How does the study of microbiology contribute to environmental science?

Microbiology is the study of microscopic organisms such as
algae, bacteria, moulds, protozoans, viruses, and yeasts. All these organisms are
collectively called microbes.  They include algae, bacteria, moulds, protozoans,
viruses, and yeasts.

Fields of microbiology includes study
of many diverse subjects such as relationships between microbes and man, animals, and
plants;  the role of microorganisms in human and animal diseases and seek ways to
prevent and cure these diseases;  plant diseases and the role of microorganisms in soil
fertility, and spoilage of farm products by microorganisms; and use of microorganisms to
produce such products as alcoholic beverages and antibiotics, citric acid. All these
subjects provide insights to the environmental scientist to understand the process by
which the nature and quality of our environment is shaped. Knowledge of these subjects
also helps us to develop ways and means to preserve and protect the environment. For
example, microbes play an important part in sewage treatment and pollution
control.