Our project is based on the idea that the combination of the sponge's filtration power and the bacteria engineered biosensing capacities will form a bioremediation agent that will be more efficient that if we just released the bacteria into the water. However we believed it was important to also take into consideration the ethical issues such a system would rise, since it would imply the use of an animal as a biosensing tool, and the introduction of a genetically modified bacteria in its microbiome.

The organisms commonly suggested as bioremediation agents are micro-organisms and plants. But the sponge is an animal, even though for a long time it was thought to be a "zoophyte", an organism at the limit between vegetal and animal. And what is often considered acceptable for micro-organisms and plants concerning genetically engineering, raises a lot more questions and debates when we want to apply them on animals.
In our case, we saw two major issues with the Sponge Patrol project:

1. even though we are not modifying the sponge's genome, we are modifying its microbiome and replacing with a synthetic one, which could be considered in some extent as a modification of the sponge.
2. the use of the Sponge Patrol system would imply that we put living sponges in waters that were likely to be polluted, and thus we would knowingly endanger the sponge's health.

We soon realized that little to no paper, conferences or legislations had ever talked about the use of an animal as a host for a genetically modified micro-organism (GMMO) to serve as a bioremediation agent, nor discussed the ethical issues such a use would raise. The focus seemed to be largely on modified micro-organisms and plants, with sometimes the mention of a GMMO intended to be symbiotic with a natural plant. We hence decided to discuss the status of such an organism between ourselves, hoping that our reflexion would bring to light the existence of such organisms, and the importance to take them into consideration in legal and ethical discussions concerning GMO. We organized a debate where we tried to address as best we could several questions that seemed important to us.

1. Is modifying an organism's microbiome the same as modifying the organism itself?

We all agreed that in the device we wanted to build, the sponge itself would not be genetically modified. We are only changing the genome of the bacteria, so the sponge would not be a GMO.
However some of us thought that changing its microbiome was still in some extent a modification of the sponge, though not a genetic one ; but they had difficulties in finding exactly why the new sponge would be different.

One of the persistent ideas was that most of cells that constitute a sponge were probably bacteria and not sponge's cells, just like the human body contains ten times more bacteria than human cells. Hence if we were to change an considerable part of the sponge's microbiome with synthetics bacteria, then the new sponge would be mostly made of genetically engineered cells.
Other team members, though, argued that the nature of an organism was not determined by the cells that are the most numerous in its body ; they made a clear distinction between the sponge's eukaryotic cells (pinacocytes, choanocytes, etc.) and the prokaryotic cells living in its microbiome (bacterias). Only a change in the eukaryotic cells containing the sponge's DNA would actually be a modification of the sponge itself.

Another observation was that by bringing engineered cells into the sponge's microbiome, we were giving the sponge a function that it didn't possess before: the ability to serve as a biosensor for toxic pollutants. Once again though, several members of the team argued that only the bacteria could be considered biosensors, and not the sponge which, in the device, would only pump water. The pumping would bring large amount of water to the bacteria who would then be able to detect the presence of pollutants, but the sponge itself didn't sense any compounds, so it would not be true to say that it has a new function.

We finally agreed to say that an organism hosting GMMO should be given a special status, as:

1. They are different from GMO in the sense that no change has been made in their DNA
2. They are different from natural organisms in the sense that their behavior of health could be affected by the engineered bacteria
3. They are different from natural organisms in the sense that releasing them out of the lab would have the same effects as releasing GMO in the environment.

We believe that such organisms, which we tentatively called Organism with Genetically Engineered Microbiome (OGEM), should be taken into consideration in legal and ethical discussions, separately from GMO and from natural organisms.


This question was very interesting because even though we did not intend to change human's microbiome, thinking about it in that way helped us understand what it would mean to change an animal's microbiome. The answers were varied and often undecided. Though most of us said they would agree to hosting temporarily a synthetic bacteria in their organism for therapeutic purpose, the majority of the group wasn't so keen to have their microbiome changed by GMMO for a long time and/or for no therapeutic reason. Others though stated that they wouldn't mind as long as it wasn't detrimental for their health.

