Journal of Pharmaceutical and Biomedical Analysis, 2005
The interaction of drugs with DNA is among the most important aspects of biological studies in dr... more The interaction of drugs with DNA is among the most important aspects of biological studies in drug discovery and pharmaceutical development processes. In recent years there has been a growing interest in the electrochemical investigation of interaction between anticancer drugs and DNA. Observing the pre and post electrochemical signals of DNA or drug interaction provides good evidence for the interaction mechanism to be elucidated. Also this interaction could be used for the quantification of these drugs and for the determination of new drugs targeting DNA. Electrochemical approach can provide new insight into rational drug design and would lead to further understanding of the interaction mechanism between anticancer drugs and DNA.
Culturable bacterial biodiversity and industrial importance of the isolates indigenous to Khewra ... more Culturable bacterial biodiversity and industrial importance of the isolates indigenous to Khewra salt mine, Pakistan was assessed. PCR Amplification of 16S rDNA of isolates was carried out by using universal primers FD1 and rP1and products were sequenced commercially. These gene sequences were compared with other gene sequences in the GenBank databases to find the closely related sequences. The alignment of these sequences with sequences available from GenBank database was carried out to construct a phylogenetic tree for these bacteria. These genes were deposited to GenBank and accession numbers were obtained. Most of the isolates belonged to different species of genus Bacillus, sharing 92-99% 16S rDNA identity with the respective type strain. Other isolates had close similarities with Escherichia coli, Staphylococcus arlettae and Staphylococcus gallinarum with 97%, 98% and 99% 16S rDNA similarity respectively. The abilities of isolates to produce industrial enzymes (amylase, carboxymethylcellulase, xylanase, cellulase and protease) were checked. All isolates were tested against starch, carboxymethylcellulose (CMC), xylane, cellulose, and casein degradation in plate assays. BPT-5, 11,18,19 and 25 indicated the production of copious amounts of carbohydrates and protein degrading enzymes. Based on this study it can be concluded that Khewra salt mine is populated with diverse bacterial groups, which are potential source of industrial enzymes for commercial applications.
International Journal of Biological Macromolecules, 2014
Biomass gasification processes generate large amounts of solid. The aim of this work is to charac... more Biomass gasification processes generate large amounts of solid. The aim of this work is to characterize the particles produced at a demonstration scale downdraft multi-stage gasification plant running on pinewood. The results have been used to understand their formation mechanism, evaluate potential applications and determine their hazardousness to human health and the environment. Chemical, physical, morphological and textural analyses suggest that most of the particles are formed via gas phase condensation reactions, with a very limited proportion resulting from direct carbonization of the original biomass feedstock. This is confirmed by a very limited micropore structure, surface area and adsorption capacity, making the particles unsuitable for use as an adsorbent in gas and water treatment applications. The particles exhibit superior fuel properties in terms of carbon content, heating value and thermal stability, which may be associated with the high temperatures at which they are generated. Due to their biomass origin, the particles contain a high proportion of calcium, potassium, magnesium and other plant micronutrients that could be beneficial if the material is used for soil conditioning and fertilizing. Regarding particle size distribution, most of the particles fitted in the range between 100 and 250 mm, with only 0.5 wt% smaller than 30 mm. This is too large for a carbon black surrogate but minimizes health risks associated with exposure to the lower regions of the respiratory tract. The concentration of biologically active PAH is sufficiently low to represent no hazard to the environment or human health.
