Having identified the design parameters for the system, the next stage was to begin ordering parts and putting it together. The system was divided into three independent, functional sub-systems to make the task of assembling the system more manageable and allowing team members to focus on the sub-system that most suited their specialty. These three sub-systems were hardware, software and biological aspects.

The function of the hardware is to contain the electronics and organisms, power the LED’s/microcontroller and maximise the light available to the plants. Containment is through the use of a sealed box, with a detachable lid for access. This box is glued with tin foil and sprayed black to minimise exchange of light with the environment. Powering the LED’s proved to be more difficult, taking our engineers many days to find the optimal solution. You can find all the grizzly details on this process here. However, essentially the system is powered from a 5V 2.1A AC adapter that plugs straight in to your mains power supply. Alternatively, you can use 4 AA batteries to power the system for short periods of time if necessary. The LED’s are wired in parallel so the same light is provided along the length of the container. This can be seen from images in the Gallery.

The purpose of the software is to control the LED’s, by allowing the user to easily adapt features such as light intensity, wavelength and also specify the length of the day/night cycle. For our design, we use the Arduino UNO microcontroller to control these characteristics as it offers a user-friendly interface and is well-suited to our design. You can find all the code laid bare and a guide to the Arduino here.

Growing in Contained Environments

The use of biotechnology to modify plants has become common place in agricultural research - but we have conceptualised this as common place in agricultural practice. (See our Human Practices). In the context of our project, the purpose of containment is to prevent recombinant DNA from transgenic organisms being transferred to populations outside of our urban farm in Newcastle’s Victoria Tunnel (although the safety principals apply to any contained environments in which our transgenic organisms are present).

Genetically engineered organisms are subject to special rules intended to ensure that they are used in a way that does not pose an unacceptable risk to human health - or the environment. In order to design our hydroponic urban farm to meet these biosafety standards, we referred to:

• Greenhouse Research with Transgenic Plants and Microbes: A Practical Guide to Containment
  (Traynor, Patricia L, Dann Adair, Ruth Irwin)
  Methods for the safe handling of transgenic materials in contained environment are also described in the National Institutes of Health’s Guidelines for Research Involving Recombinant DNA Molecules (NIH Guidelines).

Below I have taken extracts from the guide to containment that we referred to in order to design our own contained system:

• Elements of containment:
  1. Avoid unintentional transmission of rDNA-containing plant genomes or release of rDNA-derived organisms associated with plants;
  2. Minimize the possibility of unanticipated deleterious effects on organisms and ecosystems outside of the experimental facility;
  3. Avoid the inadvertent spread of a serious pathogen from a greenhouse to a local agricultural crop;
  4. Avoid the unintentional introduction and establishment of an organism in a new ecosystem.

Having read the guide, we concluded our GMO was classified as BL2-P.

• Biosafety Level 2 for Plants (BL2-P)
  "BL2-P is assigned to experiments with transgenic plants and associated organisms, which, if released outside the greenhouse, could be viable in the surrounding environment but would have a negligible impact or could be readily managed. BL2-P is required for transgenic plants that may exhibit a new weedy characteristic or that may be capable of interbreeding with weeds or related species growing in the vicinity."
• Procedures that must be followed for BL2-P:

Newcastle's Victoria Tunnel - Retrofitting for Containment

Retrofitting a structurally sound facility to meet BL2-P containment standards is far cheaper than building a new facility. Necessary modifications, if any, are usually simple, straightforward, and involve readily available materials. This is one of the reasons we have proposed a contained environment in the Victoria Tunnel - it is in a prime location running under the city centre whilst being structurally sound and accessible.

Physical containment is achieved through making appropriate choices when it comes to facility design and equipment. These choices include: glazing, sealing, screening, air flow system, and other features all affect the degree to which a contained environment is capable of isolating transgenic organisms from the surrounding environment. These systems are also effective in keeping unwanted pests out of the facility.

Layout

When retrofitting to accommodate transgenic materials: traffic patterns, process flow, and security measures should be analysed to determine if the layout should be modified. The configuration should be optimised to provide variable levels of containment and growing conditions, control of access, and ease of movement.

An efficient and manageable layout has an array of small rooms and cubicles opening off one or more common walkways; a compartmentalised arrangement of small rooms allows the facility to provide a variety of containment levels as well as individualised environmental conditions.

A contained environment can be an inhospitable for people and equipment because of the humidity, temperature, light, chemicals, and soil. An enclosed area within or adjacent to the facility, provides cleaner, more comfortable space for offices, labs, equipment, supplies, and control systems.

Additional safety considerations when designing contained environments

• Termination and Disposal
  "To prevent the unintended survival of GMOs outside the contained environment, all experimental materials must be rendered biologically inactive (devitalised) before disposal. Termination procedures for the safe disposal of soil and plant material should be part of the experimental plan for a research project. Devitalisation of plant material and soil should be completed before it leaves a contained facility to go to landfill."
• Apparel and Hygiene
  "Personnel entering BL1-P and BL2-P facilities may wear their usual street or lab clothing."


• Greenhouse Staff
  "All staff should become familiar with any differences between caring for GMOs and conventional plants that may affect their own work. In most cases, a brief orientation session is sufficient to explain the nature of the plants (or other transgenic organisms) and any special practices to be employed when handling or working around them. Both the greenhouse manager and the PI should work with the staff to ensure compliance with safety procedures and standards."
• Signage
  "Entryways into BL2-P and higher facilities should be posted with signs indicating that access is limited to authorised personnel only. If the facility uses organisms that pose a risk to the local ecosystem or agriculture, a sign so stating must be placed on the access doors to the facility. A description of the potential risk may be posted on the restricted access sign as long as this is not confidential information. The sign should state the name and telephone number of the responsible individual, the plants in use, and any special requirements for using the area. It may include contact information for the greenhouse manager and others to be called in case of emergency."