Simultaneous solid–liquid separation and primary purification of clavulanic acid from fermentation broth of Streptomyces clavuligerus using salting‐out extraction system

Abstract

Clavulanic acid (CA) is usually used together with other β‐lactam antibiotics as combination drugs to inhibit bacterial β‐lactamases, which is mainly produced from the fermentation of microorganism such as Streptomyces clavuligerus. Recently, it is still a challenge for downstream processing of low concentration and unstable CA from fermentation broth with high solid content, high viscosity, and small cell size. In this study, an integrated process was developed for simultaneous solid–liquid separation and primary purification of CA from real fermentation broth of S. clavuligerus using salting‐out extraction system (SOES). First, different SOESs were investigated, and a suitable SOES composed of ethanol/phosphate was chosen and further optimized using the pretreated fermentation broth. Then, the optimal system composed of 20% ethanol/15% K2HPO4 and 10% KH2PO4 w/w was used to direct separation of CA from untreated fermentation broth. The result showed that the partition coefficient (K) and recovery yield (Y) of CA from untreated fermentation broth were 29.13 and 96.8%, respectively. Simultaneously, the removal rates of the cells and proteins were 99.8% and 63.3%, respectively. Compared with the traditional method of membrane filtration or liquid–liquid extraction system, this developed SOES showed the advantages of simple operation, shorter operation time, lower process cost and higher recovery yield of CA. These results demonstrated that the developed SOES could be used as an attractive alternative for the downstream processing of CA from real fermentation broth.

Enhancing the Stability and Performance of Two-Dimensional Perovskite Solar Cells via Double-Step Homogeneous Precursor Mixing

“…Hence, the DMF solvent could not interact or interacted less with PbI 2 , which induced the precipitation of the precursor complexes in the solutions. This phenomenon was similar to the salting out of proteins in various biological systems. − In contrast, homogeneous mixing could provide particularly stable solvation complexes in the solutions due to much less competitive interactions between the solvent and precursors with PbI 2 ; hence, the solubility of the precursors was greatly enhanced. It is noteworthy that the competitive interactions between the PDA spacer and DMF solvent with PbI 2 in the prepared PbI 2 /PDAI 2 solutions were not high because the amount of the PDA spacer in the solutions was much smaller than that of PbI 2 (the mole ratios between PDA and PbI 2 are 1:5, 1:10, and 1:15 for n = 5, 10, and 15 perovskites, respectively), causing the solvent to efficiently coordinate with PbI 2 .…”