Microbes are the third major group of biospheric organisms after plants and animals. They are responsible for many natural circulations, including the rotation of elements. They return organic carbon for plants' use and dissolve minerals into organic cycles. Microbes contribute to the global gas and water balances. In animal digestion, they partake in the degradation and assimilation of nutrients. Typically, they act as communities where some strains are the most active at a given time point in the prevailing conditions. But they also live in a continuous state of succession, which precludes the maintenance of changeable balances. Whether functioning in soil, in our alimentary tract, or elsewhere, the micro-organisms decisively contribute to the restoration of various balances. As the microbiological scale differs significantly from our comprehension, we must nurture our understanding of the microbiome wherever it occurs. For example, one spoonful of yoghurt contains approximately as many bacterial cells as there are humans residing on Earth. Therefore, flexibility and interaction are the most advisable modes of operation in microbial biochemistry and biotechnological applications. As microbes tend to form communities, this modus operandi is worth instigating in our process industries and production technologies. The use of microbial mixed cultures most appropriately corresponds to the natural systems [1]. As biocatalysts in human endeavours of biorefining and bioengineering, they have become the most utilizable and producible kind of microbial components. Cooperation with microbes is a prerequisite for the continuous development of sustainable industries and food and health production. The microbial communities can be used to prevent and clean up pollution. In the process design, the microbiological dynamic balances make the highest productivity, repeatability, controllability, and withstanding of entropy. Although their effects have been familiar to our societies, e.g. in the fermentation of foods, their total capacity remains to be put into service. Hopefully, this book could help turn the next page in the development.