Title: Archaebacteria - Definition, Types, Characteristics and Examples
Headings: Archaebacteria
Archaebacteria
Archaebacteria Definition
Archaebacteria Characteristics
Types of Archaebacteria
Examples of Archaebacteria
Lokiarcheota
Methanobrevibacter Smithii
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Content: It has a highly unique genome, consisting of roughly 26% proteins that are known to be found in other archaebacteria, 29% proteins that are known to be found in bacteria, 32% genes that do not correspond to any known protein, and – 3.3% genes that correspond to those only found in eukaryotes. The eukaryotic genes are particularly exciting for scientists, because they are genes that appear to code for proteins that eukaryotes use to actively control the shape of their cell, including proteins for cytoskeletons, the motor protein actin, and several proteins that in eukaryotes are involved in changing cell membrane shape. Some of these genes are involved in phagocytosis, which is exciting because the process of phagocytosis could have been used by eukaryotic ancestors to “swallow” other cells – which may have gone on to become endosymbiotes, leading to the endosymbiotic relationships between eukaryotic cells and their mitochondria, chloroplasts, and nuclei. Lokiarchaeota’s unique genome makes it possibly our closest relative among prokaryotes, and possibly a transitional form in the extremely important jump from prokaryotic to eukaryotic life, which made the evolution of the animal, plant, fungi, and protist kingdoms possible. Scientists think that Lokiarchaeota and ourselves probably shared a common ancestor around 2 billion years ago. It is unknown whether this means that eukaryotes likely evolved around deep sea vents, or whether Lokiarchaeota’s relatives may once have been common in other environments before they were outcompeted and driven to extinction by their more advanced descendants, the eukaryotes. Methanobrevibacter Smithii
Methanobrevibacter smithii is a methane-producing archaebacteria that lives in the human gut. This member of Euryarchaeota helps us to break down complex plant sugars and extract extra energy from the food we eat. The microorganisms in our guts – including members of Euryarchaeota – also have a complex relationship with our health. While some studies show that many people with obesity and colon cancer hav