Production of recombinant human dipeptidyl peptidase IV from SF9 cells in microbial fermenters

The human dipeptidyl peptidase IV (hDPPIV/CD26) is expressed as an immune response in some cancer cells as well as intestine and incretin metabolism, and deficiency of the enzyme leads to metabolic disorders. In the present study, recombinant hDPPIV/CD26 genes were expressed in baculovirus–insect cell systems in a 5-L stirred-tank fermenter. Because of the shear sensitivity of the insect cell line, production from insect cells should be performed in new-generation type bioreactors, which are commonly more expensive than microbial fermenters. To optimize the process, hydrodynamic parameters and oxygen consumption of Sf9 cells at 1.5 L and 3 L were monitored, and a certain amount of serum was added to the production medium to decrease shear and stabilize the growth of insect cells that normally do not need serum addition. In this study, dimensionless numbers and some hydrodynamic parameters were calculated in 1.5 L, and predictions were made for 3 L fermenter volumes. Agitation rates of 60 rpm were determined to protect insect cells against damaging shear stress. Regarding the agitation rate, oxygen mass transfer coefficient (k L a) was 0.0129 min –1 for 1.5 L and was kept constant for 3 L (0.0133 min –1 ). The maximum enzyme activity from microbial fermenters was 2.37-fold higher than activity from T-flask in our previous work. The infection efficiency of transfected cells was 78%–81% in the 1.5-L and 3-L fermenters. © TÜBİTAK

Clinical presentations and diagnostic work-up in sarcoidosis: A series of Turkish cases (clinics and diagnosis of sarcoidosis)

Sarcoidosis is an idiopathic granulomatous disease. It usually affects the lung. The diagnosis may be problematic since the known causes of granulomatous inflammation must be excluded. This multicenter study aimed to evaluate the clinical presentations and diagnostic approaches of sarcoidosis. The study protocol was sent via internet, and the participants were asked to send the information (clinical, radiological and diagnostic) on newly diagnosed sarcoidosis cases. 293 patients were enrolled within two years. Pulmonary symptoms were found in 73.3% of the patients, and cough was the most common one (53.2%), followed by dyspnea (40.3%). Constitutional symptoms were occured in half of the patients. The most common one was fatigue (38.6%). The most common physical sign was eritema nodosum (17.1%). The most common chest radiograhical sign was bilateral hilar lymphadenomegaly (78.8%). Staging according to chest X-ray has revealed that most of the patients were in Stage I and Stage II (51.9% and 31.7%, respectively). Sarcoidosis was confirmed histopathologically in 265 (90.4%) patients. Although one-third of the bronchoscopy was revealed normal, mucosal hyperemi (19.8%) and external compression of the bronchial wall (16.8%) were common abnormal findings. The 100% success rate was obtained in mediastinoscopy among the frequently used sampling methods. Transbronchial biopsy was the most frequently used method with 48.8% success rate. Considering sarcoidosis with its most common and also rare findings in the differential diagnosis, organizing the related procedures according to the possibly effected areas, and the expertise of the team would favor multimodality diagnosis

The Sariçiçek Howardite Fall in Turkey: Source Crater of HED Meteorites on Vesta and İmpact Risk of Vestoids

The Sariçiçek howardite meteorite shower consisting of 343 documented stones occurred on 2 September 2015 in Turkey and is the first documented howardite fall. Cosmogenic isotopes show that Sariçiçek experienced a complex cosmic ray exposure history, exposed during ~12–14 Ma in a regolith near the surface of a parent asteroid, and that an ~1 m sized meteoroid was launched by an impact 22 ± 2 Ma ago to Earth (as did one third of all HED meteorites). SIMS dating of zircon and baddeleyite yielded 4550.4 ± 2.5 Ma and 4553 ± 8.8 Ma crystallization ages for the basaltic magma clasts. The apatite U-Pb age of 4525 ± 17 Ma, K-Ar age of ~3.9 Ga, and the U,Th-He ages of 1.8 ± 0.7 and 2.6 ± 0.3 Ga are interpreted to represent thermal metamorphic and impact-related resetting ages, respectively. Petrographic, geochemical and O-, Cr- and Tiisotopic studies confirm that Sariçiçek belongs to the normal clan of HED meteorites. Petrographic observations and analysis of organic material indicate a small portion of carbonaceous chondrite material in the Sariçiçek regolith and organic contamination of the meteorite after a few days on soil. Video observations of the fall show an atmospheric entry at 17.3 ± 0.8 kms-1 from NW, fragmentations at 37, 33, 31 and 27 km altitude, and provide a pre-atmospheric orbit that is the first dynamical link between the normal HED meteorite clan and the inner Main Belt. Spectral data indicate the similarity of Sariçiçek with the Vesta asteroid family (V-class) spectra, a group of asteroids stretching to delivery resonances, which includes (4) Vesta. Dynamical modeling of meteoroid delivery to Earth shows that the complete disruption of a ~1 km sized Vesta family asteroid or a ~10 km sized impact crater on Vesta is required to provide sufficient meteoroids ≤4 m in size to account for the influx of meteorites from this HED clan. The 16.7 km diameter Antonia impact crater on Vesta was formed on terrain of the same age as given by the 4He retention age of Sariçiçek. Lunar scaling for crater production to crater counts of its ejecta blanket show it was formed ~22 Ma ago

