Jin Guang, Bierma Thomas J, Hamaker Christopher G, Mucha Raymond, Schola Valeria, Stewart Jeb, Wade Caroline
Department of Health Sciences, Environmental Health Program, Illinois State University, Normal, Illinois, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2009 Jan;44(1):21-8. doi: 10.1080/10934520802515202.
This study examined the use of a whole-cell biocatalyst to transesterify triglycerides, including high-Free Fatty Acid (FFA) waste greases, in a water-containing system. The whole-cell biocatalyst derived from Rhizopus oryzae (ATCC10260) was grown and reacted at room temperature without immobilization. The effectiveness of improving biodiesel yield through alteration of reaction temperature, additional alcohol, and additional transesterification reaction was also examined. Results showed that whole-cell biocatalyst was able to produce biodiesel with a yield of about 75% for virgin canola oil, 80% for waste vegetable oil and 55% for brown grease with a 72-hr transesterification reaction using no excess methanol. Elevating the reaction temperature to 35 degrees C significantly diminished the yield. An additional dose of methanol with another 24 hours of reaction time or a second 72-hr reaction resulted in biodiesel yield approaching 90% and only 3% residual glycerides (mono-, di- and tri-glycerides). These results suggest that whole-cell biocatalysts are able to transesterify waste oils or greases that are high in FFA and contain water. Brown (trap) grease and similar degraded or complex greases may be good candidates for further whole-cell biocatalyst research.
本研究考察了在含水体系中使用全细胞生物催化剂对甘油三酯进行酯交换反应，其中包括高游离脂肪酸（FFA）的废油脂。源自米根霉（ATCC10260）的全细胞生物催化剂在室温下培养并反应，无需固定化。还考察了通过改变反应温度、添加额外的醇以及进行额外的酯交换反应来提高生物柴油产率的有效性。结果表明，使用不过量甲醇进行72小时的酯交换反应，全细胞生物催化剂能够生产生物柴油，对于初榨菜籽油产率约为75%，废植物油产率为80%，棕色油脂产率为55%。将反应温度提高到35摄氏度会显著降低产率。额外添加甲醇并延长24小时反应时间或再进行一次72小时反应，生物柴油产率接近90%，甘油酯（单甘油酯、二甘油酯和三甘油酯）残留仅为3%。这些结果表明，全细胞生物催化剂能够对高FFA且含水的废油或油脂进行酯交换反应。棕色（集油池）油脂以及类似的降解或复杂油脂可能是进一步开展全细胞生物催化剂研究的良好对象。
