Tawaf Ali Shah | ICLAB - University of Padova (Italy) (original) (raw)

Papers by Tawaf Ali Shah

Microporous and Mesoporous Materials

Environmental Science and Pollution Research

Endopolygalacturonase (EndoPGase) is one of the crucial pectinases belonging to the class of carb... more Endopolygalacturonase (EndoPGase) is one of the crucial pectinases belonging to the class of carbohydrase. The catalytic action of EndoPGase captivate the attention for production of this extremely valuable catalyst of industrial sector. The main focus was to ascertain a potential bacterial candidate for endoPGase production. The isolated bacterial strain was further identified by 16S rDNA gene sequencing. A genomic library was constructed by using Lambda ZAP II vector system to investigate the pectinolytic potential of the expressed genes. The parameters for enzyme biosynthesis were optimized by single as well as multiple factor approach at a time. The results of our investigation led to the identification of a potent strain of Bacillus subtilis NR2. The strain was found active for pectic enzyme activity under shaking- flask fermentation at pH 5.0 and 50 °C temperature of incubation. Among all monomeric and polymeric substrates, citrus pectin followed by wheat bran was considered t...

Lignin - Chemistry, Structure, and Application [Working Title]

The term lignin is derived from lignum, which means plant wood. Plant wood are mainly composed of... more The term lignin is derived from lignum, which means plant wood. Plant wood are mainly composed of extractives, hemicellulose, cellulose, and lignin. The lignin is a cross-linked polymer, made of three phenylpropanoid precursors, p-coumaryl, synapyl, and conniferyl alcohols. It is the most abundant polymer in plant world and act mechanically as a natural glue to bind hemicellulose and cellulose. Lignin is amorphous, soluble in alkali, condenses with phenol and has high melting temperature. The function of lignin is to protect the carbohydrates of the biomass from degradation, thus provide stability. The chapter includes information on types of lignin, structure, isolation, degradation, and transformation in to market value chemicals. The application of lignin and lignin base monomers for synthesis of plastic, hydrogels, adhesives, chemicals, fuels and other value added materials at industrial scale.

Journal of Plant Pathology, 2018

International Journal of Environmental Science and Technology, 2019

Biogas production from the agriculture waste biomass is a sustainable approach to managing the en... more Biogas production from the agriculture waste biomass is a sustainable approach to managing the energy demand in the future. To do so, pretreatment is needed to remove lignin from the agribiomass to make it easily digestible substrate for the fermentative organisms. The current study was carried out to screen the most effective lignin-degrading fungal culture from their natural habitat. Pretreatment with robust ligninolytic fungi could be an efficient and economical method to degrade lignin. The presence of lignin in lignocellulosic biomass is the rate-limiting factor which reduces the biogas production. So, the best fungal strains were selected based on maximal Azure B dye decolorization. The strains were actively producing lignin peroxidases and laccases and decreased 48.2% of lignin from the wheat straw (WS) within 7 days of batch incubation. The scanning electron micrograph demonstrated visible degradation only in the fungi-treated wheat straw. The ligninolytic fungal culture pretreatment of WS enhanced the biogas yield five times compared with the untreated WS sample. Notably, these fast-acting lignin-degrading fungi gave a biogas yield with a short pretreatment time and additionally reduced the lag phase during the anaerobic digestion process. These findings showed that pretreatment with natural ligninolytic fungi could be considered as a less expensive method. The treatment is also effective in increasing the digestibility of lignocellulosic biomass and suitable for biogas production.

Pakistan journal of zoology

Musa ka Musalla glacier is situated in the Allai, Manshera District, Khyber Pakhtunkhwa, Pakistan... more Musa ka Musalla glacier is situated in the Allai, Manshera District, Khyber Pakhtunkhwa, Pakistan (34.713678, 73.360806). There were 20 different water samples sites moving downstream from the glacier, which is the source of river Siran, during winter, summer and monsoon seasons taken for the analysis of water quality destruction in sense of total viable count, total coliform count, fecal coliform count, fecal E.coli count, which are indicator organisms of fecal contamination, as well as the prevalence and distribution of MBL blaNDM-1 producing Gram negative bacteria. Total viable counts were found in the range of 3×10² to 40×10² CFU/mL in winter, 5×10² to 45×10² CFU/mL in summer and 2×10² to 40×10² CFU/mL in monsoon. The range of MPN 100 mL-1 for total coliform was found 11–2400, 150–2400 and 80–2400, for fecal coliform, it was 3–700, 2–900, 2–800 and for fecal E.coli, it was 1–300, 2–450 and 1–400 in winter, summer and monsoon, respectively. While, out of total 20 samples from dif...

