Continuous culture system for production of biopolymer levan using erwinia herbicola

Keith, Jerry M.; Wiley, B. J.; Ball, D. H.; Arcidiacono, Steven; Zorfass, D A; Mayer, Jean; Kaplan, David L.

doi:10.1002/bit.260380515

Cited by 61 publications

(24 citation statements)

References 15 publications

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“…Levan is depolymerized by levanase enzymes which hydrolyze P-2,6-linkages to form oligo saccharides and fructose. levan can be in part controlled through adjustments in fermentation conditions [52]. Levan is soluble in hot water and is potentially attractive as a coating for foods or pharmaceuticals.…”

Section: Polysaccharides (Bacterial)mentioning

confidence: 99%

Introduction to Biopolymers from Renewable Resources

Kaplan¹

1998

Biopolymers From Renewable Resources

323

301

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Section: Polysaccharides (Bacterial)mentioning

confidence: 99%

Introduction to Biopolymers from Renewable Resources

Kaplan¹

1998

Biopolymers From Renewable Resources

323

301

View full text Add to dashboard Cite

“…In general, plant fructans (inulins and phleins) are relatively small with an average degree of polymerization (DP) of around 40 (Pontis and del Campillo, 1985). In contrast, those from bacteria (levans) are very large (DPϾ100,000; Keith et al, 1991). To be useful as a food source, any fructan must be metabolized at rates commensurate with the rate of passage through the rumen and must be linked to the utilization of ammonia from protein metabolism within the rumen.…”

mentioning

confidence: 99%

In vitro digestion of bacterial and plant fructans and effects on ammonia accumulation in cow and sheep rumen fluids.

Biggs

Hancock

1998

J. Gen. Appl. Microbiol.

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One of the problems encountered with the pasture plants perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) as a food source for ruminants is their relatively low levels of non-structural carbohydrates (NSC) as compared to protein. As a consequence, a significant proportion of dietary protein is metabolized to meet energy requirements and large amounts of ammonia are produced, which need to be excreted (Moller et al., 1993). This represents a loss of N and a wastage of energy. Increasing the level of dietary carbohydrate is one of the means currently being explored to correct this protein/carbohydrate imbalance in pasture plants (Beever and Thorp, 1997).We are investigating the potential of fructans to provide an alternate supply of NSC by genetic manipulation of pasture plants, as genes for levan biosynthesis are now available (van der Meer et al., 1994). Fructans are a group of fructose polymers, containing either β(2-1) or β(2-6) fructosyl-fructose linkages, synthesized by some plants and certain bacteria. In general, plant fructans (inulins and phleins) are relatively small with an average degree of polymerization (DP) of around 40 (Pontis and del Campillo, 1985). In contrast, those from bacteria (levans) are very large (DPϾ100,000; Keith et al., 1991). To be useful as a food source, any fructan must be metabolized at rates commensurate with the rate of passage through the rumen and must be linked to the utilization of ammonia from protein metabolism within the rumen. Although the degradability of some plant fructans by isolated rumen bacteria and protozoa has previously been reported (Anand, 1972; Paster and CanaleParola, 1985;Thomas, 1960;Ziolecki et al., 1992), there is no information on either the overall rate of inulin digestion or the degradability of the large bacterial levans within the rumen. Nor has the effect of levan or inulin on NH 3 metabolism in the rumen been reported.This study was undertaken to investigate the metabolism of fructans in rumen fluids from both cow and sheep. The results obtained indicate that inulin and novel bacterial levan have the potential for enhancing the food quality of forage plants for ruminants.Chicory root inulin a β(2-1) plant fructan, and levan, a β(2-6) bacterial fructan from Erwinia herbicola, were obtained from Sigma Chemicals, St. Louis, MO, USA. AnalAR grade fructose and sucrose were from BDH Limited (UK). Rumen fluid was collected from randomly selected four-year-old Romney sheep and from a 16-year-old Friesian cow grazed on identical white clover and ryegrass swards. Rumen samples were strained into an airtight container, sealed to exclude oxygen and placed into an anaerobic cabinet at 39°C in a 95% CO 2 : H 2 atmosphere. Fructan and other carbohydrates were dissolved in artificial saliva (McDougall, 1948) and aliquots of rumen fluid added to give final carbohydrate concentrations of 2 mg/ml, and a rumen fluid dilution of 1 in 5. The final concentration of sucrose was 4 mg/ml (fructose equivalent 2 mg/ml). Control samples containe...

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“…O interesse comercial pela levana motiva pesquisas tanto para a identificação de novos microrganismos produtores quanto para processos que visem à otimização de sua produção em escala industrial (REISS; HARTMEIER, 1990;KEITH et al, 1991;HARTMEIER et al, 1994;TANO;.…”

Section: Considerações Geraisunclassified

Levana Bacteriana: aspectos tecnológicos, características e produção

Ernandes

García-Cruz

2005

Sem. Ci. Agr.

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ResumoLevana é um exopolissacarídeo, constituído por unidades de frutose, unidas através de ligações β (2-6), obtido pela reação de transfrutosilação durante a fermentação de microrganismos em meio rico em sacarose mas não em frutose, glucose ou misturas de ambas. Pesquisas sobre bactérias produtoras de levana vêm sendo implementadas, uma vez que a mesma é uma fonte alternativa de frutose, além de apresentar características funcionais no organismo humano, como agente hipocolesterolêmico e anticarcinogênico. Na indústria de alimentos a levana pode ser empregada como fixador de cores e sabores, bem como espessante e estabilizante de vários alimentos. Das bactérias produtoras de levana, Zymomonas mobilis tem sido a melhor alternativa, uma vez que usa como fonte de carbono a sacarose ou resíduos industriais contendo este açúcar, em diferentes concentrações, em um meio rico em sais minerais. A produção de levana é influenciada não apenas pela fonte de carbono e sua concentração, mas também pelas variações de pH, temperatura e tipo de sais presentes, além da oxigenação do meio de fermentação, afetando também as características da molécula e o crescimento celular. Neste trabalho de revisão apresentam-se tópicos de interesse referentes à produção de levana bacteriana. Palavras-chave: Levana, produção, características tecnológicas, bactérias AbstractLevan is an exopolysaccharide, constituted by fructose units, β (2-6) linked, obtained by transfructosilation reaction during microorganisms fermentation in a sucrose rich but wi thout glucose, fructose or mixtures in the culture media. Bacterial levan production is a good alternative fructose source, besides having certain functional characteristics in the human body, such as a hypocholesterolemic and an anticarcinogenic agent. In the food industry, levan can be used to fix colors and flavors, as well as thickening and stabilizing agent. In the bacterial levan production, Zymomonas mobilis has been considered the best possible alternative, since it uses as carbon source sucrose or industrial residues that contain this sugar, in different concentrations, in a mineral salts rich medium. Levan production is not only influenced by carbon source and its concentration, but also by pH, temperature and type of salts. Moreover, the oxygenation of the fermentation medium, also affect the characteristics of the molecule and the cellular growth. In this revision some important topics concerning the bacterial levan production are presented.

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Continuous culture system for production of biopolymer levan using erwinia herbicola

Cited by 61 publications

References 15 publications

Introduction to Biopolymers from Renewable Resources

Introduction to Biopolymers from Renewable Resources

In vitro digestion of bacterial and plant fructans and effects on ammonia accumulation in cow and sheep rumen fluids.

Levana Bacteriana: aspectos tecnológicos, características e produção

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