Comparison of ethanologenic potential of Saccharomyces cerevisiae and Metschnikowia cibodasensis employing watermelon pulp hydrolysate
DOI:
https://doi.org/10.55627/zoobotanica.003.03.1768Keywords:
Watermelon pulp waste, bioethanol production, agro-waste valorization, enzymatic hydrolysis, sustainable energyAbstract
The agricultural sector in Pakistan, which is a major contributor to its economy, produces massive biomass waste such as watermelon leftovers. This paper discusses how watermelon pulp can be used as feedstock in bioethanol production and how this is a viable solution to the energy requirements of Pakistan as well as solving the problem of waste management. Fermentable sugars are found in abandoned watermelons, which can be used as a source of bioethanol. In this study, the objective was to hydrolyze the watermelon pulp Bacillus cereus FA3 using optimum conditions and ferment the resulting saccharified monomers into ethanol, utilizing yeasts; Metschnikowia cibodasensis Y34 strain and Saccharomyces cerevisiae K7 strain. To optimize the experimental conditions for hydrolysis and fermentation, Plackett-Burman and central composite designs (CCD) were developed. Under the optimized conditions of the Plackett-Burman model, i.e., 37°C, pH 4, 50:55mL buffer to pulp ratio, 0.63 IU enzyme dosage, 5 days hydrolysis period, maximum reducing sugars of 45.13±0.01 and total sugars of 82.64±0.06 g/L was achieved. Under the optimized conditions viz. 75:25% hydrolysate: synthetic media, 5% (v/v) of yeast inocula, 25 °C, 15 days, the maximum ethanol yield and content with yeast Metschnikowia cibodasensis Y34 strain was recorded as 0.43 ± 0.007g/g and 13.6 ± 0.008g/L whereas Saccharomyces cerevisiae yielded 0.41 ± 0.004g/g and 12.2 ± 0.001g/L ethanol respectively. These outcomes underscore the effectiveness of the optimized fermentation process and the promising potential of watermelon pulp valorization for sustainable ethanol production.
References
Abu-Gharbia, M. A., El-Sawy, N. M., Nasr, A. M., & Zedan, L. A. (2018). Isolation, optimization and characterization of cellulases and hemicellulases from Bacillus cereus LAZ 518 isolated from cow dung using corn cobs as lignocellulosic waste. Journal of Pharmaceutical and Applied Chemistry, 4(2), 1-13.
Ajayo, P. C., Huang, M., Zhao, L., Tian, D., Jiang, Q., Deng, S., ... & Shen, F. (2022). Paper mulberry fruit juice: a novel biomass resource for bioethanol production. Bioresources and Bioprocessing, 9(1), 3.
Amicarelli, V., Lagioia, G., & Bux, C. (2021). Global warming potential of food waste through the life cycle assessment: An analytical review. Environmental Impact Assessment Review, 91, 106677.
Bai, L., Hu, H., & Xu, J. (2012). Influences of configuration and molecular weight of hemicelluloses on their paper-strengthening effects. Carbohydrate Polymers, 88(4), 1258-1263.
Bashir, T., Nisar, A., Habib, G., & Gul, H. (2025). Efficient production of bioethanol and methanol from unappetizing pumpkin by separate saccharification and fermentation process using Saccharomyces cerevisiae. Biofuels, 1-12.
Bennett, C. (1971). Spectrophotometric acid dichromate method for the determination of ethyl alcohol. The American Journal of Medical Technology, 37(6), 217-220.
Bhattacharya, S. (2021). Central composite design for response surface methodology and its application in pharmacy. In Response surface methodology in engineering science. IntechOpen.
Bianchi, G., Rizzolo, A., Grassi, M., Provenzi, L., & Scalzo, R. L. (2018). External maturity indicators, carotenoid and sugar compositions and volatile patterns in ‘Cuoredolce®’and ‘Rugby’mini-watermelon (Citrullus lanatus (Thunb) Matsumura & Nakai) varieties in relation of ripening degree at harvest. Postharvest Biology and Technology, 136, 1-11.
Chaudhary, A., & Karita, S. (2017). Screening of yeast isolates from flowers for effective ethanol production. Turkish Journal of Biology, 41(6), 890-900.
Chaudhary, A., Akram, A. M., Ahmad, Q.U.A., Minahal, Q., Ara, C., Andleeb, S., Iqtedar, M. and Ali, Q., 2020. Rsm-Based Fermentative Ethanologenesis Employing Acid Hydrolysate Watermelon Peels. Plant Cell Biotechnology and Molecular Biology, 21(63&64):63-77.
Chaudhary, A., Hussain, Z., Ajmal, H., Abdul Rehman, R., Abbas, G., Aihetasham, A., & Tahira, S. A. (2024). Efficient Bioconversion of Mango Waste into Ethanol Employing Plackett–Burman and Central Composite Models. ACS Omega, 9(38), 39652-39662.
Dube, J., Ddamulira, G., & Maphosa, M. (2021). Watermelon production in Africa: challenges and opportunities. International Journal of Vegetable Science, 27(3), 211-219.
DuBois, M., Gilles, K. A., Hamilton, J. K., Rebers, P. A., & Smith, F. (1956). Colorimetric method for determination of sugars and related substances. Analytical Chemistry, 28(3), 350-356.
Falade, O. S., Otemuyiwa, I. O., Adekunle, A. S., Adewusi, S. A., & Oluwasefunmi, O. (2020). Nutrient composition of watermelon (Citrullis lanatus (Thunb.) Matsum. &Nakai) and egusi melon (Citrullus colocynthis (L.) Schrad.) seeds. Agriculturae Conspectus Scientificus, 85(1), 43-49.