BioEnergy Research, 2018

Biodegradation of agribiomass especially wheat straw to biohydrogen and biomethane is an encourag... more Biodegradation of agribiomass especially wheat straw to biohydrogen and biomethane is an encouraging approach to the current waste management problem. To do so, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. In the current study, out of 20 isolates from the granular sludge of full-scale anaerobic digester, four ligninolytic Bacillus sp. strains were selected based on their lignin and Azure B degradation. Further, among the four isolates, Brevibacillus agri AN-3 exhibited the highest of 88.4 and 78.1% decrease in COD of lignin and Azure B respectively. These strains were also found to secrete optimum yields of lignin peroxidase (LiP) at pH 3, laccase (Lac) at pH 5, and xylanase and cellulase enzymes at pH 7. The strains demonstrated maximum activity of Lip and Lac at 50°C and xylanase and cellulase at 60°C after 72-h growth. Among the four strains, Brevibacillus agri AN-3 showed hydrogen (H 2) yield of 1.34 and 2.9 mol-H 2 /mol from xylose and cellulose respectively. In two-phase wheat straw batch fermentation, Brevibacillus agri AN-3 produced 88.3 and 283.7 mL/gVS cumulative H 2 and methane (CH 4) respectively. Biotreatment with ligninolytic Bacillus sp. strains perceived that 261.4% more methane yield could be obtained from the wheat straw than using the untreated wheat straw in batch fermentation. This is the first study establishing not only the hydrogen potential of ligninolytic Bacillus sp. strains but also indicates a vital role of these species in developing standard inoculum and a biocatalyst for processing agribiomass.

which was 6-fold higher per day and 339.3% more in cumulative volume than the untreated WS sample... more which was 6-fold higher per day and 339.3% more in cumulative volume than the untreated WS sample. Finally, a single culture was tested for the potential of biohydrogen from Organic Fraction of Municipal Solid Waste (OFMSW). One hundred and twenty bacterial strains were isolated from heat-treated granular sludge of a full scale anaerobic digester. The best hydrolytic strains were assessed for H2 production from glucose and soluble starch. Two Bacillus sp. strains, namely F2.5 and F2.8, exhibited high H2 yields and were used as pure culture to convert OFMSW into hydrogen. The strains produced up to 61 mL of H2 per grams of volatile solids and could be considered as good candidates towards the development of industrially relevant H2-producing inoculants. This was the first successful application of pure microbial cultures in bio-hydrogen production from OFMSW.

Methanogenesis is catalyzed by syntrophic cooperation between anaerobes, acetogenic bacteria and ... more Methanogenesis is catalyzed by syntrophic cooperation between anaerobes, acetogenic bacteria and methanogenic archaea in any anaerobic biogas digester. The objective of the current study was to explore the archaea community, predominantly the methanogenic bacteria in the inoculum of a full-scale anaerobic digester. A sludge sample of the biogas reactor was tested for batch fermentation process. On the optimum methane production and fermentation time, the sludge sample was analysed by mcrA gene (a functional molecular marker of methanogenic archaea) to discover the active and functional methanogenic archaea community of the working digester. It was found that some mcrA genes phylotypes were found to be different from known methanogens and belonged to an unidentified group called “unculturable unclassified archaea”, which are might be derived from a novel methanogen group in the mesophilic biogas digester. These unclassified archaeal group may represent a putative new taxon within the...

