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Search Results: 1 - 10 of 20869 matches for " Syed Shahid Ali "
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Improvement of penicillin G acylase expression in Escherichia coli through UV induced mutations
Arshad, Rubina;Farooq, Shafqat;Ali, Syed Shahid;
Brazilian Journal of Microbiology , 2010, DOI: 10.1590/S1517-83822010000400035
Abstract: we used ultraviolet (uv) radiation to induce mutation in three locally isolated strains of escherichia coli. different dilutions of bacterial cultures were exposed to uv lamp of 254 nm wavelength for different time intervals at varied distances ranging from 5 to 210 sec and 5 to 100 cm. viable colonies were screened for mutants with an increased production of penicillin g acylase (pga) and a reduced production of β-lactamase, which are the desired properties of pga producing industrial strains. a survival curve was made to get optimum exposure time and distance. the survival percentage for each exposure period was calculated and 1-5% survival was found useful for obtaining mutants with desired change. screening for pga and β-lactamase constitutive and/or deficient mutants was made by serratia marcescens overlay test. a total of 100 survivors were selected of which 49% expressed pga activity higher than the parent strain. frequency of β-lactamase constitutive and deficient mutants was 48 and 52%, respectively. the best hyper-producing mutant (bdcs-n-m74), with almost negligible expression of β-lactamase, exhibited three-fold (22.5 mg 6-apa h-1 mg-1 wet cells) increase in pga activity compared with that in the parent strain (6.7 mg 6-apa h-1 mg-1 wet cells). the results indicated the successful induction of uv mediated mutation in e. coli for pga hyper-producing mutants lacking β-lactamase activity.
Comparative Production of 6-Aminopenicillanic Acid by Different E. coli Strains and Their Acridine Orange (AO) Induced Mutants
Rubina Arshad,Shafqat Farooq,Syed Shahid Ali
Pakistan Journal of Biological Sciences , 2007,
Abstract: The present study was conducted to see the difference in production of 6-APA I) between wild strains of E. coli collected from local environment and their acridine orange (AO) induced mutants and ii) between mutants and E. coli strains (ATCC 11105 and ATCC 9637) of American Type Culture Collection (ATCC) used commercially for enzymatic production of 6-APA. The optimum conditions for bioconversion were standardized and 6-APA was obtained in crystalline form. Relative PGA activity of local and foreign E. coli strains varied significantly with the highest being 12.7 in mutant strain (BDCS-N-M36) and the lowest 4.3 mg 6-APA h-1mg-1 wet cells in foreign strain (ATCC 11105). The enzyme activity exhibited by mutant strain (BDCS-N-M36) was also two folds higher compared to that in wild parent BDCS-N-W50 (6.3 mg 6-APA h-1 mg-1 wet cells). The overall production of 6-APA and conversion ratios ranged between 0.25-0.41 g of 6-APA per 0.5 g of penicillin G and 51-83%, respectively. Maximum conversion ratio (83%) was achieved by using crude cells of mutant strain (BDCS-N-M36) which is the highest value ever reported by crude cells on a shake-flask scale whereas reported 6-APA production by immobilized cells is 60-90% in batch and continuous systems. Results are being discussed with reference to importance of local bacterial strains and their significance for industrially important enzymes.
6-Aminopenicillanic Acid Production by Intact Cells of E. coli Containing Penicillin G Acylase (PGA)
Rubina Arshad,Shafqat Farooq,Syed Shahid Ali
Pakistan Journal of Biological Sciences , 2007,
Abstract: The aim of present study was to optimize conditions for conversion of penicillin G into 6-APA using intact crude cells of locally collected PGA producing bacterial strains as biocatalyst. Corn steep liquor medium supplemented with phenylacetic acid was used for PGA production. For enzymatic conversion of penicillin G into 6-APA by PGA impregnated bacterial cells, a maximum reaction time of 4 h was found adequate. The procedure for extraction and crystallization of 6-APA from the enzyme reaction mixture was standardized. Isolation process was carried out under controlled pH conditions and 6-APA crystals were recovered from the reaction mixture via filtration, concentration and drying. The maximum PGA activity was observed in Escherichia coli strain BDCS-N-FMu12 (6.4 mg 6-APA h-1 mg-1 wet cells) whereas Bacillus megaterium (ATCC 14945 used as check) exhibited only 2.4 mg 6-APA h-1 mg-1 wet cells. The overall yield of 6-APA crystals obtained after enzymatic conversion of penicillin G ranged between 37-55 and 47-68% in foreign and local strains, respectively. BDCS-N-FMu12 was identified as the best PGA producer with 68% 6-APA conversion whereas ATCC 14945 showed the lowest conversion (37%). The recovery of 6-APA (68%) obtained by using crude intact cells as cheap biocatalyst appeared promising. The process of enzyme fermentation and 6-APA crystallization optimized during this study seems cost-effective and environment-friendly. However, further studies are required to scale up the 6-APA biosynthesis reaction for achieving 80-90% conversion of penicillin G into 6-APA by PGA hyper-producing locally collected strains of E. coli.
