Irritable Bowel Syndrome
Nicole M. Farmer, Andres Victor Ardisson Korat in Cooking for Health and Disease Prevention, 2022
Another proposed mechanism for the effect of FODMAPs has to do with bacterial fermentation and SIBO (Sachdeva et al., 2011). The theory goes that these poorly absorbed carbohydrates are excellent sources of food for an overgrowth of bacteria in the small intestine. These bacteria and sometimes archaea (single-celled nonbacterial organisms) ferment the carbohydrates and release different gases such as hydrogen and methane (recent evidence points to hydrogen sulfide, as well) (Banik et al. 2016). The gases released can cause the symptoms of bloating and also lead to cramping, pain, and changes in the motility of the small intestine.
Bacteria
Julius P. Kreier in Infection, Resistance, and Immunity, 2022
There are presently considered to be two distinct Prokaryotic Kingdoms: (1) True Bacteria (Eubacteria) and (2) Archaebacteria; both of which are distinct from a third Kingdom: Eucarya (i.e., the eucaryotes), that includes all plants, animals, fungi, ciliates, cellular slime molds, flagellates, and microsporidia. However, some disagreement exists about the taxonomy and spelling as some authors divide the Eucarya into four separate kingdoms: (3) Protista, which includes water molds, slime molds, protozoa, and primitive eukaryotic algae; (4) Fungi, which includes yeast, multicellular molds including some with macroscopic forms; (5) Plants, and (6) Animals. If the three kingdom taxonomy is adhered to, then the four eukaryote kingdoms would be Phyla or Divisions within Eucarya. Note that the Protista and Fungi are comprised primarily of microorganisms.
An Overview of Parasite Diversity
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2015
As presently known, the adoption of parasitism has not been a conspicuous feature in the evolution of the Archaea. One species of Archaea, Nanoarchaeum equitans, has been discovered that parasitizes another member of the Archaea (Figure 2.4). Both host and parasite live in scalding hot, sulfur-rich water. However, most members of the Archaea are nonparasitic. The underlying nature of relationships of archaeal species with one another and with their hosts are variable and poorly known, so parasitism may prove to be more prominent than we currently know. Archaea inhabit extreme environments, such as hot springs or saline lakes, are commonly found in aquatic habitats, or in some cases are part of the gut flora of animals, including humans. Although archaeal species are generally not parasitic, an increasing number of examples indicates that they have contributed genes by horizontal gene transfer to bacteria that are overtly parasitic. For the two remaining domains, the Bacteria and Eukarya, as we discuss in the sections that follow, adoption of parasitism has figured prominently.
Gut non-bacterial microbiota contributing to alcohol-associated liver disease
Published in Gut Microbes, 2021
Wenkang Gao, Yixin Zhu, Jin Ye, Huikuan Chu
Archaea were originally discovered and isolated from ecosystems with extreme conditions, including environments with high temperature, strong acid or base, and high ion concentration. However, with the continuous advancing of detection techniques, archaea had also been found in some mild environments such as the ocean ecosystems.145–149 Archaea are similar to bacteria in terms of shape, size, and genetic information expression including DNA replication, RNA transcription, and protein synthesis. Beside these similarities, there are also some obvious differences between archaea and bacteria. For instance, the archaeal cell walls do not contain peptidoglycans,150 and their cell membranes are composed of L-glycerol-ether/isoprenoid lipids, which are more stable and rigid than bacterial.151 Moreover, due to its special metabolic patterns, archaea can use sunlight, inorganic or organic substances as energy sources.152
Biofilms of Halobacterium salinarum as a tool for phenanthrene bioremediation
Published in Biofouling, 2020
Leonardo Gabriel Di Meglio, Juan Pablo Busalmen, César Nicolas Pegoraro, Débora Nercessian
Hydrocarbon degrading microorganisms often exhibit high cell surface hydrophobicity, which enables adhesion to the target compound. In bacterial systems, several authors have observed the growth of biofilms in close contact with PAH crystals or at the hydrocarbon-water interphase (Vaysse et al. 2011), which led them to propose a role for bacterial attachment in improving compound mobilization (Guieysse et al. 2000; Eriksson et al. 2002; Wick et al. 2002). Less information is available concerning cell surface hydrophobicity within Archaea, but strategies seem to be similar to those found in bacteria. For instance, the halophilic archaeon Haloferax sp. MSNC14, which is able to degrade heptadecane but cannot consume phenanthrene, presented a 60–70% adhesion to heptadecane, while the adhesion to phenanthrene was lower than 20% (Djeridi et al. 2013).
Tracing protein and proteome history with chronologies and networks: folding recapitulates evolution
Published in Expert Review of Proteomics, 2021
Gustavo Caetano-Anollés, M. Fayez Aziz, Fizza Mughal, Derek Caetano-Anollés
The arrangement of domains along the sequence of multidomain proteins is referred to as ‘domain organization,’ which together with tertiary structure make up the ‘domain architecture’ of proteins (Figure 1B). While initial studies determined that more than two-thirds of protein sequences were longer than an average domain length [85,86], a later analysis in 749 genomes demonstrated that only about a third of proteins were multidomain [14]. Domains had mean lengths of 256, 280 and 281 amino acids for proteomes of Archaea, Bacteria and Eukarya, respectively. However, protein lengths in Eukarya almost doubled those in Bacteria and Archaea. Shorter prokaryotic nondomain sequences that link domains to each other in proteins accounted for the difference, suggesting these linkers evolved reductively in prokaryotes but not in eukaryotes [14].
Related Knowledge Centers
- Bacteria
- Endospore
- Eukaryote
- Metabolic Pathway
- Morphology
- Prokaryote
- Cell Nucleus
- Kingdom
- Isolation
- Gene