Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Complete genome sequence of Methanosphaera sp. ISO3-F5, a rumen methylotrophic methanogen.(American Society for Microbiology, 2024-04-11) Palevich N; Jeyanathan J; Reilly K; Palevich FP; Maclean PH; Li D; Altermann E; Kelly WJ; Leahy SC; Attwood GT; Ronimus RS; Henderson G; Janssen PH; Stedman KMMethanosphaera spp. are methylotrophic methanogenic archaea and members of the order Methanobacteriales with few cultured representatives. Methanosphaera sp. ISO3-F5 was isolated from sheep rumen contents in New Zealand. Here, we report its complete genome, consisting of a large chromosome and a megaplasmid (GenBank accession numbers CP118753 and CP118754, respectively).Item Competition for Hydrogen Prevents Coexistence of Human Gastrointestinal Hydrogenotrophs in Continuous Culture.(Frontiers Media S.A., 2020-05-29) Smith NW; Shorten PR; Altermann E; Roy NC; McNabb WC; Kappler UUnderstanding the metabolic dynamics of the human gastrointestinal tract (GIT) microbiota is of growing importance as research continues to link the microbiome to host health status. Microbial strains that metabolize hydrogen have been associated with a variety of both positive and negative host nutritional and health outcomes, but limited data exists for their competition in the GIT. To enable greater insight into the behaviour of these microbes, a mathematical model was developed for the metabolism and growth of the three major hydrogenotrophic groups: sulphate-reducing bacteria (SRB), methanogens and reductive acetogens. In batch culture simulations with abundant sulphate and hydrogen, the SRB outcompeted the methanogen for hydrogen due to having a half-saturation constant 106 times lower than that of the methanogen. The acetogen, with a high model threshold for hydrogen uptake of around 70 mM, was the least competitive. Under high lactate and zero sulphate conditions, hydrogen exchange between the SRB and the methanogen was the dominant interaction. The methanogen grew at 70% the rate of the SRB, with negligible acetogen growth. In continuous culture simulations, both the SRB and the methanogen were washed out at dilution rates above 0.15 h-1 regardless of substrate availability, whereas the acetogen could survive under abundant hydrogen conditions. Specific combinations of conditions were required for survival of more than one hydrogenotroph in continuous culture, and survival of all three was not possible. The stringency of these requirements and the inability of the model to simulate survival of all three hydrogenotrophs in continuous culture demonstrates that factors outside of those modelled are vital to allow hydrogenotroph coexistence in the GIT.