Characterization of silver resistant bacteria isolated from a mining environment /
Single colony bacterial isolates obtained from a mining environment were screened for grwoth in a Chloride-free mdeium prior to growth in the presence of silver. Out of teh thirty-one isolates, only four were found to beresistant to silver.The fate of silver in the resistant bacterial cells was then...
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Sekudai : UTM,
1993
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| author | Zaharah Ibrahim 484345 |
| author_facet | Zaharah Ibrahim 484345 |
| author_sort | Zaharah Ibrahim 484345 |
| collection | OCEAN |
| description | Single colony bacterial isolates obtained from a mining environment were screened for grwoth in a Chloride-free mdeium prior to growth in the presence of silver. Out of teh thirty-one isolates, only four were found to beresistant to silver.The fate of silver in the resistant bacterial cells was then monitored usingTransmission Electron Microscopu and Scanning Electron Microscopu. Transmission Electron Microscopy studies of the bacteria grown in the presence ofsilver showed the accumulation of silver inside the cell, at or near the cell surface and extracellularly in the form of granules or aggregates. Amodification of the cell wall region resulting in the formation of 'blebs'was also observed.Uptake of silver by non-growing cells of Pseudomonas diminuta, pseudomonas putida, Brevibacterium acetylicum and a combination of these strains (mixedculture) was carried out using Atomic Absorption Spectroscopy. It was observed that Pseudomonas diminuta accumulated the highest amount of silver i.e.41.o mg Ag=+(g dry wt)-1 as compared to 21.0 mg Ag+ (g dry wt)-1 by the mixed culture. The effect of varying pH on silver uptake by the non-growingcells was also carried out. The results show that the amount of silverbound at the cell surface increases with increasing pH values. A differentpattern of accumulation was observed for Pseudomonas diminuta grown in the presence of 50 M Ag+. Higher amounts of silver (3.45 mg Ag+ (g dry wt)-1 was accumulated at the cell surface during the lag phase. The pattern was however reversed at the early exponential phase; more silver was accumulated intracellularly i.e. 9.50 mg Ag+ (g dry wt)-1. The silver-resisteant bacteria was also screened for the presence of plasmids using the modified Method of Birnboim and Doly. Only two strains i.e. Pseudomonas putida and Klebsiella pneumoniae were found to contain plasmids. Size estimation of the Pseudomonas putida plasmid was attempted using six different Restriction Endonnucleases. However, this was complicated by multiple plasmid bands obtained from the undigested plasmid extract. An ttempt was also carried out to extract and characterize metal-binding ptoteins form Pseudomonas diminuta. Molecular wight estimation using SDS-PAGE showed the presence of low molecular weigjt proteins ranging from 10,000 to 12,500. Isoelectric focussing of the proteins extract yielded pI values ranging from 2.0 to 9.0. |
| first_indexed | 2024-03-05T00:51:20Z |
| format | |
| id | KOHA-OAI-TEST:247309 |
| institution | Universiti Teknologi Malaysia - OCEAN |
| last_indexed | 2024-03-05T00:51:20Z |
| publishDate | 1993 |
| publisher | Sekudai : UTM, |
| record_format | dspace |
| spelling | KOHA-OAI-TEST:2473092021-06-28T14:18:32ZCharacterization of silver resistant bacteria isolated from a mining environment / Zaharah Ibrahim 484345 Sekudai : UTM,1993Single colony bacterial isolates obtained from a mining environment were screened for grwoth in a Chloride-free mdeium prior to growth in the presence of silver. Out of teh thirty-one isolates, only four were found to beresistant to silver.The fate of silver in the resistant bacterial cells was then monitored usingTransmission Electron Microscopu and Scanning Electron Microscopu. Transmission Electron Microscopy studies of the bacteria grown in the presence ofsilver showed the accumulation of silver inside the cell, at or near the cell surface and extracellularly in the form of granules or aggregates. Amodification of the cell wall region resulting in the formation of 'blebs'was also observed.Uptake of silver by non-growing cells of Pseudomonas diminuta, pseudomonas putida, Brevibacterium acetylicum and a combination of these strains (mixedculture) was carried out using Atomic Absorption Spectroscopy. It was observed that Pseudomonas diminuta accumulated the highest amount of silver i.e.41.o mg Ag=+(g dry wt)-1 as compared to 21.0 mg Ag+ (g dry wt)-1 by the mixed culture. The effect of varying pH on silver uptake by the non-growingcells was also carried out. The results