Ruminal bacteria lipopolysaccharides: an immunological and microbial outlook

Abstract

Lipopolysaccharides (LPS) are outer membrane components of Gram-negative bacteria made of three regions: the O-antigen; the core oligosaccharide; and a glucosamine disaccharide linked to hydroxy fatty acids, which is named lipid A. The number phosphate groups, and hydroxy fatty acid chains is associated with the immunopotency and the immunomodulatory activity of LPS, where six-acyl chain lipid A with two phosphate groups is found in virulent strains and five- or four-acyl chain lipid A with one phosphate group are found in non-virulent bacteria strains. Ruminal bacteria are predominantly Gram-negative and their LPS have not been thoroughly investigated. In the rumen, LPS is comprised of mixed ruminal LPS. Drawing upon a body of theoretical and applied work, this paper aims to critically review the scientific literature regarding single-species and mixed ruminal bacteria LPS, highlighting the importance of ruminal LPS to the host. Lastly, future research directions are suggested in order to further our understanding of the roles of LPS in the rumen. Possible suggestions for further understanding ruminal LPS include (1) in silico evaluation of major bacteria contributing to ruminal LPS, (2) structural characterization of LPS from prominent ruminal bacteria species, such as ruminal selenomonads and Megasphaera elsdenii, and, (3) ruminal epithelial tissue immune response evaluation from single-species and mixed ruminal LPS. In conclusion, this review identifies numerous areas for future research, including setting the basis for future modeling and simulation of host microbiome interactions in ruminants.

Megasphaera elsdenii: Its Role in Ruminant Nutrition and Its Potential Industrial Application for Organic Acid Biosynthesis

“…Bacillota) and class Clostridia [ 11 ], although it was previously classified in class Negativicutes. Megasphaera is one of a few genera within its phylum to have a porous pseudo-outer membrane that results in a negative Gram-staining reaction, although details of its lipopolysaccharide structure remain sketchy [ 12 ]. Within the the genus Megasphaera are included several species as follows: M. elsdenii, M. hominis , M. cerevisiae , M. micronuciformis , M. paucivorans and M. sueciensis , which have been isolated from various sources, including the rumen, human clinical specimens, and spoiled beer [ 13 ].…”

Fine-tuning of post-weaning pig microbiome structure and functionality by in-feed zinc oxide and antibiotics use

“…Another two species linked to ZnO-free herds were M. elsdenii and Acidaminococcus fermentans . Previous studies have also reported the negative impact of ZnO on the abundance of these two species ( Pieper et al., 2020 ; Silva et al., 2021 ; Ortiz Sanjuán et al., 2022 ), which are capable of produce butyrate from lactate and glutamate, respectively ( Tsukahara et al., 2006 ; Sarmikasoglou and Faciola, 2022 ; Böck, 2009 ). Both amino-acid fermenting species are common members of the adult pig fecal microbiota and increase in the abundance as the animal grows.…”

Effects of Flammulina velutipes mushroom residues on growth performance, apparent digestibility, serum biochemical indicators, rumen fermentation and microbial of Guizhou black goat

“…The change of rumen microbes has an important relationship with the body’s immune regulation, disease resistance, and animal growth ( Wang et al, 2021 ). Lachnospiraceae_NK4A136_group and Lachnospiraceae_ND3007_group belong to the Lachnospiraceae family, and many microorganisms can produce butyric acid, which can inhibit inflammation and enhance the integrity of the epithelial barrier and are positively correlated with IgG and IgM ( Meehan and Beiko, 2014 ; Sarmikasoglou and Faciola, 2022 ). In addition, Ruminococcus may inhibit inflammation and promote growth in animals through butyrate production ( Scaldaferri et al, 2016 ).…”