The acquisition of blaNDM-1 gene by Gram negative bacteria has emerged as critical threat to huma... more The acquisition of blaNDM-1 gene by Gram negative bacteria has emerged as critical threat to human health as these organisms display high resistance to available antibiotics. The presence of this gene has been observed in both clinical as well as environmental settings. The present study was carried out to evaluate the prevalence of blaNDM-1 containing microorganisms in water sources. A total of 241 water samples were collected from different sites in Islamabad, Rawalpindi and areas of Khyber Pakhtunkhwa. Meropenem resistant organisms were isolated and PCR was used for the detection of the blaNDM-1 gene among the resistant isolates of all the water samples, 43 meropenem resistant bacteria were isolated among which 12 isolates were found to carry blaNDM-1 gene. The blaNDM-1 isolates were resistant to most of the antibiotics but sensitive to colistin and polymyxin B. The presence of blaNDM-1 gene harboring organisms in aquatic environment is concerning and poses public health threat.

This study assessed the impact of lime (Ca(OH) 2 ) soaking pretreatment on biomass digestibility ... more This study assessed the impact of lime (Ca(OH) 2 ) soaking pretreatment on biomass digestibility and potential of biogas production compare to untreated corn cob. Corn cob was soaked for different time of incubation, 7, 15, and 30 days. Scanning electron micrograph perceived destruction in the morphology of treated corn cob. The highest cumulative biogas of 360.5, 305.4, 218.6 NmL/gVS was obtained from 30, 15, 7 days pretreated corn cob respectively, which was 2-times higher than the cumulative biogas produced from the untreated corn cob 115.1 NmL/gVS. The best result for the methane yield (136.8 NmL/gVS) was obtained for 30 days soaking. The present study suggested that soaking with Ca(OH) 2 for longer time is effective for increasing digestibility of agriculture waste biomass and improving biogas production.

Abstract- Converting lignocellulosic waste biomass into biogas is a multi-step process; the rate ... more Abstract- Converting lignocellulosic waste biomass into biogas is a multi-step process; the rate limiting reaction is lignin removal. The objective of the current study was to evaluate alkali treatment for lignin removal and potential of biogas yield of pretreated waste biomass compare to untreated one. Three alkali reagents at various dosages: NaOH (1,2,3, and 5%), KOH (1,2,3, and 5%), and Ca(OH) 2 (0.5%) were tested at three different heating processes, water bath, autoclave and short time microwave. NaOH with short time microwave heating process had the highest delignification of 70-86% compare to other alkalies and heating processes. However, an opposite effect of high alkali dosage was observed on holocellulose. The highest cumulative biogas of 560 mL/gVS was obtained from 2% NaOH pretreated wheat straw, which was 2-times higher than the cumulative biogas produced from the same untreated substrates. In the present study 2% NaOH alkali and microwave heating is determined optimum...

Environmental Technology & Innovation

Abstract The microbial conversion of biomass into hydrogen is promising route for clean and renew... more Abstract The microbial conversion of biomass into hydrogen is promising route for clean and renewable bioenergy source. This study focuses on employment of endogenous microbial cultures, for hydrogen production from biomass. Two hydrogen producing strains RTUA and RTUB, isolated from anaerobic digester fed with biomass, were identified as Bacillus cereus based upon 16sRNA analysis and physiochemical characterization. Both strains exhibited wide range of hydrolytic enzymes depending upon substrate provided. This research evaluates biohydrogen potential of RTUA and RTUB from different substrates ranging from simple sugars (glucose, xylose) to complex substrates (rotten fruits, vegetables and wheat straw). Bacillus strains RTUA produced a maximum of 1.15 and 1.05 mol/mole H 2 yield from glucose and xylose. In the BioH2 fermentation of pre-treated and untreated wheat straw, rotten fruits and rotten vegetables, the cumulative H 2 production was higher from the NaOH pretreated wheat straw i.e. 156.4 mL/gVS comparable 40–78 mL/gVS from rotten vegetables and rotten fruits. Owing to diverse hydrolytic enzyme profile and high H 2 yield from complex substrates, RTUA and RTUB proved to be potential candidates for BioH2 production from biomass. The study demonstrated an effective privilege of pure culture for biohydrogen production from mixture of waste biomass and will help to establish eco-friendly and economical setup for biohydrogen production.

