Single Cell Protein Production by a Yeast Utilizing Alcoholic Waste Fluid of Sweet Potatoes

고구마 주정폐액을 자화하는 효모에 의한 SCP 생산

The waste gained from alcohol production with sweet potato was considered as a potential substrate for the production of single cell protein (SCP). The high content in organic materials, simplicity to filtrate and a suitable pH for the growth of yeasts were indicated as a good substrate. A yeast utilizing this substrate was isolated from the compost ground and identified as Candida boidinii. The strain was the highest in assimilation of this alcoholic waste and the yield was maximized at pH 5.0, $30^{\circ}C$ after 72 hrs incubation. The dry cell weight and crude protein content at optimal conditions were 1.02g/100ml and 54.5%, respectively. The growth of the yeast was stimulated with the addition of 0.2% urea, 0.1% $K_2HPO_4$, and 0.02% $MgSO_4{\cdot}7H_2O$.

절간고구마 주정폐액은 여과가 용이하고, 유기질 함량이 높으며 pH가 효모의 생육에 적합하여 미생물의 단세포 단백질(single cell protein) 생산을 위한 기질로 적합하였다. 본 실험에 사용한 Candida boidinii는 토양으로부터 분리된 고구마 주정폐액 자화성이 가장 우수한 균주로서, 72시간 배양하였을 때 배지 100ml당 1.02g의 건조균체량을 얻을 수 있었으며, 이 때의 조단백질 함량은 54.5%였다. 효모의 생육은 pH 5.0과 $30^{\circ}C$에서 72시간 배양하였을 때 최대에 달하였고 urea 0.2%와 무기염류를 첨가하면 생육이 촉진되었다.