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Effect of Pseudoanabaena sp. on emission of 2-MIB in
drinking water reservoir
Huang, Xin; Huang, Zhifeng; Chen, Xueping
School of Environment and Chemical Engineering, Shanghai University, Shanghai 200444, China;
Huang, Xin(1980- ), male, associate professor, Shanghai university.
Tel: 021-66137748; E-mail: [email protected]
Supported by the National Science Foundation Project of China (No. 51678351)
Abstract: With the increasingly serious water eutrophication, off-flavor problem
caused by cyanobacteria has been frequently reported. These problems have caused
concerns and complaints about water quality, and become a key research direction.
2-methylisoborneol (MIB) is one of the most commonly detected off-flavor chemicals
present in drinking water. However, it is difficult to real-time monitoring 2-MIB
because of the exceptionally low detection threshold, result in 2-MIB can’t prevention
timely. Quantitative real-time PCR (qPCR) is useful for quantifying responsible for
2-MIB-producers by quantifying 2-MIB synthase gene. It has been reported that genes
were closely associated with 2-MIB synthesis by culturing cyanobacteria in laboratory,
but the monitoring of 2-MIB-producer in drinking water reservoir has not been
reported.
To find the responsible for 2-MIB producers, in this study, both water samples
and sediment samples were taken from the surface layer at five locations in a drinking
water reservoir from October 2015 to September 2016. The biomass and taxonomic
units of algal communities in water samples were determined via blood counting
chamber and microscopic counting. 2-MIB concentrations were determined by
SPME-GC-MS, and the synthesis gene of which in water and sediment samples were
quantified by qpcr. The Shannon–Weaver indices (H’) were used to evaluate bacterial
diversity. Seasonal variations of algal groups analyzed by principal components
analysis（PCA）, and the effects of environmental factors on bacterial community were
analyzed by canonical correspondence analysis (CCA).
The results showed that the community of algal groups at different season were
obviously variations, and Pseudoanabaena sp. of Cyanobacteria was the dominant
algal group in summer, the biomass of which was ranged between 31.52% - 60.11%.
The species diversity indexes in summer and winter (<2) were lower than that in
spring and autumn (>2). Copy number of 2-MIB synthesis gene and the cell number
of Pseudoanabaena sp. had similar variation tendency, both of them increased in
August rapidly. There are obviously positive correlation between copy number and
cell number (R2=0.401), 2-MIB concentration (R2=0.536). Moreover, gene copy
number in water samples was strong correlated with that in sediment samples (R2 =
0.842). In addition, the CCA results suggested that TP, Chl a, phycocyanobilin and
gene copy number in sediment (p<0.05) were significantly affect the bacterial
community composition.
These results suggested that Pseudoanabaena sp. was dominant species in the
water reservoir, and which may play key role in the producer of 2-MIB. The algae
community in the water reservoir were significantly impacted by TP, Chl a,
phycocyanobilin. This study may provide appropriate management and treatment
options to water utilities. In addition, because of the high correlation coefficient
between gene in water and sediment, 2-MIB might release from sediment to water
bodies, it needs further research to strengthen the monitoring of sediment.