Efeito da temperatura e pH sobre a atividade enzimática em cepas de actinobactérias com potencial uso industrial

Abstract

Actinobacteria form a large phylum of Gram-positive bacteria that inhabit different environments freely, symbiotically or associated with plants. In addition, these microorganisms produce pigments, antibiotics, plant growth hormones and enzymes that are highly valued by the industry. The present work seeks to investigate the effect of temperature and pH on the amylolytic, cellulolytic, pectinolytic and xylanolytic activity of strains of actinobacteria and to raise applications in the field of industrial biotechnology. For this, 36 strains were tested for their enzymatic activities in solid media with starch, cellulose, pectin and xylan at temperatures of 39, 41, 43 and 45 °C and pH 4, 5, 7 and 9. The strains with pectinolytic activity were the most affected by abiotic factors, while xylanolytics were the most resistant. The highest enzymatic activities occurred at 41 °C and pH 7.0 for amylolytic, 45 °C and pH 6.0 for cellulolytic, 28 °C and pH 7.0 for pectinolytic and 45 °C and pH 4.0 for xylanolitics. The similarity grouping of all strains showed their potential use for the production of enzymatic cocktails with catalytic activities regulated by temperature and pH. Finally, the strains produced enzymes tolerant to temperature and pH variation with potential industrial applications.