It is clear that the goal of the Sponge Patrol project is not to cure sponges against the toxic effects of pollutants. Even if the change of their microbiome should lead to a better detoxification of the sea water, and hence will be beneficial to the overall health of all the fauna and flora living in the detoxified area, we cannot say that we are injecting bacteria in the sponge for therapeutical reasons. The primary reason is to detect pollutants, not to cure the sponge against some harm it could have received. To put it bluntly, we only want to modify the sponge's bacterial flora in order to use the sponge as an efficient tool.

And it appeared during our discussion that this was the reason why most of us were reluctant to being injected in their organism bacteria that would then be used as bioremediation agents: they didn't want their body to be used as a tool. One member added though that her opinion was undecided, and that since she recognized the importance of protecting the environment, she might agree to it depending on the circumstances.


Usually, when people talk about bioremediation agents, they think of micro-organisms, and sometimes of plants. But with the Sponge Patrol project, it is also an animal that would become part of a biosensing device, and we felt that the use of animals as tools should raise more ethical issues than the use of other organisms ; and hence, that we needed to have a serious discussion about it.

The 2012 Evry iGEM Team had a similar reflexion about the use of animals as tools in synthetic biology. Their question at the time was whether a frog larva could be used as a chassis in iGEM, and they concluded that using these vertebrates in such a way was not the best option. In our case, though, the animal is an invertebrate with no nervous digective or circulatory systems. In fact, it doesn't even have nervous cells. Which is probably why there are few regulations concerning the harvest of sea sponge for commercial purpose. People usually don't feel overly concerned by a sponge's well-being, because it looks so much like a plant, and because their lack of nervous cells leads us to believe they cannot feel pain.

This observation led us to wonder why people care more about certain animals than others. For example, people usually think that it's acceptable to experiment on flies in a lab, but would not always agree to experimentation on cats and dogs. There do not seem to be a logical explanation of this fact ; both flies and dogs have nervous systems and can feel pain, which is often the major concern of those who defend animals' rights. Is it the size of the animal, or the size of its brain, or something else that makes us care more about certain animals than others?

During a roundtable organized by CURIOSITas this october, "BioArt in the light of ethics", two members of our team had the opportunity to discuss this question with artists and scientists. One of the guests pointed out that the ethical comities seemed to have in mind an artificial scaling (scale? ladder? pyramid? other?) of species, since they talked about certain species a lot more than about others, as if they were more important, or if it was more important to protect them. But from a biologist's point of view, there is no such thing as more important or more evolved species ; all species are equally evolved, the only difference is that evolution took different path for each species. The scaling made by the committees was therefore, in his opinion, entirely artificial.
One of our team members then brought up an interesting theory that could explain why people often make this scaling of species: the criterium on which we would differentiate between species could be the emotional proximity we share with them. The more closely related we feel towards an animal, the higher we put it in this scaling, and the more important legislations that protect its well-being are important to us. A mammal such as a dog, which can look at us, hear us, bark at us, and which can react to many stimuli in ways we understand and can relate to, is for these reasons higher in our considerations than a worm which has few senses, very different reactions to stimuli compared to ours, and which does not appear to feel emotions like we do. We can easily understand, or at least we cant try to interpret, some of a dog's emotions, which feel familiar to us ; whereas we have trouble associating any emotion to worms other than the feeling of pain when their body is hurt.

With such a criterium, humans are, of course, at the top of the artificial pyramid. But we don't feel close to the sponges at all, because they have no brain, no nervous system, and the emotional relation we share with them is hardly stronger than the one we share with a plant. As a consequence, it is probable that the use of sponges in our Sponge Patrol project would raise few objections in ethical committees, if any, compared to the use of other animals.

