MCB ch25

Which chemical is used in both water purification and sewage treatment to provide long-term disinfection? Activated charcoal Fluorine Chlorine Copper sulfate

Chlorine

Which of the following statements regarding coliform bacteria is correct? Petri dishes used to enumerate coliforms are best incubated at 45-48°C. Coliforms from the human and bovine GI tracts differ, so identifying the specific microbe will indicate the source of contamination. Coliforms derive from the intestinal tract and therefore indicate fecal contamination. The presence of Klebsiella is a strong indicator of fecal contamination.

Coliforms derive from the intestinal tract and therefore indicate fecal contamination.

Which organism is used to initiate the fermentation of cabbage to make sauerkraut? Saccharomyces cerevisiae Streptococcus lactis Propionibacterium Spirulina Leuconostoc mesenteroides

Leuconostoc mesenteroides

the organism used to make bleu cheese is ______. Streptococcus lactis Penicillium roqueforti Propionibacterium Leuconostoc mesenteroides Micrococcus

Penicillium roqueforti

Which bacteria ferment lactose in milk, producing acids that curdle the milk? Pediococcus Saccharomyces cerevisiae Streptococcus lactis and Lactobacillus Spirulina Leuconostoc mesenteroides

Streptococcus lactis and Lactobacillus

You ask the butcher to grind a sirloin roast to be used for hamburger. You family likes hamburgers rare, so you undercook the meat. Unfortunately, within 2 days they develop the symptoms of gastrointestinal disease: diarrhea, bloating, and vomiting. Which of the following statements best describes what happened? The meat became contaminated by bacteria on the barbeque grill, coating both sides of the hamburger patties. The animal was sick before slaughter, and the sirloin was contaminated. The meat became contaminated by bacteria from other foods in your refrigerator. The meat grinder was contaminated, and bacteria were transferred and distributed throughout the meat.

The meat grinder was contaminated, and bacteria were transferred and distributed throughout the meat.

You made your first batch (ever) of wine about 6 weeks ago. You used a new plastic garbage can, covered with plastic wrap over the top, for the process. Now you get a cup of it out of the container only to find no alcohol--just really bad juice. What went wrong? The plastic of the container released chemicals that killed the yeasts. The yeasts were not under anaerobic conditions. Your yeasts mutated into non-alcohol producing organisms. You bought the wrong yeast species at the store.

The yeasts were not under anaerobic conditions.

What is made by fermenting milk with Streptococcus thermophilus and Lactobacillus bulgaricus? Cheese Yogurt Kefir Tofu Sour cream

Yogurt

which is not correct? during municipal water purification, microbes can be removed by: A. electrophoresis B. UV light C. ozone D. chlorination

a

activated sludge: A. it is used in cheese production B. contains dead bacteria C. contains anaerobic bacteria D. contains waste-degrading microorganisms

d

Sewage sludge, the solid that remains after aerobic decomposition, makes a useful fertilizer because it has been treated to remove microbes and will not be a source of pathogens. it contains significant energy in the form of methane. it is rich in nitrogen, phosphorus, and potassium. it is rich in carbon and nitrogen.

it is rich in nitrogen, phosphorus, and potassium.

Biotechnology includes all of the following except using bacterial insecticidal proteins as a means to combat mosquitoes as disease vectors. using bacterial antifreeze proteins to protect crops from lethal frosts. using genetically-modified E. coli as a tool to detect cancer. modifying antibiotics with different chemical functional groups to increase their potency.

modifying antibiotics with different chemical functional groups to increase their potency.