Virology & Mycology Infectious Diseases
 
Untitled Document
   Publications A-Z
A
»Accounting & Marketing
» Addiction Research & Therapy
»Advances in Automobile Engineering
»Advances in Pharmacoepidemiology & Drug Safety
»Advances in Robotics & Automation
»Aeronautics & Aerospace Engineering
»Agrotechnology
»AIDS & Clinical Research
»Allergy & Therapy
»Air & Water borne Diseases
»Alzheimers Disease & Parkinsonism
»Analytical & Bioanalytical Techniques
»Anaplastology
»Anatomy & Physiology
»Andrology-Open Access
»Anesthesia & Clinical Research
»Antivirals & Antiretrovirals
»Applied & Computational Mathematics
»Applied Mechanical Engineering
»Aquaculture Research & Development
»Architectural Engineering Technology
»Arthritis
»Astrophysics & Aerospace technology
»Autacoids
»Autism-Open Access
  
B
»Bacteriology & Parasitology
»Bioanalysis & Biomedicine
»Biochemistry and Analytical Biochemistry
»Biochemistry & Pharmacology: Open Access
»Biochips & Tissue Chips
»Bioenergetics: Open Access
»Bioengineering & Biomedical Science
»Bioequivalence & Bioavailability
»Biofertilizers & Biopesticides
»Biometrics & Biostatistics
»Biomolecules
»Biochemistry & Physiology: Open Access
»Bioprocessing & Biotechniques
»Bioremediation & Biodegradation
»Biosafety
»Biosensors & Bioelectronics
»Biotechnology & Biomaterials
»Bioterrorism & Biodefense
»Blood Disorders & Transfusion
»Blood & Lymph
»Brain Disorders & Therapy
»Briefing in Intellectual Property Rights
»Business and Financial Affairs
  
C
»Cancer Science & Therapy
»Carcinogenesis & Mutagenesis
»Cell and Developmental Biology
»Cell Science & Therapy
»Chemical Engineering & Process Technology
»Chemotherapy: Open Access
»Chromatography & Separation Techniques
»Civil & Environmental Engineering
»Civil & Legal Sciences
»Clinical & Cellular Immunology
»Clinical Case Reports
»Clinical & Experimental Cardiology
»Clinical & Experimental Dermatology Research
»Clinical & Experimental Ophthalmology
»Clinical & Experimental Pathology
»Clinical & Experimental Pharmacology
»Clinical Pharmacology & Biopharmaceutics
»Clinical Research & Bioethics
»Clinical Toxicology
»Clinical Trials
»Cloning & Transgenesis
»Communicable & Noncommunicable Diseases
»Community Medicine & Health Education
»Computer Science & Systems Biology
»Cytology & Histology
D
»Data Mining in Genomics & Proteomics
»Defense Management
»Dentistry
»Depression and Anxiety
»Diabetes & Metabolism
»Drug Designing
»Drug Metabolism & Toxicology
  
E
»Earth Science & Climatic Change
»Ecosystem & Ecography
»Endocrinology & Metabolic Syndrome
»Entomology, Ornithology & Herpetology
»Environmental & Analytical Toxicology
»Epidemiology: Open Access
»Emergency Medicine: Open Access
»Ergonomics
»Electrical & Electronics
»Enzyme Engineering
»Entrepreneurship & Organization Management
  
F
»Fermentation Technology
»Fertilization : In Vitro
»Food Processing & Technology
»Forensic Research
»Forest Research: Open Access
»Fungal Genomics & Biology
  
G
»Gastrointestinal & Digestive System
»Genetic Syndromes & Gene Therapy
»Glycobiology
»Glycomics & Lipidomics
»Gynecology& Obstetrics
»Geography & Natural Disasters
»Geology & Geosciences
»Geophysics & Remote Sensing
»Gerontology & Geriatric Research
  
H
»Hair : Therapy & Transplantation
»Health & Medical Informatics
»Hereditary Genetics
»Homeopathy & Ayurvedic Medicine
»Hotel & Business Management
»Human Genetics & Embryology
»Hydrology: Current Research
»Hypertension- Open Access
  
I
»Industrial Engineering & Management
»Irrigation and Drainage Systems Engineering
»Information Technology & Software
Engineering
»Internal Medicine
  
L
»Liver
  
M
»Marine Science: Research & Development
»Mass Communication & Journalism
»Material Sciences & Engineering
»Medicinal Chemistry
»Medical Advancements in Genetic Engineering
»Medicinal & Aromatic Plants
»Medical Diagnostic Methods
»Medical Microbiology & Diagnosis
»Medical & Surgical Urology
»Membrane Science & Technology
»Metabolic Syndrome
»Metabolomics:Open Access
»Microbial & Biochemical Technology
»Molecular Biology
»Molecular Biomarkers & Diagnosis
»Molecular Imaging & Dynamics
»Mycobacterial Diseases
N
»Nanomedicine & Biotherapeutic Discovery
»Nanomedicine & Nanotechnology
»Neonatal Biology
»Nephrology & Therapeutics
»Neurology & Neurophysiology
»Novel Physiotherapies
»Nuclear Energy & Power Generation
Technologies
»Nuclear Medicine & Radiation Therapy
»Nutrition & Food Sciences
»Nutritional Disorders & Therapy
»Nursing & Care
  
