subject: microbiology The results of growth can be followed using


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subject: microbiology The results of growth can be followed using a spectrophotometer to detect how much light can pass through a broth culture…the more cells, the less light passes through. Resulting growth curves are described in your text. In a growth curve, the number of cells grows logarithmically (exponentially) until a maximum number is achieved – the maximum number that can be sustained by the medium (called maximum stationary phase). Growth conditions that are not optimal result in slower rates of growth. Using this information, predict the growth rates expected results after 18 hours for six sterile tubes of an identical medium inoculated simultaneously with an enteric microbe and incubated at 15°C, 25°C, 35°C, 45°C, and 55°C. Use the symbols -, [-], =, [+], and + (these are in order of increasing growth) to indicate growth relative to the maximum growth rate at 37°C (where, if graphed, the slope of the exponential portion of the growth curve is greatest) and fill in the table below. Refer to the graph on page 27 of your lab manual to help predict these results. Temperature (°C) Expected Growth Rate After 18 Hours (-, [-], =, [+], or +) 15°C 25°C 35°C 45°C 55°C

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