An exopolysaccharide (EPS) synthesizing potentially probiotic Gram-positive bacterial strain was ... more An exopolysaccharide (EPS) synthesizing potentially probiotic Gram-positive bacterial strain was isolated from fish (Tor putitora) gut, and its EPS was structurally characterized. The isolate, designated as FW2, was identified as Lactobacillus reuteri through 16S rRNA gene sequencing and phylogenetic analysis. This isolate produces fructan-type EPS using sucrose as a substrate. Based on 13C-NMR spectroscopy, methylation analysis and monosaccharide composition, the EPS was identified as a linear levan polymer with fructose as main constituent linked via β(2 → 6) linkages. Based on molecular weight (MW) distribution, two groups of levan were found to be produced by the isolate FW2: one with high MW (4.6 × 106 Da) and the other having much lower MW (1.2 × 104 Da). The isolate yielded about 14 g/L levan under optimized culturing parameters including aeration conditions, pH, temperature and substrate concentration. The obtained bimodal molecular weight linear levan is the first of its type to be synthesized by a L. reuteri isolate from fish gut. Bimodal molecular weight prebiotic levan together with the probiotic potential of the producing strain would provide a new promising synbiotic combination for use in aqua culture.
Coal is one of the most abundant non-renewable fossil fuels in Pakistan and remained a viable sou... more Coal is one of the most abundant non-renewable fossil fuels in Pakistan and remained a viable source for the generation of electricity in the country. However, in general, the quality of local coal is too low to offset the practical, economic, and regulatory barriers to its utilization. Sulphur accounts for one of the major impurities in the coal and mainly occurs in inorganic and organic forms. Combustion of high sulphur coal releases environmental pollutants like sulphur dioxide, sulphuric acid, hydrogen and nitrogen sulphides. To enhance the quality of the coal and consequently reduce its environment damaging impact, sulphur in coal needs to be removed before its combustion. Some of the conventional chemical and physical methods have responded effectively towards the removal of sulphur, but, the use of hazardous chemicals and elevated operating temperatures make such processes unattractive and less eco-friendly. The environmental regulatory authorities all over the world are stre...
ABSTRACT Coal is one of the most abundant nonrenewable fossil fuels, in Pakistan. However, in gen... more ABSTRACT Coal is one of the most abundant nonrenewable fossil fuels, in Pakistan. However, in general, the quality of coal is too low to offset the practical, economic, and regulatory barriers to its utilization. High sulfur content comes up as one of the bottlenecks in productive usage of indigenous coal. Biotechnology can emerge as a panacea for upgrading the huge reserves of high sulfur coal. In current study, the sulfur removal potential of Rhodococcus spp. (Eu-32) was investigated using coal from Dukki, Baluchistan, Pakistan. Biodesulfurization process was optimized for various parameters and maximum decrease of 40% and 60% in total and organic sulfur contents, respectively were achieved in 15 days. The Langmuir and Brunauer–Emmett–Teller (BET) surface areas of the biotreated coal were increased by 20 and 16 times, respectively. Scanning electron microscope showed higher tendency of attachment of bacterial cells to the coal particles. Our results revealed that Eu-32 could remove significant amounts of organic sulfur from coal and could be used in the pre-combustion operations with appropriate arrangements.
Pakistan is endued with 185 billion tons colossal reserves of coal, but only 7.89 % of the countr... more Pakistan is endued with 185 billion tons colossal reserves of coal, but only 7.89 % of the country total energy requirements are met by coal. Most of the Pakistani coal reserves are sub-bituminous or lignitic in nature and contain 3-12 % sulphur. Existence of sulphur compounds in coal limits its industrial application due to environmental as well as technical problems. However, coal biotechnology can emerge as panacea for upgrading the huge reserves of coal in Pakistan. In general, coal biotechnology refers to biodesulphurization, biosolubilization and biogasification of coal. NIBGE has long term interests in the field of coal bioprocessing for tapping prime resources of indigenous coal. In NIBGE, lab scale experiments for coal biodesulphurization led to 90% efficiency in sulphur removal. Heap leaching was also carried out at the level of 10 and 20 tons coal heaps with 60% sulphur removal efficiency. Furthermore, a prototype of 300 tons coal heap was set up with a local cement indus...
Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was use... more Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering, electrophoretic mobility, and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram-negative bacterial strain, Escherichia coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics.
