What Are Bacteria?

Introduction

• Bacteria are unicellular micro-organisms. These are Prokaryotic in cellular organisation and placed under the kingdom Monera in a single Class Schizomycetes.
• Bacteria were not known until the invention of the microscope.
• Bacteria were discovered by Anton van Leeuwenhoek in Delft, Holland in 1676.
• Leeuwenhoek with the help high power lenses observed his own teeth scrapping and found that it contained millions of living creatures or organisms and he named them Animalcules.
• Ehrenberg first called these creatures as Bacteria.
• Later researches were carried out by Louis Pasteur and Robert Koch which highlighted the importance of bacteria.
• But at present a lot of information is available regarding bacteria and viruses.

Characters of Bacteria

• Bacteria are found in soil, water, air and also inside the body of living organisms.
• These can withstand extreme drought, cold and heat.
• Some bacteria live as parasites on other living organisms and plants.
• Some plants live in symbiotic association. For example., Rhizobium forms root nodules of legumes and fixes atmospheric nitrogen, Escherichia coli commonly called E.coli lives in the intestine of man.
• Bacteria are found in different shapes such as rod shape, spherical shape, comma shape, and spiral shape.
• Bacteria that change their shape according to the environment and nutrients available are called pleomorphic bacteria. For example., Acetobacter.

Microbiology

• Microbiology is a branch of biology that deals with the study of invisible organisms or micro-organisms. These organisms can be observed in the microscope only.
• Organisms such as algae, fungi, protozoa, bacteria, viruses fit into this criteria and hence are referred as micro-organisms. However some algae and fungi are macroscopic and visible with naked, yet they are studied my microbiologists.
• Microbiology employs techniques such as sterilization and the use of culture media that are necessary for successful isolation and growth of micro-organisms.
• Micro-organisms are present everywhere in our environment.
• There are some micro-organisms that can tolerate extreme acidic, alkaline conditions, high and low temperatures and salt concentrations. Such organisms are called acidophilic, alkalophilic, thermophilic and halophilic organisms respectively.

Importance of Microbiology

• Micro-organisms recycle elements such as oxygen, sulphur, carbon, nitrogen, phosphorus.
• Micro-organisms help in creating a disease free world by producing antibiotics and vaccines.
• The antibiotic Penicillin was discovered by Alexander Fleming from a fungus called Penicillium notatum.
•  Walksman obtained Streptomycin from Streptomyces griseus.
• Industrial products such as enzymes, amino acids, vitamins, organic acids and alcohols are commercially produced by micro-organisms.
• Micro-organisms play an important role in production of dairy products.
• Microbes like bacteria and fungi are used in sewage disposal.
• Micro-organisms are also used in extracting valuable metals such as uranium from the rocks. This reduces more than 20% of the cost.
• One of the biggest achievements of microbiology is the ability to alter genetic material of organisms. This is commonly referred to as Genetic Engineering.
• Micro-organisms are used as bio-control agents.
• Methane gas is also produced by the activity of  micro-organisms, which can be used as a fuel.

With the advent of RDNA technology and genetic engineering microbiology has become a weapon to unravel the challenges in the field of Biotechnology.