven agricultural activity, which is reflected in the larger quantities of agro-industrial waste generated, and requires new forms of use. Brazil has the greatest biodiversity in the world, where corn is one of the main agricultural genres, and where over 40% of the waste generated is from cobs without an efficient destination. With the aim of the valorization of these residues, we proposed to study the immobilization of laccase from Aspergillus spp. (LAsp) in residual corn cob and its application in the degradation of Remazol Brilliant Blue R (RBBR) dye. The highest yields in immobilized protein (75%) and residual activity (40%) were obtained at pH 7.0 and an enzyme concentration of 0.1 g.mL−1, whose expressed enzyme activity was 1854 U.kg−1. At a temperature of 60 °C, more than 90% of the initial activity present in the immobilized biocatalyst was maintained. The immobilized enzyme showed higher efficiency in the degradation (64%) of RBBR dye in 48 h, with improvement in the process in 72 h (75%). The new biocatalyst showed operational efficiency during three cycles, and a higher degradation rate than the free enzyme, making it a competitive biocatalyst and amenable to industrial applications.

Carbofuran (2.3-dihydro-2.2-dimethyl-benzofuranyl-N-methylcarbamate) is an insecticide belonging to the group of carbamates, widely used in pest control in crops with great commercial value, bioaccumulative and extremely toxic to the environment. An alternative to treat areas contaminated with pesticides is bioremediation, which consists of using microorganisms or their enzymes to remove persistent chemical compounds. Thus, the objective of this study was to determine the biodegradation of carbofuran, using the fungus Syncephalastrum racemosum, by evaluating fungal tolerance, enzymatic activity and quantifying residues by UV-Visible spectrophotometry. The results obtained showed that S. racemosum presented best biodegradation capacity at 15 µg mL-1carbofuran concentration (93.02%), with IVCM values of 21.95 cm day-1, laccase (0.712 U mL-1) and lignin peroxidase (0.005 U mL-1), after 168 h incubation. Thus, the degradation rate in the 25 to 100 µg mL-1 range showed values of 12.66 to 75.58%, respectively. Based on these results, the fungus has great potential for use in the bioremediation, minimizing the impacts of this pesticide on the environment.

As a consequence of intense industrialization in the last few decades, the amount of agro-industrial wastes has increasing, where new forms of valorization are crucial. In this work, five residual biomasses from Maranhão (Brazil) were investigated as supports for immobilization of lipase from Thermomyces lanuginosus (TLL). The new biocatalysts BM-TLL (babaçu mesocarp) and RH-TLL (rice husk) showed immobilization efficiencies >98% and hydrolytic activities of 5.331 U g−1 and 4.608 U g−1, respectively, against 142 U g−1 by Lipozyme® TL IM. High esterification activities were also found, with 141.4 U g−1 and 396.4 U g−1 from BM-TLL and RH-TLL, respectively, against 113.5 U g−1 by TL IM. Results of porosimetry, SEM, and BET demonstrated BM and RH supports are mesoporous materials with large hydrophobic area, allowing a mixture of hydrophobic adsorption and confinement, resulting in hyperactivation of TLL. These biocatalysts were applied in the production of hexyl laurate, where RH-TLL was able to generate 94% conversion in 4 h. Desorption with Triton X-100 and NaCl confirmed that new biocatalysts were more efficient with 5 times less protein than commercial TL IM. All results demonstrated that residual biomass was able to produce robust and stable biocatalysts containing immobilized TLL with better results than commercial preparations.

Introdução: A crescente demanda por produtos naturais tem estimulado pesquisadores a desenvolver processos biotecnológicos para a produção de compostos de aroma, como a fermentação em estado sólido (FES), em que resíduos orgânicos podem ser utilizados como substrato ou suporte inerte. Objetivo: Este trabalho tem como objetivo investigar a produção de compostos de aroma a partir da FES de Geotrichum candidum (CCT 1205) e Trichoderma harzianum (IOC 4042) utilizando borra de café in natura (BC-IN) e desengordurada (BC-DES) como suporte. Material e métodos. Para a fermentação, os suportes sólidos (5 g) foram adicionadas em erlenmeyer (250 ml), e impregnados com uma solução nutritiva contendo glicose, (NH4)2SO4, MgSO4, KH2PO4, KCl, CaCl2.H2O, FeSO4 e ZnSO4. O substrato quanto a solução nutritiva foram autoclavados a 121°C por 15 min e inoculados por 1 mL de suspensão de esporos (1,0 x 106 UFC/mL), e mantidos estacionários a 28°C por 7 dias. Os compostos produzidos foram analisados SPME, CG-EM, e caracterizados com base no índice de similaridade (%), GRAS (generally recognized as safe) e FEMA (Flavor & Extract Manufacturers Association). Resultados: A caracterização química indicou que os suportes BC-IN e BC-DES são compostos de (em % m/m, respectivamente): umidade (8,68 e 8,15), proteínas (12,01 e 11,26), lipídios (10,42 e 2,17) e carboidratos totais (67,30 e 76,40). Vários compostos de aroma foram detectados no extrato do BC-IN e BC-DES fermentado por G. candidum e T. harzianum, provando que a retirada da fração lipídica não demonstrou diferenças significativas nos compostos produzidos. Entre eles, hexanal (95%, GRAS 2557, aroma de fruta), 2-feniletanol (98%, GRAS 2858, aroma de rosa), hexanoato de etila (88%, GRAS 2439, aroma de maçã e abacaxi), e 6-pentil-α-pirona (98%, GRAS 3696, aroma de coco) são particularmente perceptíveis entre os compostos identificados via análise CG-EM. Todos os compostos de aroma identificados neste trabalho são reconhecidos pelo status FEMA e GRAS, dessa forma, o uso deles é seguro. Conclusão: Esses resultados comprovam que a produção de compostos de aroma por G. candidum e T. harzianum através do processo de fermentação da borra de café é viável.