Current Science

Bio-methane from agricultural waste has enough potential to compete with other sources of energy.... more Bio-methane from agricultural waste has enough potential to compete with other sources of energy. This study aims to examine the bio-methane potential of numerous agricultural wastes, including cotton waste, wheat bran, lentil straw, barley straw, rice bran and peanut peels straw with the aim to produce renewable energy and solve waste disposal issues. The proximate, ultimate and chemical composition analyses were performed to predict the theoretical biomethane potentials in silico. However, the potential was experimentally assayed at mesophilic conditions. Moreover, elemental and lignin based biodegradability of substrates have also been determined. The methane contents in biogas are in the range 57-64% and the yield varied from 216.3 (barley straw) to 317.6 (cotton waste) ml/g volatile solids. These results indicate that higher biodegradability of substrates resulted in higher methane production. The prediction of bio-methane potential from chemical composition, elemental composition and organic fraction were not as fit accurately as being assessed for methane potential. It merely provided the extent of biodegradability. During digestion, volatile fatty acids were produced, viz. acetic acid (58-63%), butyric acid (28-32%), propionic acid (6-13%) and converted into methane but limited concentrations of intermediate acids indicated similar microbial consortium in all digestions. Hence, it was also concluded that the lignin and hemicellulose content played a limiting role in digestion and posed negative impact on biogas production.

Journal of Plant Pathology, 2018

Gossypium herbaceum is resistant to cotton leaf curl disease but the nature of the resistance is ... more Gossypium herbaceum is resistant to cotton leaf curl disease but the nature of the resistance is poorly characterized. The reaction of G. herbaceum cv. Co Tiep Khac to infection by the Burewala strain of cotton leaf curl Kokhran virus (CLCuKoV-Bur) and cotton leaf curl Multan betasatellite (CLCuMuB) was characterized following whitefly-mediated inoculation and grafting. The CLCuKoV-Bur and CLCuMuB isolates used in this study had 97–100% nucleotide sequence identity with other isolates for which sequence information is accessible in databases. A high level of resistance was demonstrated in cv. Co Tiep Khac using 200 whiteflies per plant with no apparent disease symptoms even 90 days post-inoculation, and no detection of the virusbetasatellite complex, as shown by polymerase chain reaction (PCR) and rolling circle amplification (RCA)/PCR. Following graft-inoculation, mild foliar disease symptoms were observed in leaves proximal to the grafting sites of most of cv. Co Tiep Khac plants ...

Energy & Environment

Anaerobic digestion is a process to convert organic biomass into bio-methane. Plenty of produced ... more Anaerobic digestion is a process to convert organic biomass into bio-methane. Plenty of produced waste in Pakistan is enough to compensate energy thirst of country and have potential to replace costly fossil fuels. The lignocellulosic biomass such as wheat straw, almond shell, sugarcane bagasse, maize straw and corn cob were subjected to bio-methane potential assay after proximate, ultimate and chemical analysis. These chemical fractions provide better understanding about theoretically predicating bio-methane potentials such as neutral detergent fibre, acid detergent fibre, acid detergent lignin, cellulose, hemicellulose, carbohydrates, proteins and elemental analysis. Experimental bio-methane potentials were found, 267.74 (wheat straw), 255.32 (almond shell), 222.23 (corn cob), 247.60 (sugar cane bagasse) and 293.12 ml/g (maize straw) volatile solids and was much less than predicted methane potential. The energy content on dry basis and methane potential has been assessed to find e...

Environmental Progress & Sustainable Energy

Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to a... more Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to an ongoing waste problem. However, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. Biological pretreatment by microorganisms represents a potentially economical strategy to prepare the biomass for fermentation. We isolated seven candidate ligninolytic Bacillus sp. strains based on their robustness for lignin degradation. The production of the ligninolytic enzymes from these strains was characterized and optimized. The bacterial strains were tested for their ability to pretreat RS and increase the yield of biomethane fermentation. It was determined that using mixed combinations of bacterial cultures was more effective than using individual strains. Overall, the study demonstrates the potential of using these Bacillus sp. strains as robust biocatalysts for processing lignocellulosic waste biomass. Significance: Newly isolated Bacillus sp. strains demonstrated an efficient degradation of lignin, Azure B dye, fast hydrolysis of rice straw, and improved biogas yields. This research suggests that, Bacillus sp. strains could be a source of novel enzymes, and an ideal candidate in bioprocessing of complex substrates".

