Microalgae cultivation in sugarcane vinasse: Selection, growth and biochemical characterization

Area of Science:

• Biotechnology
• Renewable Energy
• Environmental Science

Background:

• Sugarcane ethanol production generates large volumes of vinasse, a nutrient-rich waste stream.
• Vinasse utilization presents an opportunity for sustainable bioproduct development within a biorefinery framework.

Purpose of the Study:

• To screen microalgae strains for growth in sugarcane vinasse.
• To evaluate microalgae biomass productivity in vinasse-based media.
• To determine the biochemical composition of microalgae cultivated in vinasse.

Main Methods:

• Screening of forty microalgae strains for growth in varying concentrations of sugarcane vinasse.
• Cultivation in 15L airlift flat plate photobioreactors under non-axenic conditions.
• Biomass productivity assessment and chemical composition analysis (proteins, carbohydrates, monosaccharides).

Main Results:

• Two strains, Micractinium sp. Embrapa|LBA32 and C. biconvexa Embrapa|LBA40, showed vigorous growth in undiluted vinasse.
• Higher biomass productivity was observed in vinasse-based media compared to Bold's Basal Medium.
• Algal biomass primarily consisted of proteins and carbohydrates, with glucose as the main monosaccharide (46-76% of total carbohydrates).

Conclusions:

• Sugarcane vinasse is a viable and effective medium for microalgae cultivation.
• Microalgae grown in vinasse can be a sustainable source for energy and bioproducts.
• This study demonstrates a promising biorefinery approach for valorizing ethanol production waste.