Seleção e avaliação de leveduras isoladas do fruto do pequi (Caryocar brasiliense) para a produção de lipídios como matéria-prima energética

Abstract

Due to the increased use of fossil energy sources, rising prices and environmental concerns. A promising alternative is the extraction of lipids from microorganisms, such as algae, bacteria, yeasts and filamentous fungi, which offer several advantages over plant sources. The objective of this research is to point out the uses of oleaginous yeasts isolated from the pequi fruit, with the potential to accumulate lipids in their cells, in order to point out a sustainable alternative for the use of agro-industrial residues for a new energy source. The experiment was carried out in in vitro conditions, at the General and Applied Microbiology Laboratory - LMGA, at the Federal University of Tocantins - UFT, Palmas campus - TO. The collected fruits were properly identified and separated and after isolation, the staining test was performed using the Sudan B. dye for the quantification of oleaginous yeasts. For lipid extraction, the medium was prepared using 25 mL of whey, 25 mL of manipueira and 0.5 g of yeast extract for each 100 mL -1. The extraction of lipids contained in the yeast biomass was carried out using the methodology proposed by Bligh and Dyer (1959); where the dry biomass, previously centrifuged, underwent acid digestion to break the yeast cell wall. The lipids were extracted using a solution of 10 ml of chloroform and 5 ml of methanol in a 2:1 ratio. Fifteen yeasts isolated from pequi fruit with characteristics of oleaginous microorganisms were obtained using the sudan blcak staining technique. Where, the yeast 22 isolated from the pequi pulp, was the one that presented the highest percentage of lipid accumulation, using whey and manipueira as a growth medium to obtain biomass; Thus, the conversion of a source of carbon originating from whey and cassava into biomass and lipids proved to be quite efficient, with positive and satisfactory results.