The effect of temperature on phenol degradation in wastewater.

Data are presented which show that the microbiological degradation of phenol in industrial wastewater is affected by temperature in an unexpected manner. The rate of degradation is unaffected by temperature changes in the range from 24 to 10 degrees C but falls off rapidly at temperatures below 10 degrees C. In the interval from 10 to 2 degrees C the rate of degradation is a function of temperature and is proportional to the rate of growth of the bacteria studied. By contrast, the increase in rate of phenol degradation is much greater than the increase in growth rate as the temperature increases from 10 to 24 degrees C. Field and laboratory studies show that increased efficiency of phenol degradation in wastewater is due to increase in temperature rather than to shifts in microbial populations.

Quantitative analyses of certain enteric bacteria and bacterial extracts: I. Standardization and sonic disruption of eight enteric bacterial species, each at five population levels.

Standardized individual preparations of five population levels of eight enteric organisms [Escherichia coli (O4:H3), E. coli (O111:B4:H12), Salmonella enteritidis, S. paratyphi B, S. typhimurium, Shigella boydii, S. dysenteriae, and S. sonnei) were prepared. Dry weights, calculated mean cell weight, and nitrogen content of bacterial suspensions before, and of supernatant fluids after, ultrasonic disruption are tabulated. Percentages of disruption, estimated from nitrogen concentration ratios of the suspensions and supernatant fluids, are given. These data are presented as guidelines for the preparation of bacterial extracts prior to precipitin analyses.

Quantitative Analyses of Certain Enteric Bacteria and Bacterial Extracts: II. Discrimination of Sonic Extracts by Interfacial Densitometry of Precipitin Systems.

Bacterial extracts prepared by ultrasonic disruption were reacted with both narrow- and broad-spectrum reference (homologous) and cross-reacting (heterologous) precipitins produced in rabbits. Quantitation of the reaction was obtained by densitometry of the antigen-antibody interface. Comparisons were made of sonic extracts from various starting populations all equated to the same nitrogen concentrations, and of various nitrogen levels derived from five bacterial population levels prepared separately. Sources of error are probed to show under what circumstances cross-reactions would be of greater magnitude than reference ones. The feasibility was shown of using quantitative densitometry of the interface combined with broadly reacting precipitins to identify bacteria on an intergeneric and interspecies scale. Problems associated with the use of absorbed or monospecific precipitins are explained.