Pseudomonas aeruginosa-mediated Induction of Systemic Resistance in Tomato Against Root-knot Nematode
Imran Ali Siddiqui,Syed Shahid Shaukat
Plant Pathology Journal , 2005,
Abstract: Plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6S+ suppresses root-knot nematode (Meloidogyne spp) indirectly by enhancing defense mechanism leading to induced systemic resistance in tomato. However, which determinants are important in the induction of resistant reaction in plants against nematode by IE-6S+ is yet fully understood. Salicylic Acid (SA) production by bacteria acts as endogenous signal for the activation of certain plant defense responses. In a split root trial with tomato plant as a host and M. javanica as challenging pathogen, IE-6S+ induced systemic resistance in both wild type and NahG tomato seedlings. Moreover, the bacterial efficacy against nematode was not altered when soil chemical compositions was changed by the addition of iron. These results suggest that P. aeruginosa IE-6S+ suppress root-knot nematode indirectly via enhanced defense mechanism in plants, which is independent of SA accumulation in the host.
Supply Response Analysis of Rice Growers in District Gujranwala, Pakistan  [PDF]
Sunair Junaid, Arif Ullah, Shaofeng Zheng, Syed Noor Muhammad Shah, Shahid Ali, Munir Khan
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.511116
Abstract: The study was designed to estimate the restricted profit function in district Gujranwala, Punjab, Pakistan. Data were collected from 100 respondents using proportional allocation sampling tech-nique. The analysis was done using SHAZAM software. The results indicate that the farmers are price-responsive. Rice own price elasticity was 1.873. The output supply elasticity of rice with re-spect to education, land, fertilizer price and irrigation cost were 0.0.169, 1.274, -0.873 and -0.953 respectively. Irrigation demand elasticity with respect to education, land, fertilizer price, irrigation cost and output price were 0.14, 1.14, -0.783, -1.84 and 1.78 respectively. Fertilizer demand elasticity with respect to education, land, fertilizer price, irrigation cost and output price was 0.023, 0.792, -1.65, -0.85 and 1.851 respectively. Lastly, the elasticity of profit with respect to education, land, fertilizer price, irrigation cost and output price was 0.20, 1.10, -0.83, -1.136 and 1.92 respectively. The study recommends that Government should provide consistent electricity with stable rates, so that, they irrigate their fields through electric tube wells and ultimately their cost of irrigation decreases. The study also suggests that government should stabilized fertilizer prices to encourage its application. Furthermore, government should raise procurement price of rice to encourage its supply this; it in turn will also increase the profit of the farmer.
Potential of Waste Water Sludge as Environmental-Friendly Manure after UV-Treatment
Laila Zafar,Asif Javed,Syed Shahid Ali,Zubair Anwar
Research Journal of Environmental and Earth Sciences , 2012,
Abstract: Due to exponential population increase in developing world, the wastewater and solid waste generation has tremendously increased and their management has become a serious health and environmental issue. A large amount of sewage sludge generated by sewage treatment plants however, can be re-used after proper segregation and treatment as fertilizer and for energy production. Hence, this study was carried out to find out the potential use of sludge produced at Islamabad Capital Territory (ICT) Sewage Treatment Plant (STP) as organic fertilizer. For this purpose, chemical analysis of the waste water was carried out to determine the quality of raw waste water (influent) and treated waste water (effluent) intermittently. Furthermore, post-wastewater treatment, sewage sludge was analyzed for its chemical characteristics, i.e., for Total Nitrogen (TN), Total Phosphorous (TP) and Organic Matter (OM) contents; and microbial analyses for the presence of Total Coliforms, Fecal Coliforms and E. Coli was also carried out sewage sludge was exposed to sunlight for 0, 3 and 6 months. The results were with commercial compost (control) similar characteristics. According to the results, pH, EC, TSS, COD and BOD5 were found very high in the influent however, after the waste water treatment; the effluent quality was found within the limits of National Environmental Quality standards (NEQs). On the other hand, TN, TP and OM content remained high in sewage sludge as compared to the controls. In order to enumerate harmful microbes in sewage sludge, microbial analyses for Total Coliforms, Fecal Coliforms and E. coli was carried out in pre-treated, UV-post-treated and control sludge samples. According to the results, the Total and Fecal Coliforms were found very high (>16000 MPN/g) whereas, E. Coli population remained between (7000-12000 MPN/g). The most important aspect noted in this study was: as the sludge aged, this figure (7,000, 12,000, and 1,600 MPN/g after 0, 3 and 6 months of exposure to sunlight (UVlight). However, the number of microbes was above NEQs Standard. From the results, it can be concluded that sewage sludge has the potential to be used in greenbelts, forests and can also be applied for some restricted agricultural purpose after ample sunlight exposure.
