Isolation of High Amylase-producing Filamentous Fungi from the Caatinga: Standardization of the Culture Conditions and Amylase Activity from Penicillium sp. L1

Abstract

Microbial amylases are commercially available and have almost completely replaced the chemical hydrolysis of starch in various industrial processes. Microbial amylases have a wide range of applications because they are more stable than amylases obtained from plants and animals. This work sought to isolate filamentous fungi from three different samples collected in Janaúba, in the north of the state of Minas Gerais, to select a filamentous fungus that produces amylases, to determine the best cultivation conditions for the selected fungus for amylase production, and to analyze the biochemical characteristics of the enzyme. After collecting the samples for the isolation of filamentous fungi, the macroscopic morphological characteristics of the fungi, the microculture for the determination of the possible genus, and the effect of temperature on fungal growth were determined. The screening of the fungi was performed in a submerged medium to characterize the amylase-producing microorganism through the analysis of the physicochemical parameters of the medium concerning the source of nitrogen, the type of salt solution, and the source of carbon, as well as to optimize the production of amylase. The biochemical characterization of the enzyme was performed. The fungus Penicillium sp. (L1) was selected, and the greatest production of amylase was observed in submerged Carvalho-Peixoto (CP) medium associated with Wesson salts using yeast extract and starch as nitrogen and carbon sources, respectively, at 30 ºC, over seven days. The optimum temperature and pH of the assay were 60 ºC and 5.5, respectively. Thus, the northern region of Minas Gerais was an excellent source for the strains that exhibited a potential for the production of amylase for use in industry, indicating that the fungus Penicillium sp. (L1) and the amylase produced have a relevant potential for biotechnological applications.

Produção de beta-D-frutofuranosidases por Aspergillus sp. M2.4 e caracterização bioquímica

“…A coleta ocorreu sem que suas propriedades naturais fossem modificadas, para isso, utilizouse luvas cirúrgicas estéreis; pinça metálica e um frasco de vidro, com volume aproximado de 50 mL, previamente autoclavados a 120ºC, 1.0 atm, durante 30 minutos. O material coletado foi mantido a 4ºC, até a sua posterior análise (Silva et al, 2022 andSouza et al, 2020).…”

“…Temperatura e pH ótimo da enzima: A atividade enzimática em função da temperatura e pH foi analisada de 40ºC a 70ºC, com intervalos de 5ºC, com o substrato sacarose 1% (m/v) em tampão acetato de sódio 100 mM, nos pHs 4.5; 5.0 e 5.5; e sacarose 1% (m/v) em tampão fosfato de sódio 100 mM nos pHs 6.0; 6.5 e 7.0 (Silva et al, 2022 andSouza et al, 2020).…”

“…Manteve a mistura enzima-tampão no gelo por diferentes tempos de 30 minutos 120 minutos. Decorrido o tempo de incubação, determinou-se a atividade invertásica com o substrato sacarose 1% (m/v) em tampão acetato de sódio 200 mM pH 4.5, na temperatura de 65ºC (Silva et al, 2022 andSouza et al, 2020).…”

“…Estabilidade à temperatura: A estabilidade à temperatura foi avaliada através da incubação da enzima durante o tempo de 30, 60, 90 e 120 minutos, na ausência de substrato, nas temperaturas de 50ºC a 70ºC, com intervalo de 5ºC. Posteriormente, fez-se a dosagem a 65ºC, utilizando-se o substrato sacarose 1% (m/v) em tampão acetato de sódio 100 mM pH 4.5 (Silva et al, 2022 andSouza et al, 2020).…”