[Characterization of Ipomoea batatas extract to be used as nutrient basis for culture media]

An Ipomoea batatas extract obtained by enzymatic hydrolysis with alpha amylase was characterized to be used as nutrient basis. Among its quality indicators, it had a content of over 50% whole carbohydrates with respect to the nominal mass, estimated by phenol-sulphur method. The same content of aminonitrogen detected and quantified by potentiometric titration using formaldehyde and of total nitrogen (0,23%) by Kjeldahl method were detected. The content of necessary mineral elements for microbial culture was determined by the atom absorption method. The study of biological reactivity of the vegetal extract showed the existence of essential aminoacids such as triptophane, cystine and cysteine for microorganisms. It was proved that the vegetal extract, when used as the only source of nutrients at various concentration levels (2, 4 and 10%), is capable of stimulating the growth of bacteriae and yeasts. The increase of two Candida albicans biomass, determined in a specially designed medium (SIGMA, USA), was significantly higher to that of other nutrient bases like soy peptone, yeast extract, triptone and micological peptone. It was evinced that the vegetal extract as a culture medium component did not have antimicrobial effect compounds since at 15-30 g/L concentrations, this extract did stimulate the microbial growth up to values (UFC/mL) similar to those of the reference media called agar triptone soy.