At what temperature will you treat a food product? How long does it take you to kill 90% of bacteria? How long will it take you to sterilize a food product if it had 109 bacteria on it

Drinking water can be obtained via (a) bottled spring water or (b) a sink-mounted reverse osmosis device. Briefly discuss two negative aspects of each, from a sustainability point of view.

1. Plate count data are used to calculate microbial population density as colony forming units (CFUs) per milliliter of culture. Culture density (CFU/mL) = number of colonies (dilution factor) x (volume plated, in mL) Use these data below to calculate the CFU/mL in this sample of bacteria after 1 hr of growth. **Important to know for these types of questions - only use colony counts that fall between 10 and 300. TNTC = too numerous to count, so many colonies that you can't distinguish them to count. Use the plates with numbers of colonies that can be counted, calculate the CFU on each one, and then calculate the average between all of them. Looking for more assistance? Read section 7.3 in the textbook. Time 1h Dilution (before plating) Volume spread on plate 0.1 mL 0.1 mL 0.1 mL 0.1 mL none 1:10 (1 x 10-¹) 1:100 (1 x 10-²) 1:1,000 (1 x 10-³) Number of colonies observed (replicate plates) TNTC 499 83 10 TNTC 518 87 8 TNTC indicates too numerous to count. *Cell density could not be…

Consider the following graph depicting the population growth of bacteria in an “ideal” laboratory created condition. Explain what conditions would allow for a population to grow exponentially like in this example, and why this is unlikely to occur naturally in the wild. ✓✓ Population (number of bacteria) 35000 30000 25000 20000 15000 10000 5000 0 Population Growth of Bacteria in Ideal Conditions 2 Time (hours) 3

A new intestinal isolate of E. coli is known to have a generation time of 12 minutes. If a culture contained 3, 221,225,472 bacterial cells after 6 hrs how many bacteria must have been inoculated into the culture at time 0.

As a technologist in the brewing industry, your job is to research and develop ways to improve the yield and quality of brewed beverages. You are responsible for growing and maintaining the particular strain of microorganism that is used in the fermentation of beverages. Name 2 environmental factors that would affect the growth of this organism and which you will need to optimize for abundant growth of your organism.

For the bacterial growth curve below in which phase does the number of cell divisions equal the number of cell deaths? Log of number of bacteria 0 Lag Phase Intense activity preparing for population growth, but no increase in population. lag 2019 Pearson Education, Inc. log Log Phase Logarithmic, or exponential, increase in population. stationary Stationary Phase Period of equilibrium; microbial deaths balance production of new cells. The logarithmic growth in the log phase is due to reproduction by binary fission (bacteria) or mitosis (yeast). 5 Time (hr) Death Phase Population is decreasing at a logarithmic rate. death Staphylococcus sp. 10 None of the other four answers are correct Log Phase Stationary Phase Death Phase Lag Phase

You sample cole slaw for bacteria soon after purchase, and after it has been left out on the kitchen counter for 6 hours (room temperature), and after 12 hours (at room temperature).    From the data below, CALCULATE  the generation time of the bacteria in this sample (at room temperature) – that is, the time it takes for the bacterial population to double in number. Soon after purchase:                                          4.0 x 103 bacteria per mlAt 6  hours at Room Temperature:                     1.9 x 105 bacteria per ml ( = 192 x 103 bacteria per ml)At 12 hours at Room Temperature:                    1.2 x 107 bacteria per ml  ( = 12,300 x 103 bacteria per ml)  What do you calculate the generation time to be?                                                 (generation time is the time needed for the population to double in size )                                  Hint:  What is double the initial population?                                                                Hint:…

In a population of cyanobacteria (Chlorogloeopsis fritschii) in a hot spring in Iceland, some of the bacteria can produce chlorophyll f, while some C. fritschii produce only other types of chlorophylls.  Chlorophyll f absorbs light outside of the visible light spectrum, namely near infrared light, allowing the bacteria to absorb light that has not been absorbed or reflected by the water or other organisms.  The ability to produce chlorophyll f is heritable, and the bacteria with chlorophyll f can live in low-light environments, such as underneath other organisms, or near the bottom of the light-penetrating zone of the spring.  What is the adaptation in this population of C. fritschii living in low-light environments? (Choose one.)   a) the ability to produce chlorophyll f    b) the ability to produce any type of chlorophyll    c) the ability to tolerate the high temperatures of the hot spring   d) the ability to survive and reproduce

A microbiologist inoculated a flask of nutrient broth with E. coli. The bacterial population entered exponential phase at 11:30 pm and divided every 60 min. At 6:30 am, the culture entered stationary phase with a population of 100,000,000 bacteria mL-¹. At what time was the population 50,000,000 bacteria mL-¹? 5:30 am 12:30 am 4:30 am O Can not be determined from the information given. 3:30 am