Question

The Preparation and flavouring of leaves of tea and tobacco is due to the activities of:
A. Streptococcus lactis
B. Bacillus megaterium
C. Acetobacter
D. Bacillus radicicola

Answer 1

Tea leaves are dried and lose their green colour during the curing process. It's an oxidation dry fermentation reaction in which water is removed, the leaves lose their green colour, and they become stronger and undergo chemical changes. The flavour of tea and tobacco leaves is caused by virus action. Tobacco curing refers to the method of preparing processed leaves for marketing. Curing, in more technical words, is the method of drying, decomposition of chlorophyll until the green colour of the harvested leaves disappears, hydrolysis of starch into sugars, and subsequent respiration or fermentation of sugars.

Complete explanation:
Option A: Streptococcus lactis and Streptococcus cremoris are two lactic species that are used in commercial starters for the manufacture of butter, cultured buttermilk, and some cheeses.
So, option A is incorrect.
Option B: Bacillus megaterium is responsible for the preparation and flavouring of tea and tobacco leaves. B. megaterium is used to ferment tea and tobacco leaves. Curing is the term for the procedure. Micrococcus candidans , in addition to B. megaterium , is used as a flavouring and curing agent in tobacco leaves.
So, option B is correct.
Option C: Acetobacter is a nitrogen-fixing, aerobic bacteria that produces acid as a by-product of its metabolic processes. Acetobacter bacteria, such as Acetobacter diazotrophicus, are acid-producing, nitrogen-fixing bacteria that can be isolated from coffee plants or sugarcane.
So, option C is incorrect.
Option D: The bacteria colonise plant cells inside root nodules, where they use the enzyme nitrogenase to convert atmospheric nitrogen to ammonia and then supply organic nitrogenous compounds to the plant, such as glutamine or ureides. The plant, in turn, provides organic compounds generated by photosynthesis to the bacteria.
So, option D is incorrect.

Option B is correct.

Note:
Bacillus megaterium is in charge of tea and tobacco leaf preparation and flavouring. Tea and tobacco leaves are fermented with B. megaterium. For decades, B. megaterium has been an essential industrial organism. It makes penicillin amidase, which is used to make synthetic penicillin, as well as other enzymes such as amylases, which are used in baking, and glucose dehydrogenase, which is used in glucose blood tests. It also makes enzymes for corticosteroid modification and other amino acid dehydrogenases. It is also used to make pyruvate, vitamin ${B_{12}}$, and molecules with antifungal and antiviral properties.