A promising alternative for sustainable remediation of carbendazim in aquatic environments.

The treatment of carbendazim-contaminated effluents is a challenge because of its complex composition and toxicity. A promising solution lies in biodegradation and the fungus Actinomucor elegans LBM 290 shows significant potential in this regard. Thus, the aim of this study was to biodegrade MBC by A. elegans LBM 290 in a liquid medium addressing the changes in the fungal morphology and protein production. The fungus A. elegans LBM 290 efficiently remove the fungicide carbendazim, with 86.6% removal within 8 days. This degradation is a combination of biodegradation (24.54%) and adsorption (62.08%). Exposure to carbendazim negatively affected the fungus, causing a decrease in biomass and morphological changes. Proteomic analysis revealed the fungal response to carbendazim stress through increased production of Cu-Zn superoxide dismutase, an antioxidant enzyme that combats oxidative stress, and the presence of a G protein subunit, suggesting participation in stress signaling pathways. These findings contribute to understanding the strategies of A. elegans LBM 290 to cope with carbendazim exposure in aquatic environments.

Low-cost homemade cocktails for enzymatic conversion of sugarcane and cassava bagasses.

The agricultural industries generate lignocellulosic wastes that can be modified by fungi to generate high value-added products. This work aimed to analyze the efficiency and the cost-effectiveness of the bioconversion of sugarcane and cassava bagasses using low-cost homemade enzymatic cocktails from Aspergillus niger LBM 134. Both bagasses were pretreated with a soft alkaline solution without any loss of polysaccharides. After the hydrolysis, a 28% of conversion to glucose and 42% to xylose were reached in the hydrolysis of sugarcane bagasse while an 80% of saccharification yield, in the hydrolysis of cassava bagasse using the homemade enzymes. Furthermore, a more disorganised surface and no starch granules were observed in the sugarcane and cassava bagasses, respectively. The bioethanol yield from sugarcane and casava bagasses was predicted to be 4.16 mg mL-1 and 2.57 mg mL-1, respectively. A comparison of the cost of the homemade and the commercial enzymes was carried out. Similar hydrolysis percentages were achieved employing any enzyme; however, it was 1000-2000 times less expensive using the homemade cocktails than using the commercial enzymes. Therefore, the cost of obtaining glucose from bagasses was most expensive when applying the commercial enzymes. Moreover, the hydrolysis of the cassava bagasse was most efficient with the homemade cocktails. The importance and novelty of this work lie in the similar performance and the lower cost of the homemade cocktails from the fungus A. niger LBM 134 compared with the commercial enzymes on the hydrolysis of the sugarcane and cassava bagasses.

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.

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, ß-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.

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.