Effect of culture phasing and a polysaccharide on production of xylanase by mixed culture oftrichoderma reesei D1-6 andaspergillus wentii Pt 2804

Exploring the potential of Aspergillus wentii: secondary metabolites and biological properties

Fungi are of considerable importance due to their capacity to biosynthesize various secondary metabolites with bioactive properties that draw high attention in new drug discovery with beneficial uses for improving human well-being and life quality. Aspergillus genus members are widespread and cosmopolitan species with varying economic significance in the fields of industry, medicine, and agriculture. Its species are renowned for their biosynthesis of secondary metabolites, characterized by both potent biological activity and structural novelty, making them a substantial reservoir for the development of new pharmaceuticals. The current work aimed at focusing on one species of this genus, Aspergillus wentii Wehmer, including its reported secondary metabolites in the period from 1951 to November 2023. A total of 97 compounds, including nitro-compounds, terpenoids, anthraquinones, xanthones, benzamides, and glucans. A summary of their bioactivities, as well as their biosynthesis was highlighted. Additionally, the reported applications of this fungus and its enzymes have been discussed. This review offers a useful reference that can direct future research into this fungus and its active metabolites, as well as their possible pharmacological and biotechnological applications.

Assessment and optimization of xylanase production using co-cultures of Bacillus subtilis and Kluyveromyces marxianus

Co-cultures of Bacillus subtilis and Kluyveromyces marxianus were investigated in submerged fermentation for xylanase production at shake-flask scale. Xylanase production markedly increased when arabinose, xylose, or hazelnut shells were used as the single carbon source. Maximal xylanase of 49.5 IU/mL was achieved with 4% B. subtilis, 4% K. marxianus, 40% solid load of hazelnut shells, and pH 7.0. Overall, xylanase was enhanced by 4.4-fold compared to initial un-optimized monoculture production and 2.8-fold compared to initial un-optimized co-cultured production, after optimization by response surface method.

Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis

To overcome the recalcitrant nature of biomass several pretreatment methodologies have been explored to make it amenable to enzymatic hydrolysis. These methodologies alter cell wall structure primarily by removing/altering hemicelluloses and lignin. In this work, alkali, dilute acid, steam explosion pretreatment are systematically studied for mustard stalk. To assess the structural variability after pretreatment, chemical analysis, surface area, crystallinity index, accessibility of cellulose, FT-IR and thermal analysis are conducted. Although the extent of enzymatic hydrolysis varies upon the methodologies used, nevertheless, cellulose conversion increases from <10% to 81% after pretreatment. Glucose yield at 2 and 72h are well correlated with surface area and maximum adsorption capacity. However, no such relationship is observed for xylose yield. Mass balance of the process is also studied. Dilute acid pretreatment is the best methodology in terms of maximum sugar yield at lower enzyme loading.

Method To Estimate Growth of Trichoderma reesei and Aspergillus wentii in Mixed Culture on Cellulosic Substrates

A simple differential method based on measurement of an intracellular pigment of Aspergillus wentii was developed for estimation of the individual growths of two fungi, Trichoderma reesei and A. wentii , in mixed-culture fermentation of an insoluble cellulosic substrate.

Regulatory aspects of cellulase biosynthesis and secretion

The cellulase enzyme system consists of cellobiohydrolase, endoglucanase, and beta-glucosidase and has been extensively studied with respect to its biosynthesis, properties, mode of action, application, and, most recently, secretion mechanisms. A knowledge of the factors governing the biosynthesis and secretion of these enzymes at the molecular level will be useful in maximizing enzyme productivity in extracellular fluid. Among other topics, the regulatory effects of sorbose (a noninducing sugar which is not a product of cellulose hydrolysis) on cellulase synthesis and release are described. Cellulase genes have recently been cloned into a number of microorganisms with a view to understanding the gene structure and expression and to obtaining the enzyme components in pure form. The factors governing biosynthesis and secretion of cellulases in recombinant cells are also discussed. Cellulases are known to be glycoproteins, therefore, the role of O- and N-linked glycosylation on enzyme stability and secretion is also detailed.

Coprecipitation of enzymes with water soluble starch--an alternative to freeze-drying

Krill proteases were prepared in solid form from a partially purified extract by coprecipitation of the enzymes with water-soluble starch in an organic solvent at 22 degrees C. The precipitation did not affect the activity of the enzymes. The recovery of proteolytic activity was 100%. The thermostability of the krill proteases increased when incorporated in the starch precipitate. No reduction in enzymatic activity could be seen after storage at +50 degrees C for 99 days. After milling the coprecipitate could be dispensed. The enzyme preparation consisted of irregular needle-shaped particles. This simple precipitation technique offers an alternative to freeze-drying or spray-drying.