Biodegradation of 2-Methylisoborneol by Gravel Sand Filtration

Abstract

2-Methylisoborneol (MIB) and geosmin produced by blue-green algae were successfully removed in a new gravel filter plant. Small amounts of sludge were sampled from the filter layer and the bacteria able to decompose MIB were isolated from the sludge samples. By-products of the MIB degradation by these bacteria were also investigated. Among these bacteria, efforts were mainly focused on Pseudomonas fluorescens. The components of cell free extracts of this bacterium were studied in order to verify the biological reactions in vitro. 2-Methylenebornane, 2-methyl-2-bornene and isomers of these compounds were found to be a part of the by-products of the MIB degradation in the gravel filter.

Effect of pH on the Analysis of 2-MIB and Geosmin in Water

“…Based on mass spectrum and 1 H and 13 C NMR analysis, 2-methyl-2-bornene, 2-methylenebornane, and 1-methylcamphene are suspected as the dehydration products of 2-MIB. The metabolic products of 2-MIB by bacteria isolated from backwash water and filter sludge were in accord with the dehydration products obtained by treating 2-MIB under acidic conditions (Tanaka et al 1996;Sumitomo 1992). Geosmin can transform to argosmin with aqueous acid, which have similar properties, although no odor has been discovered for the latter (Gerber and Lechevalier 1965;Gerber 1967).…”

Biodegradation of 2-Methylisoborneol (2-MIB) by Single-Bacterium Isolations from Biological Filters in Drinking Water Treatment Plants

“…The sand media can hardly remove 2-MIB physically. ,,, Previous studies have reported the biodegradation of 2-MIB, and different 2-MIB degraders have been isolated from sand filters, activated sludge, and biological activated carbon. ,,, It is hypothesized that the major reason causing this result is the different microbial communities on the biofilm-covered sand media. Therefore, samples in DWTP A were selected as the target to investigate the degradation capacity.…”

Dehydration of the off-flavor chemical 2-methylisoborneol by the R-limonene-degrading bacteria Pseudomonas sp. strain 19-rlim and Sphingomonas sp. strain BIR2-rlima

“…In both cases, the yield of metabolites was small and could easily have been the result of minor acid-catalyzed dehydration that occasionally occurs during isolation or analysis of MIB (Eaton, unpublished observation). Incubation of sludge from a gravel filter with MIB yielded seven metabolites that were tentatively identified (from GC-MS analysis) and included the two dehydration products, 2-methylenebornane and 2-methyl-2-bornene (Sumitomo 1992). Using the backwash water from a biological filter as a source, two strains, a Pseudomonas sp.…”