O
»Obesity & Weight loss Therapy
»Outlook on Developing Drugs: Open Access
»Organ Biology
»Organic Chemistry: Current Research
»Orthopedic & Muscular System: Current Research
»Otolaryngology
  
P
»Pain & Relief
»Palliative Care & Medicine
»Pancreatic Disorders & Therapy
»Pediatrics & Therapeutics
»Petroleum & Environmental Biotechnology
»Pharmaceutica Analytica Acta
»Pharmaceutical Regulatory Affairs: Open Access
»Pharmaceutics & Drug Delivery Research
»Pharmacogenomics & Pharmacoproteomics
»Physical Chemistry & Biophysics
»Plant Pathology & Microbiology
»Powder Metallurgy & Mining
»Primatology
»Primary Health Care: Open Access
»Proteomics & Bioinformatics
»Psychology & Psychotherapy
»Pulmonary & Respiratory Medicine
  
R
»Radiology: Open Access
»rDNA Technology
»Reproductive System & Sexual Disorders
»Rheumatology: Current Research
  
S
» Single Cell Genomics & Proteomics
»Sleep Disorders & Therapy
»Social & Economical Issues of Biotechnology
»Socialomics
»Sports Medicine & Doping Studies
»Spine
»Stem Cell Research & Therapy
»Steroids & Hormonal Science
»Stock & Forex Trading
»Surgery: Current Research
  
T
»Telecommunications System & Management
»Textile Science & Engineering
»Thermodynamics & Catalysis
»Thyroid Disorders & Therapy
»Tissue Science & Engineering
»Translational Medicine
»Transplantation Technologies & Research
»Trauma & Treatment
»Tourism & Hospitality
  
V
»Vaccines & Vaccination
»Veterinary Science & Technology
»Virology & Mycology
»Vitamins & Trace Elements
  
W
»Women's Health Care
  
Y
»Yoga & Physical Therapy
 
   Browse by Subjects
Clinical
»Clinical & Experimental Pharmacology
»Forensic Research
»Cell Science & Therapy
»Stem Cell Research & Therapy
»Cancer Science & Therapy
»Carcinogenesis & Mutagenesis
»Cytology & Histology
»AIDS & Clinical Research
»Anesthesia & Clinical Research
»Transplantation Technologies & Research
»Clinical Research & Bioethics
»Clinical & Cellular Immunology
»Clinical & Experimental Cardiology
»Clinical & Experimental Dermatology Research
»Clinical & Experimental Ophthalmology
»Neurology & Neurophysiology
»Clinical & Experimental Pathology
»Pulmonary & Respiratory Medicine
»Clinical Toxicology
  
Pharmaceutical Sciences
»Vaccines & Vaccination
»Antivirals & Antiretrovirals
»Bioanalysis & Biomedicine
»Drug Metabolism & Toxicology
»Bioequivalence & Bioavailability
»Pharmaceutica Analytica Acta
»Pharmaceutics & Drug Delivery Research
»Clinical Pharmacology & Biopharmaceutics
»Outlook on Developing Drugs: Open Access
»Pharmacoepidemiology & Drug Safety
»Pharmaceutical Regulatory Affairs: Open Access
  
Chemistry
»Thermodynamics & Catalysis
»Physical Chemistry & Biophysics
»Organic Chemistry
»Chromatography & Separation Techniques
»Analytical & Bioanalytical Techniques
»Medicinal Chemistry
  
Environmental
»Earth Science & Climatic Change
»Environmental & Analytical Toxicology
»Aquaculture Research & Development
»Hydrology: Current Research
»Petroleum & Environmental Biotechnology
»Ecosystem & Ecography
  
Omics
»Pharmacogenomics & Pharmacoproteomics
»Data Mining in Genomics & Proteomics
»Proteomics & Bioinformatics
»Computer Science & Systems Biology
»Health & Medical Informatics
»Glycomics & Lipidomics
»Metabolomics:Open Access
  
Life Sciences
»Agrotechnology
»Marine Science: Research & Development
»Veterinary Science & Technology
»Plant Pathology & Microbiology
»Nutrition & Food Sciences
»Bioremediation & Biodegradation
»Biometrics & Biostatistics
»Bioengineering & Biomedical Science
»Microbial & Biochemical Technology
»Bioterrorism & Biodefense
»Biofertilizers & Biopesticides
»Social & Economical Issues of Biotechnology
»Biosensors & Bioelectronics
»Nanomedicine & Biotherapeutic Discovery
»Biochips & Tissue Chips
»Molecular Imaging & Dynamics
»Yoga & Physical Therapyy
»Tissue Science & Engineering
»Biotechnology & Biomaterials
»Biochemistry and Analytical Biochemistry
»Nanomedicine & Nanotechnology
»Membrane Science & Technology
»Bacteriology & Parasitology
»Enzyme Engineering
»rDNA Technology
»Cell and Developmental Biology
»Fermentation Technology
»Chemotherapy
»Biochemistry & Physiology
»Biomolecules
»Biochemistry & Physiology: Open Access
»Biochemical Pharmacology
»Bioenergetics
»Forest Research
»Fungal Genomics & Biology
»Medical Advancements in Genetic Engineering
»Biosafety
»Medicinal & Aromatic Plants
» Single Cell Genomics & Proteomics
»Vitamins & Trace Elements
»Women's Health Care
»Primatology
  
