Butyrivibrio hungateiMB2003 competes effectively for soluble sugars released byButyrivibrio proteoclasticusB316^Tfrom growth on xylan or pectin

Abstract

Rumen bacterial species belonging to the genera Butyrivibrio are important 16 degraders of plant polysaccharides, particularly hemicelluloses (arabinoxylans) and pectin. 17Currently, four distinct species are recognized which have very similar substrate utilization 18 profiles, but little is known about how these microorganisms are able to co-exist in the rumen. To 19 investigate this question, Butyrivibrio hungatei (MB2003) and Butyrivibrio proteoclasticus 20 (B316 T ) were grown alone or in co-culture on the insoluble substrates, xylan or pectin, and their 21 growth, release of sugars, fermentation end products and transcriptomes were examined. In 22 single cultures, B316 T was able to degrade and grow well on xylan and pectin, while B. hungatei 23

Complete Genome Sequence of the Polysaccharide-Degrading Rumen BacteriumPseudobutyrivibrio xylanivoransMA3014

“…Given the observed polysaccharide-degrading abilities and lactate production, the Methylglyoxal Shunt (MS) and uronic acid metabolic pathways ( Figure 2D), have been suggested as alternatives to the EMP pathway (Cooper 1984). Previous work has also reported similar findings in other Butyrivibrio strains (Kelly, et al 2010;Palevich, et al 2019a). In this pathway the dihydroxyacetone phosphate is transformed to pyruvate via methylglyoxal and D-lactate dehydrogenase encoded by ldhA.…”

“…MA3014 is the largest P. xylanivorans genome to date, where it is 163,567 bp and 370,547 bp larger, also contains 187 and 375 more PCGs than Mz 5 T and NCFB 2399, respectively. A novel feature of MA3014 and other well-characterized Butyrivibrio genomes is the presence of chromids or secondary chromosomes (Kelly, et al 2010;Palevich, et al 2019a). Chromids are replicons with %G+C content similar to that of their main chromosome, but have plasmid-type maintenance and replication systems, are usually smaller than the chromosome (but larger than plasmids) and contain genes essential for growth along with several core genus-specific genes (Harrison, et al 2010).…”

“…This difference is due to Mz 5 T possession of 4 pectate lyases (1 PL1 and PL3) predicted to be involved in pectin degradation and utilization, of which MA3014 has none. The ability of MA3014 to breakdown starch and xylan is predicted to be based on four large (>1,000 aa) cell-associated proteins shown to be significantly up-regulated in related B. hungatei MB2003 and B. proteoclasticus B316 T cells grown on xylan (Kelly, et al 2010;Palevich, et al 2019a). These are: repeat domains (CW-binding domain, Pfam01473) at their C-termini that are predicted to anchor the protein to the peptidoglycan cell membrane (Dunne, et al 2011).…”

“…The MA3014 genome possesses methylglyoxal synthase, mgsA (FXF36_12340), glyoxalases gloA/B (FXF36_00730, FXF36_01130 and FXF36_09530) and both D-and L-lactate dehydrogenases ldh (FXF36_04170 and FXF36_11135) genes. In addition, MA3014 has the same set of genes as the previously reported and well-characterized B. hungatei MB2003 and B. proteoclasticus B316 T for the production of butyrate, formate, acetate and lactate (Kelly, et al 2010;Palevich, et al 2019a;Palevich, et al 2017).…”

The complete mitochondrial genome of the New Zealand parasitic roundwormTeladorsagia circumcincta(Trichostrongyloidea: Haemonchidae) field strain NZ_Teci_NP

“…The specimen was collected from the Palmerston North area (40 21.3 0 S, 175 36.7 0 E) and is stored (accession number: NPX120886) and available upon request from AgResearch Ltd., Grasslands Research Centre. High molecular weight genomic DNA was isolated from multiple T. circumcincta adult males using a modified phenol:chloroform protocol (Palevich et al 2017;Palevich, Kelly, et al 2019). The Illumina MiSeq (Macrogen, Korea) platform was used to amplify the entire mitochondrial genome sequence (GenBank accession number: MN013406).…”