Farzaneh Vahabzadeh

[ 1 ] - Mixture of Xylose and Glucose Affects Xylitol Production by Pichia guilliermondii: Model Prediction Using Artificial Neural Network

Production of several yeast products occur in presence of mixtures of monosaccharides. To study effect of xylose and glucose mixtures with system aeration and nitrogen source as the other two operative variables on xylitol production by Pichia guilliermondii, the present work was defined. Artificial Neural Network (ANN) strategy was used to athematically show interplay between these three c...

[ 2 ] - Sorption Performance of Live and Heat-Inactivated Loofa-Immobilized Phanerochaete chrysosporium in Mercury Removal from Aqueous Solution

The sorption behavior of loofa-immobilized Phanerochaete chrysosporium mycelia in two forms, Live (L) and Heat-Inactivated (HIA), was studied for the removal of Hg2+ ions from aqueous solution. Using the Langmuir isotherm, the two key parameters for the sorption performance, qm and the coefficient b, were obtained; the qm ...

[ 3 ] - Decolorization of Maxilon-Red by Kissiris Immobilized Phanerochaete Chrysosporium in a Trickle-Bed Bioreactor-Involvement of Ligninolytic Enzymes

The decolorization of Maxilon-red dye by Kissiris immobilized Phanerochaete chrysosporium in the trickle-bed reactor (TBR) using the basal nitrogen-limited growth medium was studied. The influence of the superficial liquid velocity (SLV) on the decolorizing ability of the fungus was examined at four SLVs (cm sec-1): 0.05, 0.075, 0.1, and 0.15. Maximum level of the decolorizing ac...

[ 4 ] - Optimization of Fermentation Time for Iranian Black Tea Production

The optimum fermentation times of black tea manufactured by two systems of Orthodox and CTC (cut, tear & curl) were investigated by measuring the quality parameters of black tea, like: theaflavin, thearubigin, highly polymerized substances and total liquid colour during the fermentation stage. Optimum fermentation times from the beginning of fermentation were determined to be 60 min and 15...

[ 5 ] - Characterization of Phosphate Membrane Transport in Saccharomyces cerevisiae CEN.PK113-5D under Low-Phosphate Conditions Using Aerobic Continuous Culture

Two different growth media, namely complex and defined media, were used to examine establishment of steady-state conditions in phosphate-limited culture system of Saccharomyces cerevisiae CEN.PK113-5D strain. Using the defined growth medium, it was possible to obtain steady state condition in the continuous culture. The effect of phosphate concentration on the growth of S. cerevisiae in pho...

[ 6 ] - Decolorization of Molasses Waste Water from an Alcoholic Fermentation Process with Phanerochaete Chrysosporium Involvement of Ligninase

Waste water from a molasses alcoholic fermentation plant (MWW) was treated biologically with Phanerochaete chrysosporium. The ability of this white-rot fungus to degrade the dark colored pigments present in MWW and the consequent decrease the effluent's color was examined. The Optimum concentration of MWW for color removal was determined and set at the ratio of 1:10. The color changes durin...

[ 7 ] - Effect of external mass transfer on activation energy of butyl oleate ester synthesis using a whole cell biocatalyst

In the present research, synthesis of butyl oleate ester from oleic acid and butanol using loofa-immobilized Rhizopus oryzae as a whole cell biocatalyst (LIC) was studied in which hexane was used as the hydrophobic solvent. Decrease of mass transfer limitations as result of the interface formation between the two immiscible substrates, positively affected on the reaction progress (87% as the es...

[ 8 ] - Biodegradation Modeling of Nitrophenolic Pollutant in a Slurry Bubble Reactor

Biodegradation kinetics of 4-nitrophenol (PNP) in aqueous solution by a gram negative soil bacterium, Ralstoniaeutropha was firstly studied in a small scale batch reactor. The degradation of PNP was evaluated at initial PNP concentrations ranging from 3 mg/L to 14 mg/L. The rate of PNP consumption by the bacterium culture was modeled using Monod and Contois kinetics in batch condition. PNP degr...

[ 9 ] - رایزوپوس اوریزا تثبیت‌یافته بر لوفا اسفنجی و نقش آن در تولید لیپاز درون‌سلولی

سابقه و اهداف: آنزیم لیپاز (EC.3.1.1.3) به عنوان عضوی از گروه کربوکسیلیک استر هیدرولازها، کاتالیز آبکافتی تری‌آسیل‌گلیسرول را جهت آزاد سازی اسیدهای چرب، گلیسریدها و گلیسرول به عهده دارد. با شناخت توانایی لیپاز جهت کاتالیز واکنش استریفیکاسیون، فصل گسترده‌ای در زمینه کارایی‌های این آنزیم آغاز شده است. قارچ رایزوپوس اوریزا، از جمله منابع میکروبی شناخته شده در تولید آنزیم لیپاز است. تمرکز مطالعه ح...

[ 10 ] - کاربرد عملیات اسیدکراکینگ و فرآیند فنتون در تصفیه پساب روغن زیتون

گسترش صنایع استخراج روغن از زیتون در سالهای اخیر، مسائل و مشکلات زیست محیطی بسیاری را به دنبال داشته است. پساب حاصل از عملیات استخراج روغن از زیتون به دلیل بار آلایندگی بسیار بالا (COD≈50-220 g/L, BOD≈30-100 g/L) و همچنین حضور ترکیبات فنلیک، اسیدهای چرب فرار، کتچین ها و سایر بازدارنده ها به طور طبیعی تخریب پذیر نمی باشند. در سالهای اخیر فرآیندهای اکسیداسیون پیشرفته که معطوف به تشکیل رادیکال‌های...

[ 11 ] - Microencapsulation of Orange Oil by Complex Coacervation and its Release Behavior (REASEARCH NOTE)

Microencapsulation of liquid orange oil as a common flavoring agent in food industries by complex coacervation in a gelatin – gum arabic polymeric wall system was studied. At a fixed ratio of 10% w/v as concentration of the materials used in this study, trend of changes of microencapsulation process variables using different wall polymeric contents along with varying levels of the core to wall ...

[ 12 ] - Bioenergetic Aspects of Dibenzothiophene Desulfurization by Growing Cells of Ralstonia eutropha

The present study focuses on effects of initial pH on dibenzothiophene (DBT) desulfurization via 4S pathway by growing cells of Ralstonia eutropha. For so doing, temporal changes of biomass concentration, glucose as a sole carbon source, pH value, and 2-hydroxybiphenyl (2-HBP) formation have been monitored during the bioprocess. The biomass concentration has been modeled by the logistic equatio...

[ 13 ] - Bioenergetic Aspects of Dibenzothiophene Desulfurization by Growing Cells of Ralstonia eutropha

The present study focuses on effects of initial pH on dibenzothiophene (DBT) desulfurization via 4S pathway by growing cells of Ralstonia eutropha. For so doing, temporal changes of biomass concentration, glucose as a sole carbon source, pH value, and 2-hydroxybiphenyl (2-HBP) formation have been monitored during the bioprocess. The biomass concentration has been modeled by the logistic equatio...

[ 14 ] - Antibacterial Activity of the Lipopeptide Biosurfactant Produced by Bacillus mojavensis PTCC 1696

Bacillus mojavensis PTCC 1696 (a member of Bacillus subtilis group) has been isolated from the Iranian oil field (Masjed-I Soleyman), to examine its ability to produce biosurfactant (lipopeptide type) [28]. The present study was designed to characterize the antibacterial activity of th...