Engineering
»Advances in Automobile Engineering
»Advances in Robotics & Automation
»Aeronautics & Aerospace Engineering
»Applied Mechanical Engineering
»Architectural Engineering Technology
»Bioprocessing & Biotechniques
»Chemical Engineering & Process Technology
»Civil & Environmental Engineering
»Electrical & Electronics
»Food Processing & Technology
»Geology and Geosciences
»Geophysics & Remote sensing
»Industrial Engineering & Management
»Information Technology & Software
Engineering
»Irrigation and Drainage Systems Engineering
»Material Sciences& Engineering
»Powder Metallurgy & Mining
»Telecommunications System & Management
»Textile Science & Engineering
  
Medical Sciences
»Genetic Syndromes & Gene Therapy
»Steroids & Hormonal Science
»Virology & Mycology
»Communicable & Noncommunicable Diseases
»Molecular Biomarkers & Diagnosis
»Psychology & Psychotherapy
»Nuclear Medicine & Radiation Therapy
»Alzheimers Disease & Parkinsonism
»Dentistry
»Pediatrics & Therapeutics
»Rheumatology: Current Research
»Hereditary Genetics
»Reproductive System & Sexual Disorders
»Addiction Research & Therapy
»Allergy & Therapy
»Diabetes & Metabolism
»Blood Disorders & Transfusion
»Endocrinology & Metabolic Syndrome
»Nutritional Disorders & Therapy
»Medical Microbiology & Diagnosis
»Human Genetics & Embryology
»Gastrointestinal & Digestive System
»Otolaryngology
»Anatomy & Physiology
»Autacoids
»Sports Medicine & Doping Studies
»Nephrology & Therapeutics
»Community Medicine & Health Education
»Translational Medicine
»Entomology, Ornithology & Herpetology
»Orthopedic & Muscular System
»Epidemiology: Open Access
»Gynecology& Obstetrics
»Mycobacterial Diseases
»Anaplastology
»Surgery: Current Research
»Radiology: Current Research
»Internal Medicine
»Blood & Lymph
»Emergency Medicine
»Fertilization : In Vitro
»Palliative Care & Medicine
»Glycobiology
»Ergonomics
»Liver
»Neonatal Biology
»Medical Diagnostic Methods
»Hair: Therapy & Transplantation
»gerontology & Geriatrics Research
»Andrology
»Clinical Case Reports
»Spine
»Pain & Relief
»Depression and Anxiety
»Obesity & Weight loss Therapy
»Sleep Disorders & Therapy
»Nursing & Care
»Trauma & Treatment
»Primary Health Care: Open Access
»Clinical Trials
»Homeopathy & Ayurvedic Medicine
»Brain Disorders & Therapy
»Pancreatic Disorders & Therapy
»Metabolic Syndrome
»Novel Physiotherapies
»Thyroid Disorders & Therapy
»Air & Water borne Diseases
»Drug Designing
»Molecular Biology
»Cloning & Transgenesis
»Hypertension-Open Access
»Organ Biology
»Arthritis
 
Management
»Accounting & Marketing
»Business and Financial Affairs
»Civil & Legal Sciences
»Defense Management
»Entrepreneurship& Organization Management
»Hotel & Business Management
»Industrial Engineering & Management
»Mass Communication & Journalism
»Stock & Forex Trading
» Socialomics
»Tourism & Hospitality
 
