RESUMEN
Aerobic heterotrophic and facultative anaerobic bacteria were isolated from all developmental stages of the sugar beet root maggot, Tetanops myopaeformis (von Röder). Two distinct bacterial symbiotic relationships were observed. Serratia liquefaciens and Serratia marcescens were found to be associated with all developmental stages. Bacterial symbiont transmission occurred from one generation to the next. Symbionts were transferred from the male reproductive system to the female reproductive system, where both an internal infiltration of the egg chorion and an external smearing of the eggs occurred during oviposition. Pseudomonas maltophilia was found in association with the larval gut and the inner surface of the puparium. Electron microscopy of the inner puparial surface revealed symbionts within the chitinous wall. In vitro symbiont chitinase production was found, using both nephelometric (turbidimetric) and N-acetylglucosamine assays. A relationship appeared to exist between adult fly emergence and enzymatic chitin degradation of the puparium by the bacterial symbionts.
RESUMEN
A possible pathway for the anaerobic utilization of benzoic acid by a methanogenic consortium is suggested. Cyclohexane carboxylic acid and 1-cyclohexene-1-carboxylic acid have been identified as intermediates before ring rupture. Suprisingly, 3-cyclohexene-1-carboxylic acid interferes with utilization of other cyclic acids. In addition, isobutyric acid or short chain acids containing carbon-carbon double bonds could not be used without induction periods of a week or longer. A number of volatile fatty acids (heptanoic, valeric, butyric, propanoic, and acetic) have been identified and are suggested intermediates.
