Zahid Anwar - Academia.edu (original) (raw)

Papers by Zahid Anwar

Catalysts

Background: Lipase is one of the most important enzymes produced from microbial fermentation. Agr... more Background: Lipase is one of the most important enzymes produced from microbial fermentation. Agricultural wastes are a good source of enzyme production because they are cost-effective and production rates are also higher. Method: In this study, eight lignolitic substrates were screened for lipase production. Results: Out of these substrates, guava leaves showed maximum activity of 9.1 U/mL from Aspergillus niger by using the solid-state fermentation method. Various factors such as temperature, pH, incubation period, moisture content, inoculum size, and substrate size that influence the growth of fungi were optimized by response surface methodology (RSM), and then characterization was performed. When all physical and nutritional parameters were optimized by RSM, the maximum lipase activity obtained was 12.52 U/mL after 4 days of incubation, at pH 8, 40 °C temperature, 3 mL inoculum size, 20% moisture content, and 6 g substrate concentration. The enzyme was partially purified through...

Biocatalysis and Agricultural Biotechnology, 2019

Optimization of process variables for enhanced production of urease by indigenous Aspergillus nig... more Optimization of process variables for enhanced production of urease by indigenous Aspergillus niger strains through response surface methodology

Journal of Agricultural Science, 2015

Co-composting produces a valuable compost material that can be used as valuable soil amendment. T... more Co-composting produces a valuable compost material that can be used as valuable soil amendment. The process of the co-composting and control of the composting factors are the current challenges for the researchers. There are different factors that govern the quality, stability and the maturity of the co-compost in terms of amount of plant nutrients and reduction of heavy metals. Among these, C:N ratio is a parameter that can affect the loss of plant nutrients. Different studies showed wide ranges of C:N ratios (14-40) for maturity of quality compost. Temperature, aeration and types of the bulking agents also regulate the process of co-composting. Most widely used co-composted materials are animal manures with agro-wastes (sawdust, wheat straw, rice straw, corn stalks etc.). This practice brought substantial loss of heavy metals and maximum retention of plant nutrients. Higher nutrients contents of the compost and favourable soil properties as a result of co-composting of the saw dust, cow dung and egg shells have been reported. The application of co-composted dairy manure with wheat straw and sawdust produced higher plant biomass. Co-compost of cattle manure with rice straw produced an organic matter, total N and C:N ratio contents suitable for soil amendment. Therefore, this review focuses on the characteristics and utilization of organic waste after a reasonable co-composting process.

International Journal of Environmental Science & Technology, 2007

Biodiesel production is worthy of continued study and optimization of production procedures becau... more Biodiesel production is worthy of continued study and optimization of production procedures because of its environmentally beneficial attributes and its renewable nature. In Egypt, millions L. of oil used for frying foods are discarded each year into sewage systems. Thus, it adds to the cost of treating effluent or pollutes waterways. This study is intended to consider aspects related to the feasibility of the production of biodiesel from waste/recycled oils in an attempt to help reduce the cost of biodiesel and reduce waste and pollution coming from waste oils. The variables affecting the yield and characteristics of the biodiesel produced from used frying oil were studied, the achieved results were analyzed and a set of recommendations was proposed. From the obtained results, the best yield percentage was obtained using a methanol/oil molar ratio of 6:1, potassium hydroxide as catalyst (1%) and 65 °C temperature for one hour. The yield percentage obtained from waste vegetable oil was comparable to that obtained from neat vegetable oil which reached 96.15% under optimum conditions. From the results it was clear that the produced biodiesel fuel, whether from neat vegetable oil or waste vegetable oil, was within the recommended standards of biodiesel fuel.

Fermentation

Delonix regia (common name: Flame tree) pods, an inexpensive lignocellulosic waste matrix, were s... more Delonix regia (common name: Flame tree) pods, an inexpensive lignocellulosic waste matrix, were successfully used to produce value-added bioethanol. Initially, the potentiality of D. regia pods as a lignocellulosic biomass was assessed by Fourier-transform infrared spectroscopy (FTIR), which revealed the presence of several functional groups belonging to cellulose, hemicellulose, and lignin, implying that D. regia pods could serve as an excellent lignocellulosic biomass. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used to optimize pretreatment conditions of incubation time (10–70 min), H2SO4 concentration (0.5–3%), amount of substrate (0.02–0.22 g), and temperature (45–100 °C). Then, RSM-suggested 30 trials of pretreatment conditions experimented in the laboratory, and a trial using 0.16 g substrate, 3% H2SO4, 70 min incubation at 90 °C, yielded the highest amount of glucose (0.296 mg·mL−1), and xylose (0.477 mg·mL−1). Subsequently, the same trial cond...

