Enhanced production of erythritol and mannitol by Yarrowia lipolytica in media containing surfactants

Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300 g L-1), erythritol production increased by 15% compared to the culture without the surfactant where it reached 142 g L-1 after 5 days, which corresponded to 0.47 g g-1 yield and productivity of 1.1 g L-1 h-1. Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.(AU)

Assessment of lipolytic activity of isolated microorganisms from the savannah of the Tocantins / Avaliação da atividade lipolítica de microrganismos isolados do Cerrado tocantinense

Current study assesses the biodiversity and selects lipase-producer microorganisms with industrial interest, from the savannah of the state of Tocantins, Brazil. Seventeen pequi microorganisms (Caryocar brasiliense) were isolated in the decomposition stage and 35 microorganisms were retrieved from the soil fraction under the collected pequi. Yarrowia lypolitica strain was used as positive control in all assays. The 52 strains were subjected to tests in a solid medium with Tween 20 for checking halos formed by crystals, indicating lipase production by inoculated strains. Another test to confirm lipase producers was conducted in microplates with liquid medium and enriched with p-nitrophenyl palmitate (pNPP) monitored at 410 m. The AS16 and AP5 strains showed the highest activity for test conditions, namely, 0.072 and 0.067 U mL-1 respectively. Rates were higher than the lipase activity of Yarrowia lypolitica(0.052 U mL-1), a reference strain in current assay.(AU)

O atual estudo avalia a biodiversidade e selecionou microorganismos produtores de lipases de interesse industrial, a partir do cerrado tocantinense. O principal objetivo deste trabalho é avaliar a biodiversidade e selecionar microrganismos do cerrado tocantinense, produtores de lipases de interesse industrial. Foram isolados 17 microrganismos de Pequi (Caryocar brasiliense) em estágio de decomposição e também 35 microrganismos provenientes da fração do solo que se encontrava abaixo do pequi coletado. Foi utilizada uma cepa de Yarrowia lypolitica como controle positivo em todos os ensaios. Todas as 52 cepas foram submetidas a testes em meio sólido, utilizando Tween 20 para a verificação da presença de halos formados por cristais, indicando produção de lipase pelas linhagens inoculadas. Outro teste para confirmação dos produtores de lipase foi realizado em microplacas contendo meio líquido e enriquecido com pNPP (Palmitato de p-nitrofenila), monitorado a 410 m. As cepas AS16 e AP5 apresentaram as maiores atividades para as condições de ensaio a que foram submetidas: 0,072 e 0,067 U mL-1 respectivamente, sendo estes valores maiores que a atividade lipolítica da Yarrowia lypolitica (0,052 U mL-1), considerada como cepa referência para este trabalho.(AU)