Schropp, S.J.2010-02-152010-02-151979http://hdl.handle.net/1969.3/26091103 p., ThesisA seasonal survey of aerobic heterotrophic and petroleum hydrocarbon- degrading bacterial populations of the Galveston Bay system was conducted. Aerobic heterotrophic bacteria ranged from 1.82 x 10exp2 to 3.32 x 10exp5 CFU/ml water and from 2.67 x 10exp4 to 9.06 x 10exp7 CFUml wet sediment. Pseudomonas, Bacillus, Vibrio and Flavobacterium were the most common genera isolated. The populations were highly variable, with temperature and river runoff being the major influencing environmental parameters. Hydrocarbon- degrading bacteria were found in all parts of the bay system. The total number of hydrocarbon-degrading bacteria ranged from less than 3.0 to 9.25 x 10exp2/ml water and from less than 3.0 x 1.10exp2 to 1.10 x 10exp6/ml wet sediment. There was no correlation between total hydrocarbon-degrading bacteria and sources of hydrocarbon input. The percentage of hydrocarbon-degrading bacteria was usually less than 1% except in the sediment during the fall. There appeared to be a positive correlation between the percentage of hydrocarbon-degrading bacteria and sources of hydrocarbon input. The predominant hydrocarbon-degrading genus was pseudomonas. The low percentage of hydrocarbon-degrading bacteria and low measured concentrations of total alkanes in the sediment indicate that the Galveston Bay system is not seriously contaminated with petroleum hydrocarbons.bacteriaaerobic bacteriapetroleum hydrocarbonsPseudomonas sp.Bacillus sp.Vibrio sp.Flavobacterium sp.microbiologyBook