Related Experiment Video
Updated: Feb 11, 2026
Improving the Success Rate of Protein Crystallization by Random Microseed Matrix Screening
Published on: August 31, 2013
Process for the successive production of calcium galactonate crystals by Gluconobacter oxydans
Xin Zhou1, Xia Hua1, Xuelian Zhou1
1Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, People's Republic of China; College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, People's Republic of China.
Abstract:
Galactonic acid and its salts can be potentially used in foodstuffs and as specialty chemicals. So far, the researches on microbial conversion of galactose to galactonate are still scarce. In this study, we initially used Gluconobacter oxydans strain NL 71 to convert galactose to galactonic acid via aerobic fermentation by fed-batch and product separation process in shaken flasks, finally 390 g/L galactonic acid could be obtained after 96 h fermentation. To harvest calcium galactonate product, an aeration-agitation bioreactor with product drain port was applied. The lower solubility of calcium galactonate aided its crystallization during fermentation and after 96 h fermentation, approximately 720 g calcium galactonate crystals were produced from 1 L broth. The results showed that successive production of calcium galactonate by a combination of fed-batch and natural crystallization in the process of fermentation was feasible.
Related Concept Videos
02:17Ecological Succession
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:25Crystal Growth: Principles of Crystallization
Initiating crystallization involves manipulating the concentration of the solute and the temperature of the solution. Since crystal growth occurs when the ratio of concentration and solubility of the solute in the solvent...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:11Scalar Product (Dot Product)
The scalar product of two vectors is obtained by multiplying...