Enzymatic Pretreatment of Microalgae: Cell Wall Disruption, Biomass Solubilisation and Methane Yield Increase
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Anaerobic digestion of microalgal biomass for biogas production may be limited due to the cell wall resulting in an inefficient bioconversion. Enzymatic pretreatments are applied for inducing cell damage/lysis and organic matter solubilisation and this way increasing biogas production. We evaluated enzymatic pretreatments in different conditions for comparing in relation to cell wall rupture, increase of soluble material and increase in biogas production through anaerobic digestion performance in BMP assay. Chlorella sorokiniana cultures were subjected to three different enzymatic pretreatments, each under four different conditions of enzyme/substrate ratio, pH and application time. The results showed increases over 21% in biogas productions for all enzymatic pretreatments. Enzymatic pretreatment was effective at damaging microalgae cell wall, releasing organic compounds and increasing the rate and final methane yield in BMP tests. We observed a synergistic activity between the mixtures enzymes, which would depend on operational conditions used for each pretreatment.
KeywordsMicroalgae Anaerobic digestion Biogas Enzymes Pretreatment Synergistic activity
OC conceived the study, designed, and performed the experiments, evaluated the data and drafted the manuscript. FP evaluated the data and drafted the manuscript. RC supervised the work and assisted in drafting the manuscript. All authors read and approved the final manuscript.
The authors want to thank Pontificia Universidad Católica de Valparaiso for the financial support. Olivia Córdova appreciates her scholarship funded by the CONICYT, Beca Nacional Doctorado, 21121012.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
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