Characteristics of the yeast strains which isolated for improvement of Choungju quality

청주의 주질 개선을 위하여 분리된 효모의 균학적 성질

  • Shin, Cheol-Seung (Department of Food Science and Technology, College of Agriculture, Chungnam National University) ;
  • Park, Yoon-Joong (Department of Food Science and Technology, College of Agriculture, Chungnam National University) ;
  • Lee, Suk-Kun (Department of Food Science and Technology, College of Agriculture, Chungnam National University)
  • 신철승 (충남대학교 농과대학 식품공학과) ;
  • 박윤중 (충남대학교 농과대학 식품공학과) ;
  • 이석건 (충남대학교 농과대학 식품공학과)
  • Published : 1996.02.29

Abstract

The yeast strains isolated for Choungju brewing in the previous report were examined for their microbiological characteristics, together with some comparative tests with Japanese sake yeasts. The isolates KP-16, 21 and 54 were identified as the strains belong to Saccharomyces cerevisae according to the morphological and physiological properties described in Lodder's 'The Yeasts - A texanomic study'. The isolates were grouped into the pink-colored strains by 2,3,5-tripheny tetrazolium chloride over-lay method. The strains KP-16 and 21 were found to be distinguished from the strain KP-54 in aspects of fermentation of sugars, assimilation of carbon sources, and pellicle formation on malt extract broth. ${\alpha}-methyl-D-glucoside$ was not assimilated or fermented by the isolated yeast strains and this is one of the different characters from the Japanese sake yeasts. The isolated strains appeared to have the requirements for biotin and pantothenate, and to have higher tolerance to ethanol than the Japanese sake yeasts. The biotin requirement was not found in the sake yeasts.

청주의 주질을 향상시키기 위한 전보의 연구에서, 유용효모로서 분리된 균주에 대하여 균학적 성질을 조사하고, 일부의 사항에 대하여는 일본청주효모와 그 특성을 비교하였다. 분리효모 KP-16, KP-21 및 KP-54 균주는 모두 saccharomyces cerevisae로 동정되었고, TTC 염색성이 pink계이었다. 맥아즙 배지에서의 피막(被膜) 형성능은 KP-16 및 KP-21 균주는 약하였으나, KP-54균주는 강하였다. 당의 발효성과 탄소원의 자화성은 KP-16과 KP-21 균주는 동일하였고, KP-54 균주는 다소 달랐다. 분리효모는 모두 ${\alpha}-methyl-D-glucoside$를 발효도 자화도 하지 못하였으며, 이는 현재 사용되고 있는 일본청주효모와 다른 점 중의 하나였다. 비타민 요구성에 있어서 분리균주는 모두 biotin과 pantothenate를 요구하였으며, biotin을 요구하는 점은 일본청주효모와는 다른 특성이었다. 내알코올성은 분리균주 모두 일본청주효모 K-7및 K-9균주보다 강하였다.

Keywords