 In this module, we will talk about the effect of heat on the medium content. So, the fermentation medium is not the any inert object that contains so many component. So, when we applied the heat for sterilization purpose that effect on the loss of different nutrients, even the denaturation of different compounds. So, the effect of heat or we can say the sterilization process resulting in the loss of mutative quality of the medium. So, the choice of regime is dictated by the requirement to achieve the desired reduction in the microbial content with the least effect on the medium, which can say that least determinant effect on the medium. So, in the next slide, we will see that how the heat have the effect on the medium content and then how that can lead to the decrease in our desired product. So, when we say that in that equation in that slide, so we can say that here you can see that here is the percentage of maximum yield of our fermentation product and this is the time of sterilization. So, as well as the time of the sterilization at constant heat when we increase that then there is the decrease in the percentage yield of the product. So, that is why you can see as we have seen here that the initial rise in the yield is due to some component of the medium being made more available to the process microorganism by the cooking effect of a brief sterilization period because that require in a beef cooking effect. But when we prolong this treatment then there is a drastically negative effect on the production yield. This is just due to the cooking effect, but this is just to prolong the heat treatment. So, this graph actually show that how the sterilization time effect on the fermentation product. So, two type of reaction which contribute to the loss of the nutrient quality during sterilization. The first case there is the interaction between nutrient component of the medium. So, one component react with another at a high temperature. So, a common occurrence during the sterilization is a malar type browning reaction which result in the discoloration of the medium as well as the loss of nutrient quality. So, these reaction are normally caused by the reaction of carbonyl groups usually happen from the reducing sugar with the amino group of the amino acids in the protein. So, because the medium contain different carbon compound nitrogen compound etcetera. So, there is many chances of such reactions. So, as an example the effect of sterilization time on the availability of the glucose in a constant liquid medium we can say in next slide in a table that how that effect. So, the problem of this type is normally resolved by sterilization of some component separately as in case of the sugar. So, this problem can be resolved just having the sterilization of glucose like material separately from the other medium. So, in this table you can see that the effect of sterilization time on glucose concentration and the product accretion rate in any antibiotic fermentation. So, if the amount of glucose remaining after the sterilization you can see that if the we sterilize just by the steam sterilize 121 degree Celsius simple and autoclave process. So, treatment time 60 minute 40 minute 30 minute and the residual glucose you can see in when there is a 60 minute per long treatment then there is a less and then you can say that the amount of that. So, if the treatment time is 30 then the remaining glucose amount is 64 percent and then we have a 100 percent relative product. So, that is why we can say here that how the treatment time have the relationship with the degradation of the nutrient. So, the degradation of heat liable component certain amount of the vitamins amino acids protein that basically degraded that is why we can say that that is the loss of a nutrient quality that ultimately effect on our fermentation product. So, in such case we can say that we have to be use in a severe cases a filtration process of fermentation of sterilization.