MCB2010L lab 28 nitrate reduction questions

What does a red color after adding Regents a and B indicate?

Positive test nitrate was reduced to nitrite

What does it mean if there is no color change after a a and b but red appears after adding zinc

Negative nitrate

was not reduced by the organism

What does no color change after adding a and B and after adding zinc mean

it is positive ammonia

What is the purpose of zinc in the nitrate reduction test?

Zinc, chemically reduces any leftover nitrate to nitrite helping confirm a Negative result

Which organism is nitrate reduction negative no reduction at all

Alcaligenes faecalis (01)

Which organism produces nitrate to nitrite

E.coli (11)

What my gas in the Durham tube indicate

The organism reduced nitrate all the way to the nitrogen gas (deification)