The Klebsiella sp. strain ATCC13883T capable of degrading carbofuran phenol (2,3-dihydro-2,2-dimethylbenzofuran-7-ol) has been separated from the soil by enrichment culture technique and immobilized in various, namely polyurethane foam (PUF), polyacrylamide, alginate, agar and alginate-bentonite clay-powdered activated charcoal (PAC). The degradation rates of 20 and 30 mM carbofuran phenol by free and immobilized cells in batch and semi-continuous shaken cultures were compared. The PUF-immobilized cells achieved higher degradation rates in a shorter time than freely suspended cells and the cells immobilized in polyacrylamide, alginate and agar. The PUF-and alginate-bentonite clay-PAC-immobilized cells could be reused for more than 36 cycles, polyacrylamideentrapped cells for 20 cycles and alginate-bentonite-PAC 28 cycles, without losing any degradation capacity and showed better tolerance to pH, temperature and concentration changes than free cells. These results showed that cells immobilized in modified alginate-bentonite-PAC immobilizers tolerated and completely degraded carbofuran phenol at initial concentrations of 20 and 30 mM and also higher. Such a bacterial strain could be used for bioremediation of environments contaminated with phenolic compounds.

Bacillus cereusPN24 was isolated from soil by a conventional enrichment culture method using eugenol as a sole source of carbon and energy. The organism also utilized eugenol, 4-vinyl guaiacol, vanillin, vanillic acid and protocatechuic acid as growth substrates. The organism degraded eugenol to protocatechuic acid, which was further metabolized by aβ-ketoadipate pathway. On the other hand, the intermediate of the eugenol-degrading pathway, such as ferulic acid was not detected in the culture medium as an intermediate, as evidenced by isolation and identification of metabolites and enzyme activities in the cell-free extract. Such a bacterial strain could be used for phenolic environmental clean-up given optimal nutrient conditions.

Abstract:Two biologically active classes of compounds coumarins and triazoles were employed to form the Schiff bases. The synthesized Schiff base viz., 3-aryl-[(1-isocyano-4-methyl-7-hydroxycoumarin)]-5-methyl-1,3,4-triazoline-2-one and its substituents were obtained by the condensation of amino group of mono and disubstituted derivatives of 3-methyl-5-oxo-1,2, 4-triazoles with 8-formyl-7-hydroxy-4-methylcoumarin in alcohol. The characterization were studied by elemental analysis, IR, 1 H NMR and mass spectra. The biological activities of the compounds were assayed against two bacterial via, B. subtilis, E.coli and two fungal strains A. niger, C.albican. The results indicate that the present compounds may serve as better fungicides when compared to bactericides. The synthesized compounds have turned to be wonder compounds possessing antimicrobial properties.

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