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An indigenous Cellulosimicrobium cellulans GS6 isolate able to solubilize insoluble phosphate complexes in soil is a potential bacterial fertilizer. Enclosure of the phosphate-solubilizing bacterium (PSB) in biodegradable capsules may protect the PSB cells inoculated into soil and, in the meantime, enable the control of cell release that confers long-term fertilizing effects. In this study, calcium alginate (CA) was used as the core matrix to encapsulate cells of C. cellulans GS6. The cell-liberating properties of the CA-based capsules were modified by blending with a variety of supplemental materials (SM), including chitin, cellulose, olive oil, and gelatin. The experimental results showed that the maximum cell-release percentage (MCR%) of the capsules decreased in the order of CA-cellulose>CA-olive oil>CA-chitin>CA-gelatin>CA. Furthermore, a mass transport model was developed to accurately describe the kinetics of cell release results for each capsule. The diffusion coefficient (D(e)) of each capsule was also determined from the model simulation. We found that the estimated D(e) values are positively correlated to the release rate with rare exceptions. Lastly, as our results underscored the crucial roles that the type of capsules plays in the rate and amount of cell release, controlled release of the bacterial fertilizer (C. cellulans GS6 cells) may be achieved via the design of capsule materials.

Immobilized microalga Chlorella sp. Wu-G23 (G23) was entrapped inside a polymer matrix or appended on the surface of a strong solid carrier. Alginates then formed a microalgae/polymeric matrix granule within the cross-linking solution. The textile wastewater bioremediation technology using immobilized G23 in textile wastewater effectively removed chemical oxygen demand (COD), ammonium nitrogen (NH4+-N) and color after 7 days of cultivation. Batch model results show that the optimal cultivation parameters for simultaneously removing textile wastewater pollutants and accumulating lipids were initial pH 10 with extra urea 1 g/L and K2HPO4 8 mg/L added without aeration. A bioreactor cultivated the immobilized G23 at hydraulic retention time of 48 h with continuously fed textile wastewater for 440 h. Peak removal efficiencies of NH4+-N 80.2%, COD 70.8% and color 77.9% with fatty acid methyl esters 10% were achieved. The color removal occurred through the biosorption mechanism using nonviable suspended and immobilized microalgae biomass. The NH4+-N and COD could be degraded in the cell-free, nonviable microalgae because the microorganism in the textile wastewater could utilize them as a nutrient source. [ABSTRACT FROM AUTHOR]

Abstract: The immobilization of B. subtilis natto Takahashi on alginate matrix was attempted for repeated production of levan. Factors that influence the stability of the immobilized-cell beads and the levan production in the process of fermentation were also investigated. The levan production and the stability of immobilized beads were greatly affected by the sucrose concentration, medium pH, metal ions and agitation speed. When the immobilized cells were cultivated in the optimal conditions, high levan production (70.6g/L) was obtained after 3 d of fermentation and no damaged beads were observed. In the repetitive cultivation, the supplement of organic nitrogen source and control of initial pH was critical for high levan production. Immobilized cells on alginate beads were reused in five successive reaction cycles (each cycle 72h) without any loss of biocatalytic activity and 9 cycles with 72% residual activity. [Copyright &y& Elsevier]