Production of Korean Domestic Wheat (keumkangmil) Vinegar with Acetobacter pasteurianus A8

Acetobacter pasteurianus A8를 이용한 우리밀(금강밀) 식초 제조

We tested the possibility of utilizing Korea domestic wheat (winter wheat variety "keumkangmil") as a source of vinegar production. After saccharification of the whole-wheat flour with wheat malt, the saccharized liquid undergoes alcoholic fermentation, followed by acetic fermentation. Acetic acid bacterium A8, which showed the highest acetic acid production (4.56%) with domestic wheat as substrate, was selected from conventional vinegars. The strain A8 was identified as Acetobacter pasteurianus A8 through phylogenetic study using 16S rDNA sequencing analysis. The optimal condition for the malt enzyme was found to be $15^{\circ}C$ for germination periods of 6 days; its amylase activity was 608.4 U. Acetic acid production from domestic wheat substrate supplemented with 5% ethyl alcohol reached 5.8% after 24 days of static fermentation at $30^{\circ}C$ with a seeding rate of 5%.

우리밀(금강밀)을 기질로 사용한 식초 생산을 위하여 초산 생성능이 우수한 초산균을 재래 식초로부터 분리하여 A. pasteurianus A8으로 동정하였다. 우리밀 엿기름의 제조를 위해 발아 조건을 살펴본 결과, $15^{\circ}C$에서 6일간 발아 시킨 밀의 amylase 활성이 608.4 unit으로 가장 높았다. A. pasteurianus A8 균주를 종균으로 사용하여 우리밀 알코올 발효액의 초산 발효 조건을 살펴본 결과, 발효온도 $30^{\circ}C$, 초기 알코올 농도 5.0%, 및 종균 접종량 5.0%에서 24일간 정치 발효하여 5.8%의 초산을 생산할 수 있었다.