The environmental toxicants such as copper are known to affect vital organ especially liver. This study examined the effects of copper sulfate (CuSO4) on the liver morphological structure of P. javanicus. The untreated control, 0.1 and 0.3 mg/L CuSO4 treated groups displayed normal polygonal structure of the hepatocyte. However, at the concentrations of 0.5, 1.0 and 5.0 mg/L CuSO4, the hepatostructure was significantly affected, as shown by the increasing number of dilation and congestion of sinusoids, vacuolation, macrophage activities and peliosis. The damage level and HSI value were increased while the number of hepatic nuclei per mm(2) was decreased with the increasing of copper concentration. In conclusion, this study shows that the degree of liver damage in P. javanicus is dependent to the dose exposure. (c) All Rights Reserved

Climbing Perch or its scientific name, Anabas testudineus is one of the freshwater fish belonging to the family of Anabantidae. It is widely distributed in ponds, swamps and estuaries in Asia. In this study, cholinesterase (ChE) was partially purified from the liver of A. testudineus through ion exchange chromatography. This purification method provided a recovery yield of 5.36% with a purification fold of 6.6. The optimum conditions for ChE assay were identified to be 2.5 mM of butyrylthiocholine iodide (BTC) with pH 8.0 in Tris-HCl buffer at 40 degrees C. Substrate specificity profile also indicated that ChE favours BTC as substrate because it records the highest catalytic efficiency (V-max/K-m). Protein analysis through Native-PAGE showed that ion exchange chromatography is an effective method to partially purify ChE. Metal ion inhibition tests were conducted and mercury (Hg) was found to show the highest inhibition effect (87.30%) whereas lead (Pb) shows the lowest inhibition effect (28.01%). All these findings showed that partially purified ChE from the liver of A. testudineus is suitable to be used as a bioindicator to detect the presence of metal ions. (c) All Rights Reserved

One of the most economical approaches for removal of toxic compounds is bioremediation. In the long term, bioremediation is economic and feasible compared to other methods, such as physical or chemical methods. A bacterium that can efficiently reduce molybdenum blue was isolated from polluted soil. Biochemical analysis revealed the identity of the bacterium as Enterobacter sp. strain Saw-1. The growth parameters for optimal reduction of molybdenum to Mo-blue or molybdenum blue, a less toxic product, were determined around pH 6.0 to 6.5 and in the range of 30 to 37 degrees C, respectively. Glucose was selected as preferred carbon source, followed by sucrose, maltose, 1-rhamnose, cellobiose, melibiose, raffinose, d-mannose, lactose, glycerol, dadonitol, d-mannitol, 1-arabinose and mucate. Phosphate and molybdate were critically required at 5.0 mM and 10 mM, respectively. The scanning absorption spectrum acquired to detect the development of complex Mo-blue showed similarity to previously isolated Mo-reducing bacteria. In addition, the spectrum closely resembled the molybdenum blue from the phosphate determination method. Heavy metals, including mercury, copper (II) and silver (I), inhibited reduction. Moreover, the bacterium also showed capability of exploiting the pesticide coumaphos as an alternative carbon source for growth. As the bacterium proved its ability to detoxify organic and inorganic xenobiotics, the usefulness of this microorganism for bioremediation is highlighted.

Aim : The cholinesterase (ChE) based inhibition studies from fish were investigated and presented here emerged to be one of the great potential biomarkers for heavy metals monitoring. Methodology : In this study, the capability of ChE extracted from the kidney of Lates calcarifer was assessed for of metal. ChE was purified through ammonium sulphate precipitation and ion exchange chromatography. Results : The purified enzyme gave 12 fold purification with the recovery of 12.17% with specific activity of 2.889 U mg(-1). The Michaelis-Menten constant (K-m) and V-max value obtained was 0.1426 mM and 0.0217 mu mol min(-1)mg(-1), respectively. The enzyme has the ability to hydrolyse acetylthiocholine iodide (ATC) at a faster rate compared to other two synthetic substrates, propionylthiocholine iodide (PTC) and butyrylthiocholine iodide (BTC). ChE gave highest activity at 20-30 degrees C in Tris-HCI buffer pH 8.0. The results showed that cholinesterase from L. calcarifer kidney was very sensitive to sensitive to copper and lead after being tested argentum, arsenic, cadmium, chromium, copper, cobalt, mercury, nickel, lead and zinc. Interpretation : The effect of heavy metals studied on the activity of ChE differed from each other. The result of the study can be used as a tool for further developing a biomarker for the detection of heavy metals in aquatic ecosystems. In addition, the information can also be used for designing a kit, that would give a rapid and accurate result.

