Effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans in an airlift reactor |
| |
Authors: | T. Roukas G. Serris |
| |
Affiliation: | (1) Department of Food Science and Technology, Aristotle University of Thessaloniki, Box 250, 540 06 Thessaloniki, Greece |
| |
Abstract: | The effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans P56 in an airlift reactor was investigated. A maximum polysaccharide concentration (18.5 g/L), biomass dry weight (14.0 g/L), polysaccharide yield (38.5%), and sugar utilization (96%) was achieved at a shear rate of 42 s−1. A. pullulans grown on beet molasses produced a mixture of pullulan and other polysaccharides. The highest value of pullulan proportion (30% of total polysaccharide) was obtained at a low shear rate (42 s−1). The apparent viscosity of the fermentation broth increased as the shear rate increased up to 42 s−1 and then decreased. On the other hand, the dissolved oxygen concentration and the volumetric mass transfer coefficient increased with the increase of the shear rate from 21 to 84 s−1. The external addition of L-glutamic acid, olive oil, and Tween-80 improved significantly the production of crude polysaccharide (27.0 g/L), but the pullulan content of the polysaccharide was low (20%). |
| |
Keywords: | Beet molasses pullulan Aureobasidium pullulans batch culture airlift reactor |
本文献已被 PubMed SpringerLink 等数据库收录! |
|