Abstract: This investigation aimed to study the synthesis pathway of 2-phenethyl alcohol, one of the characteristic aroma components of soy sauce for the purpose of enhancing the production of 2-phenethyl alcohol during soy sauce fermentation. We isolated a 2-phenethyl alcohol-producing yeast strain, designated 922-1, from fermented mash for soy sauce. This strain was identified as Candida oceani by morphologic observation, physiological and biochemical test, ITS rDNA sequencing and phylogenetic tree analysis. C. oceani 922-1 was able to grow in a high salt medium (18% NaCl). Sole nitrogen source experiments showed that C. oceani 922-1 synthesized 2-phenethyl alcohol using phenylalanine as substrate by the Ehrlich pathway. C. oceani 922-1 was capable of producing a high content of 2-phenethyl alcohol (44.70 mg/L) in the fermented mash, which was increased by 17.3 times with 1% phenylalanine addition compared with the control group. Meanwhile, both the mellow aroma and strong flavor were improved. This study highlights the promising potential of C. oceani 922-1 for flavor improvement of high-salt fermented seasonings.

Key words: soy sauce, 2-phenethyl alcohol, Candida oceani, identification, application