Lowering the price of enzymes is one of the key challenges to stablish the full potential of lignocellulosic biorefineries. Lignocellulolytic enzymes are used to deconstruct the complex plant cell ...wall, releasing fermentable sugars that can be further used in the production of lignocellulosic ethanol. Countries like Brazil, India, and China are already blending or considering blending ethanol in different proportions to gasoline, to be used in combustion engines. Fungal co-cultures are an alternative way of producing lignocellulolytic enzymes. In this review, we discuss the use of fungal co-cultures as an alternative for the on-site production of lignocellulolytic enzymes. The basic concepts and applications of fungal co-cultures are presented, covering most used strains, systems, advances achieved and challenges ahead. Co-cultures are an alternative technique to produce carbohydrate-active enzymes, and several studies highlighted here demonstrate their potential to contribute to the expansion of lignocellulosic biorefineries. However, there are still several aspects of fungal co-cultures that are not understood and need to be addressed to enable fungal co-cultures for commercial enzyme production. The necessity for more detailed studies, especially regarding the molecular interactions between participant fungi, are stressed in the article.
•Reutilization of biomass is one of the key strategies to implement a new bio-based economy.•Fungal co-cultures are a promising strategy to implement cell wall-degrading enzyme production for biorefinery use.•Co-cultures of filamentous fungi can increase certain enzyme activities, however other activities may be diminished.•New Omics studies are fundamental to improve molecular understating of fungal interactions.
A biotechnology perspective of fungal proteases de Souza, Paula Monteiro; Bittencourt, Mona Lisa de Assis; Caprara, Carolina Canielles ...
Brazilian journal of microbiology,
06/2015, Letnik:
46, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Proteases hydrolyze the peptide bonds of proteins into peptides and amino acids, being found in all living organisms, and are essential for cell growth and differentiation. Proteolytic enzymes have ...potential application in a wide number of industrial processes such as food, laundry detergent and pharmaceutical. Proteases from microbial sources have dominated applications in industrial sectors. Fungal proteases are used for hydrolyzing protein and other components of soy beans and wheat in soy sauce production. Proteases can be produced in large quantities in a short time by established methods of fermentation. The parameters such as variation in C/N ratio, presence of some sugars, besides several other physical factors are important in the development of fermentation process. Proteases of fungal origin can be produced cost effectively, have an advantage faster production, the ease with which the enzymes can be modified and mycelium can be easily removed by filtration. The production of proteases has been carried out using submerged fermentation, but conditions in solid state fermentation lead to several potential advantages for the production of fungal enzymes. This review focuses on the production of fungal proteases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.
•The review presents the main proteomic approaches used to study filamentous fungi secretomes.•Data on the secretomes from Trichoderma and Aspergillus species is presented.•Perspectives on fungi ...secretome analysis are discussed.
Filamentous fungal secretomes comprise highly dynamic sets of proteins, including multiple carbohydrate active enzymes (CAZymes) which are able to hydrolyze plant biomass polysaccharides into products of biotechnological interest such as fermentable sugars. In recent years, proteomics has been used to identify and quantify enzymatic and non-enzymatic polypeptides present in secretomes of several fungi species. The resulting data have widened the scientific understanding of the way filamentous fungi perform biomass degradation and offered novel perspectives for biotechnological applications. The present review discusses proteomics approaches that have been applied to the study of fungal secretomes, focusing on two of the most studied filamentous fungi genera: Trichoderma and Aspergillus.
The enzyme L-asparaginase (L-ASNase) is used in the treatment of Acute Lymphoblastic Leukemia. The preparations of this enzyme for clinical use are derived from bacterial sources and its use is ...associated with serious adverse reactions. In this context, it is important to find new sources of L-ASNase. In this work, the Placket-Burman Experimental Design (PBD) was used to determine the influence of the variables on the L-ASNase production then it was followed by a 2
Factorial Fractional Design (FFD). The results obtained from PBD have shown a range of L-ASNase activity, from 0.47 to 1.77 U/gcell and the results obtained from FFD have showed a range of L-ASNase activity, from 1.10 to 2.36 U/gcell. L-proline and ammonium sulfate were identified as of significant positive variables on this production enzyme by Penicillium cerradense sp. nov. The precise identification of this new species was confirmed by morphological characteristics and sequence comparisons of the nuclear 18S-5.8S-28S partial nrDNA including the ITS1 and ITS2 regions, RNA polymerase II, β-tubulin and calmodulin genomic regions. The genetic sequence coding for the L-ASNase was obtained after carrying out a full genome sequencing. The L-ASNase expressed by P. cerradense sp. nov may have promising antineoplastic properties.
Heteropolymers of mannan are polysaccharide components of the plant cell wall of gymnosperms and some angiosperms, including palm trees (Arecales and Monocot). Degradation of the complex structure of ...these polysaccharides requires the synergistic action of enzymes that disrupt the internal carbon skeleton of mannan and accessory enzymes that remove side chain substituents. However, complete degradation of these polysaccharides is carried out by an exo-hydrolase termed β-mannosidase. Microbial β-mannosidases belong to families 1, 2, and 5 of glycosyl hydrolases, and catalyze the hydrolysis of non-reducing ends of mannose oligomers. Besides, these enzymes are also involved in transglycosylation reactions. Because of their activity at different temperatures and pH values, these enzymes are used in a variety of industrial applications and the pharmaceutical, food, and biofuel industries.
