Sharif Digital Repository

Treatment of wastewater containing carbohydrates by Pichia saitoi growing on beet molasses was investigated in a well-mixed continuous tank as an alternative to bulking control. The yeast strain that used in this work was isolated from non-alcoholic beverage industrial wastewater, with a view on TOC removal compared with other strains in previous study.In this research the isolated yeast showed high COD and TOC removal at three hydraulic retention times, HRT= 48, 24 and 18 hours.Maximum COD and TOC reductions were obtained at HRT=48 hours, which were 96% and 88%, respectively.The influent COD and TOC were 2500 and 148 mg/1, respectively.The pH maintained for synthetic wastewater was about... 

DNA polymerase η (polη) is of significant value for designing new families of anticancer drugs. This protein takes a role in many stages of the cell cycle, including DNA replication, translesion DNA synthesis, and the repairing process of DNA. According to many studies, a high level of expression of polη in most cases has been associated with low rates of patients' survival, regardless of considering the stage of tumor cells. Thus, the design of new drugs with fewer side effects to inhibit polη in cancerous cells has attracted attention in recent years. This project aims to design and explore the alternative inhibitors for polη, which are based on carbohydrates and amino acids. In terms of... 

One of the main factors affecting membrane fouling in MBRs is operational conditions. In this study the influence of aeration rate, filtration mode, and SRT on hollow fiber membrane fouling was investigated using a triple fouling layers perspective. The sludge microbial population distribution was also determined by PCR method. Through various applied operational scenarios the optimal conditions were: aeration rate of 15 LPM; relaxation mode with 40s duration and 8 min. interval; and SRT of 30 days. The similarity between SMP variations in triple fouling layers with its corresponding hydraulic resistance confirmed the effect of SMP on membrane fouling. Among three fouling fractions, the... 

The main goal of this research is to use the biomass productivity, carbohydrate content, and carbohydrate productivity as useful responses for optimization of macronutrients concentrations (K2HPO4, NaHCO3, and NaNO3) in cultivation of Spirulina microalgae as a feedstock for bioethanol production. In this study, individual and synergistic effects of medium components on the mentioned responses were investigated. The culture medium was optimized using central composite design for achieving the maximize biomass productivity (165 mg L−1 day−1 at K2HPO4: 438 mg L−1, NaHCO3: 15.92 g L−1, and NaNO3: 0.5 g L−1), carbohydrate content (42.0% of dry mass at K2HPO4: 192 mg L−1, NaHCO3: 5.71 g L−1, and... 

L- asparaginase enzyme is a renown enzyme because of its chemotherapeutic properties. This enzyme may also be employed in food processing technology. The present study aimed, optimizing the agitation and aeration rate in L-asparaginase production, using C. utilis, ATCC 9950 in batch fermentation system. Beet molasses used as the carbohydrate source for enzyme production. A maximum asparaginase activity of 245.6 U/ml obtained after 20h of fermentation under optimal condition of 1.25 vvm aeration rate and 300 rpm agitation speed. Purification of the enzyme was also done by Acetone Precipitation and column chromatograph. Purified L-asparaginase revealed molecular weight 75 kDa and 82.7 % yield... 

Biological systems are highly nonlinear, and there is a significant amount of variability from one patient to another. A controller for drug infusion has to be able to achieve good performance for most of the potential patient population. These controllers are designed for the general population, as no knowledge is available before hand for each particular patient. This necessitates perforce an algorithm that will be able to compensate for the differences between individuals and external factors. Of the possibilities, fuzzy logic direct model reference adaptive control (DMRAC) is the choice for Insulin infusion control for diabetes type I as results presented herein. Safety and robustness... 

