Effect of environmental factors and carbohydrate on gellan gum production.
Submerged culture fermentation studies were carried out in batch mode for optimizing the environmental parameters and carbon source requirement by Pseudomonas elodea for the production of gellan gum. The maximum production of gellan gum was obtained with 16-h-old culture and 8% inoculum at 30 degrees C and pH 7.0 after 52 h of incubation (6.0 g/L). Of the various carbon sources tested, 2% sucrose, glucose, and soluble starch yielded considerably high amounts of gellan. Studies on the concentration of various carbohydrates on gellan gum production indicated that the optimum concentration of glucose and starch was 3%, whereas for sucrose it was 4%. The addition of glucose in the medium above 3% had a detrimental effect on gellan yield. The investigation of intermediate two-step addition of glucose under identical conditions of fermentation showed an enhanced production of gellan (8.12 g/L) as compared with the control (6.0 g/L). To optimize the recovery of gellan from fermented broth, different solvents were tested for precipitation of gellan gum. Among the various solvents tested, tetrahydrofuran gave better recovery of gellan (82%) as compared with the conventional solvent isopropanol (49%).
Kanari
Basundhara
B
School of Biochemical Engineering, Institute of Technology, Banaras Hindu University, Varanasi, India.
Banik
Ratindra Ram
RR
Upadhyay
Siddha Nath
SN
D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000494:pharmacology*; D011232:Chemical Precipitation; D003124:Colorimetry; D003470:Culture Media; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D011135:Polysaccharides, Bacterial / Q000032:analysis / Q000096:biosynthesis*; D011549:Pseudomonas / Q000254:growth & development / Q000378:metabolism*; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014783:Viscosity
D002241:Carbohydrates; D003470:Culture Media; D011135:Polysaccharides, Bacterial; D012997:Solvents; C048288:gellan gum