Gut microbiota of cattle and horses and their use in the production of ethanol and lactic acid from timothy hay

Abstract

The gut of herbivorous animals is an untapped source of the microbial consortium that could be used to improve the hydrolysis of lignocellulosic biomass. This study investigated the hydrolysis of Timothy hay by the anaerobic incubation with fecal inocula from four cows (CB) and four horses (HB) for 72 h. The microbial communities colonized timothy hay were analyzed using Illumina Mi-Seq sequencing of 16S rDNA genes. The source of the inoculum affected the structure of microbial communities that were dominated by phylum Firmicutes, Bacteroidetes, and Proteobacteria, and the dominant genera were Enterococcus, Streptococcus, Escherichia-Shigella, Bacteroides, and Prevotella. Moreover, several bacteria were observed exclusively in a specific group. For example, group CB had phylum Fibrobacterota and Spirochaetota besides genera Prevotellaceae YAB2003 and Bacteroides; and group HB had genera Weissella and Lactococcus. Moreover, function prediction revealed that the CB group has a higher abundance of genes related to carbohydrate metabolism. Group CB showed higher neutral detergent fiber degradability (NDFD), gas production, cellulase, xylanase, and xylose, and group HB showed higher dry matter degradability (DMD), glucose, ethanol, and lactic acid. The feces of cattle and horses represent a source of the bacterial consortium for enzyme production and the hydrolysis of lignocellulosic biomass.

Keywords:

• Gut bacteria
• cows
• horses
• cellulase and xylanase
• timothy
• ethanol
• lactic acid

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

We would like to acknowledge the Egyptian Ministry of High Education for its support of Alaa Rabee in fellowship at the University of Maine, USA.