Bioakumulasi merkuri oleh bakteri dart sedimen yang terkontaminasi limbah tambang emas = Bioaccumulation of Mercury by Bacteria from Sediment Contaminated by Gold Mining Wastes
| Main Author: | Perpustakaan UGM, i-lib |
|---|---|
| Format: | Article NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2005
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/17560/ http://i-lib.ugm.ac.id/jurnal/download.php?dataId=319 |
Daftar Isi:
- The aims of the research were to obtain mercury utilizing bacteria from river floor sediments and to study their capability on accumulating mercury on liquid medium containing organic mercury (CH3HgC1). Mercury utilizing bacteria were isolated through batchwise enrichment culture techniques using modified nutrient broth containing 0.1 mgL-1 methyl mercury chloride (CH3HgC1). Selection of isolates was carried out through the growth experiment based on their abilities to grow on different methyl mercury concentrations, in terms of generation time (g) and specific growth rates (p.). The effects of CH3HgC1 on the bacterial growth were observed and determined as inhibition constants (Ki). Three types of bacteria showing the highest, moderate, the lowest generation time and Ki specific were selected and purified for futher cultivation experiments. During cultivation experiment at every interval of time, the bacterial growth was monitored spectrophotometrically (A600un) and the accumulation of mercury was measured using cold vapor atomic absorption spectrometer (A3s3). The selected isolates were identified using standard methods and based on the protein profile. The results revealed that fourteen mercury utilizing bacteria were succesfully isolated from river sediment (133.5x106 CFU/ml). Only four isolates were able to grow on growth medium containing 2-4 mg L-1 at generation times of 1.3-5.5 h and specific growth rates of 0.1-0.5 generation h-1. CH3HgC1 demonstrated its inhibition on those bacterial growth stated as inhibition constants (Ki) of 1.03-1.67 mg L-1. Despite, CH3HgC1 stimulated bacterial cells to produce more mucilage mass as external capsules. The capsules enabled mercury to be accumulated. The mercury accumulation occured up to 71.7 -252.6 ug g-1 biomass by specific enzymes showed as protein bands on polyacrylamide gel with molecular weight of 22-24 kDa and 59-66 kDa. These bands had similar molecular weight as organomercurial lyase and mercury reductase enzymes. The four selected isolates were identified as Bacillus sp. (strain YLN002), Alcaligenes sp. (strain YLN004 and strain YLN005) and Pseudomonas sp. (strain YLN006). Keyword : heterotrophic, growth, accumulation, specific growth rate, generation rate, inhibition constant.