   Conferences
Upcoming Conferences
»International Conference and Exhibition on Metabolomics & Systems Biology 20-22 February 2012 San Francisco, USA.
»2nd World Congress on Pharmaceutics & Novel Drug Delivery Systems 20-22 February 2012 San Francisco, USA.
»International Conference and Exhibition on Biometrics & Biostatistics 5-7 March 2012 Omaha, USA.
»2nd World Congress on Clinical & Experimental Dermatology 5-7 March 2012 Omaha, USA
»2nd World Congress on Clinical & Experimental Cardiology 5-7 March 2012 Omaha, USA.
» 2nd World Congress on Clinical & Experimental Ophthalmology 5-7 March 2012 Omaha, USA.
»International Conference & Exhibition on Nanotechnology and Nanomedicine 12-14 March 2012 Omaha, USA.
»World Congress on Gastroenterology and Urology 12-14 March 2012 Omaha, USA
»3rd World Congress on Bioavailability & Bioequivalence: Pharmaceutical R & D Summit 26-28 March 2012 Marriott Hotel, Hyderabad, India.
» International Conference and Exhibition on Neurology &Therapeutics 14-16 May 2012 Renaissance Las Vegas Hotel, Las Vegas, Nevada, USA.
»International Conference and Exhibition on Biosensors & Bioelectronics14-16 May 2012 Las Vegas, USA.
»3rd world Congress on Biomarkers & Clinical Research 2-4 July 2012 Las Vegas, USA.
»2nd world Congress on Proteomics & Bioinformatics 2-4 July 2012 Las Vegas, USA.
»International Conference and Exhibition on Orthopedics 13-15 August 2012 Chicago, USA.
»International Conference and Exhibition on Rheumatology and Therapeutics 14-15 August 2012 Chicago, USA.
»International Conference and Exhibition on Addiction Research & Therapy 20-22 August 2012 Las Vegas, USA.
»2nd World Congress on Virology 20-22 August 2012 Las Vegas, USA.
»International Conference and Exhibition on Nephrology and Therapeutics 20-22 August 2012 Hilton Chicago/Northbrook Chicago, USA.
»2nd World Congress on Vaccines & Vaccination 20-22 August 2012 at Chicago, USA.
»World Congress on Earth Science & Climate Change 21-22 August 2012 Chicago, USA.
»International Conference and Exhibition on pathology 27-29 August 2012 Philadelphia, USA.
»International Conference on Pulmonary & Respiratory Medicine 27-29 August 2012 Philadelphia, USA.
»International Conference and Exhibition on Nutritional Science & Therapy-2012 27-29 August 2012 Philadelphia, USA.
»International Conference on Central Nervous System 5-7 September 2012 Double by Hilton Philadephia, USA.
»International Conference on Occupational Health and Safety Summit 5-7 September 2012 Philadelphia, USA.
»International Conference on Hydrology and Groundwater Expo 10-12 September 2012 Hilton San Antonio Airport, USA.
»2nd World Congress on Cancer Science & Therapy 10-12 September 2012 San Antonio, USA.
»World Congress and Expo on Biowaivers and Biosimilars 10-12 September 2012 San Antonio, TX, USA.
»3rd World Congress on Biotechnology 13-15 September 2012 HICC, Hyderabad, India.
»International Conference on Biodiversity & Sustainable Energy Development 14-15 September 2012 Hyderabad, India.
»World Toxicology Summit & Expo-2012 17-19 September 2012 San Antonio Texas, USA.
»International Conference and Exhibition on Translational medicine-2012, 24-26 September 2012 Chicago USA.
»3rd World Congress on Diabetes & Metabolism which is to be held on 24-26 September 2012 Marriott Convention Center, Hyderabad, India.
»International Conference on Tissue Science and Engineering 1-3 October 2012 San Francisco, USA.
»International conference and Exhibition on Pharmacovigilance and Clinical Trials 1-3 October 2012 San Francisco, USA.
»Omics International Integrative Biology Summit 2012 1-3 October 2012 San Francisco, USA.
»International Conference & Exhibition on Emerging Cell Therapies 1-3 October 2012 San Francisco, USA.
»World Congress on Forensic Research & Technology 15-17 October, 2012 at DoubleTree by Hilton Chicago-North Shore, USA.
»International Conference and Exhibition on Otolaryngology 15-17 October 2012 Chicago, USA.
»International conference on Biothreats and Biodefense 15-17 October, 2012 at DoubleTree by Hilton Chicago-North Shore, USA.
»International Conference on Genetic Syndromes & GeneTherapy 22-24 October 2012 at DoubleTree by Hilton Chicago-North Shore, USA.
»International Conference on Clinical and Cellular Immunology 22-24 October 2012 Las Vegas, USA.
»International Conference and Expo on Material science and Engineering 22-24 October 2012 DoubleTree by Hilton Chicago-North Shore, USA.
» International Expo and Conference on Analytrix & HPLC 22-24 October 2012 Hilton Northbrook, Chicago, USA.
»International Conference and Exhibition on Computer Aided Drug Design & QSAR 29-31 October 2012, Chicago, USA.
»World Congress on Personalised Medicine & Molecular Diagnostics 29-31 october 2012 DoubleTree by Hilton Chicago - Northshore, USA.
»2nd World Congress on Cell Science and Stem Cell Research 12-14 November 2012 Hilton San Antonio Airport, USA.
»International Conference on Clinical Microbiology & Microbial Genomics 12-14 November 2012 San Antonio, USA.
»World Congress on Regenerative and Functional Medicine 12-14 November 2012 at San Antonio, Texas, USA.
»Global Biofuels and Bioproducts Summit 19-21 November 2012 San Antonio, USA.
»International Conference on Genetic Syndromes & GeneTherapy November 19 - 21, 2012 Hilton San Antonio Airport, USA
»International Conference and Exhibition on Probiotics-2012, 19–21 November 2012, Hilton San Antonio Airport, USA.
»International Conference and Exhibition on Food Processing and Technology 22-24 November 2012 Hyderabad, India.
»3rd World Congress on Analytical & Bioanalytical Techniques November 22-24, 2012 Hyderabad International Convention Center, India
»2nd World Congress on Pharmaceutical Regulatory Affairs 23-24 November 2012 HICC Hyderabad, India
»International Conference and Exhibition on Cosmetology & Cosmetics 23-24 November 2012 HICC Hyderabad, India.
»International Conference and Exhibition on Surgery & Transplantation 26-28 November 2012 Hilton San Antonio Airport, USA.
»International conference on Hair Transplantation and Trichology 26-28 November 2012 San Antonio, USA.
»World Congress on Novel approaches in Anaesthesia and Preoperative Care during 26-28 November 2012 San Antonio, USA.
»International Conference on Obesity and Weight Management 3-5 December 2012 Philadelphia, USA.
Previous Conferences Organized/Co-organized
»2nd world Congress on Analytical and Bioanalytical Techniques 16-17 December 2011San franscico, USA.
»2nd World Congress on Diabetes & Metabolism 6-8 December 2011 Philadelphia, USA.
»World Congress on Pediatrics & Gynecology 6-8 December 2011 Philadelphia, USA.
»International Conference and Exhibition on Cell Science & Stem Cell Research 29 Nov-1 Dec 2011 Philadelphia, USA.
»2nd World Congress on Biotechnology 29 Nov -1 Dec 2011 Philadelphia, USA.
»International Conference and Exhibition on Vaccines & Vaccination 22-24 November 2011 Philadelphia, USA.
»2nd World Congress on Biomarkers & Clinical Research 12-14 September 2011 Baltimore, USA.
»International Conference and Exhibition on Virology 5-7 September 2011 Baltimore, USA.
»International Conference and Exhibition on Pharmaceutical Regulatory Affairs 6-7 September 2011 Baltimore, USA.
»International Conference and Exhibition on Cancer Science & Therapy 15-17 August 2011 Las Vegas, USA.
»International Conference on Clinical Research: Dermatology, Ophthalmology and Cardiology 5-6 July 2011 San Francisco, USA.
»International Conference & Exhibition on Proteomics & Bioinformatics 6-8 June 2011 HICC, Hyderabad, India.
»International Conference & Exhibition on Pharmaceutical Biotechnology 6-8 June 2011 HICC, Hyderabad, India.
»2nd World Congress on Bioavailability & Bioequivalence: Pharmaceutical R & D Summit 6-8 June 2011 Las Vegas, USA.
»International Conference on Pharmaceutics & Novel Drug Delivery Systems 7-8 June Las Vegas, USA.
»World Congress on Biotechnology 21-23 March 2011 Hyderabad, India.
»International Conference on Diabetes and Metabolism 13-14 December 2010 Santa Clara, USA.
»International Conference on Biomarkers & Clinical Research 22-23 November 2010 Santa Clara, USA
»International Conference and Exhibition on Analytical and Bioanalytical Techniques: Pharmaceutical R & D Summit 01 - 03 November 2010 Hyderabad, India
»International Conference & Exhibition on Bioequivalence & Bioavailability 2010, Pharmaceutical R & D Summit March 01-03, 2010.
»Integrating Glycomics with other Omics in Cancer Detection and Diagnosis, January 19-20, 2010, Stanford University School of Medicine.
»3rd World Congress of Gene-2009, December 1-7, 2009.
»7th Annual World Congress of International Drug Discovery Science & Technology, October 22-25.
»2nd WSA-2009, July 18-20, 2009
»1st CCSB-2009, February 16-17, 2009
»2nd PRICPS-4th AOHUPO, June 22-26, 2008
»95th ISCA, January 5-8, 2008

