To ensure that our project would not be hazardous either to environment or to the people executing it we took multiple definitive measures. We have described some of the consideration here. We also took measures while designing experiments, conducting experimentation, and designing a reactor to employ our device in real life scenario safely.
Safety before Lab
While coming across the idea of using Alkyl Sulfatase protein for degradation of Sodium dodecyl Sulphate our main concern was to consider isolation of its genetic sequence. As sequence corresponding to Alkyl sulfatase was complex in nature it could not be synthesised in vitro. Working with Pseudomonas aeruginosa is BSL-2. Thus, to keep our experimentation to BSL-1 we collaborated with Team Tec CEM and they gifted us the plasmid they constructed to work on a similar project that consisted of genetic sequence corresponding to Alkyl sulfatase. We used the plasmid to amplify the genetic sequence and keeping the project to BSL-1.
For all our experiments we have used the strains E. Coli Dh5-alpha and BL21. These strains are known to exhibit high transformation efficiency. Additionally, E.Coli does not pose threat to majority organisms and environment and is a relatively safe organism to work with.
Safety Practices at Lab
All experiments were carried out in BSL-1 Labs of BIRAC Bioincubator, IIT Kanpur.
Sufficient care and precautions were taken during the experiments to minimize exposure to the bacteria. Personal protective equipment like latex gloves, full sleeve clothes, and shoes was worn during experimentation along with periodic sanitization of the workplace before and after the experiment.
We also considered proper disposal of the waste product after experimentation. LB Plates were disposed of only after sterilization. All liquid waste was carefully collected in separate containers and discarded after sterilization. Each team member would only conduct the experiment under the supervision of a trained senior. Initial demonstration of each experiment was provided to team members before they conducted experiments by self.
Safety Consideration after Lab
We have created a pre-prototype of two devices for degrading SDS, both in the household setting and a direct on-site implementation in rivers.
The household device sends discharge of washing machine back into the machine after treatment with SDSase through an outlet channel. This channel also removes SDS from the solution. This is achieved by printing Dodecanol on the inner linings of the outlet channel. This serves to differentially select SDS from the solution and clean water is separated from SDS. The speed of water through outlet should be slow, as the process of differential extraction is slow.
For the on-site device, no precautions are taken to remove SDS because the treated water will be directly sent back to rivers. The natural biome of the river can take care of the protein. The properties of SDS on which the differential extraction is done is based on this paper Ambily P.S et al., (2011)