Different strategies for cyclodextrin production: Ultrafiltration systems, CGTase immobilization and use of a complexing agent.

The study comparatively evaluated diverse strategic models of cyclodextrin (CD) production by the CGTase of Bacillus firmus strain 37: continuous production and repetitive batches in ultrafiltration systems; immobilization of CGTase on curdlan and vegetable sponge natural supports; the use of the glycyrrhizin complexing agent to modulate CGTase selectivity in favor of γ-CD production. All strategies had in common the possibility of separation of CGTase from its inhibitory products and its reuse. In the continuous production model, at 48 h of assay, the highest productivity and selectivity for ß-CD were obtained, 1.47 mmol/L/h and 92.8%, respectively. Glycyrrhizin was able to modulate the production of γ-CD with selectivity of 61.2% for 30-h batches. The comparative evaluation of the different strategic models for obtaining CDs showed particularities that should be considered, and most of the models studied returned satisfactory yields as well as excellent selectivity.

Effects of immobilization, pH and reaction time in the modulation of α-, ß- or γ-cyclodextrins production by cyclodextrin glycosyltransferase: Batch and continuous process.

This study reports the immobilization of a ß-CGTase on glutaraldehyde pre-activated silica and its use to production of cyclodextrins in batch and continuous reactions. We were able to modulate the cyclodextrin production (α-, ß- and γ-CD) by immobilization and changing the reaction conditions. In batch reactions, the immobilized enzyme reached to maximum productions of 4.9mgmL-1 of α-CD, 3.6mgmL-1 of ß-CD and 3.5mgmL-1 of γ-CD at different conditions of temperature, pH and reaction time. In continuous reactor, varying the residence time and pH it was possible to produce at pH 4.0 and 141min of residence time preferentially γ-CD (0.75 and 3.36mgmL-1 of α- and γ-CD, respectively), or at pH 8.0 and 4.81min α- and ß-CDs (3.44 and 3.51mgmL-1).

New isolate for enhancement production of microbial inulinase / Novo isolado para reforço de produção microbiana inulinase

The optimization of growth conditions for the production of inulinase by Penicillium funiculosum cells were studied as well as the continuous production of the enzyme using immobilized cells. The highest amount of enzyme (163.5U/mL) was obtained when the producing cells were incubated for 96 hours at 27oC and 200 rpm in a fermentation medium containing both inulin and peptone as sole carbon and nitrogen sources respectively. However, when the cells of the tested microorganism were adsorbed on different carriers, especially linen fibers, their production ability was also successfully maintained, to different extends, for seven successive batches. Moreover, commercially pure inulin is very expensive in only small quantities, this fermentation medium was later substituted by a crude inulin solution obtained from Jerusalem artichoke tubers (Helianthus tuberosus). The crude inulin juice was able to sustain inulinase production during the second batch cultivation of the P. funiculosum, immobilized by their adsorption on linen fibers, in a satisfactory level of about 122U/mL. Moreover, the use of the previously mentioned crude inulin preparation was also compared to the use of either complete or minimal media, composed solely of 1% pure inulin. The method, adopted in this study for inulinase production, is simple, economic, time saving, non-toxic to the microorganism and the loaded linen pads are reusable.

A otimização das condições de crescimento para a produção de inulinase por células de Penicillium funiculosum foram estudados, bem como a produção contínua da enzima utilizando células imobilizadas. A maior quantidade de enzima (163.5U / mL) foi obtida quando as células produtoras foram incubadas durante 96 horas a 27 ° C e 200 rpm num meio de fermentação contendo ambos inulina e peptona como fontes de carbono e nitrogênio, respectivamente. No entanto, quando as células do microorganismo testado foram adsorvidas em diferentes suportes, especialmente fibras de linho, a sua capacidade de produção foi também mantida com sucesso, por diferentes extensões, e por sete lotes sucessivos. Por outro lado, a inulina comercialmente pura é muito dispendiosa em apenas pequenas quantidades. Este meio de fermentação foi depois substituído por uma solução de inulina bruta obtida a partir de tubérculos de alcachofra-girassol (Helianthus tuberosus). A inulina bruta foi capaz de sustentar a produção de inulinase durante o segundo lote de cultura de P. funiculosum, imobilizado pela sua adsorção nas fibras de linho, em um nível satisfatório de aproximadamente 122U / mL. Além disso, a utilização da preparação de inulina bruta anteriormente mencionada foi também comparada com o uso de meios completos ou mínimos, compostos unicamente de 1% de inulina pura. O método, adotada neste estudo para produção da enzima, é simples, de baixo custo e com economia de tempo. Além disso, não apresenta toxicidade para o microorganismo e os suportes de linho são reutilizáveis.