Gabriela Piccolo Maitan-Alfenas

• Professor at Federal University of Viçosa

The use of additives during the conversion of lignocellulosic biomass into biofuels is a promising strategy to overcome the low yield of the saccharification step. This study evaluated the potential of whey, a by-product of the dairy industry, as a cost-effective additive to minimize unproductive enzyme adsorption during the sugarcane bagasse conve...

Xylooligosaccharides (XOS) are xylose oligomers produced from agro-industrial wastes through xylanases action. They show prebiotic properties that add value to commercial products, such as beverages and foods. Soy husk, rice bran, and corn cob were pretreated and hydrolyzed by recombinant xylanases with high catalytic activity, and the XOS were qua...

The use of additives during the conversion of lignocellulosic biomass into biofuels is a promising strategy to overcome the low yield of the saccharification step. This study evaluated the potential of whey, a by-product of the dairy industry, as a cost-effective additive to minimize unproductive enzyme adsorption during the sugarcane bagasse conve...

Glucosidases for industrial applications are mainly obtained from filamentous fungi. Kretzschmaria zonata is a phytopathogen fungus that produces an arsenal of enzymes with biotechnological potential and this work aimed to produce, purify, and characterize a β-glucosidase from the fungus K. zonata for its application in supplementation of a commerc...

Xylooligosaccharides (XOS) are potential prebiotic ingredients for food industries, mainly obtained after xylan hydrolysis by endoxylanases. Enzyme immobilization offers opportunities for recovery and reuse, while also enhancing its physical and chemical characteristics, such as stability and catalytic efficiency. This work aimed to immobilize the...

This study investigated the impact of roasting profiles on the chemical and sensory characteristics of coffee beans (C. canephora and C. arabica). Different roasting times and temperatures were analyzed to understand their influence on physicochemical properties, concentrations of sugars, organic acids, and melanoidins. The research aimed to associ...

Xylooligosaccharides (XOS) are potential prebiotic ingredients for food industries, mainly obtained after xylan hydrolysis by endoxylanases. Enzyme immobilization possibilities recovery and reuse, in addition to improving its physical-chemical characteristics, such as stability and catalytic efficiency. This work aimed to immobilize the SM2 xylanas...

glucosidases for industrial applications are mainly obtained from filamentous fungi. Kretzschmaria zonata is a phytopathogenic fungus that produces an arsenal of enzymes with biotechnological potential and this work aimed to produce, to purify and to characterize a β-glucosidase from the fungus K. zonata for its application in supplementation of a...

Xylanases are widely applied for different biotechnological purposes, especially to produce xylooligosaccharides (XOS), prebiotics for the food industry. The fungus Kretzschmaria zonata produced xylanase after growth on corncob. The partial purification of the enzyme was performed through a Q‐Sepharose anion exchange column. Enzyme purity was perfo...

Enzymes from phytopathogenic fungi are desirable for biotechnological applications and a highly virulent phytopathogen shows great appeal for enzymes production. To assess the biotechnological potential of Kretzschmaria zonata, a plant pathogenic fungus, we analyzed its enzymatic profile after growth on six different types of lignocellulosic biomas...

Different lignocellulosic biomasses are found worldwide and each country has its own important industrial crop that can be converted into high-value products, such as ethanol. Therefore, evaluation of new biomasses to be used in biorefineries is important to decrease the dependence on non-renewable resources and to guarantee sustainable development...

Oligosaccharides are low molecular weight carbohydrates composed of monomeric sugars. They are naturally found in milk, vegetables, and fruits, but can also be obtained by chemical or biocatalytic processes. They can be applied as prebiotics, antimicrobials, antioxidants and others. This article will focus on the biotechnological production, health...

Biomass enzymatic hydrolysis efficiency shows some limitations, such as the non-specific adsorption of enzymes in lignin. We evaluated the adsorption of proteins and enzymes from Chrysoporthe cubensis into alkaline and acid pretreated sugarcane bagasse, containing 8.1 and 33.8% of lignin, respectively. The data from Langmuir isotherm showed that at...

Tectona grandis L.f., known as teak, is one of the most valuable tropical hardwood species that has been extensively planted in tropical zones, covering about 6,8 million hectares (Kollert and Kleine 2017). Recent advances in silvicultural management and use of improved clones have enhanced productivity and wood quality of teak plantations in Brazi...

Polygalacturonases are extensively used in food industries for pectic substances degradation. They are essential for fruit juice clarification due the degradation of insoluble viscous pectinacious compounds. Polygalacturonase production by the fungus Calonectria pteridis was performed on submerged fermentation and, after purification, the enzyme sh...

