Optimization of solid-state fermentation for enhanced production of pectinolytic complex by Aspergillus tubingensis FAT43 and its application in fruit juice processing.

The main goal of this study was to examine the efficiency of a newly isolated fungus from quince, Aspergillus tubingensis FAT43, to produce the pectinolytic complex using agricultural and industrial waste as the substrate for solid state fermentation. Sugar beet pulp was the most effective substrate inducer of pectinolytic complex synthesis out of all the waste residues examined. For endo-pectinolytic and total pectinolytic activity, respectively, statistical optimization using Placked-Burman Design and Optimal (Custom) Design increased production by 2.22 and 2.15-fold, respectively. Liquification, clarification, and an increase in the amount of reducing sugar in fruit juices (apple, banana, apricot, orange, and quince) processed with pectinolytic complex were identified. Enzymatic pre-treatment considerably increases yield (14%-22%) and clarification (90%). After enzymatic treatment, the best liquefaction was observed in orange juice, whereas the best clarification was obtained in apricot juice. Additionally, the pectinolytic treatment of apricot juice resulted in the highest increase in reducing sugar concentration (11%) compared to all other enzymatically treated juices. Optimizing the production of a highly active pectinolytic complex and its efficient utilization in the processing of fruit juices, including the generation of an increasing amount of waste, are the significant outcomes of this research.

Unveiling novel insights into Bacillus velezensis 16B pectin lyase for improved fruit juice processing.

Microbial pectinolytic enzymes are important in various industries, particularly food processing. This study focuses on uncovering insights into a novel pectin lyase, BvPelB, from Bacillus velezensis 16B, with the aim of enhancing fruit juice processing. The study examines the structural and functional characteristics of pectinolytic enzyme, underscoring the critical nature of substrate specificity and enzymatic reaction mechanisms. BvPelB was successfully expressed and purified, exhibiting robust activity under alkaline conditions and thermal stability. Structural analysis revealed similarities with other pectin lyases, despite limited sequence identity. Biochemical characterization showed BvPelB's preference for highly methylated pectins and its endo-acting mode of cleavage. Treatment with BvPelB significantly increased juice yield and clarity without generating excessive methanol, making it a promising candidate for fruit juice processing. Overall, this study provides valuable insights into the enzymatic properties of BvPelB and its potential industrial applications in improving fruit juice processing efficiency and quality.

Aspergillus welwitschiae inulinase enzyme cocktails obtained on agro-material inducers for the purpose of fructooligosaccharides production.

Production of fructooligosaccharides (FOS) is a trending topic due to their prebiotic effect becoming increasingly important for the modern human diet. The most suitable process for FOS production is the one using fungal inulinases. Introduction of new fungal inulinase producers and their implementation in production of inulinase enzymes is therefore gaining interest. This study provides a new approach to FOS synthesis by fungal enzyme complex without prior separation of any specific enzyme. Inulinase enzyme complexes could be used for the synthesis of FOS in two possible ways - hydrolysis of inulin (FOSh) and transfructosylation process of sucrose (FOSs), as demonstrated here. Depending on the fungal growth inducing substrate, a variety of inulinase enzyme complexes was obtained - one of which was most successful in production of FOSh and another one of FOSs. Substrates derived from crops: triticale, wheat bran, Jerusalem artichoke and Aspergillus welwitschiae isolate, previously proven as safe for use in food, were utilized for production of inulinase enzyme cocktails. The highest FOSs production was obtained by enzyme complex rich in ß-fructofuranosidase, while the highest FOSh production was obtained by enzyme complex rich in endoinulinase. Both FOSh and FOSs showed antioxidant potential according to ABTS and ORAC, which classifies them as a suitable additive in functional food. Simultaneous zymographic detection of inulinase enzymes, which could contribute to expansion of the knowledge on fungal enzymes, was developed and applied here. It demonstrated the presence of different inulinase isoforms depending on fungal growth substrate. These findings, which rely on the innate ability of fungi to co-produce all inulinases from a cocktail, could be useful as a new, easy approach to FOS production by fungal enzymes without their separation and purification, contributing to cheaper and faster production processes.