A bacterial culture is being tested for its ability to reduce nitrate. After incubation and growth of the bacteria in nitrate broth, there is no accumulation of gas in the Durham tube. The test for the presence of nitrite is colorless. When zinc powder is added, a bright red color develops. Interpret these results.

All this combination of reactions is summarized in that the bacteria reduced nitrate, that is, they added protons to said compound, giving nitrite as a product.

By promoting the appearance of nitrite and that it increases in its concentrations when the zinc dust is thrown away, it becomes reddish since there was a change in pH, that is, the medium was acidified.

Explanation:

Some bacteria take nitrate as a source and end up generating an oxide reduction reaction that gives nitrite as a product, if this reaction advances in a chain, that is, the nitrite is reduced after the nitrate, the product in the future would be ammonia

the correct answer is b

correct answer: understand the different control methods available

integrated pest management is an strategy that is based on the ecosystem and try to prevent the pest and the damage caused by them by applying combination of technique like habitat manipulation, biological control and use of resistant varieties.

the main aim of the integrated pest management is not to completely eliminate the pest but to strengthen the ecosystem so that conditions are favorable for plants and unfavorable for pests.