Isolated thunderstorms are when there are either thunderstorms present at the current time or there is a change for them to form, but they are scattered. These usually occur in the afternoon and the evening when the sun is out at its peak and heats up the atmoshpere.
For example, bacteria from the genus Salmonella are mostly facultative anaerobes, oxidase-negative, catalase-positive and gramnegative rods. Most strains are motile and ferment glucose with production of both acid and gas.
Purpose: to assay for the presence of the enzyme catalase. This test is used to help identify Gram positive cocci, endospore forming Gram positive bacilli, to differentiate among the Mycobacterium, and several others.