Isolation and screening of alkybenzene sulfonate-degrading bacteria from sediments in Pasig River

• Main Author: Escarcha, Ella Cecilia P.
• Format: text
• Language: English
• Published: Animo Repository 1996
• Subjects: Water > Pollution; Benzene > Biodegradation; Pasig; River; River sediments; Water > Purification > Biological treatment
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/1342
• Institution: De La Salle University

Sediment samples collected from Pasig River were enriched with different concentrations of alkylbenzene sulfonate (ABS), specifically 2.5, 5.0 and 10.0 mg/L. Bacteria were isolated from the enriched sediment samples and were streaked repeatedly in ABS-overlaid agar plates to ensure purity. Pure isolates were transferred to Mineral Salt Medium with thiamine and pyridoxine incorporated with respective ABS concentration and were allowed to incubate for a period of 14 days, after which the Classic Methlylene Blue Method was performed. Continuous testing was done every 14 days to monitor a decrease in the absorbance.Dominant isolates were characterized as Gram negative bacilli, others even are endospore formers. Formation of spores was taken as a possible means of adaptation of the microorganism to the harsh environment provided for in the study.Statistical analysis of the absorbance readings obtained during the confirmatory screening tests entailed the use of linear regression in order to determine the rate of degradation of each bacterial isolate. Results showed that majority of the absorbance readings of the isolates declined significantly with the progress of the incubation period. Such decline in the absorbance readings was correlated to a decrease also in the ABS concentration incorporated in the media provided for the isolated microorganisms.