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The performance of tunable aqueous polymer phase impregnated resins (TAPPIR) which is the combination of the solvent impregnated resin principle and an aqueous two-phase system for the separation of esterase from Serratia marcescens was evaluated in this study. Different molecular weight of polyethylene glycol (PEG) (2000, 4000 and 6000) at concentration ranging from 5% to 20% (w/w) and potassium citrate were used to construct the aqueous phase in TAPPIR technology. Optimum composition of PEG and salt for esterase partitioning was determined using response surface methodology. The optimum condition for the purification of esterase was impregnation of 25% (w/w) of PEG 2000 into 4 mm porous glass beads and extraction of esterase using 15% (w/w) potassium citrate at pH 8 containing 12% (w/w) crude loading with the addition of 4% (w/w) NaCl. Esterase from S. marcescens was successfully purified by the TAPPIR technology up to 5.32 of purification factor with a yield of 75.98%.

Lactobacillus bulgaricus is a LAB strain which is capable of producing bacteriocin substances to inhibit Staphylococcus aureus. The aim of this study was to purify a bacteriocin-like inhibitory substance (BLIS) produced by L. bulgaricus FTDC 1211 using an aqueous impregnated resins system consisting of polyethylene-glycol (PEG) impregnated on Amberlite XAD4. Important parameters influencing on purification of BLIS, such as the molecular weight and concentration of PEG, the concentration and pH of sodium citrate and the concentration of sodium chloride, were optimized using a response surface methodology. Under optimum conditions of 11% (w/w) of PEG 4000 impregnated Amberlite XAD4 resins and 2% (w/w) of sodium citrate at pH 6, the maximum purification factor (3.26) and recovery yield (82.69% ± 0.06) were obtained. These results demonstrate that AIRS could be used as an alternate purification system in the primary recovery step.

Determination of inhibition of calcium oxalate (CaOx) crystallisation in vitro by nucleation assay is based on the rates of nucleation by comparing the slope of the turbidity of a control system with that of one exposed to the extract, which was found to be inaccurate when the CaOx crystals were formed and precipitated. A need exists for improved methods to determine the inhibition activity in nucleation assay for the study of anti-urolithiasis activity. In this study, the size reduction of CaOx crystals after treated with methanolic extract of Musa acuminate x balbisiana Colla cv. Pisang Awak Legor bagasse was measured under light microscopy and correlated to the turbidity and percentage of inhibition. Different concentrations of bagasse extract (2, 10, 30, 50 and 100 mg/ml) were investigated and the result shows that high concentration of extract would promote reduction in CaOx’s stone size, but it increased the amount of sediment crystals, resulting high turbidity. The stone size was reduced up to 93.76±0.19% in the presence of 100 mg/mL extract while the inhibition percentage was negative (-102.17±0.04%) as the optical density (OD) of the extract was higher than control in the turbidity calculation. The results of this study are expected to provide an understanding on the way of calculating the activity in nucleation assay.

Background Current advances in biotechnology have been looked at as alternative approaches towards the limited product recovery due to time- and cost-consuming drawbacks on the conventional purification methods. This study aimed to purify bovine serum albumin (BSA) as an exemplary target product using an aqueous impregnated resin system (AIRS). This method implies the concept of hydrophobicity of polymer that impregnated into the resins and driven by electrostatic attractions and hydrophilicity of aqueous salt solution to extract the target product. Methods The extraction behaviors of impregnation in terms of stability and adsorption kinetics via protein-aqueous polymer impregnated resin were studied. Impregnation stability was determined by the leaching factor of polyethylene glycol (PEG). The major factors such as PEG molecular weights and concentration, pH of aqueous salt solution, extraction methods (sonication and agitation) and types of adsorbent material and concentration of aqueous salt phase influencing on partitioning of biomolecule were also investigated. Results For impregnation stability, the leaching factor for Amberlite XAD4 did not exceed 1%. The scanning electron microscopy (SEM) image analysis of Amberlite XAD4 attributes the structural changes with impregnation of resins. For adsorption kinetics, Freundlich adsorption isotherm with the highest R2 value (0.95) gives an indication of favorable adsorption process. Performance of AIRS impregnated with 40% (w/w) of PEG 2000 was found better than aqueous-two phase system (ATPS) by yielding the highest recovery of BSA (53.72%). The outcomes of this study propound the scope for the application of AIRS in purification of biomolecules.