Biosinteza, fermentacija, purifikacija i primjena surfaktina

Surfactin, a bacterial cyclic lipopeptide, is produced by various strains of Bacillus subtilis and is primarily recognized as one of the most effective biosurfactants. It has the ability to reduce surface tension of water from 72 to 27 mN/m at a concentration as low as 0.005 %. The structure of surfactin consists of seven amino acids bonded to the carboxyl and hydroxyl groups of a 14-carbon fatty acid. Surfactin possesses a number of biological activities such as the ability to lyse erythrocytes, inhibit clot formation, lyse bacterial spheroplasts and protoplasts, and inhibit cyclic 3\u27,5-monophosphate diesterase. The high cost of production and low yields have limited its use in various commercial applications. Both submerged and solid-state fermentation have been investigated with the mutational approach to improve the productivity. In this review, current state of knowledge on biosynthesis of surfactin, its fermentative production, purification, analytical methods and biomedical applications is presented.Surfaktin, ciklički lipopeptid izoliran iz različitih sojeva bakterije Bacillus subtilis, jedan je od najučinkovitijih biosurfaktanata, koji čak i u koncentraciji od 0,005 % smanjuje površinsku napetost vode sa 72 na 27 mN/m. Sastoji se od 7 aminokiselina vezanih karboksilnim i hidroksilnim skupinama na masnu kiselinu sa 14 ugljikovih atoma. Biološka je aktivnost surfaktina raznovrsna: razgrađuje eritrocite, sprečava zgrušavanje, razgrađuje bakterijske sferoplaste i protoplaste te inhibira 3\u27,5-fosfodiesterazu. Veliki troškovi proizvodnje i mali prinosi ograničavaju njegovu komercijalnu uporabu, pa je ispitana mogućnost povećanja proizvodnje surfaktina uzgojem mutanata Bacillus subtilis u tekućoj i na čvrstoj podlozi. U ovom su revijalnom prikazu opisana najnovija dostignuća u biosintezi, fermentaciji, purifikaciji, analizi i biomedicinskoj primjeni surfaktina

Gymnema sylvestre: A Memoir

Gymnema sylvestre is regarded as one of the plants with potent anti diabetic properties. This plant is also used for controlling obesity in the form of Gymnema tea. The active compound of the plant is a group of acids termed as gymnemic acids. It has been observed that there could be a possible link between obesity, Gymnemic acids and diabetes. This review will try to put forth an overall idea about the plant as well as present a molecular perspective linking the common medicine to the most common metabolic disorders

Superkritična fluidna ekstrakcija lovastatina dobivenog fermentacijom na čvrstoj podlozi od pšeničnih mekinja

The objective of the present work is to extract lovastatin with minimum impurity by using supercritical carbon dioxide (SC-CO2). A strain of Aspergillus terreus UV 1617 was used to produce lovastatin by solid-state fermentation (SSF) on wheat bran as a solid substrate. Extraction of lovastatin and its hydroxy acid form was initially carried out using organic solvents. Among the different screened solvents, acetonitrile was found to be the most efficient. SC-CO2 was used for extraction of lovastatin from the dry fermented matter. The effect of supercritical extraction parameters such as the amount of an in situ pretreatment solvent, temperature, pressure, flow rate and contact time were investigated. The maximum recovery of lovastatin was obtained with 5 mL of methanol as an in situ pretreatment solvent for 1.5 g of solid matrix, flow rate of the supercritical solvent 2 L/min, temperature 50 °C, and contact time 155 min at a pressure 300 bar. The lovastatin extract obtained after optimizing the conditions of supercritical fluid extraction was found to have 5-fold more HPLC purity than the organic solvent extract.Svrha je ovoga rada bila izdvojiti lovastatin što veće čistoće pomoću superkritičnog ugljikova dioksida (SC-CO2). Lovastatin je proizveden fermentacijom na čvrstoj podlozi od pšeničnih mekinja s pomoću soja Aspergillus terreus UV 1617. Organskim otapalima ekstrahirani su lovastatin i njegov kiselinski oblik, pa je utvrđeno da je najučinkovitija ekstrakcija acetonitrilom. Da bi se izdvojio lovastatin iz fermentirane suhe tvari, upotrijebljen je superkritični ugljikov dioksid, pri čemu je ispitan utjecaj količine otapala upotrijebljenog za predobradu in situ, temperature, tlaka, brzine protoka superkritičnog otapala i vremena kontakta. Maksimalna količina lovastatina izdvojena je nakon predobrade 1,5 g čvrste podloge in situ s 1,5 mL metanola i 155 minuta ekstrakcije pri brzini protoka superkritičnog otapala od 2 L/min, temperaturi od 50 ºC i tlaku od 300 bara. Optimiranjem uvjeta superkritične fluidne ekstrakcije postignuta je, u usporedbi s klasičnim postupkom ekstrakcije otapalom, peterostruko veća HPLC čistoća lovastatina

