Team:CIEI-China
Disposal of food waste is a huge concern in the society. Improper disposal brings serious pollution and causes tremendous nutrition loss. Considering the low osmotic pressure which is caused by high concentration of salt and sugar in food waste, survivability of the microbes and their efficiency during decomposition of the waste are significantly affected by this hypertonic environment. Our team aims to improve the survivability of the microbes and their decomposition efficiency in lower osmotic pressure conditions. Thus, we planned to transfer salt resistant genes into the functional microbes. In this research, we modified the yeast, specifically saccharomycetes cerevisiae, by inserting the E. coli glutamate synthase (gltB) gene and trehalose synthesis related genes (ScTPS1 and SpTPS1) into it, to make the yeast not only can decompose the food waste efficiently but is able to resist low osmotic pressure. These genes help produce small molecular substances (glutamate and trehalose), which enable the cells to automatically adjust the osmotic pressure in high concentration environments. Based on the survivability test of yeast under different salt concentrations which was set according to our salinity test results of the collected food waste, we assured the effectiveness of our method in helping yeast tolerate low osmotic pressure environments and improving their decomposition efficiency. In this way, we can better take care of the troublesome food waste in a more cost-effective, energy saving, and environmentally friendly way.
