MOHD KHALIZAN SABULLAH | Universiti Malaysia Sabah (original) (raw)

Papers by MOHD KHALIZAN SABULLAH

Microorganisms, Mar 23, 2022

The aim of this study is to determine the inhibitory effect of copper towards butyrylcholinestera... more 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

Agrivita : Journal of Agricultural Science, Feb 1, 2016

IOP conference series, Nov 1, 2022

Fermentation, Jun 23, 2022

Water

Currently, there is a lack of assessment of the level of microplastics (MPs) pollution on recreat... more Currently, there is a lack of assessment of the level of microplastics (MPs) pollution on recreational beaches around the world. Therefore, this study was conducted to determine the current state of MP pollution on two popular recreational beaches of Kota Kinabalu, Sabah, namely, (1) Tanjung Aru Beach and (2) UMS ODEC (Outdoor Development Center) beach. MPs from the sediments were extracted using the density separation method and analyzed through a stereoscopic microscope. The overall MPs abundance, weight, size, colors, and polymer types were recorded. Tanjung Aru beach recovered higher numbers of MPs particles for all stations, with 857 MPs/kg dry sediment with a total mass concentration of 57.72 g/kg, while UMS ODEC recorded 160 MPs/kg particles with a total mass concentration of 17.96 g/kg. The maximum MPs abundance was observed in the size of <1 mm with a high proportion of white/transparent coloring. Micro Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed tha...

IOP conference series, Nov 1, 2022

Journal of Physics: Conference Series

Insecticides are an example of an environmental contaminant that can cause harmful effects on var... more Insecticides are an example of an environmental contaminant that can cause harmful effects on various types of organisms. Implementation of continuous monitoring program is needed to ensure the level of contamination can be controlled. In this present study, acetylcholinesterase (AChE) from the brain of Monopterus albus was elucidated to determine the potential alternative source of biosensor kit, which is sensitive towards various insecticides, especially carbamates. AChE from M. albus brain was extracted and purified through ammonium sulfate precipitation followed by procainamide-based affinity chromatography. Carbamate insecticides were used, such as bendiocarb, carbaryl, carbofuran, methomyl, and propoxur, to test their ability to inhibit AChE activity. Bendiocarb and methomyl show the capability to inhibit almost half of the enzyme activity at 51.05 and 51.20 %, respectively, while carbaryl, propoxur, and carbofuran inhibit 43.03, 42.80, and 15.06 %, respectively. Bendiocarb an...

Future Microbiology

Alternative solutions are eminently needed to combat the escalating number of infections caused b... more Alternative solutions are eminently needed to combat the escalating number of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Bacteriocins produced by lactic acid bacteria are promising candidates for next-generation antibiotics. Studies have found that these stable and nontoxic ribosomally synthesized antimicrobial peptides exhibit significant potency against other bacteria, including antibiotic-resistant strains. Here the authors review previous studies on bacteriocins that have been effectively employed to manage MRSA infections. The authors' review focuses on the beneficial traits of bacteriocins for further application as templates for the design of novel drugs. Treatments that combine bacteriocins with other antimicrobials to combat pervasive MRSA infections are also highlighted. In short, future studies should focus on the pharmacodynamics and pharmacokinetics of bacteriocins–antimicrobials to understand their interactions, as this aspect would li...

Journal of Environmental Microbiology and Toxicology, 2015

Polyethylene glycols (PEGs) are employed in numerous sectors. PEGs are nephrotoxic and their biod... more Polyethylene glycols (PEGs) are employed in numerous sectors. PEGs are nephrotoxic and their biodegradation by microbes could be a potential tool for bioremediation. Numerous bacterial growth studies neglect primary modelling even though modelling exercises can reveal important parameters. Previously, we have utilized several growth models to model the growth of sludge microbes on PEG 600. We discovered that the modified Gompertz model via nonlinear regression utilizing the least square method was the best model to describe the growth curve. However, the use of statistical tests to choose the best model relies heavily on the residuals of the curve to be statistically robust. Normality tests for the residuals used in this work has indicated that the use of the modified Gompertz model in fitting of the growth curve of the sludge microbes on PEG 600 initially was not adequate due to the presence of an outlier. Upon removal of this outlier, the residuals conformed to normality test, vi...

