In the first and second generations of our microplastic processor, our primary focus was on the colorimetric module, as it directly reflected our monitoring results. However, as we were preparing for production and deployment, a biosecurity expert, Chao Shen, advised us that using this strain to release it into lakes or oceans would pose severe biosecurity concerns. "I believe many people would be uncomfortable with the idea of consuming food or water that contains bacteria," Professor Chen responded strongly, asserting that this would violate biosecurity principles.

Later, we discovered that the 2022 iGEM team from Lithuania (Vilnius-Lithuania) had characterized a highly suitable cellulose-binding protein. We decided to use this protein as a component for our bacterial cellulose-based microorganism immobilization technology. Concurrently, we procured bacterial cellulose to validate the feasibility of our immobilization technology. We designed the third generation of the microplastic processor, which, in comparison to the second generation, incorporated an additional component, INP-CBD. INP-CBD is continuously expressed within the engineered bacteria and allows CBD to be displayed on the cell surface. This, in turn, enables the engineered bacteria to anchor themselves on cellulose membranes, preventing them from dispersing in the ocean and thus mitigating potential biosecurity risks.

Following our attention to project safety, our lab instructor also educated us on important considerations during the experimental process. Professor Liang emphasized, "There have been many cases of accidents resulting from improper handling. We hope that you can take preventative measures."

Before entering the laboratory, our instructor first educated us on the "Basic Laboratory Operation Guidelines":

1. Eating, sleeping, running, and playing in the laboratory are strictly prohibited.

2. Lab coats must be worn when entering the laboratory, and long skirts and sandals are not allowed. Gloves should be worn before commencing any experiments.

3. Used gloves should not be left lying around; they must be removed before leaving the laboratory.

4. Lab attire is not permitted in the office area, and wearing gloves in the office is prohibited. Furthermore, using gloves to handle office equipment, such as computers, is strictly prohibited.

In accordance with IGEM competition requirements for safety documentation.

5. Arrange a team to be on duty every week, which is mainly responsible for the sanitary maintenance of the public area of the laboratory and the daily sterilization and inactivation of waste bacteria and petri dishes. There are several large groups of people on duty every Thursday, mainly for the overall sanitary cleaning of the laboratory, including: tidying up the table in the public area (including the glue-making room); scrubbing the table and instrument surface in the public area of the laboratory with a dishcloth soaked in Germine; sweeping under the test bench and uncommonly used areas; mop the floor twice with a mop soaked in Germine.

6. strong alkali and strong acid chemicals should be classified and stored, and then put back to the original place (under the ventilator) after use, and the corrosive materials should be put in a place that is not easy to touch.

Before entering the laboratory, in addition to some basic points for attention, the teachers also taught us how to deal with the emergency.

(1) immediately after acid burns, rinse with water. Generally, neutralizers are not needed after washing. If necessary, the wounds can be treated with 2%-5% sodium bicarbonate, 2.5% magnesium hydroxide or soapy water. After neutralization, a large amount of clean water is still used to remove the remaining neutralization solution, the heat generated by the neutralization process and the neutralization products.

(2) after alkali burn, the wound should be washed with a large amount of water and / or weak acid solution immediately. The longer the washing time, the better the effect. If the pH value of the wound reaches more than 7, you can also neutralize the wound with 0.5% acetic acid, 3% boric acid or 10% citric acid, and then rinse with clean water.

(3) in case of fire, do not panic, immediately notify the surrounding personnel and the person in charge of safety, according to the situation to fight, control or evacuate.

(4) 1.toilet paper and other uncontaminated paper are thrown into the garbage can, and the bacteria-contaminated paper is sterilized together with the germ medium; 2. Packaging bags, masks are thrown into the life trash can (black garbage bag), strictly forbidden to be thrown into the experimental trash can; 3. Toothpicks, needles to be thrown into the yellow sharp box; 4. The head of the gun is thrown into the big white bucket at the door, as shown in the picture below. The broken glass is thrown into the cardboard box under the side table. Empty reagent bottles are thrown into the cardboard boxes under the side platform, all marked separately. Gloves, used bottle sealing film and other bacteria-infected experimental garbage are thrown into the yellow garbage bag next to you. 8. According to the classification of organic waste liquid, waste acid and waste alkali, the experimental waste liquid was packed in a 25-liter waste tank respectively.