Team:ECUST China/Safety

Introduction

As the members of the synthetic biology community, we undertake the responsibilities to conduct experiments safely and securely. And the premise of doing this is to understand what it means to be safe and secure. In iGEM, safety, or in bio-safety, they covers measurement used to manage risks from accidental exposure or release in experimental procedures or practices. On one hand, bio-safety not only protect people, animals and all the other living things from exposed to harmful things from toxic drugs, chemical reagent to trans-genetic materials . On the other hand, it covers the procedures, practices or other measures used to manage risks from possible exposure or release and protect our environment .

For this part, we updated and revised our risk assessments and we have handed out safety form promptly to clarify that our lab are Safety Level A laboratories and students are hardly exposed to biological risks. Our project aims to design a kind of yeast that can produce phycocyanin which has a broad development and application prospect and has great value in food, medicine, reagent,cosmetics and other fields.

We will further explicate our assessments and show how and why we implemented bio-safety and bio-security requirements in our project in the following paragraphs.

Lab Safety
Our Laboratory

Our lab follows Chinese legislation about risk 1 bio-safety laboratory and our lab is provided with two autoclaves (respectively for waste sterilization and sterilization for future usage). With UV sterilization equipment with ventilator and several laminar flow cabinets, we can ensure the basic need of safety. Besides, our instructors have provided us with a document listing every detail we should pay attention to when we are in the lab and all of us have already read it.

Fig. These are a laboratory in East China University of technology.

Our lab has also considered every possibility for us to proceed safer experiments. For example, we use Gel Red and 4S Green Plus nucleic acid dye to reduce toxicity, and equipping Blue Light Gel Imager for the concern of our skin and eye protection, etc.

All students including us iGEMers are trying our best to follow all the protocols for better experimental reproducibility.

Besides, our labs strictly follow the rules of garbage classification—household waste and experimental waste are separated. Besides all bio-wastes containing bacteria are sterilized before disposal. As you can see in the photos, experimental waste such as tips, syringes, gloves, and plates are collected separately for pollution treatment and waste recycling.

Safety by design
Strains

We used the yeast--Saccharomyces cerevisiae S288c, which was provided by Prof. Cai Menhao’s Lab. Saccharomyces cerevisiae is classified as risk 1 so it barely cause harm to people or the other living things. The strain we've used, whether as PCR template resource or competent cell, are harmless to human being and surrounding environment. It’s world-widely used engineered strain which has been proved to be safe.

In order to ensure absolute safety, we selected food grade Saccharomyces cerevisiae and conducted experiments with amino acid nutrient deficient strains. The plasmids and genes we selected will not cause safety problems in theory.

Plasmids

We selected p426-snr52p-grna and ptdh3-dcas9 double plasmid system and both plasmids have been proved to be stable plasmids, which are widely used in experiments. They rarely produce unpredictable mutations and are very safe.

Design

Our project aims to re-construct Saccharomyces cerevisiae S288c, which can synthesize heme, an important precursor of phycocyanin, and which also contains heme oxidase Ho1. In this experiment, the genes CPCE and CPCF encoding lyase were introduced into p426-snr52p-gRNA plasmid, the gene CPCA encoding phycocyanin a subunit and the gene pcyA encoding ferredoxin reductase were introduced into ptdh3-dcas9 plasmid. After adding promoters, terminators and other regulator parts, then the two plasmids were introduced into Saccharomyces cerevisiae S288C. Heme is converted into Biliverdin XI by HO1 in mitochondria, which is catalyzed into phycocyanin by pcyA, and then forms phycocyanin with CPCA under the action of lyase CPCE, CPCF.

Food Safety
First of all, phycocyanin itself, as a natural pigment, has been widely used in the fields of food, drugs and cosmetics. It is the only sky blue pigment allowed by FDA[1] and is internationally recognized as a safe food grade pigment. In China, it is also a legal food additive in line with national standards.[2]

Our project involves food, however we have never tasted the food produced by the yeast we designed. In addition we conduct food production in a special food laboratory to completely distinguish between biological experiments and food experiments.

Our final products comply with the laws, regulations and industry regulations of relevant departments on genetically modified food. In the context of China, our products also meet the requirements of the food safety law of the people's Republic of China (order of the President No. 21) | the 2021 amendment.

[1] Electronic Code of Federal Regulations,§73.530 Spirulina extract. (https://www.ecfr.gov/cgi-bin/text-idx?SID=79a76b1d7e7a98ae9459d88005ab7058&mc=true&node=pt21.1.73&rgn=div5#se21.1.73_1530)

[2] GB 2760-2014 《National food safety standard for use of food additives》