Microporous and Mesoporous Materials

Environmental Science and Pollution Research

Endopolygalacturonase (EndoPGase) is one of the crucial pectinases belonging to the class of carb... more Endopolygalacturonase (EndoPGase) is one of the crucial pectinases belonging to the class of carbohydrase. The catalytic action of EndoPGase captivate the attention for production of this extremely valuable catalyst of industrial sector. The main focus was to ascertain a potential bacterial candidate for endoPGase production. The isolated bacterial strain was further identified by 16S rDNA gene sequencing. A genomic library was constructed by using Lambda ZAP II vector system to investigate the pectinolytic potential of the expressed genes. The parameters for enzyme biosynthesis were optimized by single as well as multiple factor approach at a time. The results of our investigation led to the identification of a potent strain of Bacillus subtilis NR2. The strain was found active for pectic enzyme activity under shaking- flask fermentation at pH 5.0 and 50 °C temperature of incubation. Among all monomeric and polymeric substrates, citrus pectin followed by wheat bran was considered t...

Lignin - Chemistry, Structure, and Application [Working Title]

The term lignin is derived from lignum, which means plant wood. Plant wood are mainly composed of... more The term lignin is derived from lignum, which means plant wood. Plant wood are mainly composed of extractives, hemicellulose, cellulose, and lignin. The lignin is a cross-linked polymer, made of three phenylpropanoid precursors, p-coumaryl, synapyl, and conniferyl alcohols. It is the most abundant polymer in plant world and act mechanically as a natural glue to bind hemicellulose and cellulose. Lignin is amorphous, soluble in alkali, condenses with phenol and has high melting temperature. The function of lignin is to protect the carbohydrates of the biomass from degradation, thus provide stability. The chapter includes information on types of lignin, structure, isolation, degradation, and transformation in to market value chemicals. The application of lignin and lignin base monomers for synthesis of plastic, hydrogels, adhesives, chemicals, fuels and other value added materials at industrial scale.

Journal of Plant Pathology, 2018

International Journal of Environmental Science and Technology, 2019

Biogas production from the agriculture waste biomass is a sustainable approach to managing the en... more Biogas production from the agriculture waste biomass is a sustainable approach to managing the energy demand in the future. To do so, pretreatment is needed to remove lignin from the agribiomass to make it easily digestible substrate for the fermentative organisms. The current study was carried out to screen the most effective lignin-degrading fungal culture from their natural habitat. Pretreatment with robust ligninolytic fungi could be an efficient and economical method to degrade lignin. The presence of lignin in lignocellulosic biomass is the rate-limiting factor which reduces the biogas production. So, the best fungal strains were selected based on maximal Azure B dye decolorization. The strains were actively producing lignin peroxidases and laccases and decreased 48.2% of lignin from the wheat straw (WS) within 7 days of batch incubation. The scanning electron micrograph demonstrated visible degradation only in the fungi-treated wheat straw. The ligninolytic fungal culture pretreatment of WS enhanced the biogas yield five times compared with the untreated WS sample. Notably, these fast-acting lignin-degrading fungi gave a biogas yield with a short pretreatment time and additionally reduced the lag phase during the anaerobic digestion process. These findings showed that pretreatment with natural ligninolytic fungi could be considered as a less expensive method. The treatment is also effective in increasing the digestibility of lignocellulosic biomass and suitable for biogas production.

Pakistan journal of zoology

Musa ka Musalla glacier is situated in the Allai, Manshera District, Khyber Pakhtunkhwa, Pakistan... more Musa ka Musalla glacier is situated in the Allai, Manshera District, Khyber Pakhtunkhwa, Pakistan (34.713678, 73.360806). There were 20 different water samples sites moving downstream from the glacier, which is the source of river Siran, during winter, summer and monsoon seasons taken for the analysis of water quality destruction in sense of total viable count, total coliform count, fecal coliform count, fecal E.coli count, which are indicator organisms of fecal contamination, as well as the prevalence and distribution of MBL blaNDM-1 producing Gram negative bacteria. Total viable counts were found in the range of 3×10² to 40×10² CFU/mL in winter, 5×10² to 45×10² CFU/mL in summer and 2×10² to 40×10² CFU/mL in monsoon. The range of MPN 100 mL-1 for total coliform was found 11–2400, 150–2400 and 80–2400, for fecal coliform, it was 3–700, 2–900, 2–800 and for fecal E.coli, it was 1–300, 2–450 and 1–400 in winter, summer and monsoon, respectively. While, out of total 20 samples from dif...

