This Small Business Innovation Research (SBIR) Phase I project proposes to develop a versatile, sensitive, and inexpensive carbohydrate monitoring system based on optoelectronics and biosensor technologies. The platform allows continuous measurement of simple carbohydrates using small, disposable fiber-optic biosensors with accuracy comparable to conventional instrumentation. This technology offers the ability to both detect carbohydrates over a large linear range and do it in a simple, automated, and online fashion. Many different bioprocesses, including fermentations to produce biofuels, amino acids, and pharmaceuticals, are based on microbial conversions of sugars to high-value products. Real-time monitoring of carbohydrate concentration during the biomass conversion would provide a great advantage in process control, leading to increased yields at decreased production costs and a lower environmental impact. No current technology is available for continuous, quantitative monitoring of specific sugars, and the sensor system to be developed will address this need. The project is designed around four specific aims that will result in the development of sensors for glucose and xylose, a method for monitoring both sugar concentrations simultaneously, and comparison of methods to sterilize these sensors. The outcome will be demonstration of a sensor for continuously monitoring glucose and xylose in bioprocesses. The broader impact/commercial potential of this project, if successful, is the development of carbohydrate sensors to enable bioprocess monitoring, control, and optimization. Each of those characteristics can increase the efficiency of a bioprocess. For example, monitoring can detect when a batch process is not performing to specification, and control and optimization allow efficient operation. Current off-line methods to measure sugar concentrations lead to poor process control, inefficient use of capital equipment, and the wasting of expensive chemicals and energy due to over-compensation. For example, more effective monitoring of carbohydrates for a corn stover biomass processing plant could result in a conservative estimated annual savings of $690,000/year. Projections of the "bio-based economy" are for an increasing volume of chemicals, beyond pharmaceuticals, to be produced biologically from different biomass feedstocks. Operation of those bioprocesses would be more environmentally and economically sustainable with the continuous, on-line monitoring provided by this sensor.
