A Fungus that Reduces Methane Emissions
Noteworthy
We face unprecedented rising global temperatures, a crisis driven largely by the burning of fossil fuels. But other sectors, like the livestock industry, also contribute by producing large amounts of greenhouse gases.
The livestock industry produces an estimated 14% of the anthropogenic greenhouse gas emissions. Most of this methane is produced in the rumen of cattle by anaerobic methanogenic archaea. Given the worldwide importance and size of this industry, mitigating methane emissions emanating from ruminants is a priority.
Fig. 1. Comparison of VHPO activity in selected fungal isolates. (A) Example of a phenol-red assay plate used to measure VHPO activity in supernatant samples from cultures of Curvularia and other fungal genera after 14 d growth. Wells E1–4 were blank while E5 contained buffer only. Well C3 shows VHPO activity from culture supernatant of fungal isolate 4388. Reactions were incubated for 24 h at 28°C. Source
Bromoform, a trihalogenated compound commonly produced by algae to prevent growth of other organisms, inhibits methanogenesis. These algae suppress ruminant methanogenesis when included as a feed additive in cattle diets. However, it is currently costly and difficult to provide sufficient algae to meet global demands.
In a recent report, a group in Australia examined new sources of bromoform for use as food additives. They screened for fungi that produced enzymes involved in the production of bromoform and showed that one bromoform-producing Curvularia soil fungal isolate suprressed methanogenesis. Culture supernatants of this strain inhibited methanogenesis by Methanobrevibacter smithii and when added to mixed cultures of rumen fluid. (See the paper for figure explanation.)
This work leverages microbial fermentation of an easily cultured fungal species to obtain an alternative and more economical source of bromoform for mitigating ruminant methane production
("Noteworthy" is the new format for STC's Thursday posts. Please read our Jan 20, 2025 post outlining this and other changes in our blog.)
