In the realm of sustainable energy and biotechnology, a groundbreaking study led by Dimitris Karayannis from the Agricultural University of Athens and Verd S.A. has paved the way for a more efficient and cost-effective method of producing 2,3-butanediol (BDO). This versatile chemical, with applications ranging from fuel additives to pharmaceuticals, could see a significant boost in production efficiency thanks to this innovative research.
The study, published in Carbon Resources Conversion, focuses on the bioconversion of crude glycerol, a byproduct of biodiesel production, into BDO using the bacterium Klebsiella oxytoca. What sets this research apart is its non-sterile, or non-aseptic, approach. Traditionally, bioprocesses require stringent sterile conditions to prevent contamination, which adds significant costs. Karayannis and his team demonstrated that thermal treatment of the substrate was not necessary, allowing for a more streamlined and cost-effective process.
“We found that the absence of thermal treatment did not negatively impact the growth of the microorganism or the bioconversion process,” Karayannis explained. “This opens up the possibility for a more efficient and less costly bioprocess.”
The researchers also successfully utilized digestate and corn steep liquor (CSL), by-products of the biogas and corn industries respectively, as the sole source of nitrogen. This not only reduces the cost of production but also addresses the challenge of waste management in these industries. “By using these by-products, we’re not only making the process more economical but also contributing to waste reduction,” Karayannis noted.
The study achieved impressive results, with a glycerol consumption rate of 2.80 g/L/h, BDO productivity of 1.12 g/L/h, and a yield of 0.46 g/g. These figures are among the highest reported for wild-type strains cultivated on crude glycerol. The process was successfully scaled up to a 250-liter pilot-scale reactor, demonstrating its potential for industrial application.
One of the key innovations in this research is the use of salting-out extraction (SOE) for BDO recovery. This method, which employs a mixture of ethanol and potassium phosphate, recovered 91.7% of BDO from the fermentation medium. This is the first time SOE has been studied in a glycerol-based medium, further enhancing the economic viability of the process.
The implications of this research are far-reaching. By providing a more efficient and cost-effective method for BDO production, it could revolutionize the energy sector. BDO can be used as a fuel additive, improving the combustion efficiency of diesel engines and reducing emissions. It also has applications in the production of biodegradable plastics, which could help reduce plastic waste.
Moreover, the use of by-products from other industries not only lowers production costs but also contributes to a more circular economy. This research could inspire similar innovations in other sectors, driving sustainability and efficiency across the board.
The study, published in Carbon Resources Conversion, translates to ‘Carbon Resources Conversion’ in English, highlights the potential for industrial-scale implementation of this bioprocess. As we move towards a more sustainable future, innovations like this will be crucial in driving progress in the energy sector and beyond.