Romanian Biotechnological Letters, 2015

In the present study, a Central Composite Design (CCD) from Response Surface Methodology (RSM) wa... more In the present study, a Central Composite Design (CCD) from Response Surface Methodology (RSM) was adopted to produce bio-ethanol using pre-treated pea peel (Pisum sativum). With an aim to achieve optimal yield the concentration of acid load; 1.0, 1.5 and 2.0%, treatment time; 15, 30 and 45 min, and temperature in the range of 100, 110 and 120 °C was selected. Solid P. sativum loading of 10% (w/v) was selected during pre-treatment. After dilute sulfuric acid pre-treatment maximum increase in glucose content (35.97%) of pea peel was achieved at their optimized conditions (1.80%, 30min. and 120°C). Maximal yield of glucose (after 72 h) from pea peel after dilute sulfuric acid pretreatment and enzymatic saccharification (50 °C, pH 4.8 and 120 rpm) by using an enzyme loading of 0.11 g celluclast 1.5 g/L cellulase and 0.05 g cellubiase/g was 17.72 g/L. Fermentation, the last and important step of bio-ethanol production was carried out using fermentative fungal S. bayanus and F. oxysporum...

Journal of Radiation Research and Applied Sciences, 2016

Agro-based materials are primarily composed of complex polysaccharides that strengthen microbial ... more Agro-based materials are primarily composed of complex polysaccharides that strengthen microbial growth for the production of industrially relevant value-added products. Therefore, in the present study, solid state fermentation (SSF) was carried out using agrobased waste materials (apple pomace, peanut shell and a mixture of both apple pomace and peanut shell with 50:50 ratio) as carriers/support for SSF to enhance citric acid production from single and co-culture consortia of Aspergillus ornatus and Alternaria alternata. During initial screening trial it was observed that growth media supplemented with apple pomace under SSF process of co-culture consortia presenting the preeminent 0.46 ± 0.42 mg/mL of citric acid. On partial optimization co-culture showed the maximum citric acid yield (2.644 ± 0.99 mg/mL) in the presence of arginine as a nutritional ingredient at 30 C in an apple pomace based medium at 50% moisture content with pH of 5 and substrate concentration (25 g) after 48th of solid state fermentation. In conclusion, a suitable addition of fermentative substrate to the SSF medium increased fungal growth, sugar utilization and citric acid production when used in lower concentrations.

Natural Product Communications, 2014

In the last several years, in serious consideration of the worldwide economic and environmental i... more In the last several years, in serious consideration of the worldwide economic and environmental issues there has been an increasing research interest in the value of naturally occurring bio-sourced materials. Agro-industrial based biomass comprised of pectin is an inexpensive, renewable, abundant natural resource that could be utilized for large-scale and cost-effective production of natural products i.e., pectinolytics. Pectinolytics are one of the most widely distributed enzymes in bacteria, fungi and plants. From ancient times to date, many methods have been introduced to improve the optimization of pectinolytics to obtain high yields of maximal purity. To expand the range of natural bio-resources the rapidly evolving tools of biotechnology can lower the conversion costs and also enhance target yield of the product of interest. This green biotechnology presents a promising approach to convert most of the agricultural materials into a value-added product with multiple applications...

Food Bioscience

Abstract Bio-based natural macromolecules are primarily composed of complex polysaccharides that ... more Abstract Bio-based natural macromolecules are primarily composed of complex polysaccharides that strengthen microbial growth for the production of industrially relevant enzymes. In this study, an initial range of natural materials was used as fungal growth and solid substrates for the support of enzyme production. After the stipulated fermentation time (72 h), a large quantity of pectinolytic cocktail complex, composed of polygalacturonase (PG), pectin lyase (PL), and pectin methylesterase (PME), was obtained. Following the initial solid substrate screening, the effects of the different parameters were optimized through response surface methodology (RSM) by adopting a central composite design (CCD) using the best-yielded material. The crude pectinolytic cocktail complex showed commendable results in the de-bittering of the investigated fruit juices. A considerable color and turbidity reduction from 100% to 45.0% and 32.5%, respectively, was recorded for apple juice. For orange juice, the color and turbidity significantly decreased by up to 38.2% and 31.6%, respectively. In conclusion, the maximum production of the pectinolytic cocktail complex in the presence of a cheaper substrate at a low concentration makes the enzyme useful for industrial sectors, especially in the juice industry.

