Mathematical modeling of the whole expanded bed adsorption process to recover and purify chitosanases from the unclarified fermentation broth of Paenibacillus ehimensis

Research Progress of Preparation Technology of Ion-Exchange Resin Complexes

As insoluble polymer materials, ion-exchange resins (IERs) can exchange their own ions with desirable charged ions in the solution. According to the affinity of active moieties for soluble counterions, IERs could be categorized into the following four types: strongly acidic cation, weakly acidic cation, strongly basic anion, and weakly basic anion exchange resins. Due to their relative safety and high drug-loading capacity, IERs have garnered extensive attention in the pharmaceutical field since the 1950s. As numerous investigations combine drugs with IERs, this article summarizes the technologies employed in these studies from four aspects: IER screening principles, combining technologies, characterization methods, and in vitro and in vivo release of drug-resinate complexes. In addition, the advantages and disadvantages of various technologies and their scope are expounded. The article provides new insights on the preparation of ion-exchange resin complexes.

Chitooligosaccharides production from shrimp chaff in chitosanase cell surface display system

Chitin refers to a natural biopolymer, which is economically significant to next-generation biorefineries. In this study, a novel high-yield method with cell surface-display chitosanase (CHI-1) was built to produce chitooligosaccharides (COS) from shrimp chaff through the co-fermentation in the presence of Bacillus subtilis and Acetobacter sp. Under the optimized co-fermentation conditions (5 g/L yeast extracts, 10 g/L KH₂PO₄, 6% ethanol, 50 g/L glucose), the final deproteinization (DP) and demineralization (DM) efficiency and the chitin yield were achieved as 94, 92 and 18%, respectively. The engineered E. coli BL21-pET23b(+)-NICHI maintained 81% of the initial enzyme activity after 40 days at room temperature. The crude CHI-1 was inactivated after one-day interacting with prepared chitosan. Moreover, E. coli BL21-pET23b(+)-NICHI still maintained excellent hydrolysis ability in 7 days, and the COS yield reached 41%. Accordingly, the proposed method exhibited excellent stability and a high hydrolysis efficiency to produce COS with whole engineered cells.

Purification of chitosanases produced by Bacillus toyonensis CCT 7899 and functional oligosaccharides production

Chitooligosaccharides (COS) have a great potential to be used by pharmaceutical industry due to their many biological activities. The use of enzymes to produce them is very advantageous, however it still faces many challenges, such as discovering new strains capable to produce enzymes that are able to generate bioactive oligosaccharides. In the present study a purification protein protocol was performed to purify chitosanases produced by Bacillus toyonensis CCT 7899 for further chitosan hydrolysis. The produced chitooligosaccharides were characterized by mass spectroscopy (MS) and their antiedematogenic effect was investigated through carrageenan-induced paw edema model. The animals were treated previously to inflammation by intragastric route with COS at 30, 300 and 600 mg/kg. The purification protocol showed a good performance for the chitosanases purification using 0.20 M NaCl solution to elute it, with a 9.54-fold purification factor. The treatment with COS promoted a decrease of paw edema at all evaluated times and the AUC0-4h, proving that COS produced showed activity in acute inflammation like commercial anti-inflammatory Dexamethasone (corticosteroid). Therefore, the strategy used to purification was successfully applied and it was possible to generate bioactive oligosaccharides with potential pharmacological use.