Yolanda Gonzalez-Garcia
Universidad de Guadalajara, MEXICO
Title: Valorization of waste bagasse from the Tequila industry via fermentation to produce polyhydroxybutyrate
Biography
Biography: Yolanda Gonzalez-Garcia
Abstract
Polyhydroxyalkanoates (PHAs) are fully biodegradable biopolyesters produced from renewable sources by many bacterial species under nutritional stress conditions, and they have similar properties to those of some petrochemical polymers such as polypropylene. Polyhydroxybutyrate (PHB) is the main PHAs representative, its production from low-cost substrates is of great interest since the culture medium cost (mainly the carbon source) has an important influence on the PHB final price. On the other hand, the Tequila industry in Mexico generates large amounts of a waste known as agave bagasse (346,700.00 tons in 2018) which represents an environmental problem. In the present research the use agave bagasse hydrolysate to produce PHB by the bacteria Burkholderia sacchari was evaluated, and the obtained polymer was characterized. The acid hydrolysis of bagasse yielded 20.6 g/L of reducing sugars, with xylose as the main monosaccharide, followed by glucose (7:3 ratio). Growth inhibitors, such as phenolic compounds, were eliminated from the hydrolysate by different methods (physical or enzymatic) and then, it was used as culture medium for the production of PHB obtaining a yield of 6.44 g/L of biomass accumulating 44% of the polymer. The PHB structure was confirmed by NMR, and presented a molecular mass of 557 kDa, while its Tm and crystallinity were 173.6 °C and 61%, respectively. It was concluded that agave bagasse could be valorized as carbon source for producing PHB.