DOAJ (DOAJ: Directory of Open Access Journals), Oct 1, 2008
ABSTRACT Xanthan gum is an extracelullar polysaccharide produced by bacteria of the genus Xanthom... more ABSTRACT Xanthan gum is an extracelullar polysaccharide produced by bacteria of the genus Xanthomonas. Its functionality is a direct consequence of its chemical structure. This structure has been widely studied because it is subject to changes, dependant on the producer microrganism and on the operational conditions applied during the fermentation. The purpose of this paper is to review the influence of the operational conditions of xanthan production in the physiochemical characteristics of the gum produced. Goma xantana é um polissacarídeo extracelular produzido pelas bactérias do gênero Xanthomonas. Sua funcionalidade é uma conseqüência direta de sua estrutura química. Esta estrutura tem sido amplamente estudada por ser passível de mudanças, sendo dependente do microrganismo produtor e das condições operacionais aplicadas durante a fermentação. O trabalho tem como objetivo revisar a influência das condições operacionais de produção de xantana nas características físico-químicas da goma produzida.
Vaccination has been a common practice to prevent or minimize the symptoms of diseases caused by ... more Vaccination has been a common practice to prevent or minimize the symptoms of diseases caused by infectious agents. Vaccines have been developed using an attenuated or inactivated microorganisms. Recently, synthetic peptides and recombinant proteins form the basis of the new generation of vaccines. However, there is need the association of these antigens wich adjuvants to increase its immunological effect. Although several substances have been evaluated for use in vaccines for veterinary use the production of vaccine remains tied to the use of aluminum salts or oily emulsions. The polysaccharide produced by the bacterium Xanthomonas sp. is a new alternative for use as an adjuvant vaccine. This study aimed to evaluate the effect of adjuvant xanthan in humoral response of mice to a vaccine for pig herpes type 1 (SuHV-1). The animals were divided into five groups, using different adjuvants for each group. The titles of antibodies were determined by ELISA, using as antigen the vaccine s...
Publisher Summary Xanthomonas species can produce a high-molecular weight polysaccharide called x... more Publisher Summary Xanthomonas species can produce a high-molecular weight polysaccharide called xanthan gum. This biopolymer is widely used in the modern food, cosmetics, and other industries. Therefore, the microorganisms that have the capability to produce this gum are extensively studied and reported in this chapter. The Xanthomonas campestris pv pruni is the causal agent of Prunus bacterial spots (PBS) and naturally infects all cultivated Prunus species. Many of them have been tested for their ability to synthesize polysaccharide in batch incubation. The biopolymers obtained have been analyzed for their productivity and chemical composition. The chapter also discusses the process of heteropolysaccharides which are produced by Xanthomonas campestris pv pruni C24 are obtained in two different fermentation media—PMII and PMI+II. Both media contain sucrose as the carbon source and salts. The type of monosaccharide and derivatives present in the biopolymers obtained at different incubation times are detected with thin layer chromatography. The chromatographic analysis reveals the presence of glucose, rhamnose, and glucuronic acid in polymers produced after 72 hours of fermentation. In polymers obtained at 96 hours, mannose was also detected. The PMI+II medium shows higher productivity than PM II, but the viscosity was higher in polymers produced in the PM II medium. The incubation time also has an influence on productivity and viscosity. This also introduce Bacteria which belongs to the genus Xanthomonas are plant-associated bacteria, with the exception of X maltophilia. It also explain the infection caused by these bacteria occurs on at least 124 monocotyledonous plants, comprising 70 genera, and 268 dicotyledonous plants species, totalling more than 170 genera.
Publisher Summary Biopolymers are produced by most microorganisms, but for commercial productions... more Publisher Summary Biopolymers are produced by most microorganisms, but for commercial productions, fungi and bacteria show the easiest adaptation. Such microorganisms have the capability to grow in large scale batch fermentations and they produce biopolymers with potential applications in a variety of industries. In a food industry, biopolymers are used as thickening agents and suspending or gelling polymers. The industrial interest is concentrated on extracellular polysaccharides, due their ease of production and purification, with high yields. For a biopolymer to satisfy a large range of applications, it must have rheological properties, in which the viscosity decreases in the presence of a shear stress. In addition, these properties must be maintained at temperature, pH, and ionic strength change. These properties are closely related to the primary chemical structure. In this context, this chapter explores the structural characteristics and rheological behavior of PS-32 and NFB polysaccharides.
