| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1489-1 | ||||
Resumo:Biosurfactants are amphipathic compounds with wide applications and advantages over chemical surfactants, such as low toxicity, biodegradability and the ability to be produced from low-cost sources and industrial waste. In this context, this study aimed to evaluate the potential for biosurfactant production by endophytic fungi isolated from the medicinal plant Kalanchoe daigremontiana and to identify different sources of carbon and nitrogen that could influence its production. The initial screening of the fungal strains was carried out in an inducing medium containing soybean oil, with the cultures maintained under agitation at 170 rpm and a temperature of 28°C for 5 days, followed by filtration to obtain a cell-free extract. This extract was used to determine the emulsification index (EI), stability and oil spreading. For the most promising isolate, two sources of carbon (sucrose and glucose) and three sources of nitrogen (yeast extract, urea and sodium nitrate) were investigated in order to assess their impact on the emulsification index of the biosurfactant. The experiments were carried out in triplicate and the statistical analysis involved the application of ANOVA and Tukey's mean comparison test, with a significance level of 5%. A total of 30 strains were evaluated, with the highest emulsification index (EI) values being achieved by isolate 13, reaching 62.5%, and by isolate 29, with 41.7%. These stains were identified as belonging to the genera Aspergillus sp. and Alternaria sp., respectively. For the promising isolates 13 and 29, the oil spill assay also revealed results above 50%, indicating the presence of biosurfactants. In addition, for isolate 13, which showed better performance in the emulsification index and oil spreading tests, significant differences were observed in the EI in relation to the carbon and nitrogen sources tested. The combination of sodium nitrate and glucose produced the best result, with an EI of 68.33%. This study highlights endophytic fungi as a promising source of biosurfactants, with emphasis on Aspergillus and Alternaria genera. Future studies will be conducted to characterize the biosurfactant molecule and optimize its production process. Palavras-chave: Bioemulsifier, Bioprospecting, Emulsification index, Alternaria sp., Aspergillus sp. Agência de fomento:UTFPR | |||||