Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii

Aybüke Kut Yılmaz; Melike Kartal; Gönül Dönmez; Sevgi Ertuğrul Karatay

doi:10.23902/trkjnat.2025104

Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii

Abstract

Background: Microalgae offer significant advantages for third-generation bioethanol production due to their rapid growth rates, high photosynthetic efficiency, and ability to accumulate substantial amounts of carbohydrates. Unlike agricultural food crops, microalgae can be cultivated on non-arable land using saline or wastewater resources, thereby avoiding competition with food crops. Moreover, their low lignin contained cell wall structure enables milder pretreatment requirements and more efficient enzymatic hydrolysis, which ultimately leads to improved sugar production and higher ethanol yields. In addition, microalgae-based bioethanol production contributes to carbon dioxide mitigation through CO2 fixation, enhancing the overall environmental sustainability of the process. For the mentioned reasons Chlorella vulgaris biomass was used as a feedstock for third-generation bioethanol production in the present study.

Aims: The aim of this study is to develop a sustainable and integrated process for third generation bioethanol production by utilizing domestic food waste. Specifically, the research focuses on:
investigating the effects of ZnO nanoparticles on the fermentation process; evaluating the performance of C. boidinii yeast in the presence of nanoparticle catalysts; optimizing cultivation conditions to achieve efficient microalgal growth and enhanced bioethanol production by C. boidinii; and examining the influence of key parameters, such as pretreatment methods (1% H2SO4 and 1% NaOH), biomass loading (50, 100, 200 g/L), and media composition, on the ethanol yield.

Methods: In this study, C. vulgaris was used as a feedstock for bioethanol several key parameters were optimized, including microalgal cultivation conditions (photoautotrophic, photoheterotrophic with glucose, and photoheterotrophic with carrot pomace), pretreatment type (1% H2SO4 and 1% NaOH), biomass loading (50, 100, and 200 g/L), and nutrient supplementation (Medium 1 and Medium 2).

Results: Candida boidinii exhibited the highest bioethanol production and productivity at 3.29 ± 0.14 g/L and 0.26 ± 0.01g/L.h, respectively. When Medium 1 was applied, bioethanol concentration and productivity further increased to 4.54 ± 0.18 g/L and 0.38 ± 0.01 g/L.h, respectively.

Conclusion: These findings demonstrate that fermentable sugars derived from C. vulgaris can be effectively converted into third-generation bioethanol by C. boidinii.

Keywords

Supporting Institution

Ankara University Research Foundation

Project Number

FDK-2022-2400 and FYL-2022-2534).

Ethical Statement

Not required.

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Details

Primary Language

English

Subjects

Plant Biotechnology

Journal Section

Research Article

Authors

Aybüke Kut Yılmaz This is me
0000-0001-5682-6942
Türkiye

Melike Kartal This is me
0009-0007-5962-5477
Türkiye

Gönül Dönmez
0000-0001-7972-5570
Türkiye

Sevgi Ertuğrul Karatay ^*
0000-0001-9544-0276
Türkiye

Publication Date

July 9, 2026

Submission Date

October 30, 2025

Acceptance Date

December 22, 2025

Published in Issue

Year 2026 Volume: 27 Number: 1

DOI

https://doi.org/10.23902/trkjnat.2025104

IZ

https://izlik.org/JA95ED42KT

Cite

RIS / Bibtex

APA

Kut Yılmaz, A., Kartal, M., Dönmez, G., & Ertuğrul Karatay, S. (2026). Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii. Trakya University Journal of Natural Sciences, 27(1), 67-75. https://doi.org/10.23902/trkjnat.2025104

AMA

1.Kut Yılmaz A, Kartal M, Dönmez G, Ertuğrul Karatay S. Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii. Trakya Univ J Nat Sci. 2026;27(1):67-75. doi:10.23902/trkjnat.2025104

Chicago

Kut Yılmaz, Aybüke, Melike Kartal, Gönül Dönmez, and Sevgi Ertuğrul Karatay. 2026. “Process Optimization for Third-Generation Bioethanol Production from Chlorella Vulgaris As a Feedstock by Candida Boidinii”. Trakya University Journal of Natural Sciences 27 (1): 67-75. https://doi.org/10.23902/trkjnat.2025104.

EndNote

Kut Yılmaz A, Kartal M, Dönmez G, Ertuğrul Karatay S (July 1, 2026) Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii. Trakya University Journal of Natural Sciences 27 1 67–75.

IEEE

[1]A. Kut Yılmaz, M. Kartal, G. Dönmez, and S. Ertuğrul Karatay, “Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii”, Trakya Univ J Nat Sci, vol. 27, no. 1, pp. 67–75, July 2026, doi: 10.23902/trkjnat.2025104.

ISNAD

Kut Yılmaz, Aybüke - Kartal, Melike - Dönmez, Gönül - Ertuğrul Karatay, Sevgi. “Process Optimization for Third-Generation Bioethanol Production from Chlorella Vulgaris As a Feedstock by Candida Boidinii”. Trakya University Journal of Natural Sciences 27/1 (July 1, 2026): 67-75. https://doi.org/10.23902/trkjnat.2025104.

JAMA

1.Kut Yılmaz A, Kartal M, Dönmez G, Ertuğrul Karatay S. Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii. Trakya Univ J Nat Sci. 2026;27:67–75.

MLA

Kut Yılmaz, Aybüke, et al. “Process Optimization for Third-Generation Bioethanol Production from Chlorella Vulgaris As a Feedstock by Candida Boidinii”. Trakya University Journal of Natural Sciences, vol. 27, no. 1, July 2026, pp. 67-75, doi:10.23902/trkjnat.2025104.

Vancouver

1.Aybüke Kut Yılmaz, Melike Kartal, Gönül Dönmez, Sevgi Ertuğrul Karatay. Process optimization for third-generation bioethanol production from Chlorella vulgaris as a feedstock by Candida boidinii. Trakya Univ J Nat Sci. 2026 Jul. 1;27(1):67-75. doi:10.23902/trkjnat.2025104