Avaliação da produção de biossurfactantes por microrganismos isolados de painéis fotovoltaicos: screening, otimização e uso de substrato alternativo

Abstract

Biotechnologically, biosurfactants are used as emulsifiers and surface tension reducers in industrial, pharmaceutical and food sectors. To reduce production costs, alternative carbon sources are used, such as agro-industrial waste. The present work aimed to select microorganisms that produce biosurfactants, previously isolated from photovoltaic panels; as well as evaluating and optimizing the production of biosurfactant using soy molasses as a substrate. The molasses was characterized and subjected to pre-treatment to increase the amount of monosaccharides accessible to microorganisms. To confirm the synthesis of biosurfactant by microorganisms, the reduction in surface tension was used as a parameter, and subsequently, production was optimized using a fractional factorial design (25-1). The selected conditions were diluted soybean molasses, at a temperature of 50ºC and rotation of 200 rpm, which resulted in the highest emulsion index and the greatest reduction in surface tension. The biosurfactants produced in tests with Psychrobacter sp. and Rhodotorula mucilaginosa emulsified different hydrophobic sources - soybean oil (93.77 and 84.03%), engine oil (80.67 and 67.99%), kerosene (85.66 and 62.01%) and diesel oil (95.30 and 88.19%); in addition to reducing surface tension (34.32 and 34.27 mN.m-1), respectively for bacteria and yeast. Finally, this work aimed to select biosurfactant-producing strains and valorize biomass to produce molecules with high added value.