Biologia

Xylanase Z (XynZ) is a prime part of cellulosome of Clostridium thermocellum. The several domains... more Xylanase Z (XynZ) is a prime part of cellulosome of Clostridium thermocellum. The several domains of the cellulosome complexes are frequently tethered to one another by intrinsically messy regions. This is multidomain xylanase comprising of N-terminus feruloyl esterase followed by substrate binding, dockerin and the catalytic domains. This study design was established to check the expression, activities and other characteristics of different variants of Xylanase Z produced by the C-terminal (XynZ-CB), N-terminal (XynZ-BC) and both terminals (XynZ-BCB) binding domain to catalytic domain in different arrangements. XynZ variants of C. thermocellum with binding domain committed with catalytic domain of C-terminal (XynZ-CB) and N-terminal (XynZ-BC) and both terminals (XynZ-BCB) binding domain and one with catalytic domain at both terminals of the binding domain (XynZ-CBC) were checked in E. coli in different levels like 15, 30, 30, and 33% of cell proteins, respectively. The specific xylanase Z activities of XynZ-CB, XynZ BC, XynZ-BCB and XynZ-BCB were 72, 68, 67 and 200 U mg−1, though their equimolar basis activities were 4176, 3944, 5092 and 19,200 U μM−1 compared to xylan (birchwood). The over-all activities of XynZ-CB, XynZ-BC, XynZ-BCB and XynZ-CBC produced in fermentation culture were 3678, 3579, 3800 and 5400 U L−1 OD600−1, respectively. The results showed that overall yield of XynZ-C remained manifold higher than all other variants due to combined effect of its specific activity and expression level while the activity of variant XynZ-CBC was increased four folds on equimolar basis as compared to its native form. The fruit saccharification increased with the treatment of xylanase and cellulase.

Waste and Biomass Valorization

We conducted a study for immobilization of cellulase produced by Aspergillus tubingensis -IMMIS2 ... more We conducted a study for immobilization of cellulase produced by Aspergillus tubingensis -IMMIS2 through pre-optimized solid-state fermentation of corn stover. Incredible increment in stability and catalytic activity of the immobilized cellulase was observed. Thermostability of the immobilized cellulase was increased to 82% at 75 °C as compared to that of free cellulase after 26 h of incubation. The cellulase activity was decreased after the 20th day of incubation of the both immobilized and free enzymes. Maximum cellulase activity was achieved at pH 4.5 (174 ± 0.4 U mL −1 min −1 ) and temperature 45 °C (179 ± 0.4 U mL −1 min −1 ) for xerogel matrix. The lowest K m value was found for the enzyme immobilized on xerogel as compared to those of immobilized on calcium alginate and free enzyme. Immobilization of cellulase on calcium alginate and xerogel matrix increased tolerance capacity of the enzyme to 75–82% against different activators and/or inhibitors like EDTA, SDS, Co 2+ , Ca 2+ and Hg 2+ . The immobilized cellulase also revealed good fruit saccharification and yielded increased juice volume and hence proved to be a suitable candidate for biotechnological and industrial applications.

Biocatalysis and Agricultural Biotechnology

Abstract Cellulose is basic structural part of cell wall of plant and cellulases digest cellulose... more Abstract Cellulose is basic structural part of cell wall of plant and cellulases digest cellulose into glucose and provide a useful utilization of this enzyme in food and feed industry. The purpose of this study was to investigate hyper production of cellulase complex from indigenous local strain of Aspergillus tubingensis IMMIS2 extracted from rotten tomato. Corn stover revealed maximum cellulase complex activity (81 ± 1.5 µg/mL/min) after screening six substrates. The conserve sequences of fungus were used to identify hyper cellulase producing fungus using primers. The optimum temperature, pH and incubation time were analyzed to be 40 °C, 4.8, 96 h with cellulase activity of 86.4 ± 2.1 µg/mL/min for Aspergillus tubingensis IMMIS2. Cellulase revealed maximum activity (112 µg/mL/min) with Response Surface Methodology (RSM) using 40 mesh size substrate, 8 g substrate, 80% moisture, 5 mL inoculum, 0.5 g urea, 0.1 g KCl, 0.1 g CaCl2 and 0.06 g MgSO4 using Aspergillus tubingensis-IMMIS2 (LT732556). Most of the factors had significant impact on cellulase yield while some factors did not have good effect on cellulase yield. Cellulases have wide spread application in fruit saccharification and saccharification value of mango was 59.54%. This optimization study paves the way for the scientists to utilize RSM for enzymes production.

Turkish Journal of Biochemistry

Objective Industrial effluents and agriculture biomass are main environmental hazards which are f... more Objective Industrial effluents and agriculture biomass are main environmental hazards which are facing by developing country like Pakistan. Along with various other industrial applications, laccases are also involved in the oxidation of various industrial hazardous compounds to detoxify them. This study was designed to produce and purify laccase from ascomyceteous fungi, i.e. Alternaria alternata through solid stat fermentation. Materials and methods Abundantly available Sarkanda grass “Saccharum spontaneum” was used as agro-waste substrate for laccase production from fungus A. alternata. Previously only white rot fungi are familiar for laccase production and almost no work has been done on laccase production by A. alternata. In this research work, different physical and chemical parameters were optimized for maximum laccase production through solid state fermentation (SSF). Results Enzyme was purified and its molecular weight was determined by sodium dodecyl sulfate polyacrylamide ...

