Flashcards in Water Bacteriology Deck (12):
Which is false?
A. Fecal streptococci are slightly more resistang to disinfection than coliform organisms
B. Fecal streptococci grow in water with moderate salt concentration
C. Fecal streptococci always multiply in polluted water
D. Fecal streptococci are secondary indicators of fecal pollution
Which is false?
A. Coliforms include E.coli, Citrobacter, Enterobacter and Klebsiella
B. Presence of E.coli = definite fecal contamination
C. Coliforms can ferment lactose in culture at 35-37 deg C
D. Coliforms are secondary indicators of fecal pollution
False about C.perfringens
B. Spore is resistant to disinfection
C. Presence of spores indicates contamination from a distant source
Colony count is useful in detecting early signs of contamination. True or false?
The presence of __ indicates that water quality is not good.
What method was used in the lab experiment for initial count of bacteria?
Heterotrophic Plate Count
Fermentation tubes were used in the experiment. What specific substance was in each tube?
Lauryl tryptose broth
Which Petri dish dilution was not part of the experiment?
If plates you see fr all dilutions have no colonies, report the count as __
Less than the reciprocal of the lowest dilution used
If the number of colonies per plate exceeds 300, what must one do?
Use a colony counter
Count colonies in 13 squares
Multiply sum by 5
In the fermentation tubes, which does not count as a positive result?
A. Presence of gas
B. Heavy growth
C. Breaking of glass
D. None of the above