Novel fusants of two and three clostridia for enhanced green production of biobutanol


Increasing strict regulations on carbon emissions highly favor the adoption and development of alternative low carbon technologies in an effort to mitigate climate change and global warming. In particular, deployment of biofuels such as biobutanol could reduce carbon dioxide emissions in mobile and distributed application like automobile where controlling carbon oxide emissions have been a great challenge. Butanol specifically has great advantages over ethanol as it can be mixed with ethanol owing to its excellent physical properties. However, several challenges still hinder the full deployment of biobutanol fuels and alternative clean energy.

For instance, generation of biofuels has been classified into three main groups: generation from edible sources by the action of microorganisms, generation from lignocellulosic products obtained from agricultural residues and generation from algae. Whereas the first-generation method poses a great threat to food security, the other two methods have attracted significant attention of researchers since they can be obtained or cultivated on nonagricultural lands. To this end, the development of efficient alternative biobutanol production technologies in highly desirable.

Recent studies have shown that the production of biobutanol from traditional substrates is ineffective due to high initial costs. To this regard, economical substrates such as agricultural residues and wastes have been thoroughly examined recently. Alternatively, anaerobic fermentation of sugar in the presence of various Clostridia species have the potential to produce sustainable biofuel products. However, the low fermentation temperature derails the fermentation activities of the metabolizing bacteria by reducing the enzyme efficiency. Therefore, enhancing the metabolism as well as the thermal stability of bacterial strains will be of great significance in enhancing biobutanol production.

To this note, Dr. Yaser Dahman, the principal investigator from Ryerson University, together with Banafsheh Mohtasebi looked at the feasibility of producing biobutanol using renewable agricultural residues in simultaneous saccharification and fermentation. This work was done in collaboration with Dr. Wensheng Qin and Miranda Maki from Lakehead University. Fundamentally, they utilized protoplast fusion technique to fuse three different anaerobic clostridia: Clostridium beijerinckiIi (Cb), Clostridium thermocellum (Ct) and Thermoanaerobacterium saccharolyticum (Ts). Additionally, they used protoplast clostridial fusants and their constituent co-cultures to examine biobutanol production. Furthermore, they compared the fermentation efficiency obtained using the fusants to that obtained by co-cultures of the individual species. Their work is published in the journal, Biofuels.

The fused strains significantly improved butanol production as compared to its co-culture strains counterparts. For instance, fused strains and co-culture strains produced 12.80 g/L and 6.25 g/L of butanol respectively. This was attribute to the improved thermostability to realize the optimum hydrolysis temperature. Additionally, the need to add enzymes during the hydrolysis process was completely eliminated due to the production of enzymes required for fermentation.

In summary, the Canadian scientists developed novel fusants for enhanced green production of biobutanol energy. To actualize their study, they investigated the genetic stability of the fused strains over several growth cycles. Interestingly, during 10 cycle growth, CbCt fused strains showed genetic stability while CbCtTs did not show clear stability in acetone-butanol-ethanol production. Altogether, the protoplast fusion is a promising solution for enhancing green production of butanol which is a key step in promoting sustainability.



About the author

Dr. Yaser Dahman is a Canadian faculty member at the rank of “Full Professor” in the department of Chemical Engineering at Ryerson University, in Toronto, Canada. He pursued his education in Canada, and holds a Ph.D. in Chemical and Biochemical Engineering in addition to an MBA. He commissioned a world class research laboratory named “Nanocomposites and Biomaterials Engineering Laboratory”, which was homed at Ryerson University. Later, this research facility became part of the “Center of Green Research Technology” that hosted all of research projects. To date, Prof. Dahman has supervised more than 50 graduate students’ projects and graduate dissertations.

His scientific disseminations and contribution includes several published books, in addition to book chapters, scientific and professional peer-reviewed original research articles and conference proceedings. His research team has participated in several national and international conferences in addition to local and regional scientific meetings. In addition to Ryerson University, his research work has been funded by several agencies including NSERC, Ontario Centre of Excellence in addition to the Agriculture and Agri-Food Canada.

Prof. Dahman has vast research activities and interests in several emerging technologies. In general, he has special interest and contribution in the industrial green technology. This includes utilizing renewable and sustainable resources of agro-industrial wastes, algal biomass, and HEMP in advanced aerobic and anaerobic Simultaneous Saccharification and Fermentation (SSF) and Separate Hydrolysis and Fermentation (SHF) to produce green biomaterials, green biodegradable plastics, and green biobutanol and bioethanol. Different pretreatment methods were intensively tested and utilized at different conditions for the conversion of agriculture cellulose and hemicellulose to monomeric sugars essential to conduct the green fermentation reactions. Biocatalysis were also broadly utilized to catalyze saccharification reactions.

About the author

Dr. Wensheng Qin is a professor in the field of biorefining and lignocellulosic biomass conversion for bioproducts at Lakehead University. Wensheng obtained his PhD from Queen’s University in Canada in 2005 followed by his postdoctoral training at Stanford University in USA (2005-2008) and was the Ontario Research Chair in Biorefining Research at Lakehead University (2008-2013).

Dr. Qin has wide study and work experience in Canada, China, Mexico and USA. He has expertise in molecular biology and biochemistry and biorefining research. He has published over 120 papers in his research.

About the author

Banafsheh Mohtasebi holds a master’s degree in Environmental Applied Science and Management from Ryerson University, Canada. She received a bachelor’s degree in Microbiology from Tehran Azad University, Iran; and has been working more than ten years as a Microbiologist in a clinical laboratory. In 2013, she became a nominee for the Governor General Gold Medal for academic excellence.

She is currently researching on environmental projects such as green biofuel production from renewable resources through the fusion of different strains of anaerobic bacteria. She nurtures a keen interest in implementing knowledge sharing and advocacy strategies to raise awareness about environmentally related issues of biofuels and sustainable management.


Mohtasebi, B., Maki, M., Qin, W., & Dahman, Y. (2019). Novel fusants of two and three clostridia for enhanced green production of biobutanol. Biofuels, 1-11.

Go To Biofuels

Check Also

Nanostructured Electrodes as Random Arrays of Active Sites: Modeling and Theoretical Characterization - Advances in Engineering

Nanostructured Electrodes as Random Arrays of Active Sites