Evaluation of Different Salts and Heavy Metal Concentrations on Bacterial Biofilm from Selected Surface and Borehole Water Samples
Dibua Nwamaka Anthonia,
Chukwura Edna Ifeoma,
Chude Charles Onuora
Issue:
Volume 6, Issue 2, June 2020
Pages:
11-17
Received:
28 February 2020
Accepted:
20 March 2020
Published:
23 April 2020
Abstract: Biofilms in drinking water systems can serve as significant environmental reservoirs for pathogenic bacteria associated with gastro-enteric diseases. The evaluation of the effects of different salts and metal concentrations on bacterial biofilm from surface and borehole water samples was conducted. Water samples were collected, from 10 selected water sources of economic importance, aseptically using sterile containers. The physicochemical properties were investigated before the biofilm generation process. The collected water samples were allowed to stand in a secluded environment for four (4) weeks at 27°C±2°C for biofilm generation. The isolates were characterized culturally, morphologically, biochemically and molecularly. The isolates were identified as Stenotrophomonas pavanii, Stenotrophomonas maltophilia, Chromobacterium violaceum, Bacillus cereus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. It was observed that the isolates exhibited growth at a wide range of temperature, salts, pH, and metal salt concentrations. To determine the metal tolerance of the isolates, different concentrations (0.05, 0.1, 0.5, and 1.0%) of four metal salts; ferrous chloride (FeCl2), zinc chloride (ZnCl2), calcium chloride (CaCl2), and magnesium oxide (MgO) was used in nutrient broth. Their ability to grow in medium containing different salt (NaCl) concentrations was also evaluated. Different concentrations of NaCl ranging from 2.0% to 10.0% were used in nutrient broth seeded with 0.1ml of the inocula and incubated at 37°C for 48 and 24hours respectively. Growth was measured in terms of OD at 660 nm using spectrophotometer. Results showed a decline in the growth of the isolates with percentage increase in concentrations of all the metal salts. The result of the effect of NaCl salt on growth showed a decrease in growth with an increase in NaCl concentration from 2% to 10%. For Stenotrophomonas pavanii, FeCl2 is negatively correlated with pH r=-.998 but there is positive correlation between CaCl2 and NaCl with r=889.
Abstract: Biofilms in drinking water systems can serve as significant environmental reservoirs for pathogenic bacteria associated with gastro-enteric diseases. The evaluation of the effects of different salts and metal concentrations on bacterial biofilm from surface and borehole water samples was conducted. Water samples were collected, from 10 selected wat...
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Physicochemical and Bacteriological Qualities of Otamiri River Water and Sediment in South Eastern Nigeria
Okechi Reuben Nwoye,
Chukwura Edna Ifeyinwa
Issue:
Volume 6, Issue 2, June 2020
Pages:
18-26
Received:
16 May 2020
Accepted:
28 May 2020
Published:
4 June 2020
Abstract: The bacteriological, physicochemical and anionic surfactants qualities of Otamiri river water and sediment were analysed, using standard techniques. The bacteriological analyses revealed the presence of Serratia marcescens (SerEW01) (33.33%), Staphylococcus (22.20%), Streptococcus (22.20%), Enterobacter (11.11%), Escherichia coli (11.11%) in Otamiri river water as well as Acinetobacter seifertii (42.10%), Bacillus (15.80%), Escherichia coli (15.80%), Klebsiella (10.53%) and Streptococcus species (5.30%), in the sediment. Some of these bacteria are indicators of fecal contamination of the river water. Iron recorded the highest value among the heavy metals (1.972 mg/l), in the river water while Co was not detected. Also, Pb, Cd, Ni, Hg, electrical conductivity and turbidity recorded values higher than WHO standards for drinking water. In the sediment, Fe and Cd had the highest and least values 19.82 and 0.025 mg/kg respectively. The pH of the river and sediment were 6.42 and 5.40. Similarly, among the anionic surfactants, sodium dodecyl sulfate (SDS) was the highest in both Otamiri river water (0.100 mg/l) and sediment (0.453 mg/kg), while perfluorobutane sulfate was not detected in the river water. These results imply that the quality of Otamiri river water and possibly the sediment are below the WHO recommendations for drinking water. People using the river water for drinking and other domestic activities should therefore purify it adequately to avert possible health hazards.
Abstract: The bacteriological, physicochemical and anionic surfactants qualities of Otamiri river water and sediment were analysed, using standard techniques. The bacteriological analyses revealed the presence of Serratia marcescens (SerEW01) (33.33%), Staphylococcus (22.20%), Streptococcus (22.20%), Enterobacter (11.11%), Escherichia coli (11.11%) in Otamir...
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