Search :     Advanced Search 

Home   |   Join   |   Contact     

    
Journal Details
 
 
Research Article Open Access
Optimization of Submerged Culture Conditions for Exo-Polysaccharides Production by Streptomyces Nasri-UV 135 in Bioreactor
Usama Beshay1*, Ayman Daba2, Yousry Gohar3
1Mubarak City for Scientific Research and Technology Applications, Genetic Engineering and Biotechnology Research Institute (GEBRI), Bioprocess Development Dept, New Bourg El-Arab City, 21934 Alexandria, Egypt
3Alexandria University, Faculty of Science, Division of Microbiology, Alexandria, Egypt
*Corresponding author: Dr. Usama Beshay, Bioprocess Development,
Dept. Genetic Engineering & Biotechnology Research Institute (GEBRI),
Mubarak City for Scientific Research and Technology Applications (MUCSAT),
New Bourg El-Arab City, Universities and Research District,
21934 Alexandria, Egypt,
Fax    : +2034593423
E-mail : ugabra10@hotmail.com, u.beshay@mucsat.sci.eg
 
Received December 19, 2009; Accepted December 27, 2009; Published December 28, 2009
 
Citation: Beshay U, Daba A, Gohar Y(2009) Optimization of submerged culture conditions for exo-polysaccharides production by Streptomyces nasri-UV 135 in bioreactor. J Microbial Biochem Technol 1: 043-046. doi:10.4172/1948-5948.1000008
 
Copyright: © 2009 Beshay U, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License,which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
 
Abstract
 
Production of Exopolysaccharides “EPS” and microbial biomass by Streptomyces nasri were influenced by the type of carbon source (glycerol, xylose, fructose, galactose, glucose, mannose, sucrose, lactose, maltose, dextrin, soluble starch, corn starch and potato starch) and the nitrogen source (glycine, aspartic acid, glutamic acid, proline, ammonium sulphate, sodium nitrate and beef extract ) used in the medium.
 
