Research Project Summary Information
Power Generation Biological Control(ST6265-1)
NYS Department of Education
Power plants in New York State need an effective, economical, and non-polluting technique for managing zebra mussel infestations. Many use broad-spectrum biocides such as chlorine. To be effective, chlorine must be applied for three continuous weeks because biocides like chlorine cause zebra mussels to close, necessitating prolonged application. Previous work funded by ESEERCO has developed a bacterium strain that can be applied dead -- its highly selective biotoxin (not an infection) kills zebra mussels in three days at commercial levels, but unlike chlorine, does not kill any non-target species tested. Funds for scale-up have recently been awarded by New York Sea Grant. This project would supplement that work by allowing larger (up to 500-L instead of 75-L), more realistic scale-up, which would allow more field trials (12 instead of four), ultimately bringing the product closer to commercialization.
The goal was to demonstrate cost-effective large-scale (up to 500-L) production of the bacteria with satisfactory growth and biotoxin production, as well as stable storage. Researchers hoped to conduct incrementally larger fermentations, from 1-L to up to 500-L, culminating in a standardized, optimized, large-scale fermentation protocol, then confirm lethality at each scale. Using the protocol, they then hoped to conduct four small-scale, two medium-scale, and six large-scale trials within power plants. Before the project began, application rates were estimated to be 100 ppm for 48 hours. The work actually performed differed slightly. Researchers performed the following tasks: (1) an improved fermentation medium was designed that produced cells of high toxicity in shake flasks, (2) a fermentation protocol was developed to produce toxic cells in 0.5-L fermentors, (3) fermentations were scaled-up to 10-L and 55-L volumes without a decrease in cell toxicity, and (4) cells harvested from 10-L and 55-L fermentors were used to treat mussels in pipes within a New York Power Authority (NYPA) facility (Crescent, NY).
Clearing zebra mussels from intake pipes will improve power plant efficiency. (For example, Ontario Hydro reports annual costs of $386,000/generating station.) This product reduces the introduction of chlorine into the environment. The product is dead, broken bacterial cells, so expensive purification is not necessary.
Laboratory bioassays demonstrated success at each level of fermentation scale-up. Field trials in the NYPA facility demonstrated that bacterial treatments at 100 ppm (dry bacterial mass/unit volume) for six hours in acrylic pipes (with Mohawk River service water flowing continually) consistently produced greater than 95% mussel kill along the full length of 17-m pipes. The success of this project shows promise for the continued development of this bacterial product toward commercialization.
More work is needed to commercialize this product. A companion project to identify the toxin was also funded by NYSERDA.
NYS Department of Education
109 South Union St., 2nd Floor
Rochester, NY 14607
Dr. Denise Mayer
Indigenous/Renewable Energy Resources
NYSERDA Contact Information
R&D - Environment & Energy Res