World Journal of Microbiology and Biotechnology, 2005
Random amplification of polymorphic DNA (RAPD), a PCR-based technique was applied to evaluate gen... more Random amplification of polymorphic DNA (RAPD), a PCR-based technique was applied to evaluate genomic diversity among three strains of Acidithiobacillus thiooxidans, five strains of Acidithiobacillus ferrooxidans and one acidophilic moderate thermophile strain, using 45 random primers of five different series. More than 2200 bands were observed, with an average of 45 bands per primer. Primer OPC-3 produced the maximum number of fragments whereas minimum numbers of fragments were produced with primer OPA-5. A dendrogram was generated using cluster analysis by the unweighted pair group method of arithmetic means (UPGMA). The dendrogram showed three groups with similarity ranging from 29 to 85%. The maximum similarity (85%) was observed between the strains T.t 1 and T.t 2 of Acidithiobacillus thiooxidans.
Out of 17 samples collected from diverse environments, 110 bacterial isolates of varied character... more Out of 17 samples collected from diverse environments, 110 bacterial isolates of varied characteristics were screened for their dibenzothiophene-desulphurizing activity. A single isolate, Eu-32, originating from a soil sample taken from the roots of a eucalyptus tree, displayed dibenzothiophene-desulphurizing activity. This isolate metabolized dibenzothiophene to 2-hydroxybiphenyl (2-HBP), as detected by HPLC, and was also able to use other organic sulphur compounds as a sole sulphur source. Based on morphological, biochemical and molecular studies, it was found that the organism belongs to the genus Rhodococcus, with a maximum of 95% identity to species in this genus for the partial sequence of the 16S rRNA gene. Isolate Eu-32 could desulphurize 0.2 mM dibenzothiophene to 2-HBP in 72 h at a temperature of 30 1C and pH 7.0. The structure and molecular mass of metabolites produced from dibenzothiophene desulphurization were identified by GC-MS, and two sulphur-free products, 2-HBP and biphenyl, were detected in ethyl acetate extract. It was concluded that isolate Eu-32 is a unique desulphurizing biocatalyst that desulphurizes dibenzothiophene through an extended, sulphurspecific degradation pathway with the selective cleavage of C-S bonds.
The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and re... more The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and recovery of uranium from aqueous streams. Ca-alginate as polymeric support was selected after screening different matrices. Immobilization of Trichoderma harzianum to Ca-alginate improved the stability as well as uranium biosorption capacity of biosorbent at 28 ± 2°C and 200 rpm. The suitability of packed bed column operations was illustrated by obtaining break through curves at different bed heights, flow rates and inlet uranium concentrations. The adsorption column containing 1.5 g dry weight of immobilized material has purified 8.5 L of bacterial leach liquor (58 mg/L U) before break through occurred and the biosorbent became saturated after 25 L of influent. Sorbed uranium was recovered in 200 ml of 0.1 N HCl resulting in 98.1-99.3% elution by 0.1 N HCl, which regenerated the biosorbent facilitating the sorption-desorption cycles for better economic feasibility without any significant alteration in sorption capacity/elution efficiency.
ABSTRACT Eleven representative lignite samples from the Thar coalfield, Pakistan were subjected t... more ABSTRACT Eleven representative lignite samples from the Thar coalfield, Pakistan were subjected to a bioassay, based on mixed methanogenic bacterial consortium (WBC-2). The samples were characterized on the basis of chemical and petrographic studies in order to determine the geological stage of coal resource. Under anaerobic conditions in sealed serum bottles, the generation of methane was observed from six coal samples in the range of 3.7 to 23.2 μmol/g of coal (2.13 to 16.33 scf/ton of coal). This methane generation from Thar lignite samples may be considered as an indicative index of the presence of biogenic coalbed methane in the reservoir. The residual coal, after methanogenesis, was investigated and prospected on a preliminary basis for the release of humic materials. Conclusively, further exploration of biogenic methane production from low rank coals and subsequent extraction of soil conditioning agents from residual coal can be followed as an alternative route of coal conversion technologies for obtaining multiple value-added chemical entities from low rank coal.
