Laboratory of Food Microbiology and Biotechnology, Department of Food Science and Technology, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, Greece.
Appl Microbiol Biotechnol. 2012 Jul;95(1):13-27. doi: 10.1007/s00253-012-4111-3. Epub 2012 May 13.
The rapid development of biodiesel production technology has led to the generation of tremendous quantities of glycerol wastes, as the main by-product of the process. Stoichiometrically, it has been calculated that for every 100 kg of biodiesel, 10 kg of glycerol are produced. Based on the technology imposed by various biodiesel plants, glycerol wastes may contain numerous kinds of impurities such as methanol, salts, soaps, heavy metals, and residual fatty acids. This fact often renders biodiesel-derived glycerol unprofitable for further purification. Therefore, the utilization of crude glycerol though biotechnological means represents a promising alternative for the effective management of this industrial waste. This review summarizes the effect of various impurities-contaminants that are found in biodiesel-derived crude glycerol upon its conversion by microbial strains in biotechnological processes. Insights are given concerning the technologies that are currently applied in biodiesel production, with emphasis to the impurities that are added in the composition of crude glycerol, through each step of the production process. Moreover, extensive discussion is made in relation with the impact of the nature of impurities upon the performances of prokaryotic and eukaryotic microorganisms, during crude glycerol bioconversions into a variety of high added-value metabolic products. Finally, aspects concerning ways of crude glycerol treatment for the removal of inhibitory contaminants as reported in the literature are given and comprehensively discussed.
生物柴油生产技术的快速发展导致了大量甘油废物的产生，甘油是该过程的主要副产物。根据各种生物柴油工厂采用的技术，理论上每生产 100 公斤生物柴油就会产生 10 公斤甘油。甘油废物可能含有多种杂质，如甲醇、盐、皂、重金属和残留脂肪酸。这一事实常常使得生物柴油衍生的甘油无法进一步提纯而变得无利可图。因此，通过生物技术手段利用粗甘油是有效管理这种工业废物的一种很有前途的替代方法。本文综述了生物柴油衍生粗甘油中存在的各种杂质污染物对其在生物技术过程中被微生物菌株转化的影响。本文介绍了目前在生物柴油生产中应用的技术，重点介绍了在生产过程的每一步中添加到粗甘油组成中的杂质。此外，还广泛讨论了杂质的性质对原核和真核微生物在将粗甘油生物转化为各种高附加值代谢产物过程中的性能的影响。最后，本文综述了文献中报道的用于去除抑制性污染物的粗甘油处理方法。
