An Interview with Konrad Siegfried

We have aimed to create a system that would be directly usable in the field. Regarding the practical implementation of the system we have considered the challenges faced by end users.

A kit has been developed by the [http://www.ufz.de/arsolux/index.php?en=20675 ARSOlux team] which can be used for a real application, in this case the detection of arsenic contamination of ground water. They have recently tested their luminescence based kit in Bangladesh, showing some considerable improvements over traditional chemical solutions. Their experiences are documented in [http://pubs.acs.org/doi/abs/10.1021/es203511k this paper], in which they demonstrate that the use of bioreporters in such environments is both feasible and practical. We wanted more details about the system that they used, in order to understand how we could alter our design to fit within current policies and still be useful.

Discussions

To this end, we conducted an interview with Dr. Konrad Siegfried, a member of the team, and perhaps the most experienced user of the ARSOlux kit in the field. Our initial discussions focussed upon the storage and distribution of the bioreporters. We were interested to see that they had used freeze-dried e.coli as their chassis. We had not really considered this as an option during our design process, as we assumed that the shelf life of such cells at room temperature would be severely limited. Viable construct containing e.coli cells have been reawakened after three months at room temperature, and after six month when kept at four degrees centigrade, implying that our original assumptions were incorrect.

However, only a few freeze-drying facilities exist in Bangladesh, potentially limiting the amount of kits which can be produced locally. As discussed in a [http://www.buet.ac.bd/itn/pages/apsudocs/review_of_locally_available_kits.pdf report by Kabir], production of arsenic measurement devices within the country should be a high priority. As any biological laboratory should have the equipment to produce bacillus spores, we maintain that bacillus should be used if possible. Nevertheless, freeze dried e.coli are a far more viable option than we had initially realized, and may be a useful alternative if the transition to bacillus fails.

We were also interested in their apparent choice to use disinfection followed by autoclaving in a university laboratory as their biocontainment method. Upon questioning this form of bacterial destruction, it transpired that this was the only viable option that the Bangladeshi and German governments permit. Alternatively, the used equipment could have been sterilized after use with boiling water. Such biocontainment methods that we have proposed (the most promising simply being the release of bleach into the culture) would first have to be approved by similar authorities before they could be implemented, delaying application of our assay by years. Initial tests would therefore most likely be conducted using similar biocontainment methods to the ARSOlux team.

The kit developed by the ARSOlux team. Images from the ARSOlux website.

Despite this, Dr. Siegfried mentioned that his team were investigating self-destruction methods, which could be applied to considerably simplify the disposal of the bioreporter cells. One of the most promising avenues of research is apparently the application of chemicals within the vials that cause destruction of the cells upon exposure to sunlight, an incredibly simple measure to apply. Such simplicity also makes it more likely that these protocols will be followed, especially if similar tests are eventually released to the general public. Lastly, we wished to focus upon the policies enacted by the Bangladeshi government regarding the use of genetically modified bioreporters, as well as their stance upon the arsenic groundwater contamination problem. Particularly interesting to us is the fact that the governmental acceptable limit of arsenic is 50μg/l, while the WHO recommendation is 10μg/l. We asked Dr. Siegfried why he believed this was.

Graph showing the remarkable sensitivity and reliablitiy of the ARSOlux kit. Images from the ARSOlux website.

It seems that the Government of Bangladesh does not presently have the resources to tackle the vast arsenic contamination problem that faces its country. Without the means to deal with such a problem, it seems that they view the measurement of arsenic levels to within the WHO standard as moot, as a high proportion of the wells in the country will have higher arsenic levels. Additionally, the sensitivity of easily available chemical kits falls more within the 50μg/l range.

Sensing of arsenic levels is still important however, as in villages where the arsenic levels are low enough in some wells, well switching can be used as a tactic for reducing exposure to arsenic.

This led to a discussion about the application of the kit. Currently the test kit is not for sale in any country. At this point in time, it is used for scientific purposes and awareness-raising. The tests that have been performed by the ARSOlux team in Germany have been conducted in a specially fitted bus and with trained professionals operating the system. Their current plans are to use this bus to travel around different villages and to characterize the arsenic contamination present in the wells of an entire village in a single day. However, the water table of Bangladesh is in constant flux, Bangladesh being one of the most waterlogged countries in the world. The changing state of the aquifers in certain contaminated areas makes it likely that the arsenic concentrations of the wells will change from month to month. Lifting the restrictions on GMO use by the villagers themselves would therefore be very useful, as it would allow continual monitoring of each well.

Conclusions

As a result of this interview, we propose the following list of priorities that future teams and present day policy makers should consider:

1) Develop a reliable self-destruction mechanism, robust enough to convince governments of the impossibility of accidental GMO release, or at least that the consequences of such a release should be minimal.

2) Develop the infrastructure necessary to produce such kits in the country of interest and encourage the set up businesses that will manufacture the kits. Competition in the market should help alleviate the image problems that have been faced by biocontainment measures in the past, such as terminator genes.

3) Encourage NGOs working in the countries affected to try existing systems such as the ARSOlux kit, and emphasise the non-profit nature of such initial steps. Much of the poor image that has faced genetic modification up to the present is based on the assumption that large genetic modification companies are not working to create the most effective products, but to create the most profitable products as cheaply as possible. Emphasizing the open-source nature of the components used in such assemblies may also help convince people of their benefits.

4) With the above three points in place, we hope that some of the laws that currently restrict distribution of such kits will be lifted. At this point, with the infrastructure and corporate structures in place for the on-site production of bioreporter kits, the kits should be distributed to villages to permit continual assessment of water quality. Funding for such distribution may come from NGOs, or the government, or even directly from the settlements themselves if the kits are made cheap enough.

We hope that these priorities, when used in South Asia, should also help the successful application of our own kit.