The first part refers to environmental biotechnology and includes two chapters regarding total recycling of agricultural and food wastes through the biodegradation and bioconversion processes that are performed by selected microbial species in controlled cultivation systems. The next chapter is dedicated to the biotechnology of biopolymer producing by saving energy comparing with the conventional chemical processes. The last two chapters of this first part are dedicated to food quality safety and preservation through the biosynthesized anti-bacterial compounds, and by keeping the phenols as functional molecules in foods. .