Cultivation and sequencing of rumen microbiome members from the Hungate1000 Collection

Abstract

Climate change and feeding a growing global population are the two biggest challenges facing agriculture 1 . Ruminant livestock have an important role in food security 2 ; they convert low-value lignocellulosic plant material into high-value animal proteins that include milk, meat and fiber products. Microorganisms present in the rumen 3,4 ferment polysaccharides to yield short-chain fatty acids (SCFAs; acetate, butyrate and propionate) that are absorbed across the rumen epithelium and used by the ruminant for maintenance and growth. The rumen represents one of the most rapid and efficient lignocellulose depolymerization and utilization systems known, and is a promising source of enzymes for application in lignocellulose-based biofuel production 5 . Enteric fermentation in ruminants is also the single largest anthropogenic source of methane (CH 4 ) 6 , and each year these animals release ~125 million tonnes of CH 4 into the atmosphere. Targets to reduce agricultural carbon emissions have been proposed 7 , with >100 countries pledging to reduce agricultural greenhouse gas emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Consequently, improved knowledge