| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1051-1 | ||||
Resumo:L-asparaginase (E.C.3.5.1.1) is an aminohydrolase that hydrolyses L-asparagine into aspartic acid and ammonia and has been widely used in the treatment of acute lymphoblastic leukaemia (ALL). Microorganisms, especially bacteria, have been the main commercial sources of L-asparaginase (L-ASNase) nowadays, being a key drug in multiple therapies against the disease, but the commercial enzymes available have high adverse effects and prospecting fungi from little known and studied environments, such as Caatinga, may be promising in the search for new sources of L-ASNase. Thus, the objective of this study is to prospect and perform an initial screening of L-ASNase production by filamentous fungi isolated from the Caatinga biome. The fungi were isolated in selective culture medium, from three types of soils (native, moderately degraded and degraded soil) of the Caatinga in the State of Alagoas. Primary analysis (screening) was performed using modified Czapek Dox (MCD) medium with phenol red as pH indicator and four types of substrates (nitrate, asparagine, glutamine and urea) and the plates incubated at 25.0 °C. The colony diameter and zone diameter were calculated by measuring the inner diameter of microorganism growth and enzyme production, respectively, after 7 days of incubation. A total of 122 filamentous fungi were recovered, of which four were positive initially. Of these four showed growth on different substrates. The maximum value of enzymatic index (EI) was 2.77, 1.44 and 1.23 for three isolates that produced glutaminase and urease free asparaginase and 1.27 for isolate 14.SMD that produced asparaginase and urease free glutaminase. In this sense, the fungi from Caatinga showed specific activity in the production of glutaminase-free L-asparaginase and urease from a selective screening method.
Palavras-chave: Leukemia, Selective method, Caatinga Agência de fomento:A Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação de Apoio à Pesquisa do Estado de Alagoas | |||||