Krieg, Microbiology, 5th ed. Cox, Principles of biochemistry, 2nd ed. Hall, Principles of fermentation technology, 2nd ed.
Growth of the inoculum does not occur immediately, but takes a little while. This is the period of adaptation, called the lag phase. This phase, where the increase of the rate of growth is checked, is the deceleration phase.
After the deceleration phase, growth ceases and the culture enters a stationary phase or a steady state.
The biomass remains constant, except when certain accumulated chemicals in the culture lyse the cells chemolysis. Mutation of the organism in the culture can also be a source of contamination, called internal contamination.
The fermenters vary from laboratory experimental models of one or two litres capacity, to industrial models of several hundred litres capacity, which refers to the volume of the main fermenting vessel.
A bioreactor differs from a fermenter in that the former is used for the mass culture of plant or animal cells, instead of micro-organisms. The chemical compounds synthesised by these cultured cells, such as therapeutic agents, can be extracted easily from the cell biomass. The design engineering and operational parameters of both fermenters and bioreactors are identical.
With the involvement of micro-organisms as elicitors in some situations, the distinction between the two concepts is being gradually obliterated. This is batch processing or batch culture.
The best advantage of batch processing is the optimum levels of product recovery. The disadvantages are the wastage of unused nutrients, the peaked input of labour and the time lost between batches.
When the initial quantity of this component is exhausted, growth ceases and a steady state is reached, but growth is renewed by the addition of the limiting component. A certain amount of the whole culture medium aliquot can also be added periodically, at the time when steady state sets in.
The addition of nutrients will increase the volume of the medium in the fermentation vessel. It is so arranged that the increased volume will drain off as an overflow, which is collected and used for recovery of products. At each step of addition of the medium, the medium becomes dilute both in terms of the concentration of the biomass and the products.
New growth, stimulated by the added medium, will increase the biomass and the products, till another steady state sets in; and another aliquot of medium will reverse the process. This is continuous culture or processing. The rate at which aliquots are added is the dilution rate that is in effect the factor that dictates the rate of growth.
The events in a continuous culture are: Hence, a chemostat is a nutrient limited self-balancing culture system, which may be maintained in a steady state over a wide range of sub-maximum specific growth rates.
The continuous processing offers the most control over the growth of cells. Commercial adaptation of continuous processing is confined to biomass production, and to a limited extent to the production of potable and industrial alcohol.
The steady state of continuous processing is advantageous as the system is far easier to control. During batch processing, heat output, acid or alkali production, and oxygen consumption will range from very low rates at the start to very high rates during the late exponential phase.
The control of the environmental factors of the system becomes difficult. In the continuous processing, the rates of consumption of nutrients and those of the output chemicals are maintainable at optimal levels. Besides, the labour demand is also more uniform.
Continuous processing may suffer from contamination, both from within and outside. The fermenter design, along with strict operational control, should actually take care of this problem.
The production of growth associated products like ethanol is more efficient in continuous processing, particularly for industrial use. A commercial organism is highly mutated such that it will produce very high amounts of the desired product. But physiologically such strains are inefficient and give way in culture to inferior producers--a kind of contamination from within.
The fermenter is designed to accommodate the increasing volumes. The system is always at a quasi-steady state. Fed-batch achieved some appreciable degree of process and product control. A low but constantly replenished medium has the following advantages: Production of baker's yeast is mostly by fed-batch culture, where biomass is the desired product.
Diluting the culture with a batch of fresh medium prevents the production of ethanol, at the expense of biomass; the moment traces of ethanol were detected in the exhaust gas. The production of penicillin, a secondary metabolite, is also by fed-batch method.This report focuses on the microbial production of α-Amylase and its applications.
At a glance: Figures. between different fermentation hours and the study revealed a high yield of alpha amylase after 48 hours of by Bacillus cereus MTCC using solid-state fermentation”. Food Technology and Biotechnology, 44 (2), Fermentation technology is a very vibrant and fast growing area of biotechnology, absorbing an ever increasing processes and products.
With a longer history than any area of biological sciences, fermentation technology has a longer and brighter future, in the service of mankind, covering such important areas as food and medicine.
Fermentation technology is a very vibrant and fast growing area of biotechnology, absorbing an ever increasing processes and products. With a longer history than any area of biological sciences, fermentation technology has a longer and brighter future, in the service of mankind, covering such important areas as food and medicine.
Production of pharmaceutical compounds through microbial fermentation. 8-Jun Biotechnology. Most people’s experience of fermentation will be through its most famous and popular use – .
Fermentation Technology is a common scientific platform which includes a wide range of disciplines under its scope for the authors to contribute towards the pool of knowledge relevant to fermentation.
Fermentation Technology is one of the best Open Acces journals of Scholarly publishing. Meaning of Fermentation Technology: Fermentation is the process involving the biochemical activity of organisms, during their growth, development, reproduction, even senescence and death. Fermentation technology is the use of organisms to produce food, pharmaceuticals and alcoholic beverages on a large scale industrial basis.