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Xochitecatl is located in a dominant position upon the summit of a 4 km-wide extinct volcano that forms a range of hills that rises approximately 200 meters above the floor of the Puebla-Tlaxcala Valley; the so-called Atlachino-Nativitas-Xochitecatl block, which is located in the centre of the valley.
Bacterial microcompartments are widespread, organelle-like structures that are made of a protein shell that surrounds and encloses various enzymes. provide a further level of organization; they are compartments within bacteria that are surrounded by polyhedral protein shells, rather than by lipid membranes. These "polyhedral organelles ...
It is primarily found in Gram-negative bacteria, such as Escherichia coli and Salmonella typhimurium. [1] Enterobactin is the strongest siderophore known, binding to the ferric ion (Fe 3+) with affinity K = 10 52 M −1. [2] This value is substantially larger than even some synthetic metal chelators, such as EDTA (K f,Fe3+ ~ 10 25 M −1). [3]
Based on solution structures and sequence alignments, bacteriocins appear to take on similar 3D structures despite little sequence homology, contributing to stability and resistance to degradation. Conopeptides and other toxoglossan peptides are the components of the venom of predatory marine snails, such as the cone snails or Conus. [24]
A microbial mat consists of several layers, each of which is dominated by specific types of microorganism, mainly bacteria.Although the composition of individual mats varies depending on the environment, as a general rule the by-products of each group of microorganisms serve as "food" for other groups.
Bacteria (prokaryotes, together with Archaea) share many common features. These commonalities include the lack of a nuclear membrane, unicellularity, division by binary-fission and generally small size. The various species can be differentiated through the comparison of several characteristics, allowing their identification and classification.
The cell wall structure of gram-positive bacteria is made routinely up by peptidoglycan which allows the passage of cephalosporin-sized molecules. The cell wall structure of gram-negative bacteria is more complex, composed of polysaccharides, lipids and proteins, and is harder to penetrate.
Mucilage is a thick gluey substance produced by nearly all plants and some microorganisms. These microorganisms include protists which use it for their locomotion, with the direction of their movement always opposite to that of the secretion of mucilage. [1] It is a polar glycoprotein and an exopolysaccharide.