Optimization of polysaccharides production by bacteria isolated from soil

Abstract

Six polysaccharide-producing bacteria, isolated from soil samples and identified as Pseudomonas and Arthrobacter (Strains 3B, 4B, 7B, 21B, 18E and 21D), were tested for the yield of polysaccharides produced during growth in two culture media: one containing glucose and the other sucrose (1, 2, 3, 4 and 5%). The yield was quantified measuring the viscosity of the broth, using the Poiscuille equation. The effect of temperature and pH of the culture media was investigated. The largest polysaccharide yield was obtained when the concentration of the carbon source was lower than 2%. Glucose and sucrose stimulated the polysaccharide production in a similar way. When the initial pH of the fermentation broth was increased from 5.0 up to 7.0, there was an increase in polysaccharide production. However, higher values (pH=8.0) caused a decrease in polysaccharide production. With regard to temperature, 30ºC was shown to be optimum, since higher or lower temperatures had a negative effect on saccharide production.

Optimization of Carbon and Nitrogen Sources for Extracellular Polymeric Substances Production by Chryseobacterium indologenes MUT.2

“…The results obtained in the present study are in agreement with the general concept expressed in the early studies (15,16) which have reported the highest exopolysaccharides yield using fructose, sucrose, and glucose as carbon sources. Recently, Zhang et al (17), studied the production of gellan exopolysaccharide by growing strains of Sphingomonas paucimobilis QHZJ UJW in the medium containing various carbon sources such as glucose, sucrose, maltose, malt extract powder, and vegetable oil.…”

Production and downstream processing of (1→3)-β-D-glucan from mutant strain of Agrobacterium sp. ATCC 31750

“…We found that the mutant strain produced maximum curdlan (22.5 g/L) and also had a high product yield (0.78) at pH 7.0. Similarly, increase in pH from 5.0 to 7.0 of fermentation medium resulted in increase of polysaccharide yields (Bueno and Cruz, 2006). Production of curdlan at pH 7.0 was studied in bioreactor.…”

Screening, production, optimization and characterization of cyanobacterial polysaccharide

“…Their physical and chemical characteristics show little variability and they are not vulnerable to variations in climatic, cultivation, production or pollution conditions. For this reason, some microbial polysaccharides are mass produced on an industrial scale and used as raw material for processed foods, in medicine and in industrial preparations (Roseiro et al 1992;Kawai et al 1992;Singh et al 2000;Bueno and Garcia-Cruz 2006).…”