Capability of Immobilized Clostridium beijerinckii TISTR 1461 on Lotus Stalk Pieces to Produce Butanol from Sugarcane Molasses

Immobilized Clostridium beijerinckii TISTR 1461 was used to enhance the butanol production efficiency from sugarcane molasses. Lotus stalk (LS) pieces were used as carriers for cell immobilization. Sugarcane molasses containing 50 g/L of sugar supplemented with 1 g/L of yeast extract was found to be an appropriate medium for bacterial cell immobilization on the LS pieces. Carrier size (4, 12 and 20 mm in length) and carrier loading (1:15, 1:30 and 1:45, w/v) were optimized for high levels of butanol production using response surface methodology (RSM). The batch fermentation was carried out under anaerobic conditions in 1 L screw-capped bottles at 37 °C and an agitation rate of 150 rpm. It was found that the optimum conditions for the butanol production were the carrier size of 4 mm and carrier loading of 1:31 (w/v). Under these conditions, the butanol concentration (PB) was 12.89 g/L, corresponding to the butanol productivity (QB) of 0.36 g/L∙h and butanol yield (YB/S) of 0.36 g/g. These values were higher than those using free cells (PB, 10.20 g/L, QB, 0.28 g/L∙h and YB/S, 0.32 g/g). In addition, it was found that a 24 h incubation time for cell immobilization was appropriate for the immobilization process, which was confirmed by the results of the scanning electron microscope (SEM) and atomic force microscopy (AFM) images and specific surface area measurement. When the fermentation using the immobilized cells was carried out in a stirred-tank reactor (STR), column reactor (CR) and CR coupled with STR, the results showed that all reactors could be used to produce butanol production from the immobilized cells on LS pieces. However, the PB using CR and CR coupled with STR were only 75% and 45% of those using the screw-capped bottle and STR.

Determination the ammonium separating in ground water by using polyurethane-derived carrier with microbial film technique

In order to determine the ammonium treating efficiency, several factors were investigated, including: carrier size and dimension, the volume of carrier, ammonium concentration… which impact on nitrification rate by two (02) techniques: moving and fixed bed microbial film. The results indicated that with moving bed microbial film technique, the best size and dimension of carrier is a cube with 1x1x1 cm, the content of carrier is of 20% in volume. However, fixed bed microbial film technique is favored by the cube of 2x2x2 cm carrier, the content of 50% in volume.

Encapsulation of Active Molecules in Microparticles Based on Natural Polysaccharides

This mini-review is focused on an engineering approach to produce polysaccharides-based microparticles for nutraceutical and pharmaceutical purposes. A brief introduction about the fundamental properties of polysaccharides and their use as microsystems in food, cosmetics, and pharmaceutics, and a summary of the most important methods of preparation are described. Then, a novel method based on the ultrasonic atomization of solutions of the two most used polysaccharides, alginate and chitosan, followed by ionotropic gelation to produce enteric microsystems for oral administration and, in particular, the basic mechanisms of the encapsulation of molecules with different size and hydrophilicity, are investigated. This mini-review will show therefore the pathway to correctly design a polysaccharide microcarrier for the encapsulation of active molecules with different properties: from the choice of materials features, to the selection and the optimization of production methods with the aim to reduce costs and energy (ionotropic gelation coupled to ultrasonic atomization), to the control of the final carrier size (by purposely developed predictive models), at last to the optimization of encapsulation properties (predicting by model the drug leakage and providing different solutions to avoid it).