TY - JOUR
T1 - Semi-continuous production of xanthan in biofilm reactor using Xanthomonas campestris
AU - Nejadmansouri, Maryam
AU - Razmjooei, Maryam
AU - Safdarianghomsheh, Reza
AU - Shad, Ehsan
AU - Delvigne, Frank
AU - Khalesi, Mohammadreza
N1 - Publisher Copyright:
© 2021 The Author(s)
PY - 2021/2/20
Y1 - 2021/2/20
N2 - Semi-continuous production of xanthan gum using self-immobilized Xanthomonas campestris cells in biofilm reactors was studied. Fermentation was carried out using two different designs of biofilm reactor equipped with a) stainless-steel support (SSS) and b) polyethylene support (PES). Fermentation was performed in three cycles with refreshing the media at the beginning of each: cycle 1, 0−27 h; cycle 2, 27−54 h; and cycle 3, 54–78.5 h. Results showed that the glucose consumption and the pH reduction in the PES biofilm reactor was faster compared to the SSS biofilm reactor. Scanning electron microscopy showed that the SSS was capable to immobilize more cells during the growth of X. campestris. The maximum concentration of xanthan gum in the SSS biofilm reactor obtained after 27 h (3.47 ± 0.71 g/L), while the maximum concentration of xanthan in the PES biofilm reactor obtained after 78.5 h (3.21 ± 0.68 g/L). Thermal stability analysis of xanthan using differential scanning calorimetry showed the presence of two fractures attributed to dehydration and degradation of polymer. The thermogram represented both endothermal and exothermal behaviour of xanthan polymer. Furthermore, the functional groups and molecular structure of the xanthan produced in this study was evaluated using Fourier transform infrared spectrometry and also proton nuclear magnetic resonance. in addition, the surface tension of (0.2 %, w/v) xanthan gum solution was in a range of 52.16–56.5 mN/m. Rheological analysis of xanthan showed that the G′ values were higher than the G″ in all frequencies demonstrating a relatively high elasticity of the produced xanthan gum.
AB - Semi-continuous production of xanthan gum using self-immobilized Xanthomonas campestris cells in biofilm reactors was studied. Fermentation was carried out using two different designs of biofilm reactor equipped with a) stainless-steel support (SSS) and b) polyethylene support (PES). Fermentation was performed in three cycles with refreshing the media at the beginning of each: cycle 1, 0−27 h; cycle 2, 27−54 h; and cycle 3, 54–78.5 h. Results showed that the glucose consumption and the pH reduction in the PES biofilm reactor was faster compared to the SSS biofilm reactor. Scanning electron microscopy showed that the SSS was capable to immobilize more cells during the growth of X. campestris. The maximum concentration of xanthan gum in the SSS biofilm reactor obtained after 27 h (3.47 ± 0.71 g/L), while the maximum concentration of xanthan in the PES biofilm reactor obtained after 78.5 h (3.21 ± 0.68 g/L). Thermal stability analysis of xanthan using differential scanning calorimetry showed the presence of two fractures attributed to dehydration and degradation of polymer. The thermogram represented both endothermal and exothermal behaviour of xanthan polymer. Furthermore, the functional groups and molecular structure of the xanthan produced in this study was evaluated using Fourier transform infrared spectrometry and also proton nuclear magnetic resonance. in addition, the surface tension of (0.2 %, w/v) xanthan gum solution was in a range of 52.16–56.5 mN/m. Rheological analysis of xanthan showed that the G′ values were higher than the G″ in all frequencies demonstrating a relatively high elasticity of the produced xanthan gum.
KW - Biofilm reactor
KW - Self-immobilization
KW - Semi-continuous
KW - Xanthan
KW - Xanthomonas campestris
UR - http://www.scopus.com/inward/record.url?scp=85099274188&partnerID=8YFLogxK
U2 - 10.1016/j.jbiotec.2021.01.004
DO - 10.1016/j.jbiotec.2021.01.004
M3 - Article
C2 - 33453292
AN - SCOPUS:85099274188
SN - 0168-1656
VL - 328
SP - 1
EP - 11
JO - Journal of Biotechnology
JF - Journal of Biotechnology
ER -