1. Facile interfacial modification of S16 phages for nanoparticle conjugation: Our working hypothesis, based on preliminary work with T4, is that alkyne functional groups can be incorporated onto S16 phage capsids in vivo using alkyne-modified unnatural amino acids, and that by using "click" chemistry, the engineered phages can be conjugated to magnetic nanoparticles for the separation/concentration of Salmonella from liquid agricultural samples.2. Ultrasensitive reporter expression via regulatory optimization: Our working hypothesis, based on preliminary data, is that the reporter enzyme resulting from the infection of a single CFU of Salmonella will be detectable if the combination of early, middle, and late promoters is optimized with the ribosome binding site.3. Multiple adhesins to increase phage host ranges: Our working hypothesis, based on preliminary data with E. coli phages, is that phages can be equipped with genes for multiple adhesins thus significantly increasing their host range. The progeny phages resulting from a single infection will consist of a cocktail of phages with various combinations of adhesins.