Journal of Pharmaceutical and Biomedical Analysis, 2005
The interaction of drugs with DNA is among the most important aspects of biological studies in dr... more The interaction of drugs with DNA is among the most important aspects of biological studies in drug discovery and pharmaceutical development processes. In recent years there has been a growing interest in the electrochemical investigation of interaction between anticancer drugs and DNA. Observing the pre and post electrochemical signals of DNA or drug interaction provides good evidence for the interaction mechanism to be elucidated. Also this interaction could be used for the quantification of these drugs and for the determination of new drugs targeting DNA. Electrochemical approach can provide new insight into rational drug design and would lead to further understanding of the interaction mechanism between anticancer drugs and DNA.
Culturable bacterial biodiversity and industrial importance of the isolates indigenous to Khewra ... more Culturable bacterial biodiversity and industrial importance of the isolates indigenous to Khewra salt mine, Pakistan was assessed. PCR Amplification of 16S rDNA of isolates was carried out by using universal primers FD1 and rP1and products were sequenced commercially. These gene sequences were compared with other gene sequences in the GenBank databases to find the closely related sequences. The alignment of these sequences with sequences available from GenBank database was carried out to construct a phylogenetic tree for these bacteria. These genes were deposited to GenBank and accession numbers were obtained. Most of the isolates belonged to different species of genus Bacillus, sharing 92-99% 16S rDNA identity with the respective type strain. Other isolates had close similarities with Escherichia coli, Staphylococcus arlettae and Staphylococcus gallinarum with 97%, 98% and 99% 16S rDNA similarity respectively. The abilities of isolates to produce industrial enzymes (amylase, carboxymethylcellulase, xylanase, cellulase and protease) were checked. All isolates were tested against starch, carboxymethylcellulose (CMC), xylane, cellulose, and casein degradation in plate assays. BPT-5, 11,18,19 and 25 indicated the production of copious amounts of carbohydrates and protein degrading enzymes. Based on this study it can be concluded that Khewra salt mine is populated with diverse bacterial groups, which are potential source of industrial enzymes for commercial applications.
International Journal of Biological Macromolecules, 2014
Biomass gasification processes generate large amounts of solid. The aim of this work is to charac... more Biomass gasification processes generate large amounts of solid. The aim of this work is to characterize the particles produced at a demonstration scale downdraft multi-stage gasification plant running on pinewood. The results have been used to understand their formation mechanism, evaluate potential applications and determine their hazardousness to human health and the environment. Chemical, physical, morphological and textural analyses suggest that most of the particles are formed via gas phase condensation reactions, with a very limited proportion resulting from direct carbonization of the original biomass feedstock. This is confirmed by a very limited micropore structure, surface area and adsorption capacity, making the particles unsuitable for use as an adsorbent in gas and water treatment applications. The particles exhibit superior fuel properties in terms of carbon content, heating value and thermal stability, which may be associated with the high temperatures at which they are generated. Due to their biomass origin, the particles contain a high proportion of calcium, potassium, magnesium and other plant micronutrients that could be beneficial if the material is used for soil conditioning and fertilizing. Regarding particle size distribution, most of the particles fitted in the range between 100 and 250 mm, with only 0.5 wt% smaller than 30 mm. This is too large for a carbon black surrogate but minimizes health risks associated with exposure to the lower regions of the respiratory tract. The concentration of biologically active PAH is sufficiently low to represent no hazard to the environment or human health.
An exopolysaccharide (EPS) synthesizing potentially probiotic Gram-positive bacterial strain was ... more An exopolysaccharide (EPS) synthesizing potentially probiotic Gram-positive bacterial strain was isolated from fish (Tor putitora) gut, and its EPS was structurally characterized. The isolate, designated as FW2, was identified as Lactobacillus reuteri through 16S rRNA gene sequencing and phylogenetic analysis. This isolate produces fructan-type EPS using sucrose as a substrate. Based on 13C-NMR spectroscopy, methylation analysis and monosaccharide composition, the EPS was identified as a linear levan polymer with fructose as main constituent linked via β(2 → 6) linkages. Based on molecular weight (MW) distribution, two groups of levan were found to be produced by the isolate FW2: one with high MW (4.6 × 106 Da) and the other having much lower MW (1.2 × 104 Da). The isolate yielded about 14 g/L levan under optimized culturing parameters including aeration conditions, pH, temperature and substrate concentration. The obtained bimodal molecular weight linear levan is the first of its type to be synthesized by a L. reuteri isolate from fish gut. Bimodal molecular weight prebiotic levan together with the probiotic potential of the producing strain would provide a new promising synbiotic combination for use in aqua culture.
