This chapter deals with the current status and future prospects of the fermentation technology (FT). It discusses the different types of fermentation processes (solid-state and submerged fermentation) as well as the different types of enzyme and antibiotics production by FT. In addition, various industrial applications (enzyme production, organic acid production, biofuel production, etc.) of solid-state fermentation are also discussed. Also discussed are the future prospects of FT with regard to enhanced value product development.
1.1 Introduction
Fermentation technology is defined as field that involves the use of microbial enzymes for production of compounds that have application within the energy production, material, pharmaceutical industries, chemical, and food industries [1].
It appears naturally in various foods. The human beings are using it from the ancient times for preservation and organoleptic properties of food. It is a well-established technology of the ancient time used for food preservation, production of bread, beer, vinegar, yogurt, cheese, and wine. From time to time, it has got refined and diversified [2].
It is the biological process in which various microorganisms such as yeast, bacteria, and fungi are involved in the conversion of complex substrate into simple compounds which are useful to humans (enzymes production, metabolites, biomass, recombinant technology, and biotransformation product) on industrial scale. Organic acid and alcohol are the main products of fermentation. In this process, there is liberation of secondary metabolites like antibiotics, enzymes, and growth factors [3, 4].
They acquire biological activity so they are also known as bioactive compounds. These compounds contain plant and food constituents in small amount which are very nutritional. Various bioactive compounds consist of secondary metabolites, for example phenolic compounds, growth factors, food pigments, antibiotics, mycotoxins, and alkaloids [5, 6]. The constituent of phenolic compounds are flavonoids, tannins, and phenolic acids. Flavanones, flavonols, flavones, anthocyanidins, and isoflavones are some major classes of flavonoids. Flavonoid comprises largest collection of plant phenolics where most of them are naturally occurring compounds [7].
According to their diverse perspectives, food and beverage are used in modern industrial fermentation processes. On the bases on different parameters such as environmental parameters and organisms required for fermentation, these techniques have become more advanced.
Generally, bioreactor is required in the middle of this process which can be arranged on the basis of their feeding of the batch, continuous and fed-batch fermentation, immobilization process. In the presence of the available amount of oxygen, mixing of substrate take place in single and mixed culture in submerged fermentation (SmF) [8].
1.2 Types of Fermentation Processes
1.2.1 Solid-State Fermentation
Solid-state (or substrate) fermentation (SSF) are define as fermentation that place in solid supporting, non-specific, natural state, and low moisture content. In this process, substrates such as nutrient rich waste can be reused. Bran, bagasses, and paper pulp are the solid substrates used in SSF. Since the process is slow the fermentation of substrate takes long time. So, the discharge of the nutrients is in controlled manner. It requires less moisture content so it is the best fermentation technology used for fungi and microorganism. However, this process is not applicable for bacteria because this fermentation cannot be used for organism that requires high water condition [9].
1.2.2 Submerged Fermentation
In SmF, microorganism required a controlled atmosphere for proficient manufacture of good quality end products; attain optimum productivity and high yield.
Batch, fed-batch, or continuous modes are used in industrial bioreactors for the production of different type of microorganism in broad range [8].
For the manufacture of alcoholic beverages (whisky, beer, brandy, rum, and wine), preservatives or acidifiers (lactic acids, citric, and vinegar) are used in food industry and for flavor enhancers (monosodium glutamate) or sweeteners (aspartate) amino acid are used in submerged batch cultivation.
In this part, there are different ways of submerged cultivation using microorganisms in bioreactors. Here we have discussed briefly about typical features and advantages and faults of each fermentation methods are displayed. Lastly, the production of microorganism in liquid medium in various type of food industrial product has been determined as the most important application for continuous, batch, and fed-batch cultivation.
1.2.2.1 Batch Cultivation
Batch culture is a closed system which works under aseptic condition. In these cultivations, inoculums, nutrients, and ...
