This STTR Phase II research project is focusing on the development and commercialization of a new, environmentally safe biopesticide for the control of zebra and quagga mussels. These freshwater, invasive bivalves foul water pipes and cause severe economic and ecological harm throughout North America and Europe. Marrone Organic Innovations, a leader in biopesticide commercialization, is partnering with biological control experts at the New York State Museum who have discovered a bacterium, Pseudomonas fluorescens, that produces a natural compound that is selectively lethal to these pest mussels. The microbial biopesticide developed in this project will be an environmentally safe alternative to the polluting, non-selective chemicals that infested facilities, due a lack of alternatives, are currently forced to rely on to control mussel infestations. The broader impacts of this research include both economic and ecological benefits to society. Mussel infestations cause hundreds of millions of dollars in additional expenses every year, and the chemical methods currently used to control them are known to be harmful to other aquatic organisms. The proposed research will advance a project of national significance and reach across numerous scientific disciplines, including biochemistry, microbiology, and invertebrate zoology, serving as a model in the effort to reduce the use of polluting pesticides. Training and learning will be fostered by involving postdoctoral, graduate, and undergraduate students. Because of its extraordinary safety, this bacterial biopesticide will serve as an example of a green technology that will benefit the environment as well as industrial and recreational users of freshwater