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

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

Biotechnological Production of Vitamins

Vitamini su prema definiciji esencijalna mikrohranjiva potrebna u tragovima, koje sisavci ne mogu sintetizirati. Osim njihove in vivo hranjive i fiziološke uloge kao faktora rasta ljudi, životinja, biljaka i mikroorganizama, oni se sve više koriste kao aditivi za hranu/krmiva, u medicinsko-terapeutske svrhe, te kao zdravstvena i tehnička pomoćna sredstva. Proizvodnja vitamina kemijskom sintezom ili njihova ekstrakcija iz poznatih izvora ima velike nedostatke, pa se takva proizvodnja sve više nastoji zamijeniti biotehnološkim procesima. Za neke od tih spojeva već postoje ili se tek razvijaju procesi koji koriste mikroorganizme ili alge. Različite metode poput optimiranja podloge, mutacije i odabira, genetičkog inženjeringa i konverzije s pomoću biokatalizatora primjenjuju se za poboljšanje proizvodnje vitamina. Ovaj rad opisuje sadašnje stanje u proizvodnji vitamina biotehnološkim procesima i njihovo značenje u usporedbi s postojećim kemijskim procesima.Vitamins are defined as essential micronutrients that are required in trace quantity and cannot be synthesized by mammals. Apart from their in vivo nutritional and physiological roles as growth factors for men, animals, plants and microorganisms, vitamins are now being increasingly introduced as food/feed additives, as medical-therapeutic agents, as health aids, and also as technical aids. Production of vitamins by chemical synthesis, or extraction from their known sources has serious disadvantages. This led to an increased interest in substituting these processes with biotechnological processes. For several of these compounds microbiological and algal processes exist, or are rapidly emerging. Different methods like media optimization, mutation and screening, genetic engineering and biocatalyst conversion have been used for improvement of the production of vitamins. The survey describes the current state of vitamin production by biotechnological processes and their significance, as compared to the existing chemical processes

Sequential Optimization Approach for Enhanced Production of Poly(γ-Glutamic Acid) from Newly Isolated 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

Microbial Cellulose: Fermentative Production and Applications

Bacterial cellulose, an exopolysaccharide produced by some bacteria, has unique structural and mechanical properties and is highly pure as compared to plant cellulose. This article presents a critical review of the available information on the bacterial cellulose with special emphasis on its fermentative production and applications. Information on the biosynthetic pathway of bacterial cellulose, enzymes and precursors involved in bacterial cellulose synthesis has been specified. Characteristics of bacterial cellulose with respect to its structure and physicochemical properties are discussed. Current and potential applications of bacterial cellulose in food, pharmaceutical and other industries are also presented

Proizvodnja celuloze s pomoću mikroorganizama i njezina primjena

Bacterial cellulose, an exopolysaccharide produced by some bacteria, has unique structural and mechanical properties and is highly pure as compared to plant cellulose. This article presents a critical review of the available information on the bacterial cellulose with special emphasis on its fermentative production and applications. Information on the biosynthetic pathway of bacterial cellulose, enzymes and precursors involved in bacterial cellulose synthesis has been specified. Characteristics of bacterial cellulose with respect to its structure and physicochemical properties are discussed. Current and potential applications of bacterial cellulose in food, pharmaceutical and other industries are also presented.Neke bakterije proizvode egzopolisaharid celulozu, jedinstvenoga sastava i mehaničkih svojstava, koja ima kudikamo veću čistoću od biljne celuloze. U ovom je radu prikazan kritički osvrt na dostupne informacije o bakterijskoj celulozi, s osobitim naglaskom na njezinu proizvodnju fermentacijom i primjenu. Navedene su informacije o putu biosinteze, te enzimima i prekurzorima koji sudjeluju u proizvodnji bakterijske celuloze, a također se raspravlja o njezinoj strukturi i fizikalno-kemijskim svojstvima. Prikazana su i dostignuća u primjeni bakterijske celuloze u prehrambenoj i farmaceutskoj industriji te u drugim industrijama

Gellan Gum: Fermentative Production, Downstream Processing and Applications

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