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Pichia pastoris is used for commercial production of human therapeutic proteins, and genome-scale models of P. pastoris metabolism have been generated in the past to study the metabolism and associated protein production by this yeast. A major challenge with clinical usage of recombinant proteins produced by P. pastoris is the difference in N-glycosylation of proteins produced by humans and this yeast. However, through metabolic engineering, a P. pastoris strain capable of producing humanized N-glycosylated proteins was constructed. The current genome-scale models of P. pastoris do not address native nor humanized N-glycosylation, and we therefore developed ihGlycopastoris, an extension to the iLC915 model with both native and humanized N-glycosylation for recombinant protein production, but also an estimation of N-glycosylation of P. pastoris native proteins. This new model gives a better prediction of protein yield, demonstrates the effect of the different types of N-glycosylation of protein yield, and can be used to predict potential targets for strain improvement. The model represents a step towards a more complete description of protein production in P. pastoris, which is required for using these models to understand and optimize protein production processes

Apple pomace powder as natural food ingredient in bakery jams

The aim of the present study was to investigate whether apple pomace powder produced by a simple drying method is suitable for replacing pectin in bakery jam products. Rheological properties of bakery jams were tested by oscillatory tests using amplitude sweep method. Apple pomace addition decreased gel strength and stability of bakery jams, while 12-month storage increased the gel strength of samples. Based on our results, dried apple pomace powder seems to be suitable to replace pectin up to 40% without changing rheological properties of bakery jams

Repetitive non-destructive extraction of lipids from Chlorella vulgaris grown under stress conditions

The aim of this study was the investigation of non-destructive lipid extraction from Chlorella vulgaris grown under stress conditions of nutrient limitation and salinity. To select a suitable solvent for extraction, the performances of decane, dodecane and hexadecane were tested based on their effect on lipid extraction and cell viability. The results showed that dodecane was the most suitable solvent for the extraction process. The concentration of extracted lipids from stressed cells was 2762.52 \ub1 11.38 mg L 121, i.e. a value 1.75 times higher than that obtained from unstressed cells. Long-term extraction was also evaluated with continuous dodecane recirculation during five-stage extraction and a recovery time of 24 h between the extraction steps, which yielded after the fifth extraction stage a total lipid amount as high as 9811.56 mg L 121. These results showed that non-destructive lipid recovery can be effectively performed by applying stress conditions and in repetitive extractions

Biodegradation of Used Engine Oil Using Mixed and Isolated Cultures

It is known that native oil-degrading microorganisms are ubiquitous. They can be isolated from contaminated soils. In this study, biodegradation experiments were carried out to evaluate the efficiency of pollutant removal by adding the selected microorganisms. Five mixed cultures and 3 single bacteria strains, Pseudomonas sp., Arthrobacter sp. and Mycobacterium sp. were isolated from hydrocarbon-contaminated soils by enrichment on either crude oil or individual hydrocarbons, as the sole carbon sources. The strains were selected based on their ability to grow in medium containing crude oil, used engine oil or both. Their ability to degrade hydrocarbon contamination in the environment was investigated using soil samples contaminated with used engine oil. The mixed starter culture #1 degraded 66 % of aliphatic compounds in the engine oil, after 60 days of incubation. The mixed starter culture #5 removed 47 % of aromatic compounds during 60 days of incubation, which is the maximum efficiency among the starter cultures, in this study

Simultaneous loading of 5-florouracil and SPIONs in HSA nanoparticles: Optimization of preparation, characterization and in vitro drug release study

Objective(s): Over the past two decades, considerable interest has been focused on utilizing biocompatible magnetic nanoparticles (MNPs) for biomedical applications. In this study, production of human serum albumin (HSA) nanoparticles using desolvation technique that were simultaneous loaded with high amounts of superparamagnetic iron oxide nanoparticles (SPIONs) and 5-flourouracil (5-FU) was investigated. Materials and Methods: 5-FU loading (%) and SPIONs entrapment efficiency (%) were optimized using response surface methodology (RSM). The design expert software used to analyse the interactive effects of pH, 5-FU and SPIONs concentrations. Results:The optimum conditions found to be pH of 8.2, drug concentration of 1.5 mg/ml and SPIONs concentration of 2.79 mg/ml. Under the mentioned optimum conditions, particles with the size of 111.8 nm, zeta potential of -37.1 mV, 5-FU loading of 15.8% and SPIONs entrapment efficiency of 41.1% were obtained. In vitro cumulative release of 5-FU from the nanoparticles was evaluated in phosphate buffer saline (pH 7.4, 37 °C). Results indicated that 85% of the 5-FU released during 95 h, which revealed a sustained release profile. In addition, Vibrating Sample Magnetometer (VSM) analyses confirmed the superparamagnetic properties of magnetic albumin nanoparticles manufactured under the optimum conditions. Conclusion: According to the findings,SPIONs and 5-FU loaded HAS  nanoparticles arepromising for use as  novel targeted delivery system due to proper magnetic and drug release behaviours

Optimization of Factors Affecting on Sulfide Oxidation from Synthetic Spent Caustic by Haloalkaliphilic Thioalkalivibrio versutus: Application of Response Surface Methodology

In the present study, the effects of four factors includin

A two-phase kinetic model for fungal growth in solid-state cultivation

A new two-phase kinetic model including exponential and logistic models was applied to simulate the growth rate of fungi at various temperatures. The model parameters, expressed as a function of temperature, were determined from the oxygen consumption rate of Aspergillus niger during cultivation on wheat bran. The model can describe the whole growth curve including the lag phase and the cessation of growth in the latter stages of the cultivation with an adequate approximation. Furthermore, the model describes the growth rate of Aspergillus oryzae on wheat properly. Comparisons between the current, logistic and previous two-phase kinetic models indicate that the new model can predict growth rate of fungi more accurately