Phenol Biodegradation by Two Xenobiotics-Tolerant Bacteria Immobilized in Polyethylene Oxide Cryogels

Abstract

Biofilms were formed on poly(ethylene oxide) (PEO) cryogels by using bacteria cultured from xenobiotics polluted environments and their phenol biodegrading capability was studied. PEO cryogels were synthesized via UV irradiation cross linking of moderately frozen aqueous system. Two xenobiotics tolerant bacterial isolates KCM R5 and KCM RG5 were used to construct the biofilms on the cryogels.
Obtained PEO-biofilms were assessed for their ability to remove phenol at concentrations 300, 400, 600 and 1000 mg L-1 for 28 days. The biofilm PEO-KCM RG5 removed phenol up to 600mg L-1/24 h, whereas the biofilm PEO-KCM R5 was able to degrade up to 1000 mg L-1/24 h. The high content of free-water in the cryogels allowed reproduction of the used bacteria. The high content of free-water in the cryogels allowed reproduction of the used bacteria. Short initial adaptation of the PEO-bio�lms with 100 mg L-1/24 h phenol was crucial for protecting the bacterial cells from dead. The obtained results showed that the liquid debit through the bio�lms on the 28th day of the experiments was lower than at the beginning. The cryogels demonstrated non-toxicity, high biocompatibility with bacteria and excellent mechanical characteristics. After aggressive phenol treatment the PEO-biofilms remained compact, porous and
elastic. The investigated new biological materials demonstrate potential for application in the industrial wastewater treatment technologies.