BioEnergy Research, 2018

Biodegradation of agribiomass especially wheat straw to biohydrogen and biomethane is an encourag... more Biodegradation of agribiomass especially wheat straw to biohydrogen and biomethane is an encouraging approach to the current waste management problem. To do so, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. In the current study, out of 20 isolates from the granular sludge of full-scale anaerobic digester, four ligninolytic Bacillus sp. strains were selected based on their lignin and Azure B degradation. Further, among the four isolates, Brevibacillus agri AN-3 exhibited the highest of 88.4 and 78.1% decrease in COD of lignin and Azure B respectively. These strains were also found to secrete optimum yields of lignin peroxidase (LiP) at pH 3, laccase (Lac) at pH 5, and xylanase and cellulase enzymes at pH 7. The strains demonstrated maximum activity of Lip and Lac at 50°C and xylanase and cellulase at 60°C after 72-h growth. Among the four strains, Brevibacillus agri AN-3 showed hydrogen (H 2) yield of 1.34 and 2.9 mol-H 2 /mol from xylose and cellulose respectively. In two-phase wheat straw batch fermentation, Brevibacillus agri AN-3 produced 88.3 and 283.7 mL/gVS cumulative H 2 and methane (CH 4) respectively. Biotreatment with ligninolytic Bacillus sp. strains perceived that 261.4% more methane yield could be obtained from the wheat straw than using the untreated wheat straw in batch fermentation. This is the first study establishing not only the hydrogen potential of ligninolytic Bacillus sp. strains but also indicates a vital role of these species in developing standard inoculum and a biocatalyst for processing agribiomass.

which was 6-fold higher per day and 339.3% more in cumulative volume than the untreated WS sample... more which was 6-fold higher per day and 339.3% more in cumulative volume than the untreated WS sample. Finally, a single culture was tested for the potential of biohydrogen from Organic Fraction of Municipal Solid Waste (OFMSW). One hundred and twenty bacterial strains were isolated from heat-treated granular sludge of a full scale anaerobic digester. The best hydrolytic strains were assessed for H2 production from glucose and soluble starch. Two Bacillus sp. strains, namely F2.5 and F2.8, exhibited high H2 yields and were used as pure culture to convert OFMSW into hydrogen. The strains produced up to 61 mL of H2 per grams of volatile solids and could be considered as good candidates towards the development of industrially relevant H2-producing inoculants. This was the first successful application of pure microbial cultures in bio-hydrogen production from OFMSW.

Methanogenesis is catalyzed by syntrophic cooperation between anaerobes, acetogenic bacteria and ... more Methanogenesis is catalyzed by syntrophic cooperation between anaerobes, acetogenic bacteria and methanogenic archaea in any anaerobic biogas digester. The objective of the current study was to explore the archaea community, predominantly the methanogenic bacteria in the inoculum of a full-scale anaerobic digester. A sludge sample of the biogas reactor was tested for batch fermentation process. On the optimum methane production and fermentation time, the sludge sample was analysed by mcrA gene (a functional molecular marker of methanogenic archaea) to discover the active and functional methanogenic archaea community of the working digester. It was found that some mcrA genes phylotypes were found to be different from known methanogens and belonged to an unidentified group called “unculturable unclassified archaea”, which are might be derived from a novel methanogen group in the mesophilic biogas digester. These unclassified archaeal group may represent a putative new taxon within the...

The acquisition of blaNDM-1 gene by Gram negative bacteria has emerged as critical threat to huma... more The acquisition of blaNDM-1 gene by Gram negative bacteria has emerged as critical threat to human health as these organisms display high resistance to available antibiotics. The presence of this gene has been observed in both clinical as well as environmental settings. The present study was carried out to evaluate the prevalence of blaNDM-1 containing microorganisms in water sources. A total of 241 water samples were collected from different sites in Islamabad, Rawalpindi and areas of Khyber Pakhtunkhwa. Meropenem resistant organisms were isolated and PCR was used for the detection of the blaNDM-1 gene among the resistant isolates of all the water samples, 43 meropenem resistant bacteria were isolated among which 12 isolates were found to carry blaNDM-1 gene. The blaNDM-1 isolates were resistant to most of the antibiotics but sensitive to colistin and polymyxin B. The presence of blaNDM-1 gene harboring organisms in aquatic environment is concerning and poses public health threat.

