Sugarcane ethanol is produced at large scale generating wastes that could be used for microalgae biomass production in a biorefinery strategy. In this study, forty microalgae strains were screened for growth in sugarcane vinasse at different concentrations. Two microalgae strains, Micractinium sp. Embrapa|LBA32 and C. biconvexa Embrapa|LBA40, presented vigorous growth in a light-dependent manner even in undiluted vinasse under non-axenic conditions. Microalgae strains presented higher biomass productivity in vinasse-based media compared to standard Bold's Basal Medium in cultures performed using 15L airlift flat plate photobioreactors. Chemical composition analyses showed that proteins and carbohydrates comprise the major fractions of algal biomass. Glucose was the main monosaccharide detected, ranging from 46% to 76% of the total carbohydrates content according to the strain and culture media used. This research highlights the potential of using residues derived from ethanol plants to cultivate microalgae for the production of energy and bioproducts.

Starch and celluloses are biodegradable resources of great importance in terms of marketing. These biopolymers can be used to generate films with interesting mechanical, optical, and thermal properties, which can substitute for plastic films in certain applications, e.g., packaging materials. This study describes the preparation of pure plasticized starch films, prepared from soluble starch and glycerol, and the preparation of microfibrillated cellulose films from oil palm empty fruit bunches fabricated via casting. Composites made of plasticized starch were also prepared with microfibrillated cellulose added in 10% increments. The density, color difference, opacity, morphology, water activity, water affinity, and thermal and mechanical characteristics of the films were investigated. Plasticized starch is a translucent material with contact transparency; it is fragile and has relatively high water and glycerol contents. The thermogravimetric analysis of materials displayed up to four stages of weight loss related to water evaporation, glycerol, starch, and cellulose thermal degradation. As a consequence, the materials with higher cellulose content exhibited better thermal resistance. The composites with 90% of microfibrillated cellulose resulted in increased tensile strength when compared to the pure materials. The pure microfibrillated cellulose presented the highest values of Young modulus. The addition of plasticized starch to microfibrillated cellulose improved the maximum strain of the composites.