L-form bacteriaL-form bacteria, also known as L-phase bacteria, L-phase variants or cell wall-deficient (CWD) bacteria, are growth forms derived from different bacteria. They lack cell walls. Two types of L-forms are distinguished: unstable L-forms, spheroplasts that are capable of dividing, but can revert to the original morphology, and stable L-forms, L-forms that are unable to revert to the original bacteria. L-form bacteria were first isolated in 1935 by Emmy Klieneberger-Nobel, who named them "L-forms" after the Lister Institute in London where she was working.
Cell membraneThe cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures.
Sulfur-reducing bacteriaSulfur-reducing bacteria are microorganisms able to reduce elemental sulfur (S0) to hydrogen sulfide (H2S). These microbes use inorganic sulfur compounds as electron acceptors to sustain several activities such as respiration, conserving energy and growth, in absence of oxygen. The final product of these processes, sulfide, has a considerable influence on the chemistry of the environment and, in addition, is used as electron donor for a large variety of microbial metabolisms.
Bloodstream infectionsBloodstream infections (BSIs), septicemia which include bacteremias when the infections are bacterial and fungemias when the infections are fungal, are infections present in the blood. Blood is normally a sterile environment, so the detection of microbes in the blood (most commonly accomplished by blood cultures) is always abnormal. A bloodstream infection is different from sepsis, which is the host response to bacteria.
Dead SeaThe Dead Sea (اَلْبَحْرُ الْمَيْتُ, Āl-Baḥrū l-Maytū; יַם הַמֶּלַח, Yam hamMelaḥ), also known by other names, is a salt lake bordered by Jordan to the east and the West Bank and Israel to the west. It lies in the Jordan Rift Valley, and its main tributary is the Jordan River. As of 2019, the lake's surface is below sea level, making its shores the lowest land-based elevation on Earth. It is deep, the deepest hypersaline lake in the world. With a salinity of 342 g/kg, or 34.
Frequency responseIn signal processing and electronics, the frequency response of a system is the quantitative measure of the magnitude and phase of the output as a function of input frequency. The frequency response is widely used in the design and analysis of systems, such as audio and control systems, where they simplify mathematical analysis by converting governing differential equations into algebraic equations.
Regulator geneA regulator gene, regulator, or regulatory gene is a gene involved in controlling the expression of one or more other genes. Regulatory sequences, which encode regulatory genes, are often at the five prime end (5') to the start site of transcription of the gene they regulate. In addition, these sequences can also be found at the three prime end (3') to the transcription start site. In both cases, whether the regulatory sequence occurs before (5') or after (3') the gene it regulates, the sequence is often many kilobases away from the transcription start site.
Lipid raftThe plasma membranes of cells contain combinations of glycosphingolipids, cholesterol and protein receptors organised in glycolipoprotein lipid microdomains termed lipid rafts. Their existence in cellular membranes remains somewhat controversial. It has been proposed that they are specialized membrane microdomains which compartmentalize cellular processes by serving as organising centers for the assembly of signaling molecules, allowing a closer interaction of protein receptors and their effectors to promote kinetically favorable interactions necessary for the signal transduction.
RNA splicingRNA splicing is a process in molecular biology where a newly-made precursor messenger RNA (pre-mRNA) transcript is transformed into a mature messenger RNA (mRNA). It works by removing all the introns (non-coding regions of RNA) and splicing back together exons (coding regions). For nuclear-encoded genes, splicing occurs in the nucleus either during or immediately after transcription. For those eukaryotic genes that contain introns, splicing is usually needed to create an mRNA molecule that can be translated into protein.
Pathogenic bacteriaPathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