Journal of Biochemistry, Microbiology and Biotechnology, 2014

The aim of this study was to compare the various staining methods based on coomassie briliant blu... more The aim of this study was to compare the various staining methods based on coomassie briliant blue and silver nitrate stain for the two-dimensional gel electrophoresis resolved with Puntius javanicus liver proteome. The staining methods were selected base on the previous report about their compatibility with the mass spectrometry analysis. Silver staining method is known as the most sensitive method to visualize the maximum number of protein spots resolved in 2D gel but it is less sensitive(incompatible) toward mass spectrometry detection. Results of this study showed that a modified staining method using colloidal coomassie blue G-250 (CCB) is roughly similarly sensitive but lower protein spot detected compared with silver staining (SS) as indicated at the number of 303±26 and 693±14 of protein resolved in both types of stained gels. The conventional methods of staining using coomassie brilliant blue G-250 and R-250 only detected less number of protein spots(128±17and 78±11, re...

Bulletin of Environmental Science and Sustainable Management (e-ISSN 2716-5353), 2014

Acetylcholinesterase (AChE) from Caridina sp. was tested its sensitivity towards selected anticho... more Acetylcholinesterase (AChE) from Caridina sp. was tested its sensitivity towards selected anticholinesterase such as malathion. Prior to this study, the optimal assay condition was determined at the temperature of 25oC, pH 8.0 and using phosphate buffer. At the concentration of 10-8 M, malathion was able to inhibit AChE activity at 1.75% and increased to 15.79% with the increasing of malathion concentration to 10-4 M. It is proven through this study that the crude extract of AChE is sensitive toward malathion exposure and provide an alternative study for biosensor development.

Bioremediation Science and Technology Research, 2020

Pollutant treatment methods are available for membrane isolation, exchange of ions, precipitation... more Pollutant treatment methods are available for membrane isolation, exchange of ions, precipitation, transformation and biosorption. Biosorption has many positive aspects of all this technology, including low running costs, very effective toxicant detoxification at low concentrations, low levels of disposal materials. In many applications, adsorption plays an important role in concentrating useful compounds or eliminating contaminants. The thermodynamic parameters of the adsorption are often obtained from the relation between the adsorption constant (KC in Lmol-1 unit) and the Gibbs free adsorption energy. When the van’t Hoff plot for the temperature range 298.2 K to 328.2 K was plotted, a nonlinear curve was obtained with poor R2 value (R=0.491). In order to calculate the ΔH° and ΔS° more accurately, the thermodynamics parameters were analysed at two processes: one between 298.2 and 301.2 K and another at between 301.2 and 328.2 K which gave a better R2 values of 1.00 and 0.995...

The continuous discharge of toxic materials into the environment has been an alarming issue faces... more The continuous discharge of toxic materials into the environment has been an alarming issue faces around the globe. Hence, matching effort of monitoring activity is vital to coping with the overwhelming amount of metal ions. Along with the significant current research being conducted, this study aims to investigate the sensitivity of acetylcholinesterase (AChE) of Sabah porcupine fish, Diodon hystrix as an alternative biosensor in the detection of heavy metals. The enzyme was precipitated followed by the purification using ammonium sulfate precipitation and procainamide-affinity chromatography, respectively, with a total recovery of 66.67% with the specific activity of 2297.50 U/mg. The enzyme works optimally at pH 9 with the best incubation temperature of 30°C. The Michaelis constant (Km) and maximal velocity (Vmax) of 1.171 mM and 879257 mol/min/mg denotes the highest catalytic efficiency (Vmax/Km) of acetylthiocholine iodide (ATC) as its preferable substrate. Inhibition study tes...

Journal of Physics: Conference Series, 2021

Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was sy... more Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was synthesised through the coupling method between soluble procainamide hydrochloride immobilised by a cross-linked agarose size exclusion, sepharose CL-6B. 1, 4-butanediol diglycidyl ether plays a role in building up a productive and rigid connecting of a biospecific ligand (Procainamide hydrochloride) to an insoluble matrix (Sephacryl CL-6B). Local freshwater eel brain was extracted and centrifuge at high speed. The supernatant was collected, and seven different volumes were separately loaded on to the column for isocratic purification where 12 fractions were collected at the end of elution stage. This study shows 1000 μL of extractant; considered as the maximum volume to load onto the column. Lastly, a stepwise elution was performed with five different concentrations of NaCl, and each of 1 mL fraction was collected then assay for determination of enzyme activity and protein content. The da...

