Effects of physicochemical parameters on volatile sulphur compound formation from L-methionine catabolism by non-growing cells of Kluyveromyces lactis

Yuyun Lu; Margarete Nawrath; Jingcan Sun; Shao-Quan Liu

doi:10.1186/s13568-018-0639-7

Effects of physicochemical parameters on volatile sulphur compound formation from L-methionine catabolism by non-growing cells of Kluyveromyces lactis

AMB Express. 2018 Jul 3;8(1):109. doi: 10.1186/s13568-018-0639-7.

Authors

Yuyun Lu¹, Margarete Nawrath¹, Jingcan Sun¹, Shao-Quan Liu^{2

3}

Affiliations

¹ Food Science and Technology Program, Department of Chemistry, National University of Singapore, Science Drive 3, Singapore, 117543, Singapore.
² Food Science and Technology Program, Department of Chemistry, National University of Singapore, Science Drive 3, Singapore, 117543, Singapore. chmlsq@nus.edu.sg.
³ National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Suzhou, Jiangsu, 215123, China. chmlsq@nus.edu.sg.

Abstract

The present study investigated for the first time the effects of various physicochemical parameters on the production of volatile sulphur compounds (VSCs) by non-growing cells of Kluyveromyces lactis supplemented with L-methionine. The results showed that the production of VSCs positively correlated with the cell biomass, but it seemed that no clear relationship with L-methionine concentration existed. Temperature and pH significantly affected the formation of VSCs with more production at 30 °C and pH 5, respectively. Nitrogen supplementation (in the form of diammonium phosphate, DAP) repressed the production of VSCs. It is interesting to note that DAP and yeast extract supplementation induced the production of methional, but not Mn²⁺ supplementation. The presence of Mn²⁺ improved the production of methionol and dimethyl disulphide, but inhibited the formation of S-methyl thioacetate. The study indicated that optimization of physicochemical conditions and media composition would be crucial for producing L-methionine-derived VSC bioflavor.

Keywords: Bio-flavors; Kluyveromyces lactis; L-Methionine; Volatile sulphur compounds.