Enhanced saccharification levels of corn starch using as a strategy a novel amylolytic complex (AmyHb) from the thermophilic fungus var. in association with commercial enzyme.

Amylases represent a versatile group of catalysts that are used for the saccharification of starch because they can hydrolyze the glycosidic bonds of starch molecules to release glucose, maltose, and short-chain oligosaccharides. The amylolytic complex of the thermophilic filamentous fungus var (AmyHb) was produced, biochemically characterized, and compared with the commercial amylase Termamyl. In addition, the biotechnological application of AmyHb in starch saccharification was investigated.

N-acetylation of toxic aromatic amines by fungi: Strain screening, cytotoxicity and genotoxicity evaluation, and application in bioremediation of 3,4-dichloroaniline.

Aromatic amines (AA) are one of the most commonly used classes of compounds in industry and the most common pollutants found in both soil and water. 3,4-Dichloaniline (3,4-DCA) is a persistent residue of the phenylurea herbicide in the environment. In this study, we used a colorimetric method as a new approach to screen 12 filamentous fungal strains of the genera Aspergillus, Chaetomium, Cladosporium, and Mucor to assess their capacity to perform AA N-acetylation since it is considered a potential tool in environmental bioremediation.

New derivatives of the iridoid specioside from fungal biotransformation.

Iridoids are widely found from species of Bignoniaceae family and exhibit several biological activities, such as anti-inflammatory, antimicrobial, antioxidant, and antitumor. Specioside is an iridoid found from Tabebuia species, mainly in Tabebuia aurea. Thus, here fungus-mediated biotransformation of the iridoid specioside was investigated by seven fungi.

Electrostatic interaction optimization improves catalytic rates and thermotolerance on xylanases.

Understanding the aspects that contribute to improving proteins' biochemical properties is of high relevance for protein engineering. Properties such as the catalytic rate, thermal stability, and thermal resistance are crucial for applying enzymes in the industry. Different interactions can influence those biochemical properties of an enzyme.

Identification of a cold-adapted and metal-stimulated β-1,4-glucanase with potential use in the extraction of bioactive compounds from plants.

Cold-adapted endo-β-1,4-glucanases hold great potential for industrial processes requiring high activity at mild temperatures such as in food processing and extraction of bioactive compounds from plants. Here, we identified and explored the specificity, mode of action, kinetic behavior, molecular structure and biotechnological application of a novel endo-β-1,4-glucanase (XacCel8) from the phytopathogen Xanthomonas citri subsp. citri.

Designing a cocktail containing redox enzymes to improve hemicellulosic hydrolysate fermentability by microorganisms.

Bioproducts production using monomeric sugars derived from lignocellulosic biomass presents several challenges, such as to require a physicochemical pretreatment to improve its conversion yields. Hydrothermal lignocellulose pretreatment has several advantages and results in solid and liquid streams. The former is called hemicellulosic hydrolysate (HH), which contains inhibitory phenolic compounds and sugar degradation products that hinder microbial fermentation products from pentose sugars.

A Collagenolytic Aspartic Protease from Thermomucor indicae-seudaticae Expressed in Escherichia coli and Pichia pastoris.

Proteases are produced by the most diverse microorganisms and have a wide spectrum of applications. However, the use of wild microorganisms, mainly fungi, for enzyme production has some drawbacks. They are subject to physiological instability due to metabolic adaptations, causing complications and impairments in the production process.

Crystal structure of a novel xylose isomerase from Streptomyces sp. F-1 revealed the presence of unique features that differ from conventional classes.

Background: Enzymatic isomerization is a promising strategy to solve the problem of xylose fermentation and, consequently, to leverage the production of advanced biofuels and biochemicals. In a previous work, our research group discovered a new strain of Streptomyces with great biotechnological potential due to its ability to produce a broad arsenal of enzymes related to lignocellulose degradation.

Methods: We applied a multidisciplinary approach involving enzyme kinetics, biophysical methods, small angle X-ray scattering and X-ray crystallography to investigate two novel xylose isomerases, XylA1F1 and XylA2F1, from this strain.

Structure-guided design combined with evolutionary diversity led to the discovery of the xylose-releasing exo-xylanase activity in the glycoside hydrolase family 43.

Rational design is an important tool for sculpting functional and stability properties of proteins and its potential can be much magnified when combined with in vitro and natural evolutionary diversity. Herein, we report the structure-guided design of a xylose-releasing exo-β-1,4-xylanase from an inactive member of glycoside hydrolase family 43 (GH43). Structural analysis revealed a nonconserved substitution (Lys ) that results in the disruption of the hydrogen bond network that supports catalysis.

A novel β-glucosidase isolated from the microbial metagenome of Lake Poraquê (Amazon, Brazil).

The Amazon region holds most of the biological richness of Brazil. Despite their ecological and biotechnological importance, studies related to microorganisms from this region are limited. Metagenomics leads to exciting discoveries, mainly regarding non-cultivable microorganisms.

New Heterofunctional Supports Based on Glutaraldehyde-Activation: A Tool for Enzyme Immobilization at Neutral pH.

Immobilization is an exciting alternative to improve the stability of enzymatic processes. However, part of the applied covalent strategies for immobilization uses specific conditions, generally alkaline pH, where some enzymes are not stable. Here, a new generation of heterofunctional supports with application at neutral pH conditions was proposed.

