Fat, or grease, is important to our life and is used in different ways. Grease contains many organic substances, and is an important alternative petroleum resource. However, a large amount of waste grease has not been properly utilized nowadays. On the contrary, grease waste has become a big problem to our life. Its discharge into suburban sewage causes serious damage to natural ecological environment. In addition, waste grease can attach to the inner walls of sewer pipes, causing sewage blockage and even overflow. In fact, many countries have this kind of grease waste problems and they mostly take physical or chemical approaches, with either low-efficiency or high-cost. Physically collected waste grease is generally burned or disposed by landfills, leading to secondary pollution to the environment.
HOW TO GET IT DONE
Therefore, it is necessary to find an economic and effective method to treat waste grease. For this reason, we aimed to develope a novel grease-degradation system consisting of differentially engineered microbial groups. The principle of our case is the chemotaxis of bacteria. In this system, bacteria can swim toward their attractant, such as serine, and move away from repellent, such as leucine. Based on this theory, we included two types of bacteria in our system: Leaders that act as a command center and a reaction center; Followers that play a role of substrate catcher. Our ultimate goal is to degrade the waste grease into fatty acids and further convert the fatty acid molecules into sophorolipids, which are considered as one of the most promising biosurfactants.
. Matsumiya Y, Wakita D, Kimura A, et al. Isolation and characterization of a lipid-degrading bacterium and its application to lipid-containing wastewater treatment [J]. Journal of Bioscience & Bioengineering, 2007, 103(4): 325-330.
. Cammarota M C, Freire D M G. Hydrolytic Enzymes in the Treatment of Wastewater with High Oil and Grease Content [J]. Cheminform, 2006, 37(46): 2195.
. Li J, Xia C, Fang X, et al. Identification and characterization of a long-chain fatty acid transporter in the sophorolipid-producing strain Starmerella bombicola[J]. Applied Microbiology & Biotechnology, 2016, 100(16): 1-14.