Hydrogen bonds are the dominant motif for organizing the three-dimensional structures of biomolecules such as carbohydrates, nucleic acids, and proteins, and serve as templates for proton transfer reactions. Computations, gas-phase acidity measurements, and pKa determinations in dimethyl sulfoxide on a series of polyols indicate that multiple hydrogen bonds to a single charged center lead to greatly enhanced acidities. A new class of Brønsted acids, consequently, is proposed. © 2009 American Chemical Society  

The effect of glucose concentration in submerged fermentation (SMF) on chitosan production by Aspergillus niger was investigated. A. niger, BBRC, 20004, from the Biochemical and Bioenvironmental Research Centre at Sharif University of Technology, Tehran, Iran, was grown in a Sabouro Dextrose media. Chitosan was extracted from the fungal mycelia using hot alkaline and acid treatment and after 12 days of cultivation, 0.8455 g chitosan /l of the fermentation medium was obtained. The content of glucose in the Sobouro Dextrose Broth media was also changed and the highest yield of chitosan 0.9121 g/l was obtained in Sobouro Dextrose Broth media containing 8% glucose. © Sharif University of... 

Fructose is utilized as a common sweetener in many food industries. Today, a large amount of HFCS (high fructose corn syrup, an equilibrium mixture of glucose and fructose) is produced by glucose isomerase, immobilized enzymes from corn starch. There are a lot of date palms in Iran. Date is a favorable source of carbohydrates, and a suitable source for HFDS (high fructose date syrup) production. In this investigation, date syrup properties were first determined and the operational conditions for glucose isomerase application were optimized respectively. Ion exchange chromatography has been utilized for carbohydrate separation. Fructose obtained from chromatographic column reached 90 %... 

PIM-1 is a serine-threonine kinase mainly expressed in tissues like the Thymus, spleen, bone marrow, and liver. Overexpression of PIM kinases occurs in various types of human tumours, such as lymphomas, prostate cancer, and oral cancer. As a result, the design of drugs to inhibit PIM-1 in cancerous cells has attracted much attention in recent years. This study aimed to design the alternative inhibitors for PIM-1 kinase, which are based on carbohydrates and amino acids and are expected to be non-toxic with the same chemotherapeutic effects as the traditional known anticancer drugs. The combinatorial use of quantum mechanics (QM) and molecular dynamic simulation (MD) has enabled us to... 

The 1H-13C coupling constants of methyl α- and β-pyranosides of d-glucose and d-galactose have been measured by one-dimensional and two-dimensional 1H-13C heteronuclear zero and double quantum, phase sensitive J-HMBC spectra to determine a complete set of coupling constants (1JCH, 2JCH, 3JCH, 2JHH, and 3JHH) within the exocyclic hydroxymethyl group (CH2OH) for each compound. In parallel with these experimental studies, structure, energy, and potential energy surfaces of the hydroxymethyl group for these compounds were determined employing quantum mechanical calculations at the B3LYP level using the 6-311++G** basis set. Values of the vicinal coupling constants involving 1H and 13C in the... 

Two-dimensional MXenes are the newly emerging family of nanomaterials with competitive performance for nano-device development. Surface functional groups and abundant binding sites make these materials ideal candidates for sensor applications. Herein, we report the successful fabrication of a MXene-based nano-bio device for capturing, sensing, and filtering the Escherichia coli (E. coli) bacteria. Mannose carbohydrate, which binds strongly to E.coli's fimH protein via glucan multivalent interactions, is used as the bio-receptor element. MXene's structure was engineered to guarantee efficient E. coli capturing without mannose detachment. Electrochemical impedance spectroscopy (EIS) and cyclic... 

Paenibacillus polymyxa ATCC 21830 was used for the production of curdlan gum for first time. A Box-Behnken experimental design was applied to optimize six variables of batch fermentation culture each at three levels. Statistical analyses were employed to investigate the direct and interactive effects of variables on curdlan production. Optimum cultural conditions were temperature (50. °C), pH (7), fermentation time (96. h), glucose (100. g/L), yeast extract (3. g/L) and agitation speed (150. rpm). The yield of curdlan production was 6.89. g/L at optimum condition medium. Response surface methodology (RSM) and artificial neural network (ANN) were used to model cultural conditions of curdlan... 