Draft genome sequence of Streptomyces sp. strain F1, a potential source for glycoside hydrolases isolated from Brazilian soil.

Here, we show the draft genome sequence of Streptomyces sp. F1, a strain isolated from soil with great potential for secretion of hydrolytic enzymes used to deconstruct cellulosic biomass. The draft genome assembly of Streptomyces sp.

Comparative genomics reveals high biological diversity and specific adaptations in the industrially and medically important fungal genus Aspergillus.

Background: The fungal genus Aspergillus is of critical importance to humankind. Species include those with industrial applications, important pathogens of humans, animals and crops, a source of potent carcinogenic contaminants of food, and an important genetic model. The genome sequences of eight aspergilli have already been explored to investigate aspects of fungal biology, raising questions about evolution and specialization within this genus.

The aldo-keto reductase: a multipurpose enzyme for biorefinery applications.

Background: In nature, termites can be considered as a model biological system for biofuel research based on their remarkable efficiency for lignocellulosic biomass conversion. Redox enzymes are of interest in second-generation ethanol production because they promote synergic enzymatic activity with classical hydrolases for lignocellulose saccharification and inactivate fermentation inhibitory compounds produced after lignocellulose pretreatment steps.

Results: In the present study, the biochemical and structural characteristics of the aldo-keto reductase (AKR-1) were comprehensively investigated.

Engineering increased thermostability in the GH-10 endo-1,4-β-xylanase from Thermoascus aurantiacus CBMAI 756.

The GH10 endo-xylanase from Thermoascus aurantiacus CBMAI 756 (XynA) is industrially attractive due to its considerable thermostability and high specific activity. Considering the possibility of a further improvement in thermostability, eleven mutants were created in the present study via site-directed mutagenesis using XynA as a template. XynA and its mutants were successfully overexpressed in Escherichia coli Rosetta-gami DE3 and purified, exhibiting maximum xylanolytic activity at pH 5 and 65°C.

A Novel Carbohydrate-binding Module from Sugar Cane Soil Metagenome Featuring Unique Structural and Carbohydrate Affinity Properties.

Carbohydrate-binding modules (CBMs) are appended to glycoside hydrolases and can contribute to the degradation of complex recalcitrant substrates such as the plant cell wall. For application in bioethanol production, novel enzymes with high catalytic activity against recalcitrant lignocellulosic material are being explored and developed. In this work, we report the functional and structural study of CBM_E1, which was discovered through a metagenomics approach and is the founding member of a novel CBM family, CBM81.

Bioethanol production by recycled Scheffersomyces stipitis in sequential batch fermentations with high cell density using xylose and glucose mixture.

Here, it is shown three-step investigative procedures aiming to improve pentose-rich fermentations performance, involving a simple system for elevated mass production by Scheffersomyces stipitis (I), cellular recycle batch fermentations (CRBFs) at high cell density using two temperature strategies (fixed at 30°C; decreasing from 30 to 26°C) (II), and a short-term adaptation action seeking to acclimatize the microorganism in xylose rich-media (III). Cellular propagation provided 0.52gdrycellweightgRS(-1), resulting in an expressive value of 45.

Crystal structure and biochemical characterization of the recombinant ThBgl, a GH1 β-glucosidase overexpressed in Trichoderma harzianum under biomass degradation conditions.

Background: The conversion of biomass-derived sugars via enzymatic hydrolysis for biofuel production is a challenge. Therefore, the search for microorganisms and key enzymes that increase the efficiency of the saccharification of cellulosic substrates remains an important and high-priority area of study. Trichoderma harzianum is an important fungus known for producing high levels of cellulolytic enzymes that can be used for cellulosic ethanol production.

Xylan-specific carbohydrate-binding module belonging to family 6 enhances the catalytic performance of a GH11 endo-xylanase.

Xylanases catalyze the hydrolysis of β-1,4-linked xylosyl moieties from xylan chains, one of the most abundant hemicellulosic polysaccharides found in plant cell walls. These enzymes can exist either as single catalytic domains or as modular proteins composed of one or more carbohydrate-binding modules (CBMs) appended to the catalytic core. However, the molecular mechanisms governing the synergistic effects between catalytic domains and their CBMs are not fully understood.

GH53 Endo-Beta-1,4-Galactanase from a Newly Isolated Bacillus licheniformis CBMAI 1609 as an Enzymatic Cocktail Supplement for Biomass Saccharification.

Galactanases (endo-β-1,4-galactanases-EC 3.2.1.

A novel cold-adapted and glucose-tolerant GH1 β-glucosidase from Exiguobacterium antarcticum B7.

A novel GH1 β-glucosidase (EaBgl1A) from a bacterium isolated from Antarctica soil samples was recombinantly overexpressed in Escherichia coli cells and characterized. The enzyme showed unusual pH dependence with maximum activity at neutral pH and retention of high catalytic activity in the pH range 6 to 9, indicating a catalytic machinery compatible with alkaline conditions. EaBgl1A is also a cold-adapted enzyme, exhibiting activity in the temperature range from 10 to 40°C with optimal activity at 30°C, which allows its application in industrial processes using low temperatures.

Molecular cloning, overexpression, purification and crystallographic analysis of a GH43 β-xylosidase from Bacillus licheniformis.

β-Xylosidases (EC 3.2.1.