ABSTRACT
100In this chapter, we discuss the mechanism of propagation and survival of microorganisms, primarily bacteria, viruses, and yeasts. Bacteria are used regularly for molecular biological experiments, including cloning heterologous genes and growing plasmid DNA. We will also discuss the main mechanisms for exchanging DNA between individual bacterial cells. In addition to their chromosome, bacteria also may carry plasmids, the extrachromosomal circular DNA, which are frequently used. We will also discuss the CRISPR/Cas system, a prokaryotic acquired immunity that confers resistance to foreign genetic elements such as those in phages and plasmids, and is being exploited successfully for genome editing practices. Yeast is an ideal eukaryotic model because many processes occur in yeast cell can be readily studied leading to significant advances in understanding eukaryotic cellular processes.
Study of the molecular basis of the various physiological processes that occur in microorganisms has been a topic of extensive research. Bacteria were instrumental in the development of molecular biology as they are easy to culture and are small. Viruses can infect humans, plants and animals. Bacteriophages or “phage,” have played important role in the development of the science of molecular biology and became “model organisms” for studying the biochemical processes of life.
