3. Aspects of the Molecular Biology of Microorganisms of Relevance to the Aquatic Environment

Our increased knowledge of living things at the molecular level has greatly ­influenced the modern approach in biology. Thus, for example, the taxonomy of microorganisms is no longer based mostly on their morphology, but also on the sequence of bases in the genes of the 16S RNA of the small subunit of the ribosomes. This chapter looks at selected basic molecular biology topics of relevance to the environment. The processes of transcription and translation in protein synthesis are discussed. The principles behind some molecular procedures such as the polymerase chain reaction and micro-arrays are discussed. Many microorganisms in environments such as water and soil are not culturable and are studied only with molecular biology. Metagenomics, or the culture-independent genomic analysis of an assemblage of microorganisms, in environments such as marine or freshwater has potential to answer fundamental questions in microbial ecology.