PNNL

Abstract

Engineered microbes are being programmed using synthetic DNA for applications in soil to overcome global challenges related to climate change, energy, food security, and pollution. However, we cannot yet predict gene transfer processes in soil to assess the frequency of unintentional transfer of engineered DNA to environmental microbes when applying synthetic biology technologies at scale. This challenge exists because of the complex and heterogeneous characteristics of soils, which contribute to the fitness and transport of cells and the exchange of genetic material within communities. Here we describe gaps in our knowledge about gene transfer in soils. We propose strategies to improve our understanding of gene transfer across soil communities, highlight the need to benchmark the performance of biocontainment measures in situ, and discuss responsibly engaging community stakeholders. We highlight opportunities to address knowledge gaps, such as creating a set of soil standards for studying gene transfer across diverse soil types and measuring gene transfer host range across communities using emerging technologies. By comparing gene transfer rates, host range, and engineered microbe persistence across different soils, we posit that community-scale models can be built that anticipate biotechnology risks. Such studies will not only enable us to design safer biotechnologies and realize their benefits, but they will allow us to mitigate the unintended release of such technologies.