Coal is one of the most abundant non-renewable fossil fuels in Pakistan and remained a viable sou... more Coal is one of the most abundant non-renewable fossil fuels in Pakistan and remained a viable source for the generation of electricity in the country. However, in general, the quality of local coal is too low to offset the practical, economic, and regulatory barriers to its utilization. Sulphur accounts for one of the major impurities in the coal and mainly occurs in inorganic and organic forms. Combustion of high sulphur coal releases environmental pollutants like sulphur dioxide, sulphuric acid, hydrogen and nitrogen sulphides. To enhance the quality of the coal and consequently reduce its environment damaging impact, sulphur in coal needs to be removed before its combustion. Some of the conventional chemical and physical methods have responded effectively towards the removal of sulphur, but, the use of hazardous chemicals and elevated operating temperatures make such processes unattractive and less eco-friendly. The environmental regulatory authorities all over the world are stre...
ABSTRACT Coal is one of the most abundant nonrenewable fossil fuels, in Pakistan. However, in gen... more ABSTRACT Coal is one of the most abundant nonrenewable fossil fuels, in Pakistan. However, in general, the quality of coal is too low to offset the practical, economic, and regulatory barriers to its utilization. High sulfur content comes up as one of the bottlenecks in productive usage of indigenous coal. Biotechnology can emerge as a panacea for upgrading the huge reserves of high sulfur coal. In current study, the sulfur removal potential of Rhodococcus spp. (Eu-32) was investigated using coal from Dukki, Baluchistan, Pakistan. Biodesulfurization process was optimized for various parameters and maximum decrease of 40% and 60% in total and organic sulfur contents, respectively were achieved in 15 days. The Langmuir and Brunauer–Emmett–Teller (BET) surface areas of the biotreated coal were increased by 20 and 16 times, respectively. Scanning electron microscope showed higher tendency of attachment of bacterial cells to the coal particles. Our results revealed that Eu-32 could remove significant amounts of organic sulfur from coal and could be used in the pre-combustion operations with appropriate arrangements.
Pakistan is endued with 185 billion tons colossal reserves of coal, but only 7.89 % of the countr... more Pakistan is endued with 185 billion tons colossal reserves of coal, but only 7.89 % of the country total energy requirements are met by coal. Most of the Pakistani coal reserves are sub-bituminous or lignitic in nature and contain 3-12 % sulphur. Existence of sulphur compounds in coal limits its industrial application due to environmental as well as technical problems. However, coal biotechnology can emerge as panacea for upgrading the huge reserves of coal in Pakistan. In general, coal biotechnology refers to biodesulphurization, biosolubilization and biogasification of coal. NIBGE has long term interests in the field of coal bioprocessing for tapping prime resources of indigenous coal. In NIBGE, lab scale experiments for coal biodesulphurization led to 90% efficiency in sulphur removal. Heap leaching was also carried out at the level of 10 and 20 tons coal heaps with 60% sulphur removal efficiency. Furthermore, a prototype of 300 tons coal heap was set up with a local cement indus...
Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was use... more Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering, electrophoretic mobility, and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram-negative bacterial strain, Escherichia coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics.