This study assessed the impact of lime (Ca(OH) 2 ) soaking pretreatment on biomass digestibility ... more This study assessed the impact of lime (Ca(OH) 2 ) soaking pretreatment on biomass digestibility and potential of biogas production compare to untreated corn cob. Corn cob was soaked for different time of incubation, 7, 15, and 30 days. Scanning electron micrograph perceived destruction in the morphology of treated corn cob. The highest cumulative biogas of 360.5, 305.4, 218.6 NmL/gVS was obtained from 30, 15, 7 days pretreated corn cob respectively, which was 2-times higher than the cumulative biogas produced from the untreated corn cob 115.1 NmL/gVS. The best result for the methane yield (136.8 NmL/gVS) was obtained for 30 days soaking. The present study suggested that soaking with Ca(OH) 2 for longer time is effective for increasing digestibility of agriculture waste biomass and improving biogas production.

Abstract- Converting lignocellulosic waste biomass into biogas is a multi-step process; the rate ... more Abstract- Converting lignocellulosic waste biomass into biogas is a multi-step process; the rate limiting reaction is lignin removal. The objective of the current study was to evaluate alkali treatment for lignin removal and potential of biogas yield of pretreated waste biomass compare to untreated one. Three alkali reagents at various dosages: NaOH (1,2,3, and 5%), KOH (1,2,3, and 5%), and Ca(OH) 2 (0.5%) were tested at three different heating processes, water bath, autoclave and short time microwave. NaOH with short time microwave heating process had the highest delignification of 70-86% compare to other alkalies and heating processes. However, an opposite effect of high alkali dosage was observed on holocellulose. The highest cumulative biogas of 560 mL/gVS was obtained from 2% NaOH pretreated wheat straw, which was 2-times higher than the cumulative biogas produced from the same untreated substrates. In the present study 2% NaOH alkali and microwave heating is determined optimum...

Environmental Technology & Innovation

Abstract The microbial conversion of biomass into hydrogen is promising route for clean and renew... more Abstract The microbial conversion of biomass into hydrogen is promising route for clean and renewable bioenergy source. This study focuses on employment of endogenous microbial cultures, for hydrogen production from biomass. Two hydrogen producing strains RTUA and RTUB, isolated from anaerobic digester fed with biomass, were identified as Bacillus cereus based upon 16sRNA analysis and physiochemical characterization. Both strains exhibited wide range of hydrolytic enzymes depending upon substrate provided. This research evaluates biohydrogen potential of RTUA and RTUB from different substrates ranging from simple sugars (glucose, xylose) to complex substrates (rotten fruits, vegetables and wheat straw). Bacillus strains RTUA produced a maximum of 1.15 and 1.05 mol/mole H 2 yield from glucose and xylose. In the BioH2 fermentation of pre-treated and untreated wheat straw, rotten fruits and rotten vegetables, the cumulative H 2 production was higher from the NaOH pretreated wheat straw i.e. 156.4 mL/gVS comparable 40–78 mL/gVS from rotten vegetables and rotten fruits. Owing to diverse hydrolytic enzyme profile and high H 2 yield from complex substrates, RTUA and RTUB proved to be potential candidates for BioH2 production from biomass. The study demonstrated an effective privilege of pure culture for biohydrogen production from mixture of waste biomass and will help to establish eco-friendly and economical setup for biohydrogen production.

