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Collection: FAU Electronic Theses and Dissertations Collection, Thesis (M.S.)--Florida Atlantic University, 1976., Summary: Laboratory model ecosystems, enriched with aldrin and dieldrin, were employed to study pesticide-induced succession and to provide microorganisms which degrade these compounds. Seventy-two pesticide-tolerant bacteria were isolated and succession was demonstrated in all systems. Bioconcentration by an alga was observed in two of the microcosms. Gram-positive bacteria were not isolatable after pesticide enrichment, indicating a greater sensitivity to these compounds. Radioautograms showed that 80% of screened isolates were capable of varying degrees of pesticide degradation. Microbial response to the pesticides appeared to be related to the presence of other organic materials with the nutritionally poor ecosystem favoring pesticide destruction. Cometabolic tendencies were demonstrated by 4 isolates in the presence of pesticides augmented with glucose and peptone., Charles E. Schmidt College of Science

Collection: FAU Electronic Theses and Dissertations Collection, Thesis (M.S.)--Florida Atlantic University, 1976., Summary: Analyses of microbial growth media containing carbon-labeled aldrin and dieldrin, strongly suggests that metabolic action on these pesticides, under optimal culture conditions, may be more extensive than previously assumed. Isolates from fresh, brackish, and littoral water, as well as adapted strains of the soil form, Arthrobacter oxydans, were cultured variously in selective media and enriched laboratory ecosystems. Growth studies of A. oxydans on pesticide-enriched media revealed that aldrin (12% decrease) and dieldrin, DDT, endrin and 2,4-D (9% decreases) were inhibitory, decreasing use of glucose and citrate. Quantitative thin-layer chromatography and 14C-labeled pesticide radioautography were used to detect pesticide degradation by A. oxydans strains, 2 Flavobacterium sp., 1 Achromobacter sp., 4 Alcaligenes sp., and 42 Pseudomonas sp. Data are compared with those from the literature to tentatively identify endrin, metabolites D, E, G and F, keto-endrin, endrin ketone and photodieldrin. Conversion of aldrin to dieldrin and vice-versa is reported., Charles E. Schmidt College of Science