Culture

Describe methods that a cell may use to adapt to heavy metal contaminated sites. Define halophile. What is a compatible solute? What are they used for?Describe the industrial uses of Dunaliella?Describe what issues cell harvesting presents on an industrial scale.Explain what stress proteins are and how they are related to the ability of cells to live in extreme environments.

You are determining the concentration of your culture, and have counted the following on your hemocytometer as shown in Figure below: (note, blue cells have taken up Trypan blue & thus are dead. Red x's are cells that should not be counted because touching one of 2 sides of square). If your cells were diluted 1:2 before counting, what is the concentration of cells in your original culture?

Give typing answer with explanation and conclusion

After performing the “Effects of Antiseptics & Disinfectants” lab which agent(s) showed potential to control S. marcescens growth? P. aeruginosa? Please explain why you believe these agent(s) work.

Imagine you repeated the counting of N. crassa conidial cells and found an average number of cells of 500. Before adding the cells to the hemocytometer, you mixed 100ul of conidial suspension with 100ul of water. You then added 10ul of this mix to the chamber. What is your density in cells/ml? O 10,000,000 cells/ml 2,500,000 cells/ml O 5,000,000 cells/ml O Impossible to determine

The culture you are working has a doubling time of 2 hours and a cell density of 3 x 106 cells per mL. For your experiment, you first dilute the culture 100 fold. Assuming that there is no lab phase and that the cells remain in exponential growth the entire time, what is the cell density (cells/mL) after 10 hours?

Develop an equation for calculation of pressure as a function of the number of passes through the homogenizer. What factor(s) did you take into consideration when selecting the number of passes? Escherichia coli cells are lysed with the same homogenization, is this organism gram-positive or gram-negative? What impact does increasing the value of the constant, a, have on the required number of passes at a given pressure? What factors impact the value of a? If fine cell debris after homogenization makes subsequent solid-liquid separation difficult, what would you recommend?

All of the following are valid measurements of growth except: A. Counting viable cells B. Estimating the weight of cells C. Determining the dry weight of cells D. Streaking for single colonies E. Measuring some cellular component F. Counting the total number of cells

You have run tests on a new centrifuge to determine the flow rate at which yeast cells break through into the clarified liquid stream.  This value was measured as 10 L/min.  The yeast were previously found to settle at 100 µm/s in a lab centrifuge operated at 500 g.  What is the Σ value of this new centrifuge?