As RhyzUp works toward implementing a GMO based fertilizer, safety was of great concern to us. Find out below how we tackled the safety challenges associated with our project.
Safety implications of RhyzUp
Our chassis
As our chassis, we chose Pseudomonas species IsoF due to its biological advantages and the practicality of our host lab already working with it. Our strain is not considered pathogenic or harmful to humans or animals, but its relatedness to Pseudomonas aeroguinosa, an opportunistic phytopathogen, and its ability to actively protect the host plant from a plethora of phytopathogens, made us unsure of our strain’s classification.1,2 We consulted iGEM and were assured that our strain is considered part of Risk Group 1, which did not need a check-in form. For more details on why we chose our chassis visit our Project Description page.
Our plants
Other than P. sp. IsoF, we made use of MicroTom (Solanum lycopersicum) plants in the testing of our product. Before starting our work with the plants, we submitted a check-in form for this strain and received the official approval by iGEM.
Environmental Safety
Even though we did not release any biological material (including our GMOs) from our lab, our project does aim to implement our bacterium in fields, exposing the environment to it. It is therefore crucial to address the safety aspects of applying our GMO.
At the current stage, the nationwide moratorium on GMOs in Switzerland would significantly complicate the field testing and application of our product3. However, as of 2024, the longevity of this law is under discussion. To find out more about the implications of the moratorium on our project, visit our Entrepreneurship and Implementation page. Regardless, our product accounts for a safe application and prevents a release beyond containment through several approaches:
Image 1: Security fence at Swiss Agroscope “Protected Site” GMO testing facility in Reckenholz
Killswitch: An important part of RhyzUp is our antitoxin-toxin based Killswitch. This part of our construct ensures the bacteria stays contained in the deliberately inoculated plant’s rhizosphere, as the survival of the bacteria is directly linked to its direct sensing of the plant roots. To learn the specifics of our Killswitch system and how we developed and tested it, visit our Engineering page.
P. sp. IsoF - a rhizosphere regulator: Though known for its competitiveness and ability to protect crops against pathogenic microbes, partially through active killing, our bacteria has a positive environmental impact. As RhyzUp de-deseritfies soil, it aids in the re-stabilization of a healthy rhizobiome, potentially boosting microbial diversity. These benefits would be most prevalent when implemented in controlled, closed system fields, such as greenhouses, or soils with a poor microbial diversity. To learn more about our plans of implementation visit our Entrepreneurship and Implementation page.
Spread of antimicrobial resistances: In order to stop the potential horizontal transfer of antibiotic resistance genes through our plasmid’s backbones, we plan to integrate all our parts in our chassi’s genome in the future.
Biosafety Level 2 lab
Image 2: Mattia working under the laminar flow hood adhering to BSL2 regulations
During the whole duration of our project we complied to iGEM’s, our University’s and our host lab’s rules and policies. As our host lab was classified as a biosafety level 2 lab, we adhered to their rules and regulations, ensuring the safety of our work and the containment of any materials from the outside environment. After absolving a safety introduction from the lab, every wet lab member had to give their credentials and sign safety forms. The lab was under restricted access and team members were only allowed in the lab with the presence of a host lab PhD student or postdoc. Wearing appropriate personal protective equipment such as lab coats and closed footwear was mandatory. We ensured sterile conditions by working under bunsen burners and laminar flow hoods. All surfaces were routinely decontaminated with 70% ethanol and hands were periodically washed. All waste was autoclaved according to BSL2 regulations before being disposed of appropriately. Find more information on our safe lab techniques in our safety form on our Team page.
Antimicrobial resistance policy: The antimicrobial resistances used as tools, mainly for plasmid selection, were approved by our lab and iGEM, and were used according to the rules and regulations of our institute.
Ethical concerns
There are no relevant ethical regulations regarding the use of bacteria in our context.
Social science research
Our human subjects research mainly consisted of interviews and in-person teaching. All our research was done in accordance with relevant laws and regulations.
Written consent
We received written, informed consent of all interviewees to record the interviews and use the material appropriately. Everyone who was interviewed or personally referenced on our wiki had ample time to proofread any material related to them and request adjustments. Any persons in photographs used on our wiki also gave consent to our use of that material.
Political awareness
Image 3: Discussion on the topic “designer babies” at our lab workshop for highschool students
As mentioned in Environmental safety, the use of GMOs and the study of synthetic biology are topics of political debate globally as well as locally in Switzerland. We were cautious not to display any political opinions toward the matter. This applies especially to our wiki, lecture series, educational visits to schools and our lab workshop. To find out more about the educational aspect of our project check out our Education page.