Xylose and glycine were the most suitable sources of carbon and nitrogen, respectively, for both production of EPS and mycelial growth. The highest EPS production was obtained in a medium containing (g/l) 30 xylose, 2.7 glycine, 4.0 NaCl, 0.5 MgSO4, 1.0 K2HPO4, and 1.0 CaCO3. Exopolysaccharides production and mycelial growth in the above suggested medium were significantly increased in a 3-l stirred tank bioreactor, where the maximum EPS concentration was 8.73 g/l, which was an approximately 1.6 time higher than that in shake culture.
 
Keywords
 
Exopolysaccharides; Streptomyces nasri; Medium composition; Stirred tank bioreactor
 
Introduction
 
During the past several decades, much interest has been generated in the subject of polysaccharides produced by microorganisms, due to their various biological and pharmacological activities, including immuno-stimulating and anti-tumour activities (Kuo et al., 1996; Lee and Kang, 1996). Many microorganisms synthesis exopolysaccharides (EPS) that either attached to the cell surface or are found in the extracellular medium in the form of amorphous slime. Microbial polysaccharides are water soluble polymers and may be ionic or non-ionic. The repeating units of these exopolysaccharides are very regular, branched or unbranched, and are connected by glycosidic linkages. Streptomyces, a Gram-positive bacterium, is well known as an important industrial microorganism for its production of natural derived antibiotics. However, EPS production in Streptomyces has only been reported very recently despite the fast progress at a molecular level in other bacterial species such as lactic acid bacteria (Welman and Maddox, 2003). In our laboratory, S. nasri- UV 135 has been identified to produce EPS, which has antimicrobial activity against a wide range of microorganisms. The produced EPS was also tested for cytotoxic activity against human brain tumor cell line using SRB assay (Gohar et al., 2006).
 
Usually, culture medium is important to the yield of any fermentation products, and carbon and nitrogen sources generally play a significant role because these nutrients are directly linked with cell proliferation and metabolite biosynthesis (Kim et al., 2003; Casas et al., 2003). Also, the nature and concentration of the carbon source can regulate secondary metabolism through phenomena such as catabolic repression. Various statistical experimental design strategies were applied to the optimization of fermentation media. But, as far as we know, there is limited knowledge about the nutritional requirement for EPS production by Streptomyces nasri-UV 135, and there have been no reports on medium optimization to improve EPS production. In this work, the effects of carbon and nitrogen sources were focused in order to improve the EPS production by submerged cultivation of S. nasri-UV 135. The information obtained is considered fundamental and useful to the development of S. nasri- UV 135 cultivation process for efficient production of EPS on a laboratory scale stirred tank bioreactor.
 
Materials and Methods
 
Microorganism and media
 
Streptomyces nasri was isolated from the desert of Kuwait by Hashem and Diab. (1973). An UV-mutant of the parent Streptomyces strain, S. nasri-UV 135 was found to produce an antibiotic active against Gram-positive bacteria and is able to produce bioactive compounds like proteopolysacchrides (Gohar et al., 2006). The initial basal medium used contains (g/l): glucose 30, NaNO3 3.0, yeast extracts 5.0, NaCl 4.0, MgSO4 0.5, K2HPO4 1.0, and CaCO3 1.0, pH 7.
 

Carbon and nitrogen source screening
 
Cultures for screening the carbon and nitrogen sources for effects on fermentation performance were conducted in 250 ml shake flasks filled with 50 ml of the medium. The flasks were inoculated with 500 μl of a spore suspension. The flasks were held at 30°C on a rotary shaker at 200 rpm and harvested on the 7th day.
 

Fermentation conditions
 
The fermentation medium was inoculated with 10% (v/v) of the seed culture and then cultivated at 30ºC in a 3-l stirred tank bioreactor (Bioflow III, New Brunswick Scientific Co., New Brunswick, NJ, USA). Unless otherwise specified, fermentation were conducted under the conditions of temperature 30ºC, aeration rate 1.0 vvm, agitation speed 300 min-1, initial pH 7.0 and working volume 2-l.
 
fig
Figure 1: Effect of different carbon sources on cell growth of S. nasri-UV 135 (A) and EPS production (B) after 7 days cultivation.
 
Analytical methods
 
All determinations reported here were performed in triplicate and the experiments at least in duplicate, and the results were given as mean values.
 
Cell biomass determination
 
Growth was measured as the dry weight per volume by centrifugation (5000 g for 10 min) and then dried to a constant weight in an oven at 60°C overnight to obtain cell dry weight (CDW).
 