Microorganisms, Mar 23, 2022

The aim of this study is to determine the inhibitory effect of copper towards butyrylcholinestera... more 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

Agrivita : Journal of Agricultural Science, Feb 1, 2016

IOP conference series, Nov 1, 2022

Fermentation, Jun 23, 2022

Water

Currently, there is a lack of assessment of the level of microplastics (MPs) pollution on recreat... more Currently, there is a lack of assessment of the level of microplastics (MPs) pollution on recreational beaches around the world. Therefore, this study was conducted to determine the current state of MP pollution on two popular recreational beaches of Kota Kinabalu, Sabah, namely, (1) Tanjung Aru Beach and (2) UMS ODEC (Outdoor Development Center) beach. MPs from the sediments were extracted using the density separation method and analyzed through a stereoscopic microscope. The overall MPs abundance, weight, size, colors, and polymer types were recorded. Tanjung Aru beach recovered higher numbers of MPs particles for all stations, with 857 MPs/kg dry sediment with a total mass concentration of 57.72 g/kg, while UMS ODEC recorded 160 MPs/kg particles with a total mass concentration of 17.96 g/kg. The maximum MPs abundance was observed in the size of <1 mm with a high proportion of white/transparent coloring. Micro Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed tha...

IOP conference series, Nov 1, 2022

Journal of Physics: Conference Series

Insecticides are an example of an environmental contaminant that can cause harmful effects on var... more Insecticides are an example of an environmental contaminant that can cause harmful effects on various types of organisms. Implementation of continuous monitoring program is needed to ensure the level of contamination can be controlled. In this present study, acetylcholinesterase (AChE) from the brain of Monopterus albus was elucidated to determine the potential alternative source of biosensor kit, which is sensitive towards various insecticides, especially carbamates. AChE from M. albus brain was extracted and purified through ammonium sulfate precipitation followed by procainamide-based affinity chromatography. Carbamate insecticides were used, such as bendiocarb, carbaryl, carbofuran, methomyl, and propoxur, to test their ability to inhibit AChE activity. Bendiocarb and methomyl show the capability to inhibit almost half of the enzyme activity at 51.05 and 51.20 %, respectively, while carbaryl, propoxur, and carbofuran inhibit 43.03, 42.80, and 15.06 %, respectively. Bendiocarb an...

Future Microbiology

Alternative solutions are eminently needed to combat the escalating number of infections caused b... more Alternative solutions are eminently needed to combat the escalating number of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Bacteriocins produced by lactic acid bacteria are promising candidates for next-generation antibiotics. Studies have found that these stable and nontoxic ribosomally synthesized antimicrobial peptides exhibit significant potency against other bacteria, including antibiotic-resistant strains. Here the authors review previous studies on bacteriocins that have been effectively employed to manage MRSA infections. The authors' review focuses on the beneficial traits of bacteriocins for further application as templates for the design of novel drugs. Treatments that combine bacteriocins with other antimicrobials to combat pervasive MRSA infections are also highlighted. In short, future studies should focus on the pharmacodynamics and pharmacokinetics of bacteriocins–antimicrobials to understand their interactions, as this aspect would li...

Journal of Environmental Microbiology and Toxicology, 2015

Polyethylene glycols (PEGs) are employed in numerous sectors. PEGs are nephrotoxic and their biod... more Polyethylene glycols (PEGs) are employed in numerous sectors. PEGs are nephrotoxic and their biodegradation by microbes could be a potential tool for bioremediation. Numerous bacterial growth studies neglect primary modelling even though modelling exercises can reveal important parameters. Previously, we have utilized several growth models to model the growth of sludge microbes on PEG 600. We discovered that the modified Gompertz model via nonlinear regression utilizing the least square method was the best model to describe the growth curve. However, the use of statistical tests to choose the best model relies heavily on the residuals of the curve to be statistically robust. Normality tests for the residuals used in this work has indicated that the use of the modified Gompertz model in fitting of the growth curve of the sludge microbes on PEG 600 initially was not adequate due to the presence of an outlier. Upon removal of this outlier, the residuals conformed to normality test, vi...

