ISSN:
1476-5535
Keywords:
Keywords: alginate; Azotobacter vinelandii; kinetics; batch fermentation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
The kinetics of growth and alginate production from glucose in a nitrogen and phosphate-rich medium by Azotobacter vinelandii DSM576 were studied in a laboratory fermenter at pH 7 and 35°C. Batch fermentations were carried out both without control of dissolved oxygen concentration (DO) and at 1, 2, 5 and 10% DO. Although growth was faster at higher DO, maximum biomass concentration was lower. No alginate was produced at 10% DO. Alginate production was faster at 5 and 2% DO but higher alginate concentrations and yields were obtained without DO control. Alginate production was growth-associated at 5% DO, but significant amounts of alginate were produced after growth had stopped at lower DO values. In fermentations without DO control the molecular weight of the polymer reached a maximum (11–17.6 × 104) when specific growth rate was between 0.02 and 0.04 h−1 and residual concentration of ammoniacal nitrogen was between 0.01 and 0.02 g L−1 and then sharply decreased.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1038/sj.jim.2900510
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