International journal of biological macromolecules, 2018

In this study, lipase (LIP) was isolated from Aspergillus crevinus, statistically optimized and p... more In this study, lipase (LIP) was isolated from Aspergillus crevinus, statistically optimized and purified via ammonium sulfate fractionation (ASF), and Sephadex G-100 gel permeation chromatography. LIP was 2.26-folds purified with a specific activity of 223.60 U/mg. The molecular mass was estimated to be 60 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (5% stacking and a 12% resolving gel) (SDS-PAGE). The active LIP fraction was immobilized onto chitosan-alginate (CTS-ALG) beads developed in a uniform size, i.e., 2.0 ± 0.25 mm diameter using ultrasonically dispersed 2.0% (w/v) chitosan and alginate along with 0.5% (w/v) glutaraldehyde as a macromolecular crosslinking agent. Prior to exploit for detergent compatibility and dehairing purposes, various parameters including pH, thermal, Michaelis-Menten kinetic constants and influence of organic/inorganic and metal ions on PF-LIP and CST-ALG-LIPs fractions were investigated. The immobilized fractions were optimally act...

International Journal of Pharmacology

BioResources

The hyper-production potential of a cellulase complex from a local strain of Aspergillus tubingen... more The hyper-production potential of a cellulase complex from a local strain of Aspergillus tubingensis S2, indigenously isolated from rotten tomato, was investigated. A total of nine fungal species of Aspergillus and Trichoderma were isolated and confirmed through triple-phase screening via 18S ribosomal DNA sequencing and construction of a phylogenetic tree. Congo red testing and the zone of clearance method were used to confirm the cellulase production from A. tubingenesis S2 isolate. A. tubingenesis S2 revealed maximum cellulase production (78 µg/mL/min) and was selected for further study. The optimum fermentative conditions, including the incubation period, pH, and temperature values, were determined to be 96 h, pH 4.8, and 40 °C, respectively, for obtaining the cellulase activity of 86.4±2.1 µg/mL/min. The cellulase was 5.14-fold purified by ammonium sulfate fractionation and gel permeation chromatography. Characterization revealed that maximum activity (130.5 µg/mL/min and 133.5 µg/mL/min) was achieved at 4.5 pH and 40 °C, respectively. A monomeric protein with an apparent molecular weight of 76 kDa was evident after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cellulase revealed maximal activity with 40-mesh size corn stover as compared with 20-mesh size corn stover and 80-mesh size corn stover after 36 h of incubation at 40 °C.

International journal of biological macromolecules, Jan 7, 2017

Biological macromolecules are primarily composed of complex polysaccharides that strengthen micro... more Biological macromolecules are primarily composed of complex polysaccharides that strengthen microbial growth for the production of industrially relevant enzymes. The presence of polysaccharides in the form of the disrupted cell wall and cell materials are among major challenges in the fruit juice industry. The breakdown of such biological macromolecules including cellulose and pectin is vital for the juices processing. In this background, pectinolytic enzymes including polygalacturonase (PG), pectin lyase (PL), and pectin methylesterase (PME) were isolated from Aspergillus ornatus, statistically optimized and purified via ammonium sulfate fractionation (ASF), dialysis, and Sephadex G-100 gel permeation chromatography. After passing through Sephadex G-100 column, PG, PL, and PME were 2.60-fold, 3.30-fold, and 4.52-fold purified with specific activities of 475.2U/mg, 557.1U/mg, and 205.7U/mg. The active PG, PL, and PME, each separately, were surface immobilized using various concentra...

Advances in Enzyme Research, 2016

Journal of Microbiology, Biotechnology and Food Sciences, 2016

International journal of physical sciences

The main objective of this study was to produce glucoamylase under optimum conditions and to stud... more The main objective of this study was to produce glucoamylase under optimum conditions and to study the effect of chemical mutagenesis on Aspergillus niger for the production of glucoamylase. The maximum activity of glucoamylase for mutant A. niger (3.185 ± 0.020 IU/ml/min) and wild A. niger (2.085 ± 0.021 IU/ml/min) was recorded in the culture filtration after 96 h of solid state fermentation of growth medium with 70% moisture level and in the presence of 0.3% yeast extract, 0.4% peptone and 4 ml Tween-80 at pH 4.8. The maximum fraction value after gel filtration for wild A. niger and mutant A. niger was 2.850 and 2.980 IU/ml/min, respectively. Purification through the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) revealed the indication of glucoamylase purification from A. niger. The high value of Km shows that substrate had great affinity for glucoamylase. Glucoamylase enzyme had many useful applications in food processing industry and fermentation biotechn...