Question

Curing of tea leaves is brought about by the activity of
(a) Viruses
(b) Fungi
(c) Bacteria
(d) Mycorrhiza

Answer 1

Hint: Curing is an oxidation dry fermentation process which is required to remove the bitterness and harshness of tea. The microorganism which is used for this process is antagonistic to a number of fungal pathogens in vitro and used to reduce Scleroital blight of tea caused by Sclerotium.

Complete answer:
Curing of tea leaves is brought about by the activity of Bacteria. The bacteria which is used in curing tea is Bacillus megaterium. Curing of tea leaves involves drying of leaves and losing green colour. It is an oxidation dry fermentation reaction in which water is driven off, the green colour is lost and the leaves assume a tougher texture and undergo chemical changes. Based on the degree and type of bacteria used for fermentation and duration, different types of tea are formed.

-In the curing stage, Flavoured teas are manufactured by spraying the tea with aromas and flavours or by storing them with their flavorings.
-Tea becomes sweet and mellow through fermentation by age or dampness.
-Amino acids and lipids break down completely, turning the leaves blackish-brown in a fully oxidized tea.
-Controlled-oxidation is typically carried out in a large room where the temperature is maintained at 25-30$^o$C and humidity stands steady at 60-70%.
So, the correct answer is ‘bacteria.’

Notes:
-Withering is the process of wilting of fresh green tea leaves in which moisture content in the leaf goes down by about 30%. Moisture content makes the leaf look limp and soft enough for rolling.
-Fixing or “kill-green” is the process which is carried out for green teas and yellow teas. It is an enzymatic browning of the wilted leaves that is controlled through the application of heat.