Atividade Enzimática de Actinobactérias do Semiárido (Enzymatic activity of actinobacteria from semiarid)

Actinobacterias sao bacterias Gram-positivas encontradas principalmente no solo e que se destacam pela capacidade de producao de enzimas hidroliticas, como amilase e celulase. Essas enzimas degradam, respectivamente, o amido e a celulose, substratos abundantes no solo, mas que por sua complexidade quimica sao indisponiveis para nutricao de outros organismos. Essas bacterias tambem crescem em condicoes extremas, como as prevalentes no Semiarido nordestino, onde ainda sao raros estudos sobre esse grupo microbiano. Assim, tendo em vista o crescente interesse sobre o funcionamento biologico do solo, aliado ao aspecto biotecnologico, esse trabalho teve por objetivo avaliar a atividade enzimatica de vinte e oito cepas de actinobacterias dos generos Streptomyces, Terrabacter, Nocardia e Micromonospora isoladas de amostras de solo do Parque Nacional de Ubajara, no Estado do Ceara. As atividades amiloliticas e celuloliticas foram determinadas pelo indice enzimatico correspondente a relacao entre o diâmetro em milimetros do halo de hidrolise e o diâmetro em milimetros da colonia de cada cepa. A atividade celulolitica foi detectada em 75% e a amilolitica em 82% das cepas avaliadas. Uma das cepas avaliadas destacou-se com um indice enzimatico da celulase igual a 6,90 enquanto o maior indice para a amilase foi 6,23. Os resultados indicaram o potencial ecologico e biotecnologico das actinobacterias do solo da regiao analisada. 800x600 Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabela normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Actinobacterias are Gram-positive bacterias found in soil and are distinguished by their production of hydrolytic enzymes, such as amylase and cellulase. These enzymes degrade starch and cellulose, respectively, which are abundant substrates in soil, but that are unavailable for use by other organisms due to their chemical complexity. These bacteria grow in extreme conditions, such as those prevalent in the Brazilian semi-arid northeast, where there are also few studies about this microbial group. Thus, due to the growing interest in the biological functioning of the soil, together with the biotechnology aspect, this work aimed to evaluate the enzymatic activity of twenty eight strains of actinobacteria of the genus Streptomyces , Terrabacter, Nocardia , and Micromonospora obtained from the soil samples of the Ubajara National Park in the state of Ceara. The amylolytic and cellulolytic activities were determined by the enzymatic index corresponding to the relation between the diameter of hydrolysis halo, in millimeters, and the diameter in millimeters of the colony of each strain. The cellulolytic and amylolytic indexes were detected in 75% and 85% of the evaluated strains, respectively. One of the strains evaluated stood out with an enzyme cellulase index equal to 6.90 while the highest rate for amylase was 6.23. The results indicated the ecological and biotechnological potential of actinobacteria from the soil of analyzed region. Keywords : enzymes, bacteria, caatinga, Northeast