The composition of mono- and di-rhamnolipids can also be modified through altering the expression levels of RhlB and RhlC. In addition, cell-free rhamnolipid synthesis by using the key enzymes and precursors from non-pathogenic sources is thought to not only eliminate pathogenic effects and simplify the downstream purification processes, but also to circumvent the complexity of quorum sensing system that regulates rhamnolipid biosynthesis.
The pathogenicity of P. The rhamnolipid production cost can also be significantly reduced if rhamnolipid purification step can be bypassed, such as utilizing the fermentation broth or the rhamnolipid-producing strains directly in the industrial applications of rhamnolipids. Keywords: Rhamnolipids, Pseudomonas, fermentation, Metabolic engineering, Application Background Surfactants are amphipathic molecules with surface activities to reduce surface tensions.
They are widely utilized as detergents, solubilizers or emulsifying agents in many industrial fields such as petroleum, food, pharmaceutical and agricultural industries [ 1 , 2 ]. The total worldwide production of surfactants is estimated to be over 15 million tons per year, and expected to increase to over 24 million tons annually by [ 3 ]. Currently, surfactants are mainly derived from petroleum products chemically due to the low cost of production.
However, synthetic surfactants are non-biodegradable, which may lead to environmental problems. Therefore, biosurfactants produced by microbial fermentation can be used to replace synthetic surfactants as environmental friendly alternatives [ 4 — 6 ]. The most attractive characteristic of biosurfactant is that they are easily biodegradable and cause less toxic impact to the environment, while having similar properties to synthetic surfactants.
Some biosurfactants are also tolerant to a wide range of extreme conditions low and high pH, high temperature and high salinity that are frequently encountered in industrial processes, as well as several interesting biological properties like antimicrobial activity [ 2 , 7 ]. Biosurfactants can be classified into several categories including glycolipids rhamnolipids, sophorolipids, trehalose lipids , lipopeptide surfactin, iturin and polymeric compounds emulsan, alasan [ 9 ].
Click on your proteins of interest in the pathway image or review below Select your genes of interest and click "add selection" When you have finished your gene selection, click "Find Products" to find assays, arrays, or create custom products Pathway Navigator Biosynthesis of Steroid Hormones Steroid hormones are crucial substances for the proper functioning of the body.
They mediate a wide variety of vital physiological functions ranging from anti-inflammatory agents to regulating events during pregnancy. Typically, endocrinologists classify steroid hormones into five major groups, based primarily on the receptor to which they bind, and the physiological outcomes: i Glucocorticoids Anti-Stress Hormones , Cortisol is the major representative in most mammals; Mineralocorticoids Ion Uptake Regulators , Aldosterone being most prominent; Androgens Male Sex Hormones , such as Androstenedione and Testosterone; Estrogens Female Sex Hormones , including Estrodiol and Estrone; and, Progestogens progestational hormones , such as Progesterone.
The steroid hormones are synthesized and secreted into the bloodstream by endocrine glands, such as the Adrenal Cortex and the Gonads Ovary and Testes. Once released into the bloodstream, these hormones travel to other parts of the body where they bring about specific responses from specific cells. The Glucocorticoids affect carbohydrate, protein, and lipid metabolism, and influence a wide variety of other vital functions including inflammatory reactions and the capacity to cope with stress.
The Mineralocorticoids largely function to regulate the excretion of salt and water by kidney. Both Androgens and Estrogens affect sexual development and function. They regulate sexual differentiation, the secondary sex characteristics, and sexual behavior patterns. Progestogens help mediate the menstrual cycle and pregnancy Ref. Steroid hormones are all characterized by the steroid nucleus which is composed of three six member rings and one five member ring. Steroid hormones are derivatives of Cholesterol, the major animal sterol.
