I-Corps: Chlorite and Chlorite Dismutase Mediated Continuous Bioprocessing Hygiene Control

The broader impact/commercial potential of this I-Corps project is to eliminate antibiotic use during biomanufacturing in the chemical and biotechnology industries, and to enable robust, contamination-free continuous processes that reduce upstream costs by 20-50%. Currently the biotechnology industry is growing at an astounding 7.5% per annum with a predicted value of $760B by 2025. However, industrial fermentation plant failure data collected over a 15-year period suggests that 1 in 10 process cultures are subject to microbial contamination and associated production failure. Furthermore, while continuous bioreactor processes significantly improve productivity and reduce unit operation costs, most biotechnology industries shy away from them because of the inherent sensitivity to contamination. Reduced bioreactor failure rate and operational cost is essential for the economic viability of bio-commodity chemicals such as biofuels, as production costs are a big impediment to large-scale manufacture; and their market demand depends primarily on their price competitiveness with petroleum-derived counterparts. Our technology can increase the productivity and profit margin of these companies. With our technology, large-scale bio-commodity chemicals production could become economically feasible. In addition to reduced operational costs, antibiotic-free production alleviates antibiotic misuse in industries to promote a positive environmental and public heath impact.<br/><br/>This I-Corps project comprises a novel biocide/biocide-resistant system that could be used to treat and prevent microbial contamination in bioreactors. This technology allows bioprocessing engineers to eliminate the microbial contamination problem by addition of a biocide into the bioprocessing hosts' growth medium. The biocide prohibits the outgrowth of accidental contaminants while a biocide-resistant enzyme protects the bioprocessing host. The system also contains an on/off switch that allows easy removal of the biocide as needed. Preliminary data demonstrates that heterologous expression of the biocide-resistant enzyme in Escherichia coli and subsequent directed evolution resulted in a biocide-resistant Escherichia coli with a half maximal inhibitory concentration (IC50) approximately 16 times higher than the negative controls. We further demonstrate that this biocide in combination with the expression of biocide-resistant enzyme can be used to successfully treat a contaminated bioreactor.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.