Holocellulase production by
Aspergillus niger
using raw sugarcane bagasse (rSCB) as the enzyme-inducing substrate is hampered by the intrinsic recalcitrance of this material. Here we report that mild ...hydrothermal pretreatment of rSCB increases holocellulase secretion by
A. niger.
Quantitative proteomic analysis revealed that pretreated solids (PS) induced a pronounced up-regulation of endoglucanases and cellobiohydrolases compared to rSCB, which resulted in a 10.1-fold increase in glucose release during SCB saccharification. The combined use of PS and pretreatment liquor (PL), referred to as whole pretreated slurry (WPS), as carbon source induced a more balanced up-regulation of cellulases, hemicellulases and pectinases and resulted in the highest increase (4.8-fold) in the release of total reducing sugars from SCB. The use of PL as the sole carbon source induced the modulation of
A. niger
’s secretome towards hemicellulose degradation. Mild pretreatment allowed the use of PL in downstream biological operations without the need for undesirable detoxification steps.
The economic viability of enzyme-based lignocellulosic biomass biorefineries depends on the low cost of holocellulose-degrading enzymes necessary for decomposing biomass into fermentable sugars and ...other value-added products. The high costs of commercial enzymes and the high enzyme loadings required for biomass hydrolysis motivates the use of lignocellulose as feedstock for on-site, integrated production of holocellulases in biorefineries. However, due to high recalcitrance, raw lignocellulose limits fungal growth and enzyme production. Pretreatment technologies can enhance enzyme production when employing lignocellulosic materials as substrate. This review provides a brief description of currently available pretreatment technologies and illustrates the potential of pretreating lignocellulosic wastes for enzyme production with filamentous fungi.
Fungal lytic polysaccharide monooxygenases (LPMOs) from family AA9 are oxidative enzymes that, in the past few years, have changed the paradigm of cellulose conversion. They are key factor in the ...lignocellulose breakdown and are widely distributed among fungi. This review focuses on LPMOs from family AA9 and gives an overview of recent discoveries relative to their structure, mode of action, and synergism with other enzymes. Finally, several aspects regarding their potential applications toward deconstruction of biomass and biorefinery processes are discussed.
Interest in lignocellulosic biomass conversion technologies has increased recently because of their potential to reduce the dependency on non-renewable feedstocks. Residues from a variety of crops ...are the major source of lignocellulose, which is being produced in increasingly large quantities worldwide. The commercial exploitation of crop residues as feedstocks for biorefineries which could be used to produce a variety of goods such as biofuels, biochemicals, bioplastics, and enzymes is an attractive approach not only for adding value to residues but also for providing renewable products required by the expanding bioeconomy market. Moreover, the implementation of biorefineries in different regions has the potential to add value to the specific crop residues produced in the region. In this review, several aspects of crop residue application in biorefineries are discussed, including the role of crop residues in the bioeconomy and circular economy concepts, the main technical aspects of crop residue conversion in biorefineries, the main crop residues generated in different regions of the world and their availability, the potential value-added bioproducts that can be extracted or produced from each crop residue, and the major advantages and challenges associated with crop residue utilization in biorefineries. Despite their potential, most biomass refining technologies are not sufficiently advanced or financially viable. Several technical obstacles, especially with regard to crop residue collection, handling, and pre-treatment, prevent the implementation of biorefineries on a commercial scale. Further research is needed to resolve these scale-up-related challenges. Increased governmental incentives and bioeconomic strategies are expected to boost the biorefinery market and the cost competitiveness of biorefinery products.
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•Interactome represents a whole set of interactions during lignocellulose breakdown.•Fungus-substrate interactome drives enzyme expression.•Enzyme-enzyme interactome involves ...synergism and LMW molecules exchanging.•Interactome can be driven to enhance biomass valorization.•Interactome can unlock the full potential of lignocellulosic components.
Biomass represents an abundant and inexpensive source of sugars and aromatic compounds that can be used as raw materials for conversion into value-added bioproducts. Filamentous fungi are sources of plant cell wall degrading enzymes in nature. Understanding the interactions between enzymes is crucial for optimizing biomass degradation processes. Herein, the concept of the interactome is presented as a holistic approach that depicts the interactions among enzymes, substrates, metabolites, and inhibitors. The interactome encompasses several stages of biomass degradation, starting with the sensing of the substrate and the subsequent synthesis of hydrolytic and oxidative enzymes (fungus-substrate interaction). Enzyme-enzyme interactions are exemplified in the complex processes of lignocellulosic biomass degradation. The enzyme-substrate-metabolite-inhibitor interaction also provides a better understanding of biomass conversion, allowing bioproduct production from recalcitrant agro-industrial residues, thus bringing greater value to residual biomass. Finally, technological applications are presented for optimizing the interactome at various levels.
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