Genetic and biochemical analysis of the effects weak organic acid stress on the SUC2 gene expression and invertase activity in Saccharomyces cerevisiae


Thesis Type: Postgraduate

Institution Of The Thesis: Bursa Uludağ University, Fen Bilimleri Enstitüsü, Moleküler Biyoloji ve Genetik, Turkey

Approval Date: 2016

Thesis Language: Turkish

Student: AYLİN KAHRAMAN

Supervisor: Sezai Türkel

Abstract:

Invertase enzyme, which is encoded by SUC2 gene, is required for the growth of Saccharomyces cerevisiae in molases. Invertase is a periplasmic enzyme and its expression is regulated by glucose repression at transcription level. Weak organic acids, such as acetic acid, citric acid, succinic acid, sorbic acid, and benzoic acid, can be found in the growth medium as natural components. These organic acid is also used as food additives. Presence of these acids in the growth medium triggers metabolic signal known as acid stress. It is known that the transcriptional regulators Msn2p, Haa1p, War1p, Hot1p involves in the acid stress response pathway in S. cerevisiae. In this research, the effects of organic acids on the SUC2 gene expression and invertase activity were investigated by using wild type and deletion mutants that lacks one of the transcriptional regulators Msn2p, Haa1p, War1p, Hot1p and also protein kinases Hog1p, Snf1p involves in the stress response.