DOAJ (DOAJ: Directory of Open Access Journals), Oct 1, 2008
ABSTRACT Xanthan gum is an extracelullar polysaccharide produced by bacteria of the genus Xanthom... more ABSTRACT Xanthan gum is an extracelullar polysaccharide produced by bacteria of the genus Xanthomonas. Its functionality is a direct consequence of its chemical structure. This structure has been widely studied because it is subject to changes, dependant on the producer microrganism and on the operational conditions applied during the fermentation. The purpose of this paper is to review the influence of the operational conditions of xanthan production in the physiochemical characteristics of the gum produced. Goma xantana é um polissacarídeo extracelular produzido pelas bactérias do gênero Xanthomonas. Sua funcionalidade é uma conseqüência direta de sua estrutura química. Esta estrutura tem sido amplamente estudada por ser passível de mudanças, sendo dependente do microrganismo produtor e das condições operacionais aplicadas durante a fermentação. O trabalho tem como objetivo revisar a influência das condições operacionais de produção de xantana nas características físico-químicas da goma produzida.
Vaccination has been a common practice to prevent or minimize the symptoms of diseases caused by ... more Vaccination has been a common practice to prevent or minimize the symptoms of diseases caused by infectious agents. Vaccines have been developed using an attenuated or inactivated microorganisms. Recently, synthetic peptides and recombinant proteins form the basis of the new generation of vaccines. However, there is need the association of these antigens wich adjuvants to increase its immunological effect. Although several substances have been evaluated for use in vaccines for veterinary use the production of vaccine remains tied to the use of aluminum salts or oily emulsions. The polysaccharide produced by the bacterium Xanthomonas sp. is a new alternative for use as an adjuvant vaccine. This study aimed to evaluate the effect of adjuvant xanthan in humoral response of mice to a vaccine for pig herpes type 1 (SuHV-1). The animals were divided into five groups, using different adjuvants for each group. The titles of antibodies were determined by ELISA, using as antigen the vaccine s...
Publisher Summary Xanthomonas species can produce a high-molecular weight polysaccharide called x... more Publisher Summary Xanthomonas species can produce a high-molecular weight polysaccharide called xanthan gum. This biopolymer is widely used in the modern food, cosmetics, and other industries. Therefore, the microorganisms that have the capability to produce this gum are extensively studied and reported in this chapter. The Xanthomonas campestris pv pruni is the causal agent of Prunus bacterial spots (PBS) and naturally infects all cultivated Prunus species. Many of them have been tested for their ability to synthesize polysaccharide in batch incubation. The biopolymers obtained have been analyzed for their productivity and chemical composition. The chapter also discusses the process of heteropolysaccharides which are produced by Xanthomonas campestris pv pruni C24 are obtained in two different fermentation media—PMII and PMI+II. Both media contain sucrose as the carbon source and salts. The type of monosaccharide and derivatives present in the biopolymers obtained at different incubation times are detected with thin layer chromatography. The chromatographic analysis reveals the presence of glucose, rhamnose, and glucuronic acid in polymers produced after 72 hours of fermentation. In polymers obtained at 96 hours, mannose was also detected. The PMI+II medium shows higher productivity than PM II, but the viscosity was higher in polymers produced in the PM II medium. The incubation time also has an influence on productivity and viscosity. This also introduce Bacteria which belongs to the genus Xanthomonas are plant-associated bacteria, with the exception of X maltophilia. It also explain the infection caused by these bacteria occurs on at least 124 monocotyledonous plants, comprising 70 genera, and 268 dicotyledonous plants species, totalling more than 170 genera.
Publisher Summary Biopolymers are produced by most microorganisms, but for commercial productions... more Publisher Summary Biopolymers are produced by most microorganisms, but for commercial productions, fungi and bacteria show the easiest adaptation. Such microorganisms have the capability to grow in large scale batch fermentations and they produce biopolymers with potential applications in a variety of industries. In a food industry, biopolymers are used as thickening agents and suspending or gelling polymers. The industrial interest is concentrated on extracellular polysaccharides, due their ease of production and purification, with high yields. For a biopolymer to satisfy a large range of applications, it must have rheological properties, in which the viscosity decreases in the presence of a shear stress. In addition, these properties must be maintained at temperature, pH, and ionic strength change. These properties are closely related to the primary chemical structure. In this context, this chapter explores the structural characteristics and rheological behavior of PS-32 and NFB polysaccharides.
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Papers by Claire Tondo Vendruscolo