Question

which of these is not a commercial use of bacteria?

a reconnecting dna technology

b treatment of sewage

c production of dairy products

d symbiotic relationship

Answer 1

Correct option is (d). Symbiotic relationship is not a commercial use of bacteria. Symbiotic bacteria is the one which forms association with either plant , animal or fungus in which bacteria as well as the host , both are benefited.
e.g. Rhizobium bacteria forms association with the root nodules of higher plants , plant provide shelter to the bacteria and bacteria helps in nitrogen fixation.

Recombinant DNA is a technology that made possible to insert a human gene into the genetic material of a common bacterium. This “recombinant” micro-organism could now produce the protein encoded by the human gene.Bacteria are used commercially for Decomposing sewage waste.Bacteria is also used commercially in food products, such as beverages, dairy products, amino acids, proteins, and nutritional supplements.

So option(d) is not commercial use of bacteria.