STUDYING THE EFFECT OF MEDIA COMPOSITION AND PH ON GROWTH OF PICHIA PASTORIS AND PRODUCTION OF RECOMBINANT THAUMATIN II

As the general population becomes more aware of the dangers of sucrose and artificial sweeteners, natural alternatives are being investigated. One such alternative is thaumatin, a popular sweetener on the market today. Biochemical synthesis methods are now being investigated because the natural production of these proteins is typically expensive. Therefore, the use of recombinant DNA technologies to achieve such desirable products through appropriate hosts is being researched. Pichia pastoris, a methylotrophic yeast, is currently one of the most studied hosts for recombinant protein production. Industrially, it is important to develop a process that ensures high protein yields at a low cost. This emphasises the need for process optimisation, which can help in understanding the factors that contribute to the maximisation of protein production. Media optimization can act as a first step in screening for the identification of the appropriate medium composition required for thaumatin production. The study showed that FM22 and BMGY media resulted in high yields of recombinant thaumatin II compared to BSM, MGY, MBSM, and d'Anjou media. Moreover, the optimum pH for P. pastoris fermentation to attain maximum recombinant thaumatin was found to be pH 6.0 although cell growth rates were similar for pH 5.0 and 6.0 in the shake flask study.