 In this module we will talk about the general requirement of a fermenter. So what are the basic requirement, we can say that if such conditions or such provisions are available then we can say that will be a good fermenter. So there are different 13 different requirement if any vessel of we can say that that will be a good fermenters. What are those 13 basic requirement? The first requirement which is very critical that is the fermentation vessel that should be capable of being operated aseptically for a number of days and should be reliable in long term operation and meet the requirement of a containment regulation that is meant. Because when there is a fermentation process sterilization is required because sterilization is very critical because there is only the opportunity to grow our choice of organism of choice. So if there is no sterilization then there is a contamination. So in the start of the fermentation we need a such vessel which can be capable of operated aseptically not only in the start but during the fermentation process that has to be continued for a number of days we have to that vessel should be in a such a way that can be operated aseptically. That is only that that vessel not allow any other organism from the outside to come inside. Side by side as contain that vessel should meet the requirement of the containment regulation what is meant by that. So sometimes our fermentation process has to use such organisms which are pathogens. So the release from the vessel fermentation vessel is also very critical. So as well as there is no contamination from the outside by the same way there should be no release of the organism from the fermenter vessels. So we can maintain the regulation which we called as containment regulations. And later module we will talk in detail that how we will fix our containment levels which are four in number. So the second is that fermentation require aeration and agitation. So the fermenter requirement is basically that that can provide the adequate aeration and agitation because that is the basic need for the metabolic process of any organisms. So if there is aeration and agitation that is very linked with the shear effect. We sometimes when you agitate the fermentation vessel that can disrupt the cells. So we have to be very critical while managing the aeration and agitation system inside the fermenter. So then is a very critical that power conduction should be as low as possible. So the motor at the agitator should be fixed according to the volume and the capacity of the fermenter. And then there should be the system of temperature control and then the pH control system and then sampling facilities because if we want to monitor the fermentation process we have to take out the sample time by time just to monitor that our process is going on. So we have to calculate the kinetic parameters then we need to have the samples during the fermentation process. So as concern the seven requirement that the evaporation loss from the fermentation vessel should be very less. That is why when we are talking about the accessories of the fermentation then we talk about the chilled water. So that should be reduce the evaporation loss. And then the eighth requirement is the vessel should be designed to require the minimal use of labour in operation, harvesting, cleaning and maintenance. So the fermenter should be designed in such a way that the labour requirement for operation, harvesting, cleaning should be very easy. Sometimes if we have some equipment then you would have very sophisticated and very high technical labour then that can increase the cost of the production. So this requirement is directly associated with the cost of the product. So then the ninth requirement is the ideal the vessel should be suitable for the range of process but this may be restricted because of containment regulations. Keep in mind the containment regulations the fermenter vessel should be designed in such a way that can be utilized for a number of process. So that is why because if you utilize the fermenter for citric acid production that can also be utilized for enzyme production that can be utilized for vaccine production etc. So the fermenter should have such provision that can be utilized for different range of the processes. As concerned the tenth requirement so that is very critical because the vessel should be concentrated to ensure the smooth internal surface because organism has to grow because when there is a minor pores and there is not a smooth surface then there is a chance of contamination and we cannot clean the internal surface of the fermenter. So we should avoid such fermenter which has the flint joints. So the eleventh requirement is the vessel should be similar geometry to both smaller and larger vessel in pilot scale or a plant to facilitate the scale up because fermenter had to design and then we need optimization of the fermentation process when we scale up the process. So the next requirement that is the twelfth one that the cheapest material should be used while fabricating the fermentation vessel because the material is very critical. Sometimes there is a glass vessels, sometimes there is a stainless steel vessels. So that is directly linked with the fermentation vessel. Glass vessel is preferred over others because that have a very smooth interval surfaces but there is a limitation because we can use the glass vessel up to a certain extent of the volume because that can only be used in ex-situ sterilization but in case of in-situ sterilization then that vessel cannot be utilized. So as required of the fermentation process because sometimes when we have acid fermentation then the pH has to reduce, we have to maintain in a very acidic condition then the material should be non-corressive to the acids. So that is why the cheapest material but that enable the satisfactory result to be achieved should be used. And last in the thirteenth requirement that is very critical. So the vessel should be designed which can behave adequate service provisions for the plant. Means sometimes when there the process is going on sometimes there is a maintenance facilities is required. So the fermenter vessels or a fermenter should be designed in such a way that there is a provision of the service provisions. So that can be maintained over the long period of time.