Current Science

Bio-methane from agricultural waste has enough potential to compete with other sources of energy.... more Bio-methane from agricultural waste has enough potential to compete with other sources of energy. This study aims to examine the bio-methane potential of numerous agricultural wastes, including cotton waste, wheat bran, lentil straw, barley straw, rice bran and peanut peels straw with the aim to produce renewable energy and solve waste disposal issues. The proximate, ultimate and chemical composition analyses were performed to predict the theoretical biomethane potentials in silico. However, the potential was experimentally assayed at mesophilic conditions. Moreover, elemental and lignin based biodegradability of substrates have also been determined. The methane contents in biogas are in the range 57-64% and the yield varied from 216.3 (barley straw) to 317.6 (cotton waste) ml/g volatile solids. These results indicate that higher biodegradability of substrates resulted in higher methane production. The prediction of bio-methane potential from chemical composition, elemental composition and organic fraction were not as fit accurately as being assessed for methane potential. It merely provided the extent of biodegradability. During digestion, volatile fatty acids were produced, viz. acetic acid (58-63%), butyric acid (28-32%), propionic acid (6-13%) and converted into methane but limited concentrations of intermediate acids indicated similar microbial consortium in all digestions. Hence, it was also concluded that the lignin and hemicellulose content played a limiting role in digestion and posed negative impact on biogas production.

Journal of Plant Pathology, 2018

Gossypium herbaceum is resistant to cotton leaf curl disease but the nature of the resistance is ... more Gossypium herbaceum is resistant to cotton leaf curl disease but the nature of the resistance is poorly characterized. The reaction of G. herbaceum cv. Co Tiep Khac to infection by the Burewala strain of cotton leaf curl Kokhran virus (CLCuKoV-Bur) and cotton leaf curl Multan betasatellite (CLCuMuB) was characterized following whitefly-mediated inoculation and grafting. The CLCuKoV-Bur and CLCuMuB isolates used in this study had 97–100% nucleotide sequence identity with other isolates for which sequence information is accessible in databases. A high level of resistance was demonstrated in cv. Co Tiep Khac using 200 whiteflies per plant with no apparent disease symptoms even 90 days post-inoculation, and no detection of the virusbetasatellite complex, as shown by polymerase chain reaction (PCR) and rolling circle amplification (RCA)/PCR. Following graft-inoculation, mild foliar disease symptoms were observed in leaves proximal to the grafting sites of most of cv. Co Tiep Khac plants ...

Energy & Environment

Anaerobic digestion is a process to convert organic biomass into bio-methane. Plenty of produced ... more Anaerobic digestion is a process to convert organic biomass into bio-methane. Plenty of produced waste in Pakistan is enough to compensate energy thirst of country and have potential to replace costly fossil fuels. The lignocellulosic biomass such as wheat straw, almond shell, sugarcane bagasse, maize straw and corn cob were subjected to bio-methane potential assay after proximate, ultimate and chemical analysis. These chemical fractions provide better understanding about theoretically predicating bio-methane potentials such as neutral detergent fibre, acid detergent fibre, acid detergent lignin, cellulose, hemicellulose, carbohydrates, proteins and elemental analysis. Experimental bio-methane potentials were found, 267.74 (wheat straw), 255.32 (almond shell), 222.23 (corn cob), 247.60 (sugar cane bagasse) and 293.12 ml/g (maize straw) volatile solids and was much less than predicted methane potential. The energy content on dry basis and methane potential has been assessed to find e...

Environmental Progress & Sustainable Energy

Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to a... more Fermenting agricultural biomass, such as rice straw (RS), to methane is a promising solution to an ongoing waste problem. However, the biomass must first be pretreated to break down lignin thereby increasing accessibility of the substrate to fermentative organisms. Biological pretreatment by microorganisms represents a potentially economical strategy to prepare the biomass for fermentation. We isolated seven candidate ligninolytic Bacillus sp. strains based on their robustness for lignin degradation. The production of the ligninolytic enzymes from these strains was characterized and optimized. The bacterial strains were tested for their ability to pretreat RS and increase the yield of biomethane fermentation. It was determined that using mixed combinations of bacterial cultures was more effective than using individual strains. Overall, the study demonstrates the potential of using these Bacillus sp. strains as robust biocatalysts for processing lignocellulosic waste biomass. Significance: Newly isolated Bacillus sp. strains demonstrated an efficient degradation of lignin, Azure B dye, fast hydrolysis of rice straw, and improved biogas yields. This research suggests that, Bacillus sp. strains could be a source of novel enzymes, and an ideal candidate in bioprocessing of complex substrates".