Chemically Enhanced Primary Wastewater Treatment (CEPT) in Conjunction with H2O2/UV Technology in Controlled Atmosphere
Nida Asif,Syed Shahid Ali,Zulfiqar Bhatti,Rabeea Zafar
Research Journal of Environmental and Earth Sciences , 2013,
Abstract: The contrast of decrease in fresh water supply and an increasing demand for multiple uses of water has adversely affected the quality of waste water. Water-borne illnesses caused by the addition of agricultural and industrial chemicals, by-product wastes and sewage in water reservoirs, have become a serious problem to human health. Sustainable use of water resources, conservation and efficient treatment processes for the re-use of waste water are inevitable. The current study was designed to find the degree of deterioration of water and to formulate the cost-effective technique or method for waste water treatment. Chemically Enhanced Primary Treatment (CEPT) with alum in conjunction with Advance Oxidation Process (AOPs) with H2O2/UV to meet specific objectives in municipal Waste Water Treatment (WWT) was evaluated. This study reports a reduction in COD (70%), BOD (58%) and Turbidity (81%) with an optimum dose of alum (14mg/L). Further degradation of such chemicals with 40% Waste Hydrogen Peroxide and Ultra Violet radiation (H2O2/UV) was also investigated. Reduction in COD (96%) and BOD (95%) of wastewater was observed in samples treated with an exposure to 3ml H2O2. Moreover, a 100% reduction in colony forming units (CFU/ml) of fecal coliform was observed after 90 min treatment with 3ml of 40% H2O2/L wastewater coupled with exposure to UV light. Use of wasted H2O2 is economical as compared to other chemical treatment methods besides reducing H2O2 pollution. Thus CEPT treatment along with H2O2UV exhibited a promising approach without causing any negative impact on the environment.
A Case Study of Hospital Waste Management in Balochistan and Its Impact on Health and Environment
Rabeea Zafar,Syed Shahid Ali,Zaheer Uddin,Maqsood A. Khan
Research Journal of Environmental and Earth Sciences , 2013,
Abstract: Hospital waste is a mixture of general refuse, biomedical laboratory and pathological wastes. Between 75-90% of the waste produced by the health care providers is non-risk health care waste whereas, the remaining 10-25% consist of infectious pathological waste and is of great health concern, if not segregated from general hospital waste. Various studies have reported the waste generation in urban centers of Pakistan, however, no data has been reported previously for Balochistan. Current study surveyed public sector hospitals in Balochistan (Quetta City) and hospital waste was segregated based on their specification and categorized into: general, bio-medical and hazardous wastes. The amount of waste produced in Surgical departments/Operation Theatres was approximately: general (1.75 kg/bed/day), medical (0.30 kg/bed day) and hazardous (0.013 kg/bed/day). Similarly, the average daily waste produced for General/Non-surgical Wards was: general (0.350 kg/bed/day), medical (0.050 kg/bed/day) and hazardous (0.002 kg/bed/day). Amount of biomedical waste from all hospitals consisted of needles (0.45 kg/bed/day), gloves (0.480 kg/bed/day), drain tubes (0.30 kg/bed/day), cottons and gauze (0.40kg/bed/day), napkins (0.02 kg/bed/day), plastic syringes (0.30 kg/bed/day), swap (0.005 kg/bed/day) and body parts (0.40 kg/bed/day). As a whole, 8-10% of total waste was hazardous, 10% was biomedical of the total waste. Although the data is comparable with other cities of Pakistan, more studies are warranted to enumerate other private medical facilities in order to find their generation and means of disposal
Minimally Invasive Esophagectomy for Esophageal Cancer: The First Experience from Pakistan
Farrukh Hassan Rizvi,Syed Shahrukh Hassan Rizvi,Aamir Ali Syed,Shahid Khattak,Ali Raza Khan
International Journal of Surgical Oncology , 2014, DOI: 10.1155/2014/864705
