Caracterización de bacterias productoras de polihidroxialcanoatos (PHA) utilizando azúcares presentes en residuos agroindustriales

Abstract

The low-cost production of polyhydroxyalkanoates has been a current challenge for the biological world. The present work has identified a strain that has not yet been reported with production capacity of said biopolymer, Citrobacter freundii. This pathogenic bacterium commonly present in water, soil or even in the intestines of animals, can metabolize different sugars such as lactose, citrate or alcohols such as glycerol. In this study, the substrates for said bacteria have been: lactose and xylose (sugars present in agroindustry residues as in the whey of milk or in the bagasse of rice, corn etc., respectively). The specific growth rates are: 0.6009 and 0.6175h-1 respectively and the consumption of sugar for 24 hours, has been around 5 grams for every liter. The concentrations of PHA accumulated were evaluated at 48 and 72 hours, being at 48 hours, the highest peaks, reaching between 25 to 28 grams for every liter. One way to verify that this species produces the biopolymer, was identifying the gene PHA synthase in its genome, which is responsible for producing said biopolymer, analysis made in silico,obtaining 80 percent of the gene to be compared that corresponds to the PHA synthase.