Team:SUIS Alpha Shanghai/project

Our Project

Project Experiment Collaboration Human Practice InterLab Parts Attributions Team

OUR PROJECT

What is gutter oil?
Inexpensive, delicious and quaintly traditional, for many people, locals and expats alike in China, munching down on fired snacks such as fired dough stick, dumplings, barbecues from street food vendors or small family run eateries is part of a daily routine. Chinese gutter oil incidents, broke out in 2010, but with successive exposure over the year, became a severe concern among the public. Gutter oil is the illicit cooking oil which has been recycled from waste oil collected from sources such as restaurant fryers, grease traps and sewage from sewer drains. While government control has tightened, the oil safety issue has continue to be a problem especially in unlicensed street vendors, which are difficult to track. The high profit of illegal cooking oil recycling was the main reason for the continuation of gutter oil industry. According to food security researches, the price of 1 ton of gutter oil was the 1700-1800 yuan, while the price of 1 ton of rapeseed oil was 7000-8000 yuan. Gutter oil can be extremely harmful to human health. There are many kinds of toxic compounds found in gutter oil, malondialdehyde is one of them. Malondialdehyde(MDA) is the organic compound with formula CH2(CHO)2 that results from lipid peroxidation. An increase in free radicals causes overproduction of MDA. Apart from endogenous source, we acquire lipids via food and cooking oils in our diets. The quality and quantity of lipids in our dietary source of lipid, therefore, influence the blood lipid parameters in body, which is why high contents of peroxidation products like MDA are hazardous and related to several pathological processes including cancer, diabetes, liver diseases, and cardiovascular diseases(Doureradjou and Koner; Ayala et.al). MDA could react with cellular and tissular proteins or DNA to form adducts that results in damages(Ayala et.al). Heating increases the level of MDA significantly in cooking oil(Doureradjou and Koner). Repeated heating and reusing of oil create unsafe oil products with high contents in MDA.

Primary Research: A. Ayala, M.F. Munoz, and S. Arguelles. "Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde and 4-Hydroxy-2-Nonenal,"Oxidative Medicine and Cellular Longevity, vol.2014, article ID 360438, 8 May 2014.

D. Peroumal and B.C. Koner. "Effect of different cooking vessels on heat induced lipid peroxidation of different edible oils" Journal of Food Biochemistry. 32(6):pp740-751. November 2008.

Blair, I. (2008). DNA adducts with lipid peroxidation products. Journal Of Biological Chemistry, 283(23), 15545-15549.

Our Solution Lack of action taken by governments and street food vendors lead to the prevalence of gutter oil and call for the necessity of consumer awareness. In our project, we aim to produce a synthetic E. coli which is capable of safely breaking down the potentially carcinogenic MDA in recycled cooking oil into safe byproducts. One pathway of MDA metabolism involves metabolic action by two enzymes aldehyde dehydrogenase (aldA) and malonate-semialdehyde dehydrogenase to form acetate. Acetate is the main source of acetyl-CoA, which is further broken down to CO2 and H2O in the citric acid cycle in aerobic organisms.This process could form part of standard protocols for the treatment of waste oil in industrial oil refinery plants, with the aim of protecting the community from the illegal activity of using recycled oil for human consumption.

Fig.1 Figure showing the process of MDA metabolism. Enzyme 4 is Aldehyde Dehydrogenase, and enzyme 5 is Melonate-semialdehyde dehydrogenase. Photo from A. Ayala, M.F. Munoz, and S. Arguelles. "Lipid Peroxidation: Production, Metabolism, and Signaling Mechanisms of Malondialdehyde and 4-Hydroxy-2-Nonenal,"Oxidative Medicine and Cellular Longevity, vol.2014, article ID 360438, 8 May 2014.

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Our Team Our team is composed of a group of young and motivated students with helpful advisors from Shanghai United International School Wanyuan Campus. We all love synthetic biology. We aim to make a contribution for the society and improve the food safety issue.

Our team is composed of a group of young and motivated students with helpful advisors from Shanghai United International School Wanyuan Campus. We all love synthetic biology. We aim to make a contribution for the society and improve the food safety issue.