Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment

This study presents an integrated strategy to optimize biofuel production from <i>Chlorella sorokiniana</i> (CSO) and <i>Chlorella vulgaris</i> (CVU) by combining salt-induced stress and thermal pretreatment. The microalgae were cultivated in anaerobic digestate effluent (ADE...

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Main Authors: Themistoklis Sfetsas, Sopio Ghoghoberidze, Petros Samaras, Polycarpos Falaras, Thomas Kotsopoulos
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Fuels
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Online Access:https://www.mdpi.com/2673-3994/6/2/23
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author Themistoklis Sfetsas
Sopio Ghoghoberidze
Petros Samaras
Polycarpos Falaras
Thomas Kotsopoulos
author_facet Themistoklis Sfetsas
Sopio Ghoghoberidze
Petros Samaras
Polycarpos Falaras
Thomas Kotsopoulos
author_sort Themistoklis Sfetsas
collection DOAJ
description This study presents an integrated strategy to optimize biofuel production from <i>Chlorella sorokiniana</i> (CSO) and <i>Chlorella vulgaris</i> (CVU) by combining salt-induced stress and thermal pretreatment. The microalgae were cultivated in anaerobic digestate effluent (ADE) under stress and non-stress conditions to evaluate nutrient availability’s impact on biomass composition. Salt stress significantly enhanced lipid accumulation, with CVU exhibiting a 51.6% increase. Thermal pretreatment of biomass at 90 °C for 10 h achieved the highest methane yield (481 mL CH<sub>4</sub>/g VS), with CVU outperforming CSO. Milder pretreatment conditions (40 °C for 4 h) were more energy-efficient for CSO, achieving a yield of 2.67%. Fatty acid profiles demonstrated species-specific biodiesel properties, with CSO rich in oleic acid (33.47%) offering enhanced oxidative stability and cold flow performance, while CVU showed a higher polyunsaturated fatty acid content. This research highlights the economic viability of using ADE as a low-cost cultivation medium and the potential for scalable thermal pretreatments. Future research should focus on reducing energy demands of pretreatment processes and exploring alternative stress induction methods to further enhance biofuel yields. These findings offer valuable insights for tailoring cultivation and processing strategies to maximize lipid and methane production, supporting sustainable and economically viable dual biofuel production systems.
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spelling doaj-art-dfdd767c32294291919414971e099ea32025-08-20T02:21:06ZengMDPI AGFuels2673-39942025-03-01622310.3390/fuels6020023Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat PretreatmentThemistoklis Sfetsas0Sopio Ghoghoberidze1Petros Samaras2Polycarpos Falaras3Thomas Kotsopoulos4Department of Hydraulics, Soil Science and Agricultural Engineering, School of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceQlab Private Company, Research & Development, Quality Control and Testing Services, 57008 Thessaloniki, GreeceLaboratory of Technologies for Environmental Protection and Utilization of Food By-Products, Department of Food Science and Technology, International Hellenic University (IHU), Sindos, 57400 Thessaloniki, GreeceInstitute of Nanoscience and Nanotechnology, National Center of Scientific Research “Demokritos”, Agia Paraskevi, 15310 Athens, GreeceDepartment of Hydraulics, Soil Science and Agricultural Engineering, School of Agriculture, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceThis study presents an integrated strategy to optimize biofuel production from <i>Chlorella sorokiniana</i> (CSO) and <i>Chlorella vulgaris</i> (CVU) by combining salt-induced stress and thermal pretreatment. The microalgae were cultivated in anaerobic digestate effluent (ADE) under stress and non-stress conditions to evaluate nutrient availability’s impact on biomass composition. Salt stress significantly enhanced lipid accumulation, with CVU exhibiting a 51.6% increase. Thermal pretreatment of biomass at 90 °C for 10 h achieved the highest methane yield (481 mL CH<sub>4</sub>/g VS), with CVU outperforming CSO. Milder pretreatment conditions (40 °C for 4 h) were more energy-efficient for CSO, achieving a yield of 2.67%. Fatty acid profiles demonstrated species-specific biodiesel properties, with CSO rich in oleic acid (33.47%) offering enhanced oxidative stability and cold flow performance, while CVU showed a higher polyunsaturated fatty acid content. This research highlights the economic viability of using ADE as a low-cost cultivation medium and the potential for scalable thermal pretreatments. Future research should focus on reducing energy demands of pretreatment processes and exploring alternative stress induction methods to further enhance biofuel yields. These findings offer valuable insights for tailoring cultivation and processing strategies to maximize lipid and methane production, supporting sustainable and economically viable dual biofuel production systems.https://www.mdpi.com/2673-3994/6/2/23microalgae (MA)anaerobic digestion effluent (ADE)biodiesel<i>C. sorokiniana</i><i>C. vulgaris</i>biogas potential
spellingShingle Themistoklis Sfetsas
Sopio Ghoghoberidze
Petros Samaras
Polycarpos Falaras
Thomas Kotsopoulos
Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
Fuels
microalgae (MA)
anaerobic digestion effluent (ADE)
biodiesel
<i>C. sorokiniana</i>
<i>C. vulgaris</i>
biogas potential
title Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
title_full Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
title_fullStr Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
title_full_unstemmed Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
title_short Enhancing Bioenergy Production from <i>Chlorella</i> via Salt-Induced Stress and Heat Pretreatment
title_sort enhancing bioenergy production from i chlorella i via salt induced stress and heat pretreatment
topic microalgae (MA)
anaerobic digestion effluent (ADE)
biodiesel
<i>C. sorokiniana</i>
<i>C. vulgaris</i>
biogas potential
url https://www.mdpi.com/2673-3994/6/2/23
work_keys_str_mv AT themistoklissfetsas enhancingbioenergyproductionfromichlorellaiviasaltinducedstressandheatpretreatment
AT sopioghoghoberidze enhancingbioenergyproductionfromichlorellaiviasaltinducedstressandheatpretreatment
AT petrossamaras enhancingbioenergyproductionfromichlorellaiviasaltinducedstressandheatpretreatment
AT polycarposfalaras enhancingbioenergyproductionfromichlorellaiviasaltinducedstressandheatpretreatment
AT thomaskotsopoulos enhancingbioenergyproductionfromichlorellaiviasaltinducedstressandheatpretreatment