Does that mean that it would be acceptable to change sponges' microbiome in a lab, and to use them as tools? Not necessarily. It may not be for us to decide. When we explained our project to other scientists, though, they did not think that using sponges were problematic. Several scientists working on sponges even offered to give us a specimen of Spongia officinalis for our project if we had the means to transport it safely, which lead us to assume that it was probably acceptable to change their microbiome, and to use them as biosensing tools.

One thing we weren't sure of, though, was whether relocating sponges in polluted waters, aka in potentially harmful areas, was ethical.


We thought that our project could potentially be dangerous for the health of the sponge we would use, either because of the bacteria, or because of the pollutants.

The danger posed by the synthetic bacteria is that it could have an unexpected behavior when put inside the sponge. Even though the only modification we want to make in the bacteria is to add a biosensing system that is not harmful in any way, we can never fully predict the consequences of adding a new organism in an ecosystem ; here, the ecosystem is the sponge's microbiome. It cannot be ruled out that the new bacteria will have negative consequence of the sponge ; for example, if the new bacteria were to take over the other species living inside the sponges, and if some of those species were vital to their host like our gut bacteria are vital to us, then it would harm the sponge. We actually don't know much about Spongia officinalis' microbial flora, nor about the relation between this sponge and its microbiome, so it is not possible to predict what could happen.

However, we have strong reasons for believing that it is highly improbable that our engineered Pseudovibrio would take over other microbial species. On the opposite, it is very likely that the opposite will occur. In fact, to the best of our knowledge, researchers have yet never been able to build a GMMO with new functions that was competitive against natural species. The new functions added to the engineered microorganisms are always a burden that make them unable to compete against the species, because they use a lot of energy doing these functions that are, most of the time, not even useful for their own survival. So if we did went ahead with the Sponge Patrol project and actually inserted our transformed bacteria in the microbiome of the sponge, it would probably not live long in it. We would need to inject new bacteria in the sponge each time we want to test water toxicity, or to find a way that would enable the survival of our bacteria for prolonged period of times.


The danger posed by pollutants appeared more problematic to us. In order to use Sponge Patrol in an efficient way, we would need to put it in areas which we know are susceptible of being polluted. Which means that we would knowingly put the sponge in an environment that could be toxic and affect its health.
We realized how paradoxical it would be to intentionally move animals into dangerous areas that were likely to be toxic, when the goal of our project is precisely to protect marine species from toxic compounds. Not only would it endanger the sponge's health, but also the health of the species eating the sponge, including starfish, turtles and several fish.
But there are actually several ways Sponge Patrol could be used, and not all of them would be dangerous for the sponge:

1. We could have sponges living in an aquarium. When we want to test the quality of a water sample, we would change the water of the aquarium to the water we want to test, and see if Pseudovibrio denitrificans produces a fluorescent protein. Then we would replace the water to clean water. This way, the sponge would be exposed only a limited time to potentially polluted water, which should not endanger its health.

2. We could have sponges living in an area where we specifically want to protect the fauna and flora from pollution. These areas would not be chosen because they are thought to be highly polluted, but because we want to preserve them, which means that we would not intentionally put the sponge in danger. The sponge would then serve to alert us if dangerous concentrations of pollutants were to come in the area, endangering the health of all the species living there, so that we could take the necessary measures.

3. The most problematic way of using the sponge would be to specifically put it in areas which we know are likely to be toxic, like at the exit of plants' sewers or of water-treatment plants. A solution in these cases would be to only place the sponges for a limited time in those potentially polluted areas, assuming that only a long exposure to pollutants is dangerous for its health. Another solution would be to engineer the bacteria so that it could not only detect the pollutants, but also degrade them in a efficient way, in order to protect the sponge. Moreover, if the bacteria could degrade the pollutants, we could use the sponge in areas we already know are polluted, in order to use it as a bioremediation agent that would detoxify the water.

(est-ce que je cite WatchFrog pour montrer qu'utiliser des animaux comme biosenseurs d'eau polluée se fait déjà de façon légale ?)