Partitioning of pristinamycins in aqueous two‐phase systems: A first step toward the development of antibiotic production by extractive fermentation

Abstract

The partitioning of pristinamycins was studied in dextran and polyethylene glycol (PEG) aqueous two-phases systems. Pristinamycins partitioned preferentially into the PEG-rich top phase. The partition coefficient was independent of molar mass of PEG and dextran and of antibiotic concentration, but, increased exponentially with the tieline length of the system. Partition of pristinamycins was greatly improved when fatty acids esters of PEG were mixed with PEG. In such mixtures, the partition of coefficient increased up to a value of 24, dependent on the carbon chain length of fatty acids and the modified PEG concentrations. Moreover, in such system, the two groups of pristinamycins, I and II, were extracted in accordance with their hydrophobicity. Recovery of pristinanamycins produced by Streptomyces pritinaespiralis in a fermentation broth was achieved with a dextran/PEG system. Cells were confined into the bottom phase and pristinamycins partitioned in the top phase. However, due to binding of the pristinamycins to the cells, the partition coefficient was slightly lower than of pure antibiotics solutions. (c) 1994 John Wiley & Sons, Inc.

Medium Optimization Based on Statistical Methodologies for Pristinamycins Production by Streptomyces pristinaespiralis

“…Therefore, it is clearly suggested that pristinamycins production was not associated with the mycelia growth, and it might be a typical example of a growth-disassociated product. On the other hand, because of the degradation of pritinamycins by enzymes, a limitation of the antibiotic production was observed after reaching the maximum, which was in agreement with the previous report [35]. The reducing sugar concentration slowly increased in the first 29 h and decreased thereafter until to 1.29 g/L.…”

ATPS applied to extraction of small molecules – polycetides – and simultaneous clarification of culture media with filamentous microorganisms

“…Yang et al [8] showed that ATPS were able to extract cephalosporin C from whole culture medium, separating early in the process, cells and desacetyl cephalosporin C, a by-product with a molecular structure close to the target molecule. Paquet et al [9] studied partitioning of prestinamycins from whole culture medium and observed that cells were confined into the bottom phase and prestinamycins partitioned to the top phase.…”

Partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid in PEG/ammonium sulfate aqueous two‐phase systems

“…The partitioning behaviour of cephalexin and 7‐ADCA was investigated in ATPS consisting of ammonium sulfate and PEG with different molecular weights. The compositions of the ATPS system were designed to produce the same TLL to assess the influence of PEG molecular weight 11. TLL was calculated according to:20 where W is the concentration of PEG or ammonium sulfate (A) in the top (T) or bottom (B) phase.…”

“…Increasing published data concerning the partition of low‐molecular‐weight substances, however, indicate that it is possible for them to partition unequally in ATPS 9. 10 Some papers also reported that bioconversion of low‐molecular‐weight substances in ATPS is practicable 11–14. Bioconversion in ATPS had been studied in the production of oligosaccharides,14 peptides,15 aspartame derivatives,16 etc.…”