ClimateCow: Reducing ruminant methane emission by killing methanogenic archaea with viruses

Methane (CH4) is a powerful greenhouse gas produced in ruminants via methanogensis (CO2 + 4 H2 → CH4 + 2 H2O), a form of anaerobic respiration only known to be conducted by methanogenic archaea, mainly Methanobrevibacter. This archaea is highly abundant in high methane emitting cows and a major methane-producer. Archaeal viruses are viruses killing archaea in a host specific manner and offer an attractive tool to reduce ruminant methane production by killing Methanobrevibacter. Unfortunately, most archaea carry efficient CRISPR-Cas systems not only protecting them against viral attack in the rumen, but also making isolation of such viruses difficult due to lack of suitable hosts for virus screening. Here, by using bioinformatic tools we will determine which archaeal viruses  from a given rumen sample are able to attack specific strains of Methanobrevibacter. Based on this information we will in a targeted manner isolate Methanobrevibacter viruses from rumen samples. Subsequently we will in a non-GMO manner engineer the isolated viruses enabling them to efficiently kill wildtype Methanobrevibacter therefore reducing methane-production.