Ship-in-a-bottle complex of nickel(II) containing the ligand N,N′-bis(2,4-dihydroxyacetophenone)-2,2-dimethylpropandiimine (H 2{salnptn(4-OH)2}) has been synthesized in zeolite Y. The characteristics of the encapsulated complex are identified by the methods of EDX, SEM, XRD, FT-IR and cyclic voltammetry. A catalytic effect in the electrochemical oxidation of glucose, fructose and sucrose, and a blocking effect in stevioside oxidation are demonstrated on the Ni II{salnptn(4-OH)2}-Y/CPE. The effects of some parameters, such as potential scan rate and concentration of carbohydrates are investigated. The rate constants for the catalytic reaction (k′) of carbohydrates are also obtained. The... 

Fungal delignification can be considered as a feasible process to pre-treat lignocellulosic biomass in biofuel production, if its performance is improved in terms of efficiency thorough a few modifications. In this study, Trichoderma viride was utilized to investigate the effect of wet-milling, addition of surfactant (Tween 80) and optimization of operating factors such as temperature, biomass to liquid medium ratio and glucose concentration on biodelignification of rice straw. Next, the enzymatic hydrolysis of pretreated biomass was studied at various pretreatment times. Results revealed that the wet milling and addition of surfactant increases the lignin removal about 15% and 11%,... 

Introduction: It is 23 years since carbon allotrope known as carbon nanotubes (CNT) was discovered by Iijima, who described them as "rolled graphite sheets inserted into each other". Since then, CNTs have been studied in nanoelectronic devices. However, CNTs also possess the versatility to act as drug- and gene-delivery vehicles.Areas covered: This review covers the synthesis, purification and functionalization of CNTs. Arc discharge, laser ablation and chemical vapor deposition are the principle synthesis methods. Non-covalent functionalization relies on attachment of biomolecules by coating the CNT with surfactants, synthetic polymers and biopolymers. Covalent functionalization often... 

The derivatives of glucose such as glucosamine (β-D-GlcN) and N-acetyl-D-β-glucosamine (GlcNAc) are significant in several biological systems. D-GlcN has been used widely to treat osteoarthritis in humans and animal models as well as GlcNAc has been proposed as a treatment for autoimmune diseases. The DFT/B3LYP/6–311++G (d,p) method as well as QTAIM and NBO analyses were used to the acidity values of D-GlcN and GlcNAc sugars and their complexes with alkali ions in the gas phase. The Li+, Na+ and K+ prefer bi-dentate chelate in these complexes. The computed results indicate that metal ion affinity (MIA) in GlcNAc is higher than that in D-GlcN. There are direct correlations between the MIA... 

Polyrotaxanes consisting of cyclodextrin rings, polyethylene glycol axes and quantum dot (QD) stoppers were synthesized and characterized. The molecular self-assembly of polyrotaxanes led to spindlelike nano-objects whose shape, size and position were dominated by QD stoppers. Due to their well-defined molecular self-assemblies, carbohydrate backbone, high functionality and several types of functional groups together with the high luminescence yield, synthesized hybrid nanostructures were recognized as promising candidates for biomedical applications. The potential applications of the molecular self-assemblies as drug-delivery systems was investigated by conjugation of doxorubicin (DOX) to... 

A bacterial strain was isolated and cultured from the oil excavation areas in tropical zone in southern Iran. It was affiliated with Pseudomonas. The biochemical characteristics and partial sequenced 16S rRNA gene of isolate, MR01, was identical to those of cultured representatives of the species Pseudomonas aeruginosa. This bacterium was able to produce a type of biosurfactant with excessive foam-forming properties. Compositional analysis revealed that the extracted biosurfactant was composed of high percentages lipid (∼65%, w/w) and carbohydrate (∼30%, w/w) in addition to a minor fraction of protein (∼4%, w/w). The best production of 2.1 g/l was obtained when the cells were grown on...