The genetic material of bacteria and plasmids is dsDNA but of bacteriophages it may be dsRNA, dsDNA, ssRNA, or ssDNA. The two major and essential functions of genetic material are replication and expression in all organisms. Microbial genetics means genetics of microbes (bacteria, Archaea, viruses, including bacterial viruses i.e., bacteriophages and unicellular or mycelial eukaryotes including
... [Show full abstract] yeasts, other fungi,
algae and protozoa). Microbial genetics has applications in medicine, veterinary, agriculture, food and pharmaceutical industries. Because of simplicity in physiology microbes have been exploited for understanding interaction of biochemical, physiological and genetic components of the life. It has successfully furnished details of genetic code and the regulation of gene function. Besides, microbes being both useful and pathogenic, genetic studies have helped in understanding pathogenesis of infectious as well as genetic and non-infectious diseases, and variability in pathogens. The first chapter on microbial
genetics started by George W. Beadle (1903–1989) and Edward L. Tatum (1909–1975) while investigating genetics of tryptophan metabolism and nicotinic acid synthesis in Neurospora, a fungus postulating the "one gene one enzyme" hypothesis. However, studies on bacterial genetics started in 1947(Joshua Lederberg) with demonstration of exchange of genetic factors in Escherichia coli through conjugation, mediated through plasmids, “fertility factors”. Later on process of transformation, transduction and chromosomal gene mobilization lead to genome (chromosome) mapping in bacteria. These techniques combined with restriction enzyme analysis lead to sequencing, cloning and expression of several genes (prokaryotic and eukaryotic) in microbes. There are nine chapters in book on different aspects of microbial genetics including bacteriophages and transduction, plasmids and conjugations, mutations and mutagenesis, transformation genetics and bioinformatics.