Considering bioethanol production, extensive research has been performed to decrease inhibitors produced during pretreatments, to diminish energy input, and to decrease costs. In this study, sugarcane bagasse was pretreated with NaOH, H2SO4, and water. The higher concentration of phenols, 3.3 g/L, was observed in biomass liquid fraction after alkal...

BACKGROUND Endo‐1,4‐β‐xylanases have marked hydrolytic activity towards arabinoxylans. Xylanases (xynA) produced by the anaerobic fungus Orpinomyces sp. strain PC‐2 have been shown to be superior in specific activity, which strongly suggests their applicability in the bakery industry for the processing of whole‐wheat flour containing xylans. In the...

The use of enzymes in food production, including dairy products, is below expected due the high costs associated with their production and purification. Microbial enzymes have great potential for industrial applications since they can be produced via large-scale fermentation and they are easily expressed by cloning in well-known cultivated microorg...

The phytopathogenic fungus Ceratocystis fimbriata produced an extracellular β-xylosidase when grown in mineral medium with wheat bran as carbon source. The enzyme was purified and characterized. The molecular mass was estimated by SDS-PAGE (161.6 kDa). The enzyme showed maximum activity at pH 3.9 and 65 °C, and it showed to be significantly thermos...

Two intracellular invertases from Aspergillus terreus were purified and characterized. Invertase 1 has been shown maximal activity at pH 3.0 and optimum temperature at 60°C, while invertase 2 presented maximal activity at pH 4.6 and optimum temperature at 55°C. Km of invertase 1 and 2 for sucrose were 9.8 and 6.2 mM, respectively. Invertase 2 showe...

A set of β-glucosidases from the phytopathogenic fungus Chrysoporthe cubensis was partially purified, characterized and evaluated for its potential application in the process of sugarcane bagasse saccharification. C. cubensis was grown in solid state fermentation (SSF) containing wheat bran as carbon source. The group of β-glucosidases, containing...

Xylanases from the pathogen fungus Chrysoporthe cubensis were produced under solid state fermentation (SSF) using wheat bran as carbon source. The enzymatic extracts were submitted to ion exchange (Q Sepharose) and gel filtration chromatography methods (Sephadex S-200) for purification. The xylanases were divided into three groups: P1 showed better...

Two xylanases from Aspergillus nidulans, XlnB and XlnC, were expressed in Pichia pastoris, purified and characterized. XlnB and XlnC achieved maximal activities at 60 °C and pH 7.5 and at 50 °C and pH 6.0, respectively. XlnB showed to be very thermostable by maintaining 50% of its original activity after 49 hours incubated at 50 °C. XlnB had its hi...

Efficient polysaccharide degradation depends on interaction between enzymes acting on the main chain and the side chains. Previous studies demonstrated cooperation between several enzymes, but not all enzyme combinations have been explored. A better understanding of enzyme cooperation would enable the design of better enzyme mixtures, optimally pro...

Plant-degrading enzymes can be produced by fungi on abundantly available low-cost plant biomass. However, enzymes sets after growth on complex substrates need to be better understood, especially with emphasis on differences between fungal species and the influence of inhibitory compounds in plant substrates, such as monosaccharides. In this study,...

An intracellular β-glucosidase from Debaryomyceshansenii UFV-1 was produced in an YP medium with cellobiose as the carbon source. This enzyme was purified, characterised and presented a Mr of 65.15kDa. Yeast cells containing the intracellular β-glucosidase were immobilised in calcium alginate. The free β-glucosidase and immobilised cells containing...

The interest in the conversion of plant biomass to renewable fuels such as bioethanol has led to an increased investigation into the processes regulating biomass saccharification. The filamentous fungus Aspergillus niger is an important microorganism capable of producing a wide variety of plant biomass degrading enzymes. In A. niger the transcripti...

Blending of the enzyme extracts produced by different fungi can result in favorable synergetic enhancement of the enzyme blend with regards to the main cellulase activities, as well as the inclusion of accessory enzymes that may not be as abundant in enzyme extracts produced by predominantly cellulase producing fungi. The Chrysoporthe cubensis:Peni...

A novel multienzyme complex, E1C, and a free endoglucanase, E2 (GH5), from Fusarium verticillioides were purified. The E1C contained two endoglucanases (GH6 and GH10), one cellobiohydrolase (GH7) and one xylanase (GH10). Maximum activity was observed at 80°C for both enzymes and they were thermostable at 50 and 60°C. The activation energies for E1C...