• a)  You have been provided with Plate Count Agar that has 154 colonies on the plate. The agar plate was inoculated with 0.1ml of 10^-5 serial dilution of a pond water sample. Calculate the total number of aerobic bacteria present in the pond water.
• b)  As a quality control officer in Company A, you are challenged with sporadic contamination of your pineapple juice product. Initial plating of the juice showed two (2) mixed colony morphologies on general purpose media. With the knowledge that fruit juice products are typically contaminated with yeast and bacteria, describe the methods you will use to isolate and differentiate the microbial contaminants in your pineapple juice.
• c)  A student has been tasked to observe microorganisms present in pond water under a microscope and draw them. Given that E. coli., amoeba, paramecium, algae, yeast, and Streptococcus are some of the microorganisms present in the pond water, describe the methods the student can employ to accomplish this assignment.
• d)  As part of microbiology laboratory practical, you are given a mixed culture that contains Salmonella spp., E. coli, Enterococcus spp., Staphylococcus aureus and Saccharomyces cerevisiae and other microorganisms. Describe the methods you can use to isolate and identify Salmonella spp., E. coli and Staphylococcus aureus from the mixed culture?