Sekvencijsko optimiranje prinosa poli(γ-glutaminske kiseline) iz novoizoliranoga soja Bacillus subtilis

A bacterial strain of marine origin showing production of poly(γ-glutamic acid) (PGA) has been identified by taxonomical and 16S rRNA studies as Bacillus subtilis. A sequential optimization approach was applied for improving the PGA production. The effect of carbon sources, nitrogen sources and pH on the production of PGA was investigated by one factor-at-a-time method. Plackett-Burman design was then adopted to select the most important nutrients influencing the yield of PGA. After identifying the most significant nutrients, response surface methodology (RSM) was used to develop a mathematical model to identify the optimum concentrations of the key nutrients for higher PGA production, and confirm its validity experimentally. PGA production was further improved by supporting the medium with α-ketoglutaric acid. The PGA production increased from 7.64 to 25.38 g/L by using the sequential optimization methods.Provedbom taksonomske i 16S rRNA studije identificiran je novi soj bakterije Bacillus subtilis, podrijetlom iz mora, koji proizvodi poli(γ-glutaminsku kiselinu) (engl. PGA). Za poboljšanje proizvodnje PGA primijenjeno je sekvencijsko optimiranje. Jednofaktorskom metodom istražen je utjecaj izvora ugljika i dušika te pH-vrijednosti na proizvodnju PGA. Primjenom Plackett-Burmanovog dizajna odabrana su hranjiva koja najviše utječu na prinos, a metodom odzivnih površina razvijen je matematički model za određivanje optimalnih koncentracija hranjiva za povećanje prinosa PGA, te eksperimentalno potvrđena ispravnost tog modela. Dodatkom α-ketoglutarne kiseline podlozi dodatno je poboljšana proizvodnja PGA. Sekvencijskim optimiranjem prinos PGA povećan je sa 7,64 na 25,38 g/L

Superkritična fluidna ekstrakcija lovastatina dobivenog fermentacijom na čvrstoj podlozi od pšeničnih mekinja

The objective of the present work is to extract lovastatin with minimum impurity by using supercritical carbon dioxide (SC-CO2). A strain of Aspergillus terreus UV 1617 was used to produce lovastatin by solid-state fermentation (SSF) on wheat bran as a solid substrate. Extraction of lovastatin and its hydroxy acid form was initially carried out using organic solvents. Among the different screened solvents, acetonitrile was found to be the most efficient. SC-CO2 was used for extraction of lovastatin from the dry fermented matter. The effect of supercritical extraction parameters such as the amount of an in situ pretreatment solvent, temperature, pressure, flow rate and contact time were investigated. The maximum recovery of lovastatin was obtained with 5 mL of methanol as an in situ pretreatment solvent for 1.5 g of solid matrix, flow rate of the supercritical solvent 2 L/min, temperature 50 °C, and contact time 155 min at a pressure 300 bar. The lovastatin extract obtained after optimizing the conditions of supercritical fluid extraction was found to have 5-fold more HPLC purity than the organic solvent extract.Svrha je ovoga rada bila izdvojiti lovastatin što veće čistoće pomoću superkritičnog ugljikova dioksida (SC-CO2). Lovastatin je proizveden fermentacijom na čvrstoj podlozi od pšeničnih mekinja s pomoću soja Aspergillus terreus UV 1617. Organskim otapalima ekstrahirani su lovastatin i njegov kiselinski oblik, pa je utvrđeno da je najučinkovitija ekstrakcija acetonitrilom. Da bi se izdvojio lovastatin iz fermentirane suhe tvari, upotrijebljen je superkritični ugljikov dioksid, pri čemu je ispitan utjecaj količine otapala upotrijebljenog za predobradu in situ, temperature, tlaka, brzine protoka superkritičnog otapala i vremena kontakta. Maksimalna količina lovastatina izdvojena je nakon predobrade 1,5 g čvrste podloge in situ s 1,5 mL metanola i 155 minuta ekstrakcije pri brzini protoka superkritičnog otapala od 2 L/min, temperaturi od 50 ºC i tlaku od 300 bara. Optimiranjem uvjeta superkritične fluidne ekstrakcije postignuta je, u usporedbi s klasičnim postupkom ekstrakcije otapalom, peterostruko veća HPLC čistoća lovastatina