Journal of Biochemistry, Microbiology and Biotechnology, 2014

The aim of this study was to compare the various staining methods based on coomassie briliant blu... more The aim of this study was to compare the various staining methods based on coomassie briliant blue and silver nitrate stain for the two-dimensional gel electrophoresis resolved with Puntius javanicus liver proteome. The staining methods were selected base on the previous report about their compatibility with the mass spectrometry analysis. Silver staining method is known as the most sensitive method to visualize the maximum number of protein spots resolved in 2D gel but it is less sensitive(incompatible) toward mass spectrometry detection. Results of this study showed that a modified staining method using colloidal coomassie blue G-250 (CCB) is roughly similarly sensitive but lower protein spot detected compared with silver staining (SS) as indicated at the number of 303±26 and 693±14 of protein resolved in both types of stained gels. The conventional methods of staining using coomassie brilliant blue G-250 and R-250 only detected less number of protein spots(128±17and 78±11, re...

Bulletin of Environmental Science and Sustainable Management (e-ISSN 2716-5353), 2014

Acetylcholinesterase (AChE) from Caridina sp. was tested its sensitivity towards selected anticho... more Acetylcholinesterase (AChE) from Caridina sp. was tested its sensitivity towards selected anticholinesterase such as malathion. Prior to this study, the optimal assay condition was determined at the temperature of 25oC, pH 8.0 and using phosphate buffer. At the concentration of 10-8 M, malathion was able to inhibit AChE activity at 1.75% and increased to 15.79% with the increasing of malathion concentration to 10-4 M. It is proven through this study that the crude extract of AChE is sensitive toward malathion exposure and provide an alternative study for biosensor development.

Bioremediation Science and Technology Research, 2020

Pollutant treatment methods are available for membrane isolation, exchange of ions, precipitation... more Pollutant treatment methods are available for membrane isolation, exchange of ions, precipitation, transformation and biosorption. Biosorption has many positive aspects of all this technology, including low running costs, very effective toxicant detoxification at low concentrations, low levels of disposal materials. In many applications, adsorption plays an important role in concentrating useful compounds or eliminating contaminants. The thermodynamic parameters of the adsorption are often obtained from the relation between the adsorption constant (KC in Lmol-1 unit) and the Gibbs free adsorption energy. When the van’t Hoff plot for the temperature range 298.2 K to 328.2 K was plotted, a nonlinear curve was obtained with poor R2 value (R=0.491). In order to calculate the ΔH° and ΔS° more accurately, the thermodynamics parameters were analysed at two processes: one between 298.2 and 301.2 K and another at between 301.2 and 328.2 K which gave a better R2 values of 1.00 and 0.995...

The continuous discharge of toxic materials into the environment has been an alarming issue faces... more The continuous discharge of toxic materials into the environment has been an alarming issue faces around the globe. Hence, matching effort of monitoring activity is vital to coping with the overwhelming amount of metal ions. Along with the significant current research being conducted, this study aims to investigate the sensitivity of acetylcholinesterase (AChE) of Sabah porcupine fish, Diodon hystrix as an alternative biosensor in the detection of heavy metals. The enzyme was precipitated followed by the purification using ammonium sulfate precipitation and procainamide-affinity chromatography, respectively, with a total recovery of 66.67% with the specific activity of 2297.50 U/mg. The enzyme works optimally at pH 9 with the best incubation temperature of 30°C. The Michaelis constant (Km) and maximal velocity (Vmax) of 1.171 mM and 879257 mol/min/mg denotes the highest catalytic efficiency (Vmax/Km) of acetylthiocholine iodide (ATC) as its preferable substrate. Inhibition study tes...

Journal of Physics: Conference Series, 2021

Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was sy... more Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was synthesised through the coupling method between soluble procainamide hydrochloride immobilised by a cross-linked agarose size exclusion, sepharose CL-6B. 1, 4-butanediol diglycidyl ether plays a role in building up a productive and rigid connecting of a biospecific ligand (Procainamide hydrochloride) to an insoluble matrix (Sephacryl CL-6B). Local freshwater eel brain was extracted and centrifuge at high speed. The supernatant was collected, and seven different volumes were separately loaded on to the column for isocratic purification where 12 fractions were collected at the end of elution stage. This study shows 1000 μL of extractant; considered as the maximum volume to load onto the column. Lastly, a stepwise elution was performed with five different concentrations of NaCl, and each of 1 mL fraction was collected then assay for determination of enzyme activity and protein content. The da...