keerti

  Development of microbiology in 19 th (Golden era of microbiology -1857 to 1954) Discovery of microbial role in transformation of organic matter: Germ theory of fermentation : After the controversy over spontaneous generation, the role of microorganism in the transformation of organic matter was found out. The two types of chemical changes in the organic matter ; fermentation and putrefaction. Fermentation is defined as the process   that results in the formation of alcohol or organic acids. Putrefaction is a process of decomposition that results in the formation of ill smelling products, occasionally in meat as a consequence of proteins degradation. Germ theory states that the fermentation process is caused due to microorganism (involvement of microorganism in fermentation). Fermentation as biological process was recognized in 1837 by three scientists: Latour, Schwann, Kutzing.  They independently proposed that microscopic yeast cells were responsible for the

 Applications of genetically modified microorganisms: a. Starter cultures b. Genetically modified foods i. Food grade Bio-preservatives ii. Recombinant Dairy enzymes / a. Starter cultures Introduction and History Starter cultures  are an essential component of nearly all commercially produced  fermented foods . Simply defined, starter cultures consist of  microorganisms  that are inoculated directly into food materials in order to bring about desired and predictable changes in the finished product. These changes may include enhanced preservation, improved  nutritional value , modified  sensory qualities , and increased economic value. Although many fermented foods can be made without a starter culture, the addition of concentrated microorganisms, in the form of a starter culture, provides a basis for insuring that products are manufactured on a consistent schedule, with consistent product qualities. Fermented foods and beverages have long been manufactured without the use of commercial