Extraction and separation of exopolysaccharides (EPS)
 
Mycelial pellets were separated by centrifugation at 3000 g for 10 min. The supernatant was concentrated to 1/10 its initial volume by a rotary evaporator (Heidolph WB2000, Germany). The concentrates were mixed with equal volume of chilled absolute ethanol to precipitate the exopolysaccharides. To enhance precipitation, these samples were stored at 4ºC for 24 h. The precipitates were recovered by centrifugation at 4000g for 15 min and then dried at 55ºC overnight (van Geel-Schutten et al., 1998).
 
Results and Discussion
 
Effect of carbon sources
 
The following set of experiments examined the effects of various types of carbon sources on cell growth of S. nasri-UV 135 and the production of EPS. In all cases, nitrogen was provided as yeast extract at the same concentration used in basal medium, where each carbon source was added to the basal medium at 30 g/l instead of glucose. Figure 1 shows the time profile of biomass concentration (A) and EPS production (B) for cultures carried out with all carbon sources tested and without any carbon source as control. The results in shake-flask experiments revealed that, the change of the carbon source employed affected both the amount of biomass produced and the EPS production. Although maltose, sucrose, and lactose also gave good mycelial growth, they led to low EPS yields. The preferred carbon sources, xylose and glucose, generally gave the highest EPS production of 4.5 and 3.8 g/l, respectively as shown in Table 1. These results are in agreement with the general concept expressed in early studies (Kornmann et al., 2003; Bueno et al., 2006). They mentioned that fructose, sucrose and glucose have been reported to provide the highest exopolysaccharides yield. Recently, Celik et al. (2008) studied the production of exopolysaccharides by growing strains of Pseudomonas aeruginosa G1 and Pseudomonas putida G12 in medium containing various carbon sources such as glucose, mannose, fructose and xylose. They found that the highest EPS production of the two strains was found in the xylose containing medium.
 
Table 1: Effects of different carbon sources on the growth of Streptomyces nasri-UV 135 and its extracellular polysaccharide (EPS) production during cultivation in shake-flasks for 7 days at 30°C.
1Control culture without any carbon source
 
fig
Figure 2: Effect of different nitrogen sources on cell growth of S. nasri-UV 135 (A) and EPS production (B) after 7 days cultivation.
 
Effect of nitrogen source
 
To investigate the effect of nitrogen source on the production of EPS and mycelial growth eight different nitrogen sources were examined (Figure 2). These N-sources were added on the basis of an equivalent N-content. Although glutamine and aspartic acid were favorable for the mycelial growth of Streptomyces nasri, the maximum EPS production of 5.15 g/l was achieved when glycine (2.7 g/l) was employed (Figure 2B). Improvement in cell growth, EPS production, and EPS/CDW ratio with different nitrogen sources are gathered in Table 2.
 
Cultivation of S. nasri-UV 135 in shake-flasks with optimized medium
 
Using all optimized medium components, trials in a series of shake-flasks were carried out using 30 g/l xylose as carbon source and 2.7 g/l glycine as nitrogen source. The time course of cell growth, EPS production and pH values are shown in Figure 3. The maximal EPS production indicated 5.4 g/l after 6.5 days of fermentation, while maximum mycelial yield was 7.25 g/l after 6.5 days. This indicates 36% increase of the EPS production used the optimized medium (5.4 g/l) compared to EPS production using the basal medium (3.98 g/l) as previously described by Gohar et al. (2006). In addition, similar improvement in biomass concentration was achieved using the optimized medium.
 
Fermentation of S. nasri-UV 135 in stirred tank bioreactor
Although shake flasks are the bioreactors most frequently used in biotechnology for initial process development, very little is known regarding their characteristics from an engineering point of view (Buechs and Zoels, 2001; Buechs, 2001). There are some reports in the literature regarding the scaling-up of processes from shake flasks to stirred tank bioreactors (Muley et al., 1999; Katzer et al., 2001). Therefore, the bioreactor fermentation process was developed on the basis of data obtained from shake flasks cultivation experiments. The production of EPS was studied in a 3 liter bioreactor using the basal and the optimized culture medium.
 
Figure 4 shows the time courses of mycelial growth and EPS production by Streptomyces nasri-UV 135 in a 3-L stirred tank fermenter with the basal medium and the optimized culture medium. In a basal medium, the EPS concentration reached a maximum level of 5.6 g/l after 5.5 d, while maximum mycelial concentration was 3.9 g/l after 4.5 d (Figure 4A). In an optimized culture medium as shown in Figure 4B, the mycelial growth was continuously increased towards the end of fermentation and its final mycelial concentration indicated 13.6 g/l at day 5.5. The initial pH of the fermentation broth slowly decreased from 6.94 to 5.6. The EPS production reached 8.73 g/l after 5 d of fermentation, which were 1.6 times higher than that in fermentation in basal medium. Optimization of operating parameter (e.g. agitation, aeration, and dissolved oxygen tension) in bioreactor fermentation deserves further investigation, which is being carried out in our laboratory.
 
