Evaluation of new xylanolytic-producing isolates of Aspergillus from Misiones subtropical rainforest using sugarcane bagasse

Bioengineered xylanase from Misiones Argentina rainforest: A bakery enhancement approach

In this study, we pursued the heterologous expression of the xylanase gene from Trichoderma atroviride, a native fungus in the province of Misiones, and used it to enhance the textural properties of baked goods through varying enzymatic concentrations. This marks the inaugural exploration into its functionality in the context of bread production. The recombinant xylanase exhibited improved activity, reaching 36,292 U L-1, achieved by supplementing the culture medium with dextrose. Following the optimization of recombinant xylanase concentration, promising results emerged, notably reducing hardness and chewiness parameters of bread significantly. Our findings underscore the potential of this native fungal enzyme for industrial processes, offering a sustainable and efficient means to enhance the quality of baked goods with broad implications for the food industry. No prior research has been documented on the heterologous expression of the xylanase gene derived from T. atroviride, from the Misiones rainforest, expressed in Kluyveromyces lactis. PRACTICAL APPLICATION: This research, focusing on the isolation and cloning of xylanase enzyme from Trichoderma atroviride, a native fungus in the province of Misiones, offers a valuable tool for improving the texture of bakery products. By optimizing enzyme concentrations, our findings present a practical approach for the food industry, offering a viable solution to improve the overall quality and consumer satisfaction of bakery products.

High tolerance and degradation of fungicides by fungal strains isolated from contaminated soils

The aim of this work was to isolate fungal strains from phytotoxic agricultural soils, screen them, categorize the most tolerant fungi to three fungicides, and identify them by a molecular approach. In this study, 28 fungal strains were isolated from phytotoxic agricultural soil with intensive use of pesticides. The capacity of fungi to resist and degrade different concentrations of carbendazim, captan, and zineb was determined by an exploratory multivariate analysis. Actinomucor elegans LBM 239 was identified as the most tolerant fungus to these fungicides, degrading a 86.62% of carbendazim after 7 days of treatment. In conclusion, A. elegans LBM 239 demonstrated the highest tolerance and capacity to biodegrade carbendazim, becoming a potential candidate for bioremediation of contaminated soils with carbendazim, captan, or zineb.

Exploring novel Penicillium lipolytic activity from the Paranaense rainforest

In this study, we evaluated the presence of lipases in twenty fungal strains of the genus Penicillium using an efficient and low-cost method with a view to an application in the treatment of cooking oil residues. The Paranaense rainforest is one of the most biodiverse places on the planet, making it the most likely site to find new fungal strains with lipolytic potential. The objective of this study was to determine the lipolytic potential and the isoenzyme profile of fungi belonging to the Penicillium genus isolated from the Paranaense rainforest. Seven fungal strains were selected using qualitative screening. Quantitative analysis revealed that the isolate Penicillium sp. LBM 088 was the best producer of lipase, reaching 1224 U mL^-1 of lipolytic activity. Zymogram gels of the seven selected strains showed different enzymatic profiles: In general, the molecular mass of proteins varied from 26 to 42 kDa. Also, proteins from fungi grown on olive oil showed a higher variation in their molecular mass than proteins from fungi grown without the oil. The search for new lipase-secreting organisms should lead to the exploitation of biodiversity in the region.

Aspergillus niger LBM 134 isolated from rotten wood and its potential cellulolytic ability

Aspergillus

is a genus of filamentous and cosmopolitan fungi that includes important species for medical mycology, food, basic research and agro-industry areas. Aspergillus section Nigri are efficient producers of hydrolytic enzymes such as cellulases that are employed in the cellulose conversion. Hence, the search of new cellulolytic isolates and their correct identification is important for carrying out safe biotechnological processes. This study aimed to characterise the cellulolytic potential of Aspergillus sp. LBM 134, isolated from the Paranaense rainforest (Argentina) and to identify the isolate through a polyphasic approach. The fungus was identified as Aspergillus niger and its cellulolytic potential was evaluated by using Congo red technique and fluorescence plate assays for carboxymethyl cellulase, β-glucosidase and cellobiohydrolase, respectively. All three cellulase activities were positive; this bio-prospective positioned A. niger LBM 134 as a promising alternative for industries that require organisms capable of carrying out cellulosic biomass processing.

Identification and characterization of Colletotrichum species causing apple bitter rot in New York and description of C. noveboracense sp. nov

Apple bitter rot caused by Colletotrichum species is a growing problem worldwide. Colletotrichum spp. are economically important but taxonomically un-resolved. Identification of Colletotrichum spp. is critical due to potential species-level differences in pathogenicity-related characteristics. A 400-isolate collection from New York apple orchards were morphologically assorted to two groups, C. acutatum species complex (CASC) and C. gloeosporioides species complex (CGSC). A sub-sample of 44 representative isolates, spanning the geographical distribution and apple varieties, were assigned to species based on multi-locus phylogenetic analyses of nrITS, GAPDH and TUB2 for CASC, and ITS, GAPDH, CAL, ACT, TUB2, APN2, ApMat and GS genes for CGSC. The dominant species was C. fioriniae, followed by C. chrysophilum and a novel species, C. noveboracense, described in this study. This study represents the first report of C. chrysophilum and C. noveboracense as pathogens of apple. We assessed the enzyme activity and fungicide sensitivity for isolates identified in New York. All isolates showed amylolytic, cellulolytic and lipolytic, but not proteolytic activity. C. chrysophilum showed the highest cellulase and the lowest lipase activity, while C. noveboracense had the highest amylase activity. Fungicide assays showed that C. fioriniae was sensitive to benzovindiflupyr and thiabendazole, while C. chrysophilum and C. noveboracense were sensitive to fludioxonil, pyraclostrobin and difenoconazole. All species were pathogenic on apple fruit with varying lesion sizes. Our findings of differing pathogenicity-related characteristics among the three species demonstrate the importance of accurate species identification for any downstream investigations of Colletotrichum spp. in major apple growing regions.

Secretomic analysis of cheap enzymatic cocktails of Aspergillus niger LBM 134 grown on cassava bagasse and sugarcane bagasse

Currently, agroindustrial wastes are little used for generating value-added products; hence, their use of these waste to produce enzymatic cocktails for the conversion of lignocellulosic biomass to fermentable sugars is a very interesting alternative in the second-generation bioethanol process. The Ascomycota fungus Aspergillus niger LBM 134 produces hydrolytic enzymes in large proportions. In this work, A. niger LBM 134 was grown on sugarcane and cassava bagasses under optimized conditions. To identify the extracellular enzymes involved in the degradation of these agroindustrial wastes, the secretomes of the culture supernatants of the fungus were analyzed and validated by biochemical assays of the enzymatic activities. A. niger LBM 134 secreted higher quantities of xylanases and accessory hemicellulases when it grew on sugarcane bagasse, whereas more cellulases, amylases, and pectinases were secreted when it grew on cassava bagasse. These findings suggest two promising enzyme cocktails for the hydrolysis of lignocellulose carbohydrate polymers to fermentable sugars. These bioinformatic analysis were functional validates through enzymatic biochemical assays that confirm the biotechnological potential of A. niger LBM 134 for the bioconversion of hemicellulosic substrates such as sugarcane and cassava bagasses.