World Journal of Microbiology and Biotechnology, 2005
Random amplification of polymorphic DNA (RAPD), a PCR-based technique was applied to evaluate gen... more Random amplification of polymorphic DNA (RAPD), a PCR-based technique was applied to evaluate genomic diversity among three strains of Acidithiobacillus thiooxidans, five strains of Acidithiobacillus ferrooxidans and one acidophilic moderate thermophile strain, using 45 random primers of five different series. More than 2200 bands were observed, with an average of 45 bands per primer. Primer OPC-3 produced the maximum number of fragments whereas minimum numbers of fragments were produced with primer OPA-5. A dendrogram was generated using cluster analysis by the unweighted pair group method of arithmetic means (UPGMA). The dendrogram showed three groups with similarity ranging from 29 to 85%. The maximum similarity (85%) was observed between the strains T.t 1 and T.t 2 of Acidithiobacillus thiooxidans.
Out of 17 samples collected from diverse environments, 110 bacterial isolates of varied character... more Out of 17 samples collected from diverse environments, 110 bacterial isolates of varied characteristics were screened for their dibenzothiophene-desulphurizing activity. A single isolate, Eu-32, originating from a soil sample taken from the roots of a eucalyptus tree, displayed dibenzothiophene-desulphurizing activity. This isolate metabolized dibenzothiophene to 2-hydroxybiphenyl (2-HBP), as detected by HPLC, and was also able to use other organic sulphur compounds as a sole sulphur source. Based on morphological, biochemical and molecular studies, it was found that the organism belongs to the genus Rhodococcus, with a maximum of 95% identity to species in this genus for the partial sequence of the 16S rRNA gene. Isolate Eu-32 could desulphurize 0.2 mM dibenzothiophene to 2-HBP in 72 h at a temperature of 30 1C and pH 7.0. The structure and molecular mass of metabolites produced from dibenzothiophene desulphurization were identified by GC-MS, and two sulphur-free products, 2-HBP and biphenyl, were detected in ethyl acetate extract. It was concluded that isolate Eu-32 is a unique desulphurizing biocatalyst that desulphurizes dibenzothiophene through an extended, sulphurspecific degradation pathway with the selective cleavage of C-S bonds.
The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and re... more The ability of Ca-alginate immobilized Trichoderma harzianum has been explored for removal and recovery of uranium from aqueous streams. Ca-alginate as polymeric support was selected after screening different matrices. Immobilization of Trichoderma harzianum to Ca-alginate improved the stability as well as uranium biosorption capacity of biosorbent at 28 ± 2°C and 200 rpm. The suitability of packed bed column operations was illustrated by obtaining break through curves at different bed heights, flow rates and inlet uranium concentrations. The adsorption column containing 1.5 g dry weight of immobilized material has purified 8.5 L of bacterial leach liquor (58 mg/L U) before break through occurred and the biosorbent became saturated after 25 L of influent. Sorbed uranium was recovered in 200 ml of 0.1 N HCl resulting in 98.1-99.3% elution by 0.1 N HCl, which regenerated the biosorbent facilitating the sorption-desorption cycles for better economic feasibility without any significant alteration in sorption capacity/elution efficiency.
ABSTRACT Eleven representative lignite samples from the Thar coalfield, Pakistan were subjected t... more ABSTRACT Eleven representative lignite samples from the Thar coalfield, Pakistan were subjected to a bioassay, based on mixed methanogenic bacterial consortium (WBC-2). The samples were characterized on the basis of chemical and petrographic studies in order to determine the geological stage of coal resource. Under anaerobic conditions in sealed serum bottles, the generation of methane was observed from six coal samples in the range of 3.7 to 23.2 μmol/g of coal (2.13 to 16.33 scf/ton of coal). This methane generation from Thar lignite samples may be considered as an indicative index of the presence of biogenic coalbed methane in the reservoir. The residual coal, after methanogenesis, was investigated and prospected on a preliminary basis for the release of humic materials. Conclusively, further exploration of biogenic methane production from low rank coals and subsequent extraction of soil conditioning agents from residual coal can be followed as an alternative route of coal conversion technologies for obtaining multiple value-added chemical entities from low rank coal.
Uploads
Papers by afzal Ghauri