Enhancing yeast growth with carboxylates under multiple nutrient limitations

by Yusof, T.Y., Lian, M.Q., Ong, E.B.B., Teh, A.-H.

Normal ammonium concentrations become toxic to yeast when essential nutrients such as potassium and lipid are limited but glucose is sufficient. Tengku Yasmin Yusof and Melissa Qianyue Lian, under the supervision of Teh Aik Hong, have found that besides reducing ammonium concentration, adding carboxylate salts such as gluconate, formate or alginate could also alleviate the ammonium toxicity under these conditions.  The yeast cells still achieved almost 90% of the optimum growth when the essential nutrients were reduced as much.  Interestingly, simultaneously reducing ammonium as well as adding gluconate stimulated yeast growth even further when the essential nutrients were reduced to only 2%. While carboxylates functioned to buffer the pH drop in the media, it is unclear why the yeast cells seemed more susceptible to low pH under the nutrient-limited conditions as the cells were expected to generate enough ATP from glucose to pump out H+.  Nevertheless, these results show that the much cheaper carboxylate salts may prove to be a cost-efficient replacement for large proportions of essential nutrients in industrial yeast cultivation.



Link :  https://doi.org/10.1007/s13205-021-02955-w


CCB Ref.:  2021_RH_1_tah
Date :  29/09/2021