Under what conditions is the fecal coliform test incubated?

The fecal coliform test is specifically designed to detect the presence of fecal coliform bacteria, which are indicators of fecal pollution in water. The correct incubation conditions for this test are set at 44.5°C for 24 hours. This temperature is optimal because it enhances the growth of fecal coliform organisms while suppressing the growth of other non-fecal bacteria, thereby providing a more accurate assessment of fecal contamination.

In choosing 44.5°C and a 24-hour incubation period, laboratories utilize conditions that best favor the growth of Escherichia coli and other fecal coliforms, ensuring that detectable levels of these organisms can be cultivated and identified, leading to effective water quality assessments related to public health risks.

Other temperature and time combinations presented may not adequately promote the specific growth required for fecal coliform detection or may allow for the growth of non-fecal organisms, thereby confounding results. Thus, the selected option aligns perfectly with standard microbiological protocols for coliform testing in environmental health practices.