The microorganisms responsible for the degradation of a mixture of phenol, 4-chlorophenol (4CP), 2,4-dichlorophenol (24DCP) and 2,4,6-trichlorophenol (246TCP) were isolated and characterized in terms of its degradation rate. Activated sludge was acclimated for 70 days to 40 mg phenols/l. After this period the microorganisms responsible for the chlorinated phenol degradation were isolated and identified. Four types of Gram negative bacteria (Aeromonas sp., Pseudomonas sp. Flavimonas oryzihabitans, and Chryseomonas luteola) and Mycobacterium sp. were identified. The degradation kinetics of each phenol by Aeromonas sp.,Pseudomonas sp. Flavimonas oryzihabitans, Chryseomonas luteola and activated sludge were determined. The degradation of phenolic compounds was sequential: phenol and 4CP were first degraded, following by 24DCP and then by 246TCP. The acclimated activated sludge was from one to two orders of magnitude faster than the pure strains, when uptake rates were calculated in terms of the viable biomass (CFU). The qx for acclimated activated sludge varied between 8.2 and 15.8 × 10−7 mg/CFU-d (407–784 mg/gVSS-d). Aeromonas sp. presented the highest qx of the pure strains, based on a VSS basis (33–57 mg/gVSS-d) but, in terms of viable biomass (5.0–15.6 × 10−8 mg/CFU-d) Pseudomonas sp. did. Specific substrate uptake rate was 1.8 mg chlorinated phenols/g VSS-d for non-acclimated activated sludge.
Since surface plays a key role in bioactivity, the response of the host to the biomaterial will determine the success or failure of the prosthesis. The purpose of this study is to make an exhaustive analysis of the histological and histochemical characteristics of new bone tissue around Zr implants anodized at 60 V (Zr60) supported by histomorphometric methods in a rat model. Fibrous tissue was observed around the control implants (Zr0) and osteoblasts were identified on the trabeculae close to the implantation site that showed typical cytological characteristics of active secretory cells, regardless of the surface condition. The histomorphometrical analysis revealed a significant increase in cancellous bone volume, trabecular thickness and in trabecular number together with a decrease in trabecular separation facing Zr60. TRAP staining showed that there was a relative increase in the number of osteoclasts for Zr60. In addition, a larger number of osteoclast with a greater number of nuclei were detected in the tibiae for Zr60. This research demonstrated that the new bone microarchitecture in contact with Zr60 is able to improve the early stages of the osseointegration process and consequently the primary stability of implants which is a crucial factor to reduce recovery time for patients.
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