Poster Presentations

Session Title: Novel Technologies and Methods: Functional Community Analysis
Presentation Date: Thursday, August 21, 2008
Poster Board Number: 0235

DIVERSITY OF FILAMENTOUS BACTERIA IN DUBAI SEWAGE TREATMENT PLANT

S.M. Faheeem, M.A. Khan, A. Arora
Manipal University Dubai Campus, Biotechnology, Dubai, United Arab Emirates

Excessive growth of filamentous bacteria is the main cause of foaming & bulking problems in activated sludge systems. Activated sludge plants in several countries have been extensively studied but little or no information describing the filamentous bacterial diversity is available on Dubai Sewage Treatment Plant in UAE. Effective long term control of bulking and foaming begins with the basic knowledge of native filamentous bacteria. The objective of this study was to identify and determine the frequency of dominant filamentous bacteria in mixed liquor and foam over a specific period using both traditional and modern 16S rRNA based approaches. Activated sludge mixed liquor and foam sample smears were stained using Gram and Neisser staining techniques. The individual abundance level of each filament and phenotypic diversity was determined according to various characteristics outlined in literature. Fluorescent in situ hybridization analysis using published 16S rRNA targeted probes against filamentous bacteria was conducted on sludge samples. The dominant filamentous bacteria identified from mixed liquor & foam samples in descending order of frequency included: long branched form of Nocardioform, Type 021N, Thiothrix, Sphaerotilus natans, Beggiatoa and Nostocoida limicola. Fluorescent in situ hybridization indicated the presence of single celled and branched Nocardioform members; however branched form was the most dominant Nocardioform. All filamentous bacteria identified were present in mixed liquor and foam samples throughout the study. It can be concluded that the filamentous bacteria populations in foaming and bulking sludge were constant throughout the period of study irrespective of variable wastewater characteristics and harsh weather conditions.