Use of mutant strains has been increased in industrial microbiology.

Explanation

Industrial microbiology is releated to the commerical use of microbes in which various economic, social and environmental processes and products are included.
ii. The industrial production of milk products, etc., required that strict hygiene and cleanliness be maintained by use of techniques like sterilization. This is mainly because essential bacteria can be attacked by viruses or ounumbered by other unwanted bacteria.
iii. Thus, using mutant strains of bacteria, that are resistant to viruses help avoid unnecessary steps/materials and reduce costs and processing time.
iv. Some mutant strains are also capable of growing on cheaper substrates, thus reducing th cost of production.
v. Mutant strains of certain microbes can also be used for improved production of methabolites such as antibioties.
vi. In alcohol industry, mutant strains can be used to improve quality and flavour of wine, beer, etc. Thus use of mutant strains has been increased in industrial microbiology.