Proizvodnja gelan gume fermentacijom, njezino izdvajanje, pročišćavanje i primjena

The microbial exopolysaccharides are water-soluble polymers secreted by microorganisms during fermentation. The biopolymer gellan gum is a relatively recent addition to the family of microbial polysaccharides that is gaining much importance in food, pharmaceutical and chemical industries due to its novel properties. It is commercially produced by C. P. Kelco in Japan and the USA. Further research and development in biopolymer technology is expected to expand its use. This article presents a critical review of the available information on the gellan gum synthesized by Sphingomonas paucimobilis with special emphasis on its fermentative production and downstream processing. Rheological behaviour of fermentation broth during fermentative production of gellan gum and problems associated with mass transfer have been addressed. Information on the biosynthetic pathway of gellan gum, enzymes and precursors involved in gellan gum production and application of metabolic engineering for enhancement of yield of gellan gum has been specified. Characteristics of gellan gum with respect to its structure, physicochemical properties, rheology of its solutions and gel formation behaviour are discussed. An attempt has also been made to review the current and potential applications of gellan gum in food, pharmaceutical and other industries.Tijekom fermentacije mikroorganizmi izlučuju egzopolisaharide, polimere topljive u vodi. Gelan guma je biopolimer odnedavno uvršten u skupinu mikrobnih polisaharida koji se zbog svojih novih svojstava sve više primjenjuje u industriji hrane te farmaceutskoj i kemijskoj industriji. Proizvodi ga tvrtka C.P. Kelco u Japanu i SAD-u. Dodatnim istraživanjem i razvojem tehnologije biopolimera proširit će se njegova primjena. U ovom je radu dan kritički osvrt na podatke o sintezi gelan gume s pomoću Sphingomonas paucimobilis, a osobito na proizvodnju fermentacijom te izdvajanje i pročišćavanje proizvoda. Opisana su i reološka svojstva medija tijekom proizvodnje te problemi vezani uz prijenos tvari. Navedeni su podaci o biosintetskom putu, enzimima i prekurzorima koji sudjeluju u njezinoj proizvodnji te primjena metaboličkog inženjeringa radi poboljšanja prinosa. Također se raspravljalo o značajkama gelan gume s obzirom na strukturu, fizičko-kemijska svojstva, reologiju otopina te ponašanje pri formiranju gela. Autori su prikazali sadašnju i buduću primjenu gelan gume u industriji hrane, farmaceutskoj industriji i ostalim industrijama

Skleroglukan: proizvodnja fermentacijom, izdvajanje, pročišćavanje i primjena

Exopolysaccharides produced by a variety of microorganisms find multifarious industrial applications in foods, pharmaceutical and other industries as emulsifiers, stabilizers, binders, gelling agents, lubricants, and thickening agents. One such exopolysaccharide is scleroglucan, produced by pure culture fermentation from filamentous fungi of genus Sclerotium. The review discusses the properties, fermentative production, downstream processing and applications of scleroglucan.Razni mikroorganizmi proizvode egzopolisaharide koji imaju višestruku primjenu u proizvodnji hrane, farmaceutskoj industriji i drugim industrijama, kao emulgatori, stabilizatori, učvršćivači, te sredstva za geliranje, podmazivanje i zgušnjavanje. Jedan takav polisaharid je skleroglukan proizveden fermentacijom s pomoću filamentoznih gljiva iz roda Sclerotium. U ovom se revijalnom prikazu raspravlja o svojstvima skleroglukana, njegovoj proizvodnji fermentacijom te izdvajanju i primjeni

Skleroglukan: proizvodnja fermentacijom, izdvajanje, pročišćavanje i primjena

Exopolysaccharides produced by a variety of microorganisms find multifarious industrial applications in foods, pharmaceutical and other industries as emulsifiers, stabilizers, binders, gelling agents, lubricants, and thickening agents. One such exopolysaccharide is scleroglucan, produced by pure culture fermentation from filamentous fungi of genus Sclerotium. The review discusses the properties, fermentative production, downstream processing and applications of scleroglucan.Razni mikroorganizmi proizvode egzopolisaharide koji imaju višestruku primjenu u proizvodnji hrane, farmaceutskoj industriji i drugim industrijama, kao emulgatori, stabilizatori, učvršćivači, te sredstva za geliranje, podmazivanje i zgušnjavanje. Jedan takav polisaharid je skleroglukan proizveden fermentacijom s pomoću filamentoznih gljiva iz roda Sclerotium. U ovom se revijalnom prikazu raspravlja o svojstvima skleroglukana, njegovoj proizvodnji fermentacijom te izdvajanju i primjeni