Chapter 2: Microbial Biotechnology Scope & Techniques

Microbial Biotechnology Scope & Techniques examines the development of DNA vaccines, which utilize engineered plasmids to elicit immune responses without infectious agents, and explores the vast potential of microbial secondary metabolites. Key examples include the discovery of avermectins from Streptomyces for treating river blindness and lymphatic filariasis, zaragozic acids as cholesterol-lowering squalene synthase inhibitors, and the anticancer drug taxol derived from endophytic fungi. In the agricultural sector, the text details the creation of transgenic plants via Agrobacterium-mediated gene transfer to engineer traits such as herbicide tolerance, insect resistance using Bacillus thuringiensis endotoxins, and viral resistance through coat protein expression and RNA silencing. It also covers the use of microbial inoculants for nitrogen fixation and stress tolerance, exemplified by the introduction of trehalose biosynthesis genes into rice to withstand drought and salt. The chapter further explores food technology, describing the role of lactic acid bacteria in fermentation, the preservation properties of the lantibiotic nisin, and the genomic adaptations of Lactobacillus sakei to meat environments. It also discusses the use of monensin in cattle feed to improve efficiency and the production of single-cell protein from Fusarium venenatum as a meat substitute. Environmental applications are addressed through wastewater treatment strategies, the bioremediation of oil spills and chlorinated pollutants, and the immobilization of radionuclides like uranium by Geobacter species and polyphosphate-accumulating bacteria. Additionally, the text reviews biomining techniques for copper and gold extraction, microbial coal desulfurization, and the use of fungi to remove pitch in paper manufacturing. The chapter concludes by emphasizing the shift toward green chemistry, showcasing sustainable innovations like the production of biodegradable polylactic acid polymers from cornstarch and the eco-friendly enzymatic synthesis of 6-aminopenicillanic acid using penicillin acylase.