The broth in this contains Phenol Red, a pH indicator. A pH below 6.4 will turn the Phenol Red to Yellow. During fermentation, acids are produced that lower pH. You CAN have one result without the other, or both as the same result (Gas and Fermentation).
A compound modifier is a sequence of modifiers of a noun that function as a single unit. It consists of two or more words (adjectives, gerunds, or nouns) of which the left-hand component modifies the right-hand one, as in the dark-green dress: dark modifies the green that modifies dress.ompound verbs composed of a noun and verb are comparatively rare, and the noun is generally not the direct object of the verb. In English, compounds such as *bread-bake or *car-drive do not exist. Yet, we find literal action words, such as breastfeed, and washing instructions on clothing as for example hand wash.
Definition. A noun phrase is word group with a noun or pronoun as its head. The simplest noun phrase consists of a single noun, as in the sentence  Bells were ringing.. The head of a noun phrase can be accompanied by modifiers, determiners (such as the, a, her), and/or complements, as in . An example of a noun-noun phrase is 'resource availability.' This phrase means 'availability of resources.' To shorten phrases like this, it is very common in scientific English for the second part (of resources) to be moved in front of the headword (availability).