title: Process optimization and kinetic modelling of cyclic (1→3, 1→6)-β-glucans production from Bradyrhizobium japonicum MTCC120.
abstract: Cyclic (1→3, 1→6)-β-glucans are water soluble, biocompatible polymers with potential applications in food and pharmaceutical industries but have not yet been exploited due to their poor yield. In the present study statistical experimental design methodology was employed to improve their production. Initial screening indicated arabinose and peptone as best carbon and nitrogen source respectively, for glucan production. Arabinose and osmolyte concentrations as well as pH significantly contributed to the glucan production. Central composite design indicated a significant interaction between osmolyte concentration and pH on glucan production. The maximum amount of cyclic glucan produced was 6.7g/L in a 2.5L reactor in batch conditions. The logistic equation for cell growth and Luedeking-Piret equation for glucan production could satisfactorily simulate the batch kinetics data. Cyclic β-glucans could efficiently encapsulate a hydrophobic molecule, curcumin and increase its solubility in water, thus indicating that these glucans have potential as drug delivery systems.
authors.affiliation: Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Anju V
authors.initials: AV
authors.lastname: Nair
authors.affiliation: Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India.
authors.forename: Sathyanarayana N
authors.initials: SN
authors.lastname: Gummadi
authors.affiliation: Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India. Electronic address: mukeshd@iitm.ac.in.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Doble
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D020369:Bradyrhizobium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D002244:Carbon / Q000494:pharmacology; D003474:Curcumin / Q000494:pharmacology; D005936:Glucans / Q000096:biosynthesis*; D007700:Kinetics; D008962:Models, Theoretical; D009584:Nitrogen / Q000494:pharmacology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors
chemical_list: D005936:Glucans; C033671:epiglucan; D002244:Carbon; D003474:Curcumin; D009584:Nitrogen
keywords: Bradyrhizobium japonicum; Cyclic (1→3, 1→6)-β-glucans; Encapsulation; Kinetic modelling; Response surface methodology