The present work of investigation has for fundamental aim(lens) of obtaining a biopolímero from the fermentation of the substratum: flour of yam, which physicist was treated chemically to obtain glucose in a quantity of 14 g/L, which(who) later was fermented to obtain lactic acid, which final concentration of lactic acid in the birreactor was of 0,216 g/L, (being later the final concentration of the lactic acid of 2,162 g/L). The concentrated acid was mixed by a plastificante, agar-agar there being obtained a biodegradable plastic of rugose aspect, which weight of the obtained biopolímero was of 0,2g. Later it was submitted to the test of biodegradabilidad, where the turbidez and presence of bubbles in the biorreactor (CO2, O2), compared with the initial observations indicate the presence of source(fountain) of microorganism, as mud I activate, that is to say qualitative growth of biom...