Table 2: Effects of different nitrogen sources on the growth of Streptomyces nasri-UV 135 and its extracellular polysaccharide (EPS) production during cultivation in shake-flasks for 7 days at 30°C.

 
fig
Figure 3: Batch cultivation of S. nasri-UV 135 in shake flasks using the optimized medium.
 
fig
Figure 4: Batch fermentation of S. nasri-UV 135 in stirred tank bioreactor in basal medium (A) and in the optimized medium (B)
 
References
 
  1. Amade P, Mallea M, Bouaicha N (1994) Isolation, structural identification and biological activity of two metabolites produced by Penicillium olsoniibainier and Sartory. J Antibiot 47: 201-207.»  CrossRef  »  PubMed »  Google Scholar

  2. Buechs J (2001) Introduction to advantages and problems of shaken cultures. Biochem Eng J 7: 91-98.»  CrossRef »  PubMed  »  Google Scholar

  3. Buechs J, Zoels B (2001) Evaluation of maximum to specific power consumption ratio in shaking bioreactors. J Chem Eng Jpn 34: 647-653. »  CrossRef  »  Google Scholar


  4. Bueno SM, Garcia-Cruz CH (2006) Optimization of polysacchrides production by bacteria isolated from soil. Brazilian J Microbiol 37: 296-301. »  CrossRef»  Google Scholar

  5. Casas Lopez JL, Sanchez Perez JA, Fernandez Sevilla JM, Acien Fernandez FG, Molina Grima E, et al. (2003) Production of lovastatin by Aspergillus terreus: effects of the C:N ratio and the principal nutrients on growth and metabolite production. Enzyme Microbial Technol 33: 270-277. »  CrossRef»  Google Scholar

  6. Celik GY, Aslim B, Beyatli Y (2008) Characterization and production of the exopolysaccharides (EPS) from Pseudomonas aeruginosa G1 and Pseudomonas putida G12 strains. Carbohydrate Polymers 73: 178-182.»  CrossRef »  Google Scholar

  7. Gohar Y, Beshay U, Daba A, Hafez E (2006) Bioactive compounds from Streptomyces nasri and its mutants with special reference to proteopolysaccharides. Polish J Microbiology 55: 179- 187.»  CrossRef  »  PubMed »  Google Scholar

  8. Hashem MA, Diab A (1973) Some physiological studies on Streptomyces nasri sp. from the desert of Kuwait. Zentralbl Bakteriol Parasitenkd Infektionskr 128: 356-362. »  PubMed  »  Google Scholar

  9. Katzer W, Blackburn M, Charman K, Matin S, Penn J, et al. (2001) Scaleup of filamentous organisms from tubes and shake-flasks into stirred vessels. Biochem Eng J 7: 127-134. »  CrossRef»  PubMed »  Google Scholar

  10. Kim SW, Xu CP, Hwang HJ, Choi JW, Kim CW, et al. (2003) Production and characterization of exopolysaccharides from an enthomopathogenic fungus Cordyceps militaris NG3. Biotechnol Prog 19: 428-35. »  CrossRef  »  PubMed »  Google Scholar

  11. Kornmann H, Duboc P, Marison I, Stockar U (2003) Influence of nutritional factors on the nature, yield, and composition of exopolysacchrides produced by Gluconobacter xylinus I-2281. Appl Env Microbiol 69: 6091- 6098.  »  CrossRef »  Google Scholar

  12. Kuo YC, Eum WJ, Shiao MS, Chen CF, Lin CY (1996) Cordyceps sinensis as an immunomodulatory agent. Am J Chin Med. 24: 111- 125. »  CrossRef»  PubMed  »  Google Scholar

  13. Lee SY, Kang TS (1996) Production conditions and characterization of the exo-polymer produced by submerged cultivation of Ganoderma lucidum mycelium. Korean Journal of Applied Microbiology and Biotechnology 24: 111-118.»  CrossRef»  Google Scholar

  14. Muley R, Sarkar S, Arunkumar B, Narayanan M, Naik S (1999) Scale-up approach for fermentation process of production of Bacillus thuringiensis var kenyae based biopesticide. J Sci Ind Res 58: 781-784. »  CrossRef»  Google Scholar

  15. van Geel-Schutten GH, Flesch F, Brink B, Smith MR, Dijkhuizen L (1998) Screening and characterization of Lactobacillus strains producing large amounts of exopolysaccharides. Appl Microbiol Biotechnol 50: 697-703. »  CrossRef»  Google Scholar

  16. Welman AD, Maddox IS (2003) Exopolysaccharides from lactic acid bacteria: perspectives and challenges. Trends Biotechnol 12: 269-274. »  CrossRef»  PubMed»  Google Scholar

 
 
 
This Article
DOWNLOAD
» XML (79 kB)
» PDF (1,156 kB)
» Citation
   
CONTRIBUTE
» Write a Response
» Read other Responses
» Publishing with OPG
   
SHARE
» E-mail This Article
» Print This Article
» Rights and Permissions
   
Share
EXPLORE
Related Article at
» Pubmed
» DOAJ
» Scholar Google
 
 
 
 
Untitled Document
| More
OMICS Publishing Group: An Open Access Publisher
OMICS Publishing Group is the member of/publishing partner of/source content provider to
All Published content, except where otherwise noted, is licensed under a Creative Commons Attribution License.