Abstract
Water-in-oil (W/O) fermentation technology has the potential for overcoming the problems related with high broth viscosity in xanthan fermentations. By dispersing the aqueous broth in a continuous organic phase, the broth-thickening mechanisms are confined within the aqueous droplets without significantly increasing the overall viscosity. In this study, xanthan fermentations were made with perfluorocarbon (PFC) or vegetable oil as the organic phase. The results were compared with those obtained previously using n-hexadecane as the organic phase, to evaluate the effects of various properties. PFC provided easy phase separation at the end of fermentation but required higher power input for agitation, a direct result of its high density. The aqueous droplets formed were large (400–450 μm), limiting the cell concentration employable due to the occurrence of oxygen starvation in the inner core. One main advantage of using vegetable oil was its low cost. In addition, vegetable oil provided much finer droplets (<120 μm) and produced high xanthan concentrations (>100 g l−1). However, complete phase separation for product recovery was difficult to achieve. Fermentations in both organic phases were terminated by the occurrence of phase inversion to highly viscous O/W dispersions at aqueous-phase volume fractions of 0.53–0.56. The initial fraction was 0.3 but changed due to base addition for pH adjustment and nutrient addition for prolonged production.
Similar content being viewed by others
References
Air Products (1987) Product manual on multifluor inert fluid, APF-215. Air Products, Allentown, Pa.
Galindo E, Torrestiana B, Garcia-Rejon A (1989) Rheological characterization of xanthan fermentation broths and their reconstituted solutions. Bioprocess Eng 4:113–118
Ju L-K, Ho CS (1989) Oxygen diffusion coefficient and solubility in n-hexadecane. Biotechnol Bioeng 34:1221–1224
Ju L-K, Zhao S (1993) Xanthan fermentations in water/oil dispersions. Biotechnol Techn 7:463–468
Ju L-K, Lee JF, Armiger WB (1991a) Effect of the interfacial surfactant layer on oxygen transfer through the oil/water phase boundary in perfluorocarbon emulsions. Biotechnol Bioeng 37:505–511
Ju L-K, Lee JF, Armiger WB (1991b) Enhancing oxygen transfer in bioreactors by perfluorocarbon emulsions. Biotechnol Prog 7:323–329
Junker BH, Hatton TA, Wang DIC (1990) Oxygen transfer enhancement in aqueous/perfluorocarbon fermentation systems: I. experimental observations. Biotechnol Bioeng 35:578–585
Kuttuva SG, Sundararajan A, Ju L-K (1998) Model simulation of water-in-oil xanthan fermentation. J Dispersion Sci Technol 19:1003–1029
Michel BJ, Miller SA (1962) Power requirements of gas-liquid agitated systems. AIChE J 8:262–266
Pons A, Dussap CG, Gros JB (1990) Xanthan batch fermentations: compared performances of a bubble column and a stirred tank fermentor. Bioprocess Eng 5:107–114
Restrepo AS, Ju L-K (2003) Poly(methacrylic acid) grafted with poly(ethylene glycol) and n-dodecane as pH-sensitive surfactants for water-in-oil fermentations. Ind Eng Chem Res 42:4296–4302
Suh IS, Schumpe A, Deckwer WD (1992) Xanthan production in bubble column and air-lift reactors. Biotechnol Bioeng 39:85–94
Udeh KO, Janas P, Grobelski M (2002) Microbial synthesis of xanthan gum and application. Biotechnologia 2002:113–129
Yang S-T, Lo Y-M, Min DB (1996) Xanthan gum fermentation by Xanthomonas campestris immobilized in a novel centrifugal fibrous-bed bioreactor. Biotechnol Prog 12:630
Zhao S (1994). Application of water-in-oil cultivation technology in viscous xanthan fermentation: a feasibility study. MSc thesis, University of Akron, Akron, Ohio
Zhao S, Kuttuva SG, Ju L-K (1999) Oxygen transfer characteristics of multiple-phase dispersions simulating water-in-oil xanthan fermentations. Bioprocess Eng 20:313–323
Acknowledgement
This work was supported in part by the Ohio Board of Regents for the Ohio Bioprocessing Research Consortium.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kuttuva, S.G., Restrepo, A.S. & Ju, LK. Evaluation of different organic phases for water-in-oil xanthan fermentation. Appl Microbiol Biotechnol 64, 340–345 (2004). https://doi.org/10.1007/s00253-003-1461-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00253-003-1461-x