Abstract
Natural 6-dodecen-4-olide (Butte lactone) was produced from plant oils containing high unsaturated fatty acids via two-stage microbial hiotransformation. After unsaturated fatty acids were liberated from plant oil by microbial lipase, these were converted to optically active hydroxyl fatty acid (HFA) by hydroxylation reaction of Pseudomonas sp. NRRLB-2994. When safflower oil containing >75% unsaturated fatty acid, linoleoic acid wasused, Pseudomonas sp. produced 8g/L of 10-hydroxy-12(z)-octadecanoicacid with average of 39.2% bioconversion efficiency during 48 hr biotransformation period. The recovered 10-hydroxy-12-octadecanoic acid was further bioconverted to 4-hydroxy-6-dodecenoic acid via partial ${\beta}-oxidation$ by Yarriowia lipolytica ATCC34088. 4-hydroxy-6-dodecenoic acid in culture was lactonized by lowering pH to 4.0 using $4N\;H_{2}SO_{4}$ and heating for 5 min to 6-dodecen-4-olide (Butter lactone). Natural 6-dodecen-4-olide had characteristic aroma properties when compared to 6-dodecan-4-oilde (dodecalactone) and 4-decen-4-olide (decalactone).
2-단계 미생물 생물전환법을 이용하여 불포화 지방산을 다량 함유하고 있는 식물유로부터 천연 6-dodecen-4-oilde (butter lactone)을 생산하였다. Microbial lipase를 이용하여 식물유에 함유된 불포화 지방산을 분리한 후, Pseudomonas sp. NRRL B-2994의 hydroxylation 기작을 이용하여 광활성의 hydroxyl fatty acid (HFA)로 전환시켰다. Pseudomonas sp.는 불포화지방산linoleic acid를>75% 함유한 홍화유를 48시간의 생물전환공정 과정을 통해 8 g/L의 10-hydroxy-12(z)-octadecenoic acid를 생성하였으며 평균 39.2% 생물전환률을 보였다. 원심 분리된 10-hydroxy-12(z)-octadecenoic acid는 2차적으로 Yarrowia llipolytica ATCC34088의 제한적인 ${\beta}-oxidation$ 기작을 이용하여 4-hydroxy-6-dodecenoic acid로 전환되었다. 배양액 내 존재하는 4-hydroxy-6-dodecenoic acid는 $4N\;H_{2}SO_{4}$를 첨가하여 배양액을 pH 4.0로 낮추고 $100^{\circ}C$에서 5분 동안 가열하여 6-dodecen-4-oilde (butter lactone)으로 lactone화하였다. 천연 6-dodecen-4-oilde는 불포화 lactone으로 기존에 사용된 6-dodecan-4-oilde (dodecalactone) 및 4-decan-4-olide 비교하여 독특한 향 특성을 지니고 있다.
