Susan M. Boyetchko

Structure, chemistry, and biological activity of pseudophomins A and B, new cyclic lipodepsipeptides isolated from the biocontrol bacterium Pseudomonas fluorescens

Pseudophomins A and B are cyclic lipodepsipeptides isolated from Pseudomonas fluorescens strain BRG100, a bacterium with potential application for biocontrol of plant pathogens and weeds. Their chemical structures were established by a combination of spectroscopic data, X-ray crystallography, and selective chemical degradation. This unique chemical degradation allowed the unambiguous determination of the absolute configuration of the amino acid residue Leu-1, due to gamma-lactam formation followed by selective cleavage of the adjacent N(8)-C(7) bond. To the best of our knowledge this is the first application of gamma-lactam formation to the determination of absolute configuration of an adjacent amino acid. Pseudophomin B showed higher antifungal activity against the phytopathogens Phoma lingam/Leptosphaeria maculans and Sclerotinia sclerotiorum than pseudophomin A, and is likely to be the main component responsible for the antifungal activity of EtOAc extracts of strain BRG100. By contrast, pseudophomin A showed stronger inhibition of green foxtail (Setaria viridis) root germination than pseudophomin B.

Innovative Applications of Microbial Agents for Biological Weed Control

The world chemical pesticide market was valued at

Screening of adjuvants for bioherbicide formulations with Colletotrichum spp. and Phoma spp.

26.8 billion in 1991, with herbicides accounting for 44% of the market (Powell and Jutsum, 1993). Annual yield losses due to weeds were

Biological Control Agents of Canola and Rapeseed Diseases — Status and Practical Approaches

984 million in 58 commodities grown in Canada and

Genome Sequence of Pseudomonas chlororaphis Strain PA23

1,060 million in vegetable, fruit and nut crops grown in the United States (Chandler et al., 1984; Charudattan and DeLoach, 1988; Swanton et al., 1993). Rising economic, environmental, and social costs associated with agricultural inputs, spray drift, pesticide residues, government legislation for reduced pesticide use, and development of herbicide-resistance in weeds make biopesticide products attractive alternatives to chemicals (Jacobsen and Backman, 1993; Pimental et al., 1991; Swanton et al., 1993). Countries such as Denmark, Sweden, and the Netherlands have implemented programs to reduce pesticide use by 50% (Pimentai et al., 1991). In Ontario, Canada, a government initiative was proposed to reduce pesticide applications by 50% by the year 2002 (Swanton et al., 1993).

Technoeconomic analysis of large scale production of pre-emergent Pseudomonas fluorescens microbial bioherbicide in Canada

Abstract A study was conducted to determine whether certain surfactants (Tween series: 20, 40, 80, and Tergitol NP series: 9, 10) and adjuvants (sorbitol and gelatin) would be useful components in bioherbicide formulations of Colletotrichum (10 isolates) and Phoma (5 islolates). The effect of adjuvants on conidial germination and mycelial growth varied with adjuvant, adjuvant concentration (0.01, 0.1, 1, and 5%), fungal isloates, and conidial density (105–108 conidia/ml). Tween 20 reduced germination and mycelial growth in some Phoma and all Colletotrichum isolates, whereas Tween 40 and Tween 80 stimulated germination without detrimental effects on mycelial growth of all isolates. Tween 40 and Tween 80 released conidia from self-inhibition of germination in Colletotrichum as compared to the germination of conidia at 107 conidia/ml in the absence of the adjuvant. Tergitol NP often reduced germination and mycelial growth. There were no trends in fungal responses to sorbitol. The responses of Colletotrichum were highly variable to gelatin, but for Phoma, gelatin increased germination and mycelial growth, and also released self-inhibition of germination. In summary, gelatin, Tween 40, and Tween 80 were useful components for bioherbicide formulations to increase conidial germination and mycelial growth of Phoma, whereas Tween 40 and Tween 80 were useful for Colletotrichum.

High-Quality Draft Genome Sequence of Biocontrol Strain Pantoea sp. OXWO6B1.

Although initial exploration in biological control of plant pathogens began in the mid 1920s, it is a technology in plant pathology that has experienced more intensive investigation by researchers and industry over the last 25 to 3 0 years (Cook, 1993; Utkhede, 1996; Weiler, 1988). “The general accepted definition of biological control, proposed by Baker and Cook (1974), is the reduction of inoculum density or disease-producing activities of a pathogen or parasite in its active or dormant state, by one or more organisms, accomplished naturally or through manipulation of the environment, host, or antagonist, or by mass introduction of one or more antagonists”.

High-Quality Draft Genome Sequence of Bacillus subtilis Strain WAUSV36

ABSTRACT Pseudomonas chlororaphis strain 189 is a potent inhibitor of the growth of the potato pathogen Phytophthora infestans. We determined the complete, finished sequence of the 6.8-Mbp genome of this strain, consisting of a single contiguous molecule. Strain 189 is closely related to previously sequenced strains of P. chlororaphis.

High-Quality Draft Genome Sequence of Arthrobacter sp. OY3WO11, a Strain That Inhibits the Growth of Phytophthora infestans.

The study presents an ex ante technoeconomic analysis of commercial production of Pseudomonas fluorescens BRG100 bioherbicide in Canada. An engineering economic model is designed in SuperPro Designer® to investigate capital investment scaling and profitability. Total capital investment for a stand-alone BRG100 fermentation plant at baseline capacity (two 33,000L fermenters; 3602tonnesannum(-1)) is

Social and economic drivers shaping the future of biological control: a Canadian perspective on the factors affecting the development and use of microbial biopesticides.

17.55million. Total annual operating cost is