Survival of bacterias Escherichia coli and Acinetobacter junii at various concentrations of sodium chloride

Adamović, Angelina (2010) Survival of bacterias Escherichia coli and Acinetobacter junii at various concentrations of sodium chloride. Diploma thesis, Faculty of Science > Department of Biology.

[img] PDF
Restricted to Registered users only
Language: Croatian

Download (3MB) | Request a copy

Abstract

The survival of two heterotrophic bacteria in conditions of various concentrations of sodium chloride was researched. Both bacteria can commonly enter marine environments through sewage or wastewater treatment plant effluents; the Escherichia coli is a common enteric bacterium and Acinetobacter junii is a phosphate-accumulating bacterium inhabiting activated sludge. When cultivated in nutrient rich media (COD 8700 mg O2 L-1), both bacteria were multiplying during 72 h at concentrations of sodium chloride up to 5% for E. coli and 3.5% for A. junii. Total die-off od E. coli was detected at 72 h by sodium chloride concentration of 20%. Total die-off od A. junii was detected at 72 h by sodium chloride concentration of 10%. When the same bacteria were cultured at nutrient depleted media (COD 90 mg O2 L-1), the multiplitation of E. coli stopped at 3.5% of sodium chloride and higher, but the cells were able to survive for longer period of time at extreme sodium chloride concentrations of 20 and 30%. The negative influence of sodium chloride to A. junii was pronounced in conditions of organic matter shortage and rapid die-off was observed at 3.5% of sodium chloride and higher. Both bacteria seemed to be osmotolerant when cultured in nutrient-rich media, but not in nutrient-depleted media.

Item Type: Thesis (Diploma thesis)
Keywords: enteric bacteria, phosphate-accumulating bacteria, propagation, dying, Nutrient Broth
Supervisor: Hrenović, Jasna
Date: 2010
Number of Pages: 37
Subjects: NATURAL SCIENCES > Biology
Divisions: Faculty of Science > Department of Biology
Depositing User: Grozdana Sirotic
Date Deposited: 01 Jul 2014 12:24
Last Modified: 01 Jul 2014 12:24
URI: http://digre.pmf.unizg.hr/id/eprint/2411

Actions (login required)

View Item View Item