Phenol redPhenol red (also known as phenolsulfonphthalein or PSP) is a pH indicator frequently used in cell biology laboratories. Phenol red exists as a red crystal that is stable in air. Its solubility is 0.77 grams per liter (g/L) in water and 2.9 g/L in ethanol. It is a weak acid with pKa = 8.00 at . A solution of phenol red is used as a pH indicator, often in cell culture. Its color exhibits a gradual transition from yellow (λmax = 443 nm) to red (λmax = 570 nm) over the pH range 6.8 to 8.2. Above pH 8.
AgrochemicalAn agrochemical or agrichemical, a contraction of agricultural chemical, is a chemical product used in industrial agriculture. Agrichemical refers to biocides (pesticides including insecticides, herbicides, fungicides and nematicides) and synthetic fertilizers. It may also include hormones and other chemical growth agents. Agrochemicals are counted among speciality chemicals. biological activity In most of the cases, agrochemicals refer to pesticides.
Sulfate-reducing microorganismSulfate-reducing microorganisms (SRM) or sulfate-reducing prokaryotes (SRP) are a group composed of sulfate-reducing bacteria (SRB) and sulfate-reducing archaea (SRA), both of which can perform anaerobic respiration utilizing sulfate (SO42-) as terminal electron acceptor, reducing it to hydrogen sulfide (H2S). Therefore, these sulfidogenic microorganisms "breathe" sulfate rather than molecular oxygen (O2), which is the terminal electron acceptor reduced to water (H2O) in aerobic respiration.
Koch's postulatesKoch's postulates (kɒx ) are four criteria designed to establish a causal relationship between a microbe and a disease. The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884, based on earlier concepts described by Jakob Henle, and the statements were refined and published by Koch in 1890. Koch applied the postulates to describe the etiology of cholera and tuberculosis, both of which are now ascribed to bacteria. The postulates have been controversially generalized to other diseases.
Hoechst stainHoechst stains are part of a family of blue fluorescent dyes used to stain DNA. These bis-benzimides were originally developed by Hoechst AG, which numbered all their compounds so that the dye Hoechst 33342 is the 33,342nd compound made by the company. There are three related Hoechst stains: Hoechst 33258, Hoechst 33342, and Hoechst 34580. The dyes Hoechst 33258 and Hoechst 33342 are the ones most commonly used and they have similar excitation–emission spectra.
Bacteriostatic agentA bacteriostatic agent or bacteriostat, abbreviated Bstatic, is a biological or chemical agent that stops bacteria from reproducing, while not necessarily killing them otherwise. Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics and preservatives can be distinguished. When bacteriostatic antimicrobials are used, the duration of therapy must be sufficient to allow host defense mechanisms to eradicate the bacteria. Upon removal of the bacteriostat, the bacteria usually start to grow rapidly.
Hydrogen sulfideHydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The underground mine gas term for foul-smelling hydrogen sulfide-rich gas mixtures is stinkdamp. Swedish chemist Carl Wilhelm Scheele is credited with having discovered the chemical composition of purified hydrogen sulfide in 1777.
AzotobacterAzotobacter is a genus of usually motile, oval or spherical bacteria that form thick-walled cysts (and also has hard crust) and may produce large quantities of capsular slime. They are aerobic, free-living soil microbes that play an important role in the nitrogen cycle in nature, binding atmospheric nitrogen, which is inaccessible to plants, and releasing it in the form of ammonium ions into the soil (nitrogen fixation). In addition to being a model organism for studying diazotrophs, it is used by humans for the production of biofertilizers, food additives, and some biopolymers.
YogurtYogurt (UKˈjɒɡərt; USˈjoʊɡərt, from yoğurt, also spelled yoghurt, yogourt or yoghourt) is a food produced by bacterial fermentation of milk. The bacteria used to make yogurt are known as yogurt cultures. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and characteristic tart flavor. Cow's milk is the milk most commonly used to make yogurt. Milk from water buffalo, goats, ewes, mares, camels, and yaks are also used to produce yogurt.
SepsisSepsis (septicaemia in British English), or blood poisoning, is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection.
