WHAT IS ZEQUANOX
ZEQUANOX™ - Environmentally Friendly Biological Control of Zebra and Quagga Mussels with Pseudomonas fluorescens Strain CL145A
Environmentally Friendly Mussel Treatment Has Advantages
Power generation facilities require annual maintenance and preventive programs to keep infestations of fouling zebra and quagga mussels (Dreissena spp.) in their cooling water intake systems under control. Currently it is necessary at many of these and other infested raw-water dependent infrastructures to administer controlled dosages of chlorine or other types of biocides for this purpose. Natural resource interest groups and regulatory agencies are reexamining the negative long-term use of biocides for this purpose. Both groups have made it clear that safe, non-chemical alternatives for controlling mussel fouling would be environmentally beneficial. Chlorination, for example, is a common control method, and when chlorine combines with organic compounds in water, potentially carcinogenic substances such as trihalomethanes and dioxins are formed (United States Environmental Protection Agency 1999; Thornton 2000). Should future regulatory actions result in the loss of chemical biocides, without an alternative control option, electric generation organizations and many other industries that rely on the withdrawal of surface waters for operational reasons are certain to experience economic penalties. These losses would be the result of decreased production brought on by increased facility maintenance and downtime. The availability of an equally effective, yet more environmentally benign, mussel control method to replace chlorine and other biocides is critically needed by power plants and other infested facilities.
Research Paradigm – Why Microorganisms?It is widely accepted that the screening of diverse microorganisms and plant species for the natural products they produce is a worthwhile activity due to the discovery of drugs that can prevent or cure animal diseases, particularly cancers. More than 50% of today’s drugs were derived from natural sources. Likewise, 11% of pesticides in use today are derived from plants and microorganisms. Therefore, it makes sense to look to microorganisms for unique natural products that have potential as highly selective biopesticides. In fact, the use of microbial natural product compounds already has a clear record of commercial success and environmental safety in the control of invertebrate pests in North America, as well as globally (Rodgers 1993). New York State Museum (NYSM) laboratory has been involved in such research for over two decades. Marrone Bio Innovations, the commercial developer of this mussel control product, has a team of scientists and a management team that has been involved in the biopesticide industry since its inception and is recognized leaders in “green chemistry” research, development and marketing. The MBI team has successfully introduced several biopesticide products to domestic and international markets over the past thirty years.
|
Mussel Killing BacteriaInception of Project – NYSM Screens Bacteria for Killing Zebra and Quagga Mussels
Faced with the threat of zebra mussels fouling electric power facilities within New York State, the Empire State Electric Energy Research Corporation (ESEERCO1) contracted with NYSM F ield Research Laboratory in 1991 for the screening of bacteria as potential biological control agents. Extensive laboratory screening trials of more than 700 bacterial strains identified a North American isolate, strain CL145A of Pseudomonas fluorescens, to be lethal to these mussels. Of the strains of P. fluorescens that have been laboratory tested to date, only Pf-CL145A has been found to be highly lethal, i.e., at dosages that produce >90% adult zebra and quagga mussel kill and 100% larval kill with Pf-CL145A.
Pseudomonas fluorescens is worldwide in distribution and is present in all North American water bodies. In nature, it is a harmless bacterial species that is found protecting the roots of plants from plant diseases. NYSM research has shown that the Pf-CL145A strain of this species may be fortuitously used for another purpose — the control of Dreissena spp. (Molloy 2002). A patent for this purpose has been issued in both the United States (Molloy 2001) and Canada (Molloy 2004). Mussels Die from a Natural Product: Dead Bacteria Kill Equally As WellAlthough phytoplankton is their preferred food, Dreissenamussels can filter out and consume bacteria as a food source (Mikheev and Sorokin 1966; Frischer et al. 2000). When a zebra or quagga mussel ingests artificially high densities of strain CL145A, however, compounds within these bacterial cells destroy the mussel's digestive system. Dead cells are equally as lethal as live cells, providing clear evidence that the mussels die from natural compounds not from infection. Economical methods have been developed by MBI to kill the bacteria without any reduction in their lethality to the mussels. Findings from recent trials and bench tests indicate that MBI has significantly increased efficacy against zebra and quagga mussels. Commercial products developed by MBI based on this microorganism, which will be marketed as Zequanox®, contain dead cells, thus further reducing environmental concerns.
|