Capital intensity is among the current constraints on industrial-scale fermentation, because the hardware for steam sterilization of bioreactors is complex and expensive. After recently emerging from stealth status, the startup company Biosphere (Oakland, Calif.; www.biosphere.io) has launched a new reactor for industrial biotechnology applications that is equipped with a system to maintain sterility with ultraviolet (UV) radiation. The proprietary design of the new bioreactor creates an aseptic environment with a UV sterilize-in-place protocol.
The UV-enabled design (photo) simplifies the bioreactor hardware and eliminates the need for the complex infrastructure required for steam sterilization. The company says the UV system allows a 10-fold increase in production capacity, compared to conventional steam-sterilized fermentation systems, for the same level of investment.
“This bioreactor allows the use of less expensive vessels and eliminates the need for the majority of process valves, steam pipes and condensate traps,” explains Biosphere CEO Brian Heligman. “It can also accelerate sterilization protocols by a factor of six,” he adds. “All of which will enable large-scale production of bioproducts with economics that are not attainable with conventional technology.”
In designing the bioreactor, two key engineering challenges were the following: establishing radiation dosage per unit of reactor surface area to ensure that sufficient radiation energy reaches all bioreactor surfaces; and engineering non-porous surfaces that would not harbor microbes.
The company reports consistent UV sterilization of bioreactors that were coated in microbial spores for testing. “We were able to clean the reactor surfaces, apply UV radiation, then load the reactor with nutrient media. We observed no microbial growth over 3–5 day sterile holds,” Heligman says.
Biosphere has already built a bank of bench-scale UV-sterilizable bioreactors, and the company is now constructing a 2,000-L demonstration system. They are actively searching for partners interested in utilizing this capacity to manufacture bioproducts.