Microbes and the Next Nitrogen Revolution

Abstract

The Haber Bosch process is among the greatest inventions of the 20th century. It provided agriculture with reactive nitrogen and ultimately mankind with nourishment for a population of 7 billion people. However, the present agricultural practice of growing crops for animal production and human food constitutes a major threat to the sustainability of the planet in terms of reactive nitrogen pollution. In view of the shortage of directly feasible and cost-effective measures to avoid these planetary nitrogen burdens and the necessity to remediate this problem, we foresee the absolute need for and expect a revolution in the use of microbes as a source of protein. Bypassing land-based agriculture through direct use of Haber Bosch produced nitrogen for reactor-based production of microbial protein can be an inspiring concept for the production of high quality animal feed and even straightforward supply of proteinaceous products for human food, without significant nitrogen losses to the environment and without the need for genetic engineering to safeguard feed and food supply for the generations to come.

Greater Contribution From Agricultural Sources to Future Reactive Nitrogen Deposition in the United States

“…Alternatively, studies point to microbial protein as a food source as the ultimate solution to tackle Nr pollution while sustaining the growing population. (Pikaar et al, 2018;Pikaar et al, 2017). Results for comparison between deposition level and the average CL are provided in Figure S13.…”

Emerging Opportunities for Synthetic Biology in Agriculture

“…A long standing target for improvement in plant based agriculture is nitrogen fixation [ 76 , 77 ]. Nitrogen in a bioavailable form for crops is incredibly expensive to produce and environmentally costly, using 1% of the total annual world energy expenditure [ 78 ]. While plants are unable to fix atmospheric nitrogen, microbes can and do, particularly rhizobia in legumes.…”

Taking the technical microbiome into the next decade

“…The current lower production rates, compared to direct carboxylate production via fermentation, and subsequent high operational and capital cost, which are a factor of 5–10 higher than the actual value of, for example, acetate (Christodoulou and Velasquez‐Orta, ), do not yet enable economic application of electrosynthesis as such. As a final option, biogas can serve as a carbon and energy source to produce microbial protein as animal feed or even human food (Matassa et al , b; Pikaar et al , ). This can be carried out either directly by using methane as carbon and energy source for methane oxidizing bacteria (Strong et al , ; Verstraete et al , ) or indirectly as energy source to produce electricity for hydrogen gas production through water electrolysis for hydrogen oxidizing bacteria (Matassa et al , a).…”