Potencial de produção de polihidroxialcanoatos e enzimas amilase e xilanase por bactérias bioprospectadas de água do rio Mimoso (Bonito, MS)

Abstract

Microorganisms are essential for life on Earth, since they promote nutrient cycling and in addition, with the advent of biotechnology are responsible for several bioproducts currently produced by industry, such as enzymes and biopolymers. This type of production has environmental advantages, since they come from renewable sources, besides being biodegradable. An extremely important factor since many products and processes such as the production of conventional plastics leave permanent waste on the planet. The present study aimed to bioprospect bacteria with the potential production of enzymes with commercial interest amylase and xylanase and also with the potential to produce the biopolymer polyhydroxyalcanoate (PHA) from water samples of the Mimoso River (Bonito, MS). The minimum medium containing starch or xylana as the only source of carbon selected those strains with production potential of amylase enzymes and xylanase, respectively. Ten potentially producing amylase isolates and ten potentially xylanase-producing isolates were obtained. These bacteria were submitted to the evaluation of the Enzymatic Index (EI) calculated from the ratio between the diameter of the colony and the degradation halo formed around the colonies. From the ten bacteria isolated with starch, seven presented (IE)>2.0. From the ten xylana isolates as a carbon source, eight presented (EI)>2.0. Aiming at the production of PHA isolation was carried out in ISP9 medium supplemented with glycerol (2%), in which 10 bacteria were isolated and evaluated for the production of PHAs through an initial screening with colony color with Sudan Black B 0.02%, the positive colonies were later evaluated after growth in the medium of cultivation with red nile dye (25 μg. ml-1 ). After 24 and 48 hours the plates were evaluated on the photocumenter to check for fluorescence conferred when bacteria produce PHAs. The results obtained in this study demonstrate that the isolates studied have a high potential to produce PHA, amylase and xylanase bioproducts when compared to the literature data.