In the testing of water for coliforms,the presumptive test involves detection of

Question

Quizplus · Accepted Answer

The presumptive test for coliforms involves the detection of gas production in a lactose broth medium by using an inverted Durham tube. If gas is produced, it indicates the presence of coliforms, which are lactose-fermenting, gram-negative, non-spore-forming rods. Sheen production on a selective medium (B) is used to detect the presence of fecal coliforms, which are a subgroup of coliforms. Choice D is incorrect because a gram-negative nonspore-forming rod (C) is a characteristic of coliforms but not specific for their detection.

In the Testing of Water for Coliforms,the Presumptive Test Involves