Volatiles production and attractiveness to the Mexican fruit fly of Enterobacter agglomerans isolated from apple maggot and Mexican fruit flies.

We investigated two strains of uricase (+) Enterobacter agglomerans, one isolated from the apple maggot fly (AMF) and one from the Mexican fruit fly (MFF), for 1) attractiveness to MFF, and 2) production of attractive chemicals. Regarding chemicals demonstrated attractive to the MFF, the MFF bacterial strain produced more 2,5-dimethylpyrazine, 2-phenylethanol, and indole than the AMF strain, whereas the AMF, but not the MFF strain, produced 3-hydroxybutanone. Cell types that predominated in plated subcultures varied from batch to batch resulting in variation in volatiles production, especially by the AMF strain where indole was sometimes a major component of the odor and at other times not detectable.

A continuous spectrophotometric assay for the determination of diamondback moth esterase activity.

Conventional methods to determine esterase activity from insects are composed of a three-step process where the enzyme is allowed to hydrolyze a 1-naphthyl acetate substrate, that reaction is quenched by a SDS detergent, and then a Fast Blue B dye complex is formed with 1-naphthol, the product of 1-naphthyl acetate hydrolysis. These methods measure dye-product complex rather than the product, 1-naphthol. A new assay is presented that continuously monitors the formation of 1-naphthol with the hydrolysis of an esterase substrate.