Production and separation of dipeptidyl peptidase IV from Lactococcus lactis: Scale up for industrial production

Lactococcus lactis spp. lactis and Lactococcus lactis spp. cremoris are widely used in the manufacture of fermented milk. These strains were compared for production of Dipeptidyl Peptidase IV (DPP IV) enzyme in terms of enzyme activity, specific growth rates and productivity. Lactococcus lactis spp. lactis was produced in 3 L bioreactor and scaled up to 30 and 150 L stirred tank bioreactors, and the enzyme activities were found as 110, 110 and 122 mU mL -1, respectively. After 8 h of production, separation steps were performed. While purification fold was 127 and yield was 2.69 %, the molecular weight of the enzyme was estimated as 68 kDa. Partially purified enzyme was enteric coated with capsules and a 95.5 % of DPP IV enzyme passed into the artificial intestine. Results show that production of DPP IV enzyme by Lactococcus lactis spp. lactis strain in submerged culture is comparable with the productions by commercial strains, mostly Aspergillus, in solid state fermentations based on productivity. © Springer-Verlag 2012

Production of inulinase by mixed culture of Aspergillus niger and Kluyveromyces marxianus

Inulinase activity produced by a mixed culture of Aspergillus niger and Kluyveromyces marxianus growing on Jerusalem artichoke powder was investigated. Inulinase produced by this mixed culture had a higher invertase-type activity than inulinase from respective monocultures. When hydrolysis was carried out at 50°C with Jerusalem artichoke exctract (total sugar 16% w/v) at pH 5.0, 90% hydrolysis was achieved after 4 h with 5% v/v of crude cell free enzyme preparation

Encapsulation of ?-amylase in a starch matrix

In this study thermostable ?-amylase was encapsulated in a pregelatinized potato starch to obtain a controlled degradation upon water uptake. Encapsulation was performed using kneading, a (thermo) mechanical process. The aim of the study was to evaluate the possibility to encapsulate a degrading enzyme for a system, which can be triggered to degrade upon water uptake instead of direct water contact. After the encapsulation process, the enzyme (?-amylase) activity in the samples was found to have 90 ± 5% of activity of the unprocessed enzyme. It was seen that there was initial degradation of the starch matrix during processing, proportional to the enzyme concentration. The encapsulated enzyme was inactive during storage under low humidity conditions (RH ? 60%) and could be reactivated upon water uptake by incubation of samples in humid atmosphere (90% RH). The reduction of the molecular weight, upon activation of the encapsulated enzyme was also proportional to the concentration of the encapsulated enzyme. © 2002 Elsevier Science Ltd. All rights reserved

Production and properties of inulinase from Aspergillus niger

A thermostable inulinase was identified in a strain of A. niger. The highest activity was observed at 50 °C (50 Lml-1) and 77% and 34% of this was retained at 60° and 65°C, respectively. pH stability, the effect of thermal stabilizers such as Propylene glycol (10%) and Sorbitol (10%) and effects of different cations were investigated. It was found that the activity was completely inhibited by Ag+ and Hg2+, while Na+ had an activator effect. © 1994 Lonsdale Press Ltd

Modeling and optimization of syngas production from biomass gasification

The detrimental environmental impacts of fossil fuels are increasing due to the growing global energy consumption. Thus, energy recovery from waste will inevitably become the dominant option in the future with population growth and the reduction in fossil resources. In this study; the synthesis gas composition obtained by gasification of biomass attained from a mixture of carbon black obtained from waste tires and sewage sludge originating from the yarn industry was modeled by the response surface method and optimized using Box-Behnken design. The R-2 values obtained for H-2, CO, CH4, and the heating value that make up the synthesis gas composition are 92.86%, 95.40%, 96.15%, and 96.80%, respectively. These are the indicators that the models were statistically significant. Optimum conditions obtained from the model were as follows; reaction time 31.14 min, gas flow rate 0.05 L/minute, and biomass amount 19.66 g. As a result of the validation experiments conducted under optimum conditions, the percentages of H-2, CH4, CO were found as 12.75%, 8.07%, and 7.87%, respectively, and the heating value was 1420.3 kcal/m(3). In conclusion, the gasification process is an appropriate treatment for obtaining high-quality syngas from waste materials with high carbon and low moisture content and the Box-Behnken design is applicable for the optimization of the gasification process