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This study has investigated the biodegradable potential of the Streptomyces microflavus CKS6 growing microbial cells for the colored waste water treatment. The Crystal violet and Safranin T basic dyes have been employed as a model compounds for decolorization evaluation by exploring the correlation with the other rate-dependent environmental parameters. Through the measuring of color reduction by UV Vis spectroscopic monitoring analysis, the results revealed well operational properties of Streptomyces microflavus CKS6 for the successful refinement of dyes contaminate water solutions. Optimized process parameters were found to be apparently mild, involving the use of the reaction temperature of 27-30 degrees C and pH 6-7. With the lower dye concentrations, the decolorization efficiency was found to be more effective and rapid, wherein the 1 mg/L of Crystal violet was removed within the 2.5 h of the treatment time, while the solution with the same content of the Safranin T dye required 30 h. A possible mechanism for the working medium decolorization was accomplished in two consecutive steps, by the primarily dye adsorption onto the bacterial cells surface, followed to biodegradation by the active microbial enzymatic system, wherein the lignin peroxidase acts a notable role. The phytotoxicity analysis of the degradation products revealed less toxicity to the plants, compared to parental chemicals. In addition, the adaptation of individual dye optimized parameters was effectively implemented in the real waste water system containing the mixture of these two dyes. The overall results may postulate that Streptomyces microflavus CKS6 may be promising applicants for dye contaminated Water treatment.

This study has explored the feasibility of using spent coffee grounds as a good supporting material for the Paenibacillus chitinolyticus CKS1 cellulase immobilization. An optimal operational conditions in a batch-adsorption system were found to be: carrier mass of 12 g/L, under the temperature of 45 degrees C and no pH adjustments. The immobilization yield reached about 71%. An equilibrium establishment between the cellulase and the carrier surface occurred within 45 min, whereas the process kinetics may be predicted by the pseudo-second-order model. An immobilized cellulase preparation expressed very good avicelase activity, this reached up to 2.67 U/g, and revealed an improved storage stability property, compared to free enzyme sample counterpart. The addition of metal ions, such as K+ and Mg2+ did not affect positively immobilization yield results, but on the contrary, contributed to an improved bio-activities of the immobilized cellulase, thus may be employed before each enzyme application. The method developed in this study offers a cheap and effective alternative for immediate enzyme isolation from the production medium and its stabilization, compared to other carriers used for the immobilization.

This study aims to investigate the biological processes related to the biodegradable potential of growing microbial cells for contaminated water treatment. Thus, the use of the Streptomyces fulvissimus CKS 7 (CKS7) has been evaluated for decolorizing efficiency of a solution containing a cationic triphenylmethane dye, crystal violet. The color reduction was monitored by UV-Vis spectroscopic analysis, through changes in their absorption spectrum and comparing the results with those of the respective controls. It was found that the CKS7 performed well and reached up to 100% effectiveness. The required process parameters have been apparently mild and include the reaction temperature of 27-30 degrees C, 10% inoculum size, under shaking conditions, whereas the time course of decolorization had been concentration dependent. A possible mechanism for removing dye from the working medium was accomplished in two steps: the binding of the dye on the bacterial cell surface, in addition to the dye biodegradation by the bacterial intracellular enzymes. After one cycle of the complete dye removal, the adapted culture was successfully reused for the same purpose. The phytotoxicity analysis revealed that non-toxic compounds were present in decolorized medium, indicating that the CKS7 bacteria seem to be a promising application for contaminated water treatment.