In a previous study, we isolated Leifsonia sp. strain SIU, a new bacterium from agricultured soil. The bacterium was tested for its ability to degrade caffeine. The isolate was encapsulated in gellan gum and its ability to degrade caffeine was compared with the free cells. The optimal caffeine degradation was attained at a gellan gum concentration of 0.75% (w/v), a bead size of 4 mm diameter, and 250 beads per 100 mL of medium. At a caffeine concentration of 0.1 g/L, immobilised cells of the strain SIU degraded caffeine within 9 h, which is faster when compared to the case of free cells, in which it took 12 h to degrade. The immobilised cells degraded caffeine completely within 39 and 78 h at 0.5 and 1.0 g/L, while the free cells took 72 and 148 h at 0.5 and 1.0 g/L, respectively. At higher caffeine concentrations, immobilised cells exhibited a higher caffeine degradation rate. At concentrations of 1.5 and 2.0 g/L, caffeine-degrading activities of both immobilised and free cells were inhibited. The immobilised cells showed no loss in caffeine-degrading activity after being used repeatedly for nine 24-h cycles. The effect of heavy metals on immobilised cells was also tested. This study showed an increase in caffeine degradation efficiency when the cells were encapsulated in gellan gum.

Acetylcholinesterase (AChE) from the brain tissue of local freshwater fish, Tor tambroides was isolated through affinity purification. Acetylthiocholine iodide (ATCi) was preferable synthetic substrate to purified AChE with highest maximal velocity (V-max) and lowest biomolecular constant (K-m) at 113.60 Umg(-1) and 0.0689 mM, respectively, with highest catalytic efficiency ratio (V-max/K-m) of 1648.77. The optimum p11 was 7.5 with sodium phosphate butler as medium, while optimal temperature was in the range of 25 to 35 degrees C. Bendiocarp, carbofuran, carbaryl, methomyl and propoxur significantly lowered the AChE activity greater than 50%, and the IC50 value kvas estimated at inhibitor concentration of 0.0758, 0.0643, 0.0555, 0.0817 and 0.0538 ppm, respectively.

Another alternative source of cholinesterase (ChE) that is sensitive towards metal ion has been revealed. ChE from muscle and blood of Anabas testudineus were extracted and purified through ammonium sulphate precipitation followed by an ion exchange chromatography with a total recovery of 47.66% and 7.92%, respectively. Kinetic study measured that BTC was the most preferable synthetic substrate to blood ChE while muscle ChE preferred PTC with the biomolecular constant of 1.07 and 0.53 mM, respectively. Optimum pH for blood and muscle ChE were determined at 8 and 9. Both ChE shared an optimum temperature of 30 degrees C. Inhibition study showed that muscle ChE has inhibited more than 50% of metal ions namely arsenic, chromium, copper, mercury and zinc compared to blood ChE with only copper and mercury. Studies on half inhibitory effect (IC50) of blood and muscle ChE were tested with series concentration of mercury calculated at 1.003 and 1.048 mg/L. This result will be used as a reference for future development of biosensor.

Due to the latest industrial development, many dangerous chemicals have been released directly or indirectly which resulted in the polluted water bodies. Water rehabilitation is an alternative way to restore the quality of water, followed by the environmental management to control the waste discharge to ensure the balance of the degradation rates or detoxifying by environmental factors. However, this process consumed a lot of time and cost. Besides, most of the metal ions, especially copper which is capable to bioaccumulate in aquatic organism and at the elevated level may cause physiological and biochemical alteration which leads to mortality. Environmental monitoring is the initial step presupposed evaluating the potential toxicity of effluent gushing at its purpose to discharge, avoiding the determining effects of contaminant in water bodies. Due to the high sensitivity of the aquatic life towards dissolving toxicant, the fish has been utilized as the biological measurement (Biomarker) to indicate the existence of toxicant exposure and/or the impact towards the evaluation of molecular, cellular to physiological level. Thus, this paper gives an overview of the manipulation of fish as a biomarker of heavy metals through behavior response, hepatocyte alteration, enzymatic reaction and proteomic studies which have proven to be very useful in the environmental pollution monitoring. (c) All Rights Reserved

