Recovering of biological products, such as enzymes, proteins, nucleic acids, amino acids and microorganisms, from the contaminants requires many steps, each removal of the contaminants, isolating of target product and purification of product closer to the demand. For the success of the large scale production, there is a need for improving process economic, efficient and delicate downstream technique enough to preserve the properties of bio-products. Aqueous two phase systems (ATPSs) have overcome these demands and emerged as a powerful method for the downstream processing of bio-products. This paper is intended to encourage a starting idea for beginners in using ATPSs technique with biological products. Factors contributing to the partition behavior of biomolecules between the two phases including polymer molecular weight and concentration, biomolecule size, surface charge, pH and temperature are presented.

Fermented rice noodle is a major source of food industry generating highly complex organic content (starch) wastewater. This study investigated the treatment of fermented rice noodle wastewater using calcium alginate entrapped yeast cells compared to the free cells. The treatment includes a two-step process: acid hydrolysis for breaking down starch to glucose and fermentation for degrading glucose to ethanol. Yeast culture, Saccharomyces cerevisiae, was used in this study. The experiment was conducted to examine optimum acid concentration and cell entrapment condition for fermentation. Sulfuric acid concentrations ranged from 0.25 to 1.00% by volume were tested while the cells entrapped in calcium alginate at cell-to-matrix (alginate) ratios (by volume) of 1:5, 1:10, and 1:20 were varied. The result showed that the optimum acid concentration of 1.00% provided 5-time higher glucose concentration compared to that in raw wastewater. After the batch fermentation, the entrapped cells reduced total chemical oxygen demand (COD) by 33-46% and glucose concentration by 88-90% while the free cells cannot obviously remove COD and reduced glucose concentration by 62%. The entrapped cells at the cell-to-matrix ratio of 1:5 achieved the best glucose biotransformation performance. The treatment reaction followed second-order kinetics. The entrapped and free cell systems gave the treatments with kinetic constants of 0.007 to 0.010 and 0.001 L/mg/hr, respectively. The entrapped and free yeast cell system potentially produced ethanol of 643 to 801 mg/L.

This research has focused on the optimization of immobilized laccase condition and utilization in degradation of acetaminophen contaminated in aqueous solution. Laccase from Lentinus polychrous was immobilized in barium alginate. The effects of laccase immobilization such as sodium alginate concentration, barium chloride concentration and gelation time were studied. The optimal conditions for immobilization were sodium alginate 5% (w/v), barium chloride 5% (w/v) and gelation time of 60 min. Immobilized laccase was then used for acetaminophen removal. Acetaminophen was removed quickly in the first 50 min. The degradation rate and percentage of removal increased when the enzyme concentration increased. Immobilized laccase at 0.57 U/g-alginate showed the maximum removal at 94% in 240 min. The removal efficiency decreased with increasing initial acetaminophen concentration. The K value for immobilized laccase (98.86 µM) was lower than that of free laccase (203.56 µM), indicating that substrate affinity was probably enhanced by immobilization. The immobilized enzyme exhibited high activity and good acetaminophen removal at pH 7 and temperature of 35°C. The activation energies of free and immobilized laccase for degradation of acetaminophen were 8.08 and 17.70 kJ/mol, respectively. It was also found that laccase stability to pH and temperature increased after immobilization. Furthermore, immobilized laccase could be reused for five cycles. The capability of removal and enzyme activity were retained above 70%.

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