While cholesterol can be synthesized in many body tissues, further differentiation into steroid hormones takes place only in the Adrenal Cortex and in its embryological cousins, the Ovaries and the Testes. The parent compound Cholesterol contains a ring system composed of 27 Carbons. It is made up of three hexagonal carbon rings and a pentagonal carbon ring to which a side-chain Carbons is attached at position 17 of the polycyclic hydrocarbon. Two angular methyl groups are also found at position 18 and Removal of part of the side-chain gives rise to Ccompounds of the Pregnane series Progestogens and Corticosteroids.
Total removal of the side chain produces Csteroids of the Androstane series including the Androgens , whereas loss of the Methyl group followed by aromatization yields the Estrane C18 series, to which Estrogens belong. Individual compounds are characterised by the presence or absence of specific functional groups mainly Hydroxy, Keto oxo and Aldehyde functions for the naturally occurring steroids at certain positions of the Carbon skeleton particularly at positions 3, 5, 11, 17, 18, 20 and The Adrenals produce both Androgens and Corticosteroids Mineralocorticoids and Glucocorticoids , the Ovaries depending on the stage of the Ovarian Cycle can secrete Estrogens and Progestogens, and the Testes mainly Androgens.
However, the biochemical pathways involved are strikingly similar in all tissues, the difference in secretory capacity being mostly due to the presence or absence of specific enzymes. It is therefore possible to give a general outline of the major biosynthetic pathways which is applicable to all Steroid-secreting glands Ref. Lipoproteins taken up from plasma are most important. Biosynthesis of steroid hormones requires a battery of oxidative enzymes located both in Mitochondria and ER Endoplasmic Reticulum.
Pregnenolone is derived from Cholesterol by two hydroxylations at C20 and C22, followed by cleavage between C20 and C22 as catalyzed by the mitochondrial enzyme CYP11A1 , the net result being the removal of six Carbons from the C17 side chain. Pregnenolone itself is not a hormone, but is an intermediate for the synthesis of all Steroid hormones. Progesterone, made from Pregnenolone, is the primary progestogen. Progesterone is made by the Corpus Luteum and the Placenta, induces development of endometrium and mammary glands, mediates menstrual cycle and is needed for preparing the uterus for implantation of the ovum, and maintenance of pregnancy Ref.Mariaamalraj Samykannu, Anant Achary. The Steroid hormones are released into the blood circulation as soon as they are formed, travel to various parts of the body, and act on specific cells to bring about specific responses. Cortisol is the main Glucocorticoid secreted by human Adrenal Glands. Maier, Robin Polt, and Jeanne E. Satya Pal Verma, Biswajit Sarkar. Seba George, K.
The basic cyclopentanoperhydrophenanthrene ring structure and carbon numbering system of all steroid hormones is depicted to the right, using pregnenolone as an example. It is therefore possible to give a general outline of the major biosynthetic pathways which is applicable to all Steroid-secreting glands Ref. Individual compounds are characterised by the presence or absence of specific functional groups mainly Hydroxy, Keto oxo and Aldehyde functions for the naturally occurring steroids at certain positions of the Carbon skeleton particularly at positions 3, 5, 11, 17, 18, 20 and Click on your proteins of interest in the pathway image or review below Select your genes of interest and click "add selection" When you have finished your gene selection, click "Find Products" to find assays, arrays, or create custom products Pathway Navigator Biosynthesis of Steroid Hormones Steroid hormones are crucial substances for the proper functioning of the body. Preparative Biochemistry and Biotechnology , 48 3 ,
Furthermore, rhamnolipids have been shown to have anti-viral and zoosporicidal activities. This article has been cited by other articles in PMC. Variants of lipopeptides and glycolipids produced by Bacillus amyloliquefaciens and Pseudomonas aeruginosa cultured in different carbon substrates. Corticosterone, an intermediate in the conversion of Progesterone to Aldosterone, is a minor Glucocorticoid in humans, but important in other species. Therefore, extensive studies have been carried out to explore safe and economical methods to produce rhamnolipids. Cited By This article is cited by publications.