Screening of microorganisms for production of aggregated-value chemicals from glycerin bioconversion

The worldwide biodiesel production reached 26 million m³ in 2013 and it is expected to increase 54% until 2023, reaching thereafter 40 million m³ per year. The main commercial route used in the biodiesel production is the transesterification process of vegetable oils and fat with alcohols in the presence of an alkaline catalyst. Besides biodiesel, glycerin is produced as byproduct. However, currently it has low commercial value due to its impurities. In the context of biorefinery, the use of glycerin for production of fuels and chemicals by biotechnological routes has been evaluated. In this work, strains of filamentous fungi and bacteria, isolated from Brazilian biodiversity, were screened for production of aggregated-value chemicals through the conversion of soybean crude glycerin. About 300 microbial strains were grown in cultivation media with crude glycerin as the sole carbon source. The evaluated microorganisms were classified in three different groups related to the growth rate. Afterwards, some strains were selected from each group and cultivated in submerged fermentation. Samples from fermentation were analyzed using liquid chromatography (LC) and mass spectrometry (MS) approaches to identify chemical compounds produced by the strains. Different chemical products, such as polyols and organic acids, were detected by high resolution fingerprinting MS. Nowadays, major compounds identification are being performed using tandem MS coupled with LC techniques to guarantee the complete characterization.