StepⅠ Laboratory Experiment
At the very beginning, we are going to do our experiments in the laboratory to affirm that the modified Starmerella bombicola can produce the appropriate-ratio-mixed sophorolipid which can degrade the cyanobacteria with the highest efficiency and the output of the sophorolipid can meet our expectation at the same time.
Fig1. Degradation test
Fig2. Degradation test（with different SL ratio）
StepⅡ Test in Experimental Field
After the results was confirmed in the laboratory, we are going to do a small test in a real water environment—an experimental field in our school which the consequences can be controllable.
In this area, we’ll simulate a real water environment and test three parts: First, we’ll enrich and degrade the cyanobacteria and test the degradation effect; Then, we’ll put the sophorolipid into the water directly and test the degrading effect of cyanobacteria; Finally, toxins and other substances which may exist in the water will be detected, and the biomass will be measured as well in order to determine the influence of direct release and offer a theoretical support for the future direct release to the natural water.
Fig3. Test Field in school
StepⅢ Test in Treatment Plant
Before we release our product into a real natural water environment, we’d test the degradation effect of appropriate-ratio-mixed sophorolipid in a treatment plant. In the treatment plant, cyanobacteria are enrichened and we are going to test whether our product can degrade the cyanobacteria efficiently as the same as using the physical methods while can make less pollution than it at the same time.
Fig4,5&6. Treatment Plant
Step Ⅳ Release in Natural Water (Imagination)
At the end of our present project’s implementation, we’ll do a final test in a real natural water body—release the sophorolipid product into the water body directly, if the first three steps give us a good result back. We won’t put our product into a big range of the water body at first, but only release the sophorolipid into a small part of a lake and using the UAV(Unmanned Aerial Vehicle) technology to monitor the degrading results in real time, and keep testing the water quality till the data can prove that it’s safe for the environment to release our product directly into the natural water. If the result is ideal, we can release our product into a large scale of the natural water body to reach our goal: to degrade the cyanobacteria efficiently and harmlessly. Well, this part is totally an imagination right now, because there are still many factors need to be considered when we are in real water circumstances. But it’s not bad for us to make it our goal, because once the dream comes true, it’ll contribute to making our world better.
Fig7&8. Taihu Lake
Starmerella bombicola ATCC 22214 is chosen as our production strain, which is non-pathogenic both to us and our environment. If this microorganism escapes from factories, it won’t do harm to the natural environment, human beings and other species because it mainly makes use of glucose for blooming and produce the sophorolipid by using the oleic oil which are harmless. Although the engineered strain put into production was a genetically modified strain, the CRISPR/Cas9 system would not function for a long time because it only expresses instantaneously; And the final strain did not have hygromycin resistance because it had the hygromycin self-emergence system. These conditions to a certain extent ensure the human and environmental safety of the strain used. Well, to be on the safe side, we’ll make sure to implement autoclaving to the strains and cultures before releasing to the outside consideration every time.
The product—sophorolipids, which also has the characteristics of non-toxic, 100% biodegradable and environmental friendliness, won’t do harm to human beings. However, it is essentially a surfactant that can affect other organisms in natural water bodies. Therefore, we’re not going to put it in a natural body of water until we've done the research.
Fig9. Advantages of SL
Our project uses the fermentation techniques. The fermentation is always with mild conditions which do less harm to the laborers whom working in the factories.
Preservation and Transportation
We will produce the sophorolipid into powder and seal the package. Products only need to be transported under dry and cool conditions, so there is no big risk in transit and preservation. If leakage occurs, the sophorolipid will not have a significant impact on the natural environment due to its non-toxic and biodegradable nature.
Probable Secondary Pollution
After cyanobacteria are degraded, a substance called “algal toxin” will be released, which can enter human body through alimentary tract, causing diarrhea, neural paralysis and liver damage to infected people. In severe cases, people can be poisoned or even die from it. Therefore, the probable secondary pollution caused by the degradation of cyanobacteria to water should also be taken into consideration. That’s why we have mentioned in implement-part Ⅳ that we can release the production directly into the natural water only when the concentration of algal toxins is in a safe range after degradation. Hence, given the detection technology and other limitations, direct release remains in the concept stage.
However, through the advanced study, maybe we can put the production into water at the beginning period of cyanobacteria bloom with the help of UAV real-time monitoring, eliminating the cyanobacteria at its early growth stage and reduce the release of algal toxins which are in a safe concentration, in order to achieve the goal of direct release of our production. In sewage treatment plant, the objects can be further processed to become non-pollutive, eliminating the secondary pollution to natural environment.
Sophorolipid is a kind of glycolipid biological surfactant. It has the general properties of solubilization, emulsification, wetting, foaming, dispersing and reducing surface tension of conventional surfactants, and it also has the characteristics of non-toxic, 100% biodegradable, temperature resistance, high salt resistance, wide pH range and environmental friendliness.
As a result, the sophorolipid has many applications in different fields. For example, as a surfactant, it can be used into Oil-displacing agent, detergent, daily chemical products, medicine, food, agriculture, fodder as well as environment protection etc.
Fig10. Application of SL
Thus, the raw material manufacturer of sophorolipid, government and customers whom are the audiences of terminal products of sophorolipid, can all be our end users or our prospect customers.
However, GenScript, an international biotechnology company, once found us to talk over the application of sophorolipids: how to scale-up production little by little, how to apply sophorolipids to our environment, and most importantly, how to profit through sophorolipids. We went to search online and finally found out that sophorolipids are not even on the list of Inventory of Existing Chemical Substances in China, which means factories are not allowed to product it until it is registered legally. However, registering a kind of chemical is not that easy, which is an arduous procedure and takes more than 1,000,000 RMB. And once a company register it successfully and is going to put into production, other companies will definitely swarm into producing it and take a share of the spoils.
So from this sight, government seems like to be best choice of our partners. Without the permission of the government, putting sophorolipids into use would be time-consuming and cost a huge amount of money.
In summary, our present project is aiming at producing the appropriate-ratio-mixed sophorolipids to degrade cyanobacteria and the government could be our biggest end user because they have the responsibility and great need to solve the water problem to ensure people’s welfare in Wuxi. Besides, they are the only one who have the right to apply sophorolipids into environmental protection.
As for the way to put sophorolipids into use, originally, we thought out two ways: using sophorolipids to degrade cyanobacteria after salvage or throwing sophorolipids into lake directly.
The first way is still time-consuming and labor-intensive, while the second way will cost a lot of sophorolipids.
So we went to, Zhou Xiaohong, professor of the Environmental Research Institution of Jiangsu University, for some instruction. She recommended us to take the natural concentration of cyanobacteria into consideration and do not use an extreme concentration to measure the degradation efficiency. In regard to the application method, we reached a consensus that we should use the sophorolipid in the beginning of the bloom. In that way, there is no need to spend a lot of sophorolipids.
When sophorolipids become popular, people who release specific ratio of sophorolipids into the environment could test in which ratio the degradation efficiency would be the best for their unique water sample. Thus, they could choose the best ratio and keep using it in a long run.
Unable to be produced by companies
Because sophorolipid is not on the list of Inventory of Existing Chemical Substances in China, it is hard for companies to produce in scale. So there is still a long way to go to find out how to scale up the production of it.
Although our project aims at producing the specific ratio sophorolipid, it’s still hard for us to control whether the gross output can reach our expectation. Besides, the specific ratio of sophorolipid may change when extracting the mix sophorolipid that causes the properties damage.
The product properties may influence by different water environment in different geographical factors. It’s hard to estimate the product properties in every water environment, and this may cause an uncertainty of our product effect when using it in a new area.