FAO (2023). FAOSTAT. Food and Agriculture Organization of the United Nations, Rome, Italy. http://www.fao.org/faostat/en/#data.
Figueroa, R. H. H., López-Malo, A., & Mani-López, E. (2024). Antimicrobial activity and applications of fermentates from lactic acid bacteria–a review. Sustainable Food Technology, 2(2), 292-306.
Gebeyhu, B., & Markos, G. (2023). Assessment of soil mulching field management, and deficit irrigation effect on productivity of watermelon varieties, and Aqua Crop model validation. Heliyon, 9(11).
Jatoi, A. S., Nguyen, H. M., & Ahmed, J. (2025). Enhanced acido-thermophilic invertase production via a derepressed mutant of Pichia kudriavzevii in batch cultures. Biomass Conversion and Biorefinery, 1, 713–727.
Kalangi, C., Rathod, N. J., Madhuri, K. S., Kumar, S., Pandey, V., Sahni, M., & Leon-Castro, E. (2025). Performance optimization of ethanol blends in diesel model using Taguchi and grey relational approach. Scientific Reports, 15(1), 36048.
Kurtzman, C., Fell, J. W., & Boekhout, T. (Eds.). (2011). The yeasts: a taxonomic study. Elsevier.
Lane, S., Xu, H., Oh, E. J., Kim, H., Lesmana, A., Jeong, D., ... & Kim, S. R. (2018). Glucose repression can be alleviated by reducing glucose phosphorylation rate in Saccharomyces cerevisiae. Scientific Reports, 8(1), 2613.
Mahmood, K., & Munir, S. (2018). Agricultural exports and economic growth in Pakistan: an econometric reassessment. Quality & Quantity, 52(4), 1561-1574.
Mendonça-Hagler, L. C., Hagler, A. N., & Kurtzman, C. P. (1993). Phylogeny of Metschnikowia species estimated from partial rRNA sequences. International Journal of Systematic Bacteriology, 43(2), 368-373.
Mgeni, S. T., Mero, H. R., Mtashobya, L. A., & Emmanuel, J. K. (2024). The prospect of fruit wastes in bioethanol production: A review. Heliyon, 10(19).
Miller, G. L. (1959). Modified DNS method for reducing sugars. Analytical Chemistry, 31(3), 426-428.
Moon, S. Y., An, N. Y., & Lee, J. Y. (2025). Transforming non-conventional yeasts into key players in biotechnology: advances in synthetic biology applications. Frontiers in Microbiology, 16, 1600187.
Nadeem, M., Navida, M., Ameer, K., Siddique, F., Iqbal, A., Malik, F., ... & Javaria, S. (2022). Watermelon nutrition profile, antioxidant activity, and processing. Food Science and Preservation, 29(4), 531-545.
Quirós, M., Rojas, V., Gonzalez, R., & Morales, P. (2014). Selection of non-Saccharomyces yeast strains for reducing alcohol levels in wine by sugar respiration. International Journal of Food Microbiology, 181, 85-91.
Saleem, A., Hussain, A., Chaudhary, A., Ahmad, Q. U. A., Iqtedar, M., Javid, A., & Akram, A. M. (2022). Acid hydrolysis optimization of pomegranate peels waste using response surface methodology for ethanol production. Biomass Conversion and Biorefinery, 12(5), 1513-1524.
Samantaray, B., Mohapatra, S., Mishra, R. R., Behera, B. C., & Thatoi, H. (2024). Bioethanol production from agro-wastes: a comprehensive review with a focus on pretreatment, enzymatic hydrolysis, and fermentation. International Journal of Green Energy, 21(6), 1398-1424.
Scapini, T., Bonatto, C., Dalastra, C., Bazoti, S. F., Camargo, A. F., Júnior, S. L. A., ... & Treichel, H. (2023). Bioethanol and biomethane production from watermelon waste: a circular economy strategy. Biomass and Bioenergy, 170, 106719.
Shah, K. R., Vyas, R., & Patel, G. (2019). Bioethanol production from pulp of fruits. Bioscience Biotechnology Research Commmunications, 12(2), 464-471.
Shrefler, J., Brandenberger, L., Rebek, E., Damicone, J., & Taylor, M. (2015). Watermelon production. Oklahoma Cooperative Extension Service, HLA-6236.
Tarazona‐Díaz, M. P., Viegas, J., Moldao‐Martins, M., & Aguayo, E. (2011). Bioactive compounds from flesh and by‐product of fresh‐cut watermelon cultivars. Journal of the Science of Food and Agriculture, 91(5), 805-812.
Yücekan, İ., & Önal, S. (2011). Partitioning of invertase from tomato in poly (ethylene glycol)/sodium sulfate aqueous two-phase systems. Process Biochemistry, 46(1), 226-232.
Zhang, L., Zhao, H., Gan, M., Jin, Y., Gao, X., Chen, Q., ... & Wang, Z. (2011). Application of simultaneous saccharification and fermentation (SSF) from viscosity reducing of raw sweet potato for bioethanol production at laboratory, pilot and industrial scales. Bioresource Technology, 102(6), 4573-4579.
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Asma Chaudhary, Afifa Syeda, Ayesha Aihetasham, Pakeeza Fatima, Amina Asghar, Sher Ali

This work is licensed under a Creative Commons Attribution 4.0 International License.