show that the amount of silverbound at the cell surface increases with increasing pH values. A differentpattern of accumulation was observed for Pseudomonas diminuta grown in the presence of 50 M Ag+. Higher amounts of silver (3.45 mg Ag+ (g dry wt)-1 was accumulated at the cell surface during the lag phase. The pattern was however reversed at the early exponential phase; more silver was accumulated intracellularly i.e. 9.50 mg Ag+ (g dry wt)-1. The silver-resisteant bacteria was also screened for the presence of plasmids using the modified Method of Birnboim and Doly. Only two strains i.e. Pseudomonas putida and Klebsiella pneumoniae were found to contain plasmids. Size estimation of the Pseudomonas putida plasmid was attempted using six different Restriction Endonnucleases. However, this was complicated by multiple plasmid bands obtained from the undigested plasmid extract. An ttempt was also carried out to extract and characterize metal-binding ptoteins form Pseudomonas diminuta. Molecular wight estimation using SDS-PAGE showed the presence of low molecular weigjt proteins ranging from 10,000 to 12,500. Isoelectric focussing of the proteins extract yielded pI values ranging from 2.0 to 9.0.Thesis (PhD) -- Universiti Teknologi Malaysia, 1993Single colony bacterial isolates obtained from a mining environment were screened for grwoth in a Chloride-free mdeium prior to growth in the presence of silver. Out of teh thirty-one isolates, only four were found to beresistant to silver.The fate of silver in the resistant bacterial cells was then monitored usingTransmission Electron Microscopu and Scanning Electron Microscopu. Transmission Electron Microscopy studies of the bacteria grown in the presence ofsilver showed the accumulation of silver inside the cell, at or near the cell surface and extracellularly in the form of granules or aggregates. Amodification of the cell wall region resulting in the formation of 'blebs'was also observed.Uptake of silver by non-growing cells of Pseudomonas diminuta, pseudomonas putida, Brevibacterium acetylicum and a combination of these strains (mixedculture) was carried out using Atomic Absorption Spectroscopy. It was observed that Pseudomonas diminuta accumulated the highest amount of silver i.e.41.o mg Ag=+(g dry wt)-1 as compared to 21.0 mg Ag+ (g dry wt)-1 by the mixed culture. The effect of varying pH on silver uptake by the non-growingcells was also carried out. The results show that the amount of silverbound at the cell surface increases with increasing pH values. A differentpattern of accumulation was observed for Pseudomonas diminuta grown in the presence of 50 M Ag+. Higher amounts of silver (3.45 mg Ag+ (g dry wt)-1 was accumulated at the cell surface during the lag phase. The pattern was however reversed at the early exponential phase; more silver was accumulated intracellularly i.e. 9.50 mg Ag+ (g dry wt)-1. The silver-resisteant bacteria was also screened for the presence of plasmids using the modified Method of Birnboim and Doly. Only two strains i.e. Pseudomonas putida and Klebsiella pneumoniae were found to contain plasmids. Size estimation of the Pseudomonas putida plasmid was attempted using six different Restriction Endonnucleases. However, this was complicated by multiple plasmid bands obtained from the undigested plasmid extract. An ttempt was also carried out to extract and characterize metal-binding ptoteins form Pseudomonas diminuta. Molecular wight estimation using SDS-PAGE showed the presence of low molecular weigjt proteins ranging from 10,000 to 12,500. Isoelectric focussing of the proteins extract yielded pI values ranging from 2.0 to 9.0.42PRZSLMicroorganismsSilverTransmission electron microscopes |
| spellingShingle | Microorganisms Silver Transmission electron microscopes Zaharah Ibrahim 484345 Characterization of silver resistant bacteria isolated from a mining environment / |
| title | Characterization of silver resistant bacteria isolated from a mining environment / |
| title_full | Characterization of silver resistant bacteria isolated from a mining environment / |
| title_fullStr | Characterization of silver resistant bacteria isolated from a mining environment / |
| title_full_unstemmed | Characterization of silver resistant bacteria isolated from a mining environment / |
| title_short | Characterization of silver resistant bacteria isolated from a mining environment / |
| title_sort | characterization of silver resistant bacteria isolated from a mining environment |
| topic | Microorganisms Silver Transmission electron microscopes |
| work_keys_str_mv | AT zaharahibrahim484345 characterizationofsilverresistantbacteriaisolatedfromaminingenvironment |