Abstract: Background. Two common procedures for esophageal resection are Ivor Lewis esophagectomy and transhiatal esophagectomy. Both procedures have high morbidity rates of 20–46%. Minimally invasive esophagectomy has been introduced to decrease morbidity. We report initial experience of MIE to determine the morbidity and mortality associated with this procedure during learning phase. Material and Methods. Patients undergoing MIE at our institute from January 2011 to May 2013 were reviewed. Record was kept for any morbidity and mortality. Descriptive statistics were presented as frequencies and continuous variables were presented as median. Survival analysis was performed using Kaplan Meier curves. Results. We performed 51 minimally invasive esophagectomies. Perioperative morbidity was in 16 (31.37%) patients. There were 3 (5.88%) anastomotic leaks. We encountered 1 respiratory complication. Reexploration was required in 3 (5.88%) patients. Median operative time was 375 minutes. Median hospital stay was 10 days. The most frequent long-term morbidity was anastomotic narrowing observed in 5 (9.88%) patients. There were no perioperative mortalities. Our mean overall survival was 37.66 months (95% confidence interval 33.75 to 41.56 months). Mean disease-free survival was 24.43 months (95% CI 21.26 to 27.60 months). Conclusion. Minimally invasive esophagectomy, when performed in the learning phase, has acceptable morbidity and mortality. 1. Introduction Neoadjuvant treatment for locally advanced esophageal cancer is the standard of care [1, 2]. Esophagectomy has historically remained a very morbid procedure [3]. There are various modes of intervention among both open and minimally invasive groups. Previously, it was considered that transthoracic esophagectomy is the standard of care for oncological resection, but Orringer challenged this claim in the 1970s and redescribed the transhiatal procedure as equally effective but less morbid than transthoracic procedure owing to less postoperative pulmonary complications [4]. With the advent of laparoscopes, there has been a gradually increasing interest in minimally invasive procedures. Minimally invasive esophagectomy is a well-established intervention for esophageal resection. It is a complex procedure requiring greater operative time, but it is associated with shorter hospital stay and lesser blood transfusion requirements [5–8]. At our institution open esophagectomy remains the standard mode of intervention since 1998. Since 2011, we have started performing minimally invasive esophagectomy, with thoracic part of the
Clean Development Mechanism: Laterite as Supplementary Cementing Material (SCM)
Syed Zaighum Abbass,Syed Shahid Ali,Jabar Zaman Khan Khattak,Zubair Anwar
Research Journal of Applied Sciences, Engineering and Technology , 2013,
Abstract: Carbon dioxide (CO2) a major Green House Gas (GHG) in the atmosphere, is believed to be largely responsible for global climate change through industrial emissions. The level of CO2 concentration has exponentially increased from about 280 ppm at the start of the industrial revolution to about 380 ppm to date. Although Kyoto protocol has bound industrialized nations to reduce green house gas emissions by 5.2% below 1990 levels around year 2008-2012, but violation continues. The cement industry is one of the major emitter of green house gases, particularly CO2 due to its energy intensive production process. It is estimated that approximately 1 tone of CO2 is released during the manufacturing of each tone of Portland cement. Most of CO2 emissions originate from burning fossil fuels and de-carbonization of limestone in a cement plant. During past several decades, the use of by-product materials in concrete, either as components of blended cements or as admixtures, has increased significantly. In this study, another alternate Supplementary Cementing Material (SCM), Laterite has been used with the objectives: to evaluate the performance of cement containing different percentages of laterite (5, 10, 15, 20, 25, and 30 %); to identify the optimum replacement percentage; and to investigate the effects of different concentrations of laterite on various properties of cement. For that purpose, laterite was tested: before blending (for elemental and mineralogical composition by using XRF, SEM and XRD): after blending (Elemental analysis using XRF, fineness test by using Blaine’s air permeability test and for particle size % on 45, 90 and 200 μ sieve, respectively); and after hydration (for mineralogical analysis using SEM). Furthermore, physical tests of manufactured cement, i.e., water consistency, setting time, Le-Chatlier-expansion and compressive strength were also evaluated and compared with limestone and fly-ash cement blends. The results show that with the replacement level of up to 15%, the quality of cement is not disturbed. In addition, the requirement of intake of energy has also decreased (~30%). Current findings indicate that by using Laterite, as SCM, cement production can be increased without consuming more energy and hence reduce GHG emissions.
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