The aim of this study is to determine the inhibitory effect of copper towards butyrylcholinesterase (BChE) activity. Using the Lineweaver-Burk plot, Puntius javanicus BChE activity was found to be noncompetitively inhibited by copper. The maximal velocities of untreated (control) BChE, 0.5 and 10 mg/L copper-treated BChE are 53.70, 31.81 and 14.30 Umg(-1), respectively, while the biomolecular constant (K-m) values of both tests shows no significant difference (p>0.05). The in vitro IC50 of copper ion to the BChE was found to be 0.0948 (0.0658 to 0.1691) mg/L. In vivo tests showed that in the presence of 0.1 mg/L copper, the BChE activity was slightly higher compared to the untreated control. Copper sulfate at 0.3 mg/L concentration showed no significant inhibition compared to control. However, the activity decreased with increasing copper concentrations of 0.5, 1.0 and 5.0 mg/L, with the remaining activity at 87.60, 84.60 and 73.00 %, respectively. This study suggests that BChE isolated from P. javanicus liver tissue is a potentially new source of biomarker for copper contamination.

Bioremediation of pollutants including heavy metals and xenobiotics is an economic and environmentally friendly process. A novel molybdenum-reducing bacterium with the ability to utilize the pesticide glyphosate as a carbon source is reported. The characterization works were carried out utilizing bacterial resting cells in a microplate format. The bacterium reduces molybdate to Mo-blue optimally between pH 6.3 and 6.8 and at 34 degrees C. Glucose was the best electron donor for supporting molybdate reduction followed by lactose, maltose, melibiose, raffinose, d-mannitol, d-xylose, I-rhamnose, I-arabinose, dulcitol, myo-inositol and glycerol in descending order. Other requirements include a phosphate concentration at 5.0 mM and a molybdate concentration between 20 and 30 mM. The molybdenum blue exhibited an absorption spectrum resembling a reduced phosphomolybdate. Molybdenum reduction was inhibited by mercury, silver, cadmium and copper at 2 ppm by 45.5, 26.0, 18.5 and 16.3%, respectively. Biochemical analysis identified the bacterium as Klebsiella oxytoca strain Saw-5. To conclude, the capacity of this bacterium to reduce molybdenum into a less toxic form and to grow on glyphosate is novel and makes the bacterium an important instrument for bioremediation of these pollutants.

The purification of a soluble cholinesterase (ChE) from Puntius javanicus liver using affinity chromatography was studied. Affinity matrix was synthesised through the cooling system of ligands procainamide to epoxy-activated Sephacryl 6B and purification process was performed using calibrated flow rate at 0.2 mL/min. Non-denaturing electrophoresis condition was employed and the single band native form of ChE was detected at 66.267 kDa after being stained with commasie brilliant blue. ChE detection was performed using gel filtration; ZORBAX column attached to the HPLC with the flow rate of 1 mL/min. Only a single peak was detected at the retention time of 3.720. From the assay evaluation, the final purified ChE procedure displayed the highest sensitivity of detecting the anticholinesterase namely mercury, copper, malaoxon and carbofuran compared to the impure ChE and the results were further discussed in detail to the potential application of ChE from P. javanicus as a biomarker for those toxicants. (C) 2015 Friends Science Publishers

Fish are ubiquitous organisms that have many features that designate their potential as a biomarker of heavy metals pollution. Thus, an investigation was done to detect the effect of heavy metals on cholinesterase (ChE) activity from Lates calcarifer organs which were gill and muscle. Ammonium sulphate precipitation was performed along with ion exchange chromatography to purify the enzyme. In the substrate specificity study, ChE from L. calcarifer gills was capable of breaking down acetylthiocholine iodide (ATC) at a faster rate compared to the other two synthetic substrates, which are butyrylthiocholine iodide (BTC) and propionylthiocholine iodide (PTC). In contrast, the muscle ChE has a higher affinity towards PTC. The maximum activity of ChE observed at the temperature ranging from 20 to 30 A degrees C in Tris-HCl buffer pH 8. ChE from the two organs of L. calcarifer showed an inhibitive reaction towards heavy metals, but with different effects. ATC from gills showed 50 % inhibition by Cu, Hg and Pb, while PTC from muscle showed 50 % inhibition by Pb. The variation of inhibitory effect that was shown by ChE from L. calcarifer organs can be further studied in designing a biosensor kit that is sensitive towards heavy metal.