In this work, a new optical screening method for acrylamide was developed. Bacterial Bacillus sp. strain ZK 34 was used to hydrolyse acrylamide to the corresponding acid and ammonia. Nessler's reagent was used to detect the produced ammonia and the yellow complex formed was treated as signal. Bacterial pellet was immobilised in the alginate membrane. The optimum composition of alginate used is 2%. The mass ratio of alginate:bacterial of 1:0.5 gave the optimum respond. Optimum concentration for NaOH and Nessler's reagent were 0.075 M and 2.5 mM, respectively. The yellow complex of mercury (II) amido-iodine formed was directly proportional to the concentrations of acrylamide up to 50.00 ppm with the limit of detection of 1.30 ppm. This sensor shows a good reproducibility which the relatives standard deviation (RSD) values from 3.17-6.15%. Therefore, the detection of acrylamide based on the amidase hydrolysis is suitable for screening this carcinogen compound.

Crude extract of ChE from the liver of Puntius javanicus was purified using procainamide-sepharyl 6B. S-Butyrylthiocholine iodide (BTC) was selected as the specific synthetic substrate for this assay with the highest maximal velocity and lowest biomolecular constant at 53.49 μmole/min/mg and 0.23 mM, respectively, with catalytic efficiency ratio of 0.23. The optimum parameter was obtained at pH 7.5 and optimal temperature in the range of 25 to 30°C. The effect of different storage condition was assessed where ChE activity was significantly decreased after 9 days of storage at room temperature. However, ChE activity showed no significant difference when stored at 4.0, 0, and -25°C for 15 days. Screening of heavy metals shows that chromium, copper, and mercury strongly inhibited P. javanicus ChE by lowering the activity below 50%, while several pairwise combination of metal ions exhibited synergistic inhibiting effects on the enzyme which is greater than single exposure especially chromium, copper, and mercury. The results showed that P. javanicus ChE has the potential to be used as a biosensor for the detection of metal ions.

A locally isolated Acinetobacter sp. Strain AQ5NOL 1 was encapsulated in gellan gum and its ability to degrade phenol was compared with the free cells. Optimal phenol degradation was achieved at gellan gum concentration of 0. 75% (w/v), bead size of 3 mm diameter (estimated surface area of 28. 26 mm2) and bead number of 300 per 100 ml medium. At phenol concentration of 100 mg l-1, both free and immobilized bacteria exhibited similar rates of phenol degradation but at higher phenol concentrations, the immobilized bacteria exhibited a higher rate of degradation of phenol. The immobilized cells completely degrade phenol within 108, 216 and 240 h at 1,100, 1,500 and 1,900 mg l-1 phenol, respectively, whereas free cells took 240 h to completely degrade phenol at 1,100 mg l-1. However, the free cells were unable to completely degrade phenol at higher concentrations. Overall, the rates of phenol degradation by both immobilized and free bacteria decreased gradually as the phenol concentration was increased. The immobilized cells showed no loss in phenol degrading activity after being used repeatedly for 45 cycles of 18 h cycle. However, phenol degrading activity of the immobilized bacteria experienced 10 and 38% losses after the 46 and 47th cycles, respectively. The study has shown an increased efficiency of phenol degradation when the cells are encapsulated in gellan gum. � 2011 Springer Science+Business Media B.V.

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 (Vmax) and lowest biomolecular constant (Km) at 113.60 Umg-1 and 0.0689 mM, respectively, with highest catalytic efficiency ratio (Vmax/Km) of 1648.77. The optimum pH was 7.5 with sodium phosphate buffer as medium, while optimal temperature was in the range of 25 to 35�C. Bendiocarp, carbofuran, carbaryl, methomyl and propoxur significantly lowered the AChE activity greater than 50%, and the IC50 value was estimated at inhibitor concentration of 0.0758, 0.0643, 0.0555, 0.0817 and 0.0538 ppm, respectively. � Triveni Enterprises.

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 (Km) 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. � by PSP.

The increasing phenol and phenolic wastes necessitates the screening of bacteria that are able to degrade phenol. 115 bacterial isolates from several industrial sites and farms in Malaysia were screened for phenol degrading activity in minimal salt media (MSM) containing 0.5 gL-1 phenol. Thirty seven bacterial isolates exhibited phenol degrading activity and of this total, 6 isolates showed high phenol activity after 8 days of incubation. The isolate with the highest phenol degrading activity was subsequently identified as Acinetobacter sp. Strain AQ5NOL 1 based on BiologTM GN plates and partial 16S rDNA molecular phylogeny. The optimum conditions for achieving high phenol degradation were 0.04% (w/v) (NH4)2SO4, 0.01% (w/v) NaCl, pH 7, and temperature of 30�C. Acinetobacter sp. Strain AQ5NOL 1 was found to degrade phenol of up to 1500 mgL-1 concentrations under the optimized conditions. The isolation of Acinetobacter sp Strain AQ5NOL 1 provides an alternative for the bioremediation of phenol and phenolic wastes.

Copper is a significant trace element necessary for the normal growth and metabolism of living organisms. However, this element may become very dangerous if used beyond its limit, turning into continuous metal compounds with the ability to accumulate in water and cause imbalance to the biological system. Aquaculture activities can also be affected due to the increase in environmental pollution. Copper is observed with the ability to cause some deleterious effects on fish by its toxicity, which can be evaluated from the molecular and structural level of the organism. This is because fish is one of the aquatic organisms that are able to accumulate heavy metals in their tissue. Generally, this accumulation is influenced by several factors namely, metal concentration, time of exposure, ways of metal uptake, environmental condition (water temperature, pH) and intrinsic factors (fish age, size). Different organs of fish show different affinity to copper accumulation. Therefore, this review was conducted with the purpose of investigating the harmful effects of copper on fish as a result of the accumulation of copper in fish organs and the histopathological alteration encountered in fish. � Universiti Putra Malaysia Press.