Phenol degradation by environmental bacteria entrapped in cryogels
2015
Satchanska, Galina | Topalova, Yana | Dimkov, Raĭcho | Groudeva, Veneta | Petrov, Petar | Tsvetanov, Christo | Selenska-Pobell, Sonja | Golovinsky, Evgeny
The aim of this study was to assess the capability of bacterial isolates immobilized on poly(ethylene oxide) (PEO) cryogels to degrade and utilize phenol as a sole source of carbon and energy. Two xenobiotic-degrading bacteria were isolated from industrial areas polluted with heavy metals and aromatics. Sequencing of their 16S rDNA classified them as Pseudomonas rhodesiae (denoted as KCM R₅) and Bacillus subtilis (denoted as KCM RG₅). The following operation parameters were used: sequencing batch process, 24 h cycle of feeding, increasing phenol concentrations from 300 to 1000 mg·L⁻¹, volume of inflow – 250 mL, volume of outflow – from 212 to 7 mL and temperature of 28 °C. The PEO-KCM R₅ biofilter was found to remove phenol at a concentration of 1000 mg·L⁻¹, while the PEO-KCM RG₅ system was unable to degrade phenol at a concentration of about 600 mg·L⁻¹. After four weeks of biodegradation, the PEO biofilms remained compact, porous and elastic, while containing compact microbial biofilm as shown by scanning electron microscopy analysis of the cryogels. Taken together, our results demonstrate that our novel bacterial entrapment system in PEO cryogels is highly effective and sustainable for phenol degradation and can be relevant for application in the detoxification technologies of industrially polluted waters.
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