CHARACTERIZATION OF BIOFILM FORMATION IN WATER WELLS AT THE ARAVA VALLEY

Groundwater is an important source of fresh water in arid countries, like Israel, where the human population depend on its availability. In Israel water wells are the main means for extracting groundwater. These wells have a high tendency to clog making extraction a costly, inefficient and difficult process. Most of well fouling develop due to biofilm formation. To date there is a lack of information regarding the bacterial populations which take part in biofouling of water wells. In particular, at the Arava valley. The clogging process in the Arava wells occurs rapidly in comparison to water wells worldwide. Such rapid biofouling provides an opportunity to investigate the process in relatively short time periods. In addition, developing more accurate methods to investigate such biofilm formation and development will provide better characterization of the microbial population in clogged water wells enabling the development of treatment and prevention methods. Thus to investigate biofilm formation in water wells we developed a coupon sampling protocol enabling periodic removal of samples with minimal disturbance to the naturally developing biofilm. Coupons made up of glass, steel and stainless steel were inserted into rehabilitated water wells at the Arava valley for 14 month period. The environmental samples were analyzed under electron and confocal laser microscopy to study their chemical element map and formed biofilm. Metagenomics of 16S rRNA gene were used to investigate bacterial diversity in and between the samples. In addition, bacterial biofilm potentials were analyzed in the lab using culturing methods, static and flowing assays. Better understanding of changes occurring in biofilm development following water well rehabilitation, may lead to the development of new methods for treatment.