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oai:figshare.com:article/33771616 2026-09-15T05:33:56Z category_1061 portal_316 item_type_3 month_year_09_2026

Supplementary file 1_Growing microalgae in treated vinasse: effects on cell morphology and growth rate.docx Vitória G. Navarrete (24912454) Vinicius S. Ferreira (4856917) Tiago Venâncio (3138750) Rafael C. Pulgrossi (24912457) Luis Henrique Zanini Branco (5342558) Ana T. Lombardi (24912460) Industrial Microbiology (incl. Biofeedstocks) Chlorolobion braunii industrial effluent mixotrophy sugarcane industry Tetradesmus sp. wastewater reuse Introduction<p>Vinasse is an organic and nutrient-rich byproduct of the ethanol industry with potential for microalgae cultivation. Although its use is generally limited by the need for dilution, appropriate vinasse pretreatment can improve its suitability as a culture medium, enabling microalgae to thrive. This study investigated the feasibility of cultivating microalgae in 100% previously treated vinasse and evaluated the use of vinasse-grown cultures as inoculum for successive cultivation cycles.</p>Methods<p>Nine microalgal species were evaluated in an initial screening test to determine their tolerance to full-strength treated vinasse. Three species, Chlorolobion braunii, Tetradesmus sp., and Haematococcus pluvialis, were selected for further testing in 6-well plates with 12 mL cultures. Growth rate, cell volume, and the effect of inoculum origin (vinasse vs. synthetic culture medium), were evaluated. Additionally, vinasse was characterized by nuclear magnetic resonance spectroscopy (NMR) before and after algal growth.</p>Results & Discussion<p>C. braunii had the best performance in full-strength treated vinasse, achieving the highest growth rate (1.3 d⁻¹), compared to 0.66 d⁻¹ for Tetradesmus sp. and 0.68 d⁻¹ for H. pluvialis. Notably, C. braunii was the only species that showed a higher growth rate in vinasse than in its control, suggesting mixotrophic growth. Mixed effect modeling showed that cell volume increased 1.6 times in vinasse-grown C. braunii (208 μm3) and 6.3 times in Tetradesmus sp. (250 μm3) in comparison to their controls, but H. pluvialis cell volume was maintained (5575 μm3). Compared to the respective controls, when the inoculum was obtained from vinasse, C. braunii presented 3.2 times lower growth rate (0.4 d⁻¹) and larger cells, but no variation in growth response was observed for Tetradesmus sp. cultures (0.67 d⁻¹ growth rate; cell volume 13.2 times larger), while H. pluvialis formed small cysts. NMR results showed that acetate and butyrate were consumed by the microbial consortium. Additionally, H. pluvialis cultures in vinasse released cis-aconitate, a compound that can be related to physiological adjustments in a stressing condition.</p>Conclusion<p>This study advances the circular economy concept in the ethanol industry by showing that full-strength treated vinasse can serve as a viable culture medium for microalgae, given appropriate species selection.</p> 2026-09-15T05:33:56Z Dataset Dataset 10.3389/finmi.2026.1917607.s001 https://figshare.com/articles/dataset/Supplementary_file_1_Growing_microalgae_in_treated_vinasse_effects_on_cell_morphology_and_growth_rate_docx/33771616 CC BY 4.0