Nanotubular structures developed from whey‐based α‐lactalbumin fractions for food applications

Whey proteins have high nutritional value providing use in dietary purposes and improvement of technological properties in processed foods. Functionality of the whey‐based α‐lactalbumin (α‐La) may be increased when assembled in the form of nanotubes, promising novel potential applications subject to investigation. The purpose of this study was to extract highly pure α‐La from whey protein isolate (WPI) and whey powder (WP) and to construct protein nanotubes from them for industrial applications. For protein fractionation, WPI was directly fed to chromatography, however, WP was first subjected to membrane filtration and the retentate fraction, whey protein concentrate (WPC), was obtained and then used for chromatographic separation. α‐La and, additionally β‐Lg, were purified at the same batches with the purities in the range of 95%–99%. After enzymatic hydrolysis, WPI‐based α‐La produced chain‐like and long nanotubules with ～20 nm width while WPC‐based α‐La produced thinner, miscellaneous, and fibril‐like nanostructures by self‐assembly. Raman and FT‐IR spectroscopies revealed that α‐La fractions, obtained from both sources and the nanostructures, developed using both fractions have some structural differences due to conformation of secondary structure elements. Nanotube formation induced gelation and nanotubular gel network entrapped a colorant uniformly with a transparent appearance. Dairy‐based α‐La protein nanotubules could be served as alternative gelling agents and the carriers of natural colorants in various food processes. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:1301–1310, 2014     

Distribution of spoligotyping defined genotypic lineages among drug-resistant Mycobacterium tuberculosis complex clinical isolates in Ankara, Turkey

Background

Investigation of genetic heterogeneity and spoligotype-defined lineages of drug-resistant Mycobacterium tuberculosis clinical isolates collected during a three-year period in two university hospitals and National Tuberculosis Reference and Research Laboratory in Ankara, Turkey.

Methods and Findings

A total of 95 drug-resistant M. tuberculosis isolates collected from three different centers were included in this study. Susceptibility testing of the isolates to four major antituberculous drugs was performed using proportion method on Löwenstein–Jensen medium and BACTEC 460-TB system. All clinical isolates were typed by using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) methods. Seventy-three of the 95 (76.8%) drug resistant M. tuberculosis isolates were isoniazid-resistant, 45 (47.4%) were rifampicin-resistant, 32 (33.7%) were streptomycin-resistant and 31 (32.6%) were ethambutol-resistant. The proportion of multidrug-resistant isolates (MDR) was 42.1%. By using spoligotyping, 35 distinct patterns were observed; 75 clinical isolates were grouped in 15 clusters (clustering rate of 79%) and 20 isolates displayed unique patterns. Five of these 20 unique patterns corresponded to orphan patterns in the SITVIT2 database, while 4 shared types containing 8 isolates were newly created. The most prevalent M. tuberculosis lineages were: Haarlem (23/95, 24.2%), ill-defined T superfamily (22/95, 23.2%), the Turkey family (19/95, 20%; previously designated as LAM7-TUR), Beijing (6/95, 6.3%), and Latin-America & Mediterranean (LAM, 5/95 or 5.3%), followed by Manu (3/95, 3.2%) and S (1/95, 1%) lineages. Four of the six Beijing family isolates (66.7%) were MDR. A combination of IS6110-RFLP and spoligotyping reduced the clustering rate from 79% to 11.5% among the drug resistant isolates.

Conclusions

The results obtained showed that ill-defined T, Haarlem, the Turkey family (previously designated as LAM7-TUR family with high phylogeographical specifity for Turkey), Beijing and LAM were predominant lineages observed in almost 80% of the drug-Resistant M. tuberculosis complex clinical isolates in Ankara, Turkey.     

Purification and characterization of superoxide dismutase from chicken liver

Superoxide dismutase (SOD; EC 1.15.1.1) is an enzyme that protects against oxidative stress from superoxide radicals in living cells. This enzyme has been isolated, purified and partially characterized from chicken liver. The following steps were carried out in order to purify chicken liver SOD. Initially, the liver was homogenized and hemoglobin was removed. Subsequently protein precipitation was effected with (NH(4))(2)SO(4), methanol, (NH(4))(2)SO(4)-methanol and polyethylene glycol methods. The product from polyethylene glycol-3350 precipitation was found to have the highest SOD activity. Polyethylene glycol was removed by chromatography using a PD-10 column. After passing through an ultrafilter, the superoxide dismutase was fractionated by DEAE-ion chromatography and then Sephadex G-75 gel filtration chromatography. During this purification procedure, a specific activity of 4818.2 IU/mg was reached, corresponding to 285.8-fold purification. The purified enzyme, which was characterized as cyanide-sensitive SOD, contained two subunits having Cu and Zn elements with a molecular weight of 16000+/-500 for each. The optimum pH of purified CuZnSOD was determined to be 8.9. The enzyme was found to have good pH stability in the pH range 6.0-7.5 at 25 degrees C over a 2-h incubation period and displayed good thermal stability up to 45 degrees C at pH 7.4 over a 1-h incubation period. The SOD enzyme was not inhibited by DTT and beta-mercaptoethanol, but inhibited by CN(-) and H(2)O(2). In the presence of 2 mM iodoacetamide, the enzyme showed an approximately 40% activity loss. Finally, the inhibitory effect of ionic strength on SOD was also investigated.     

Ultrasound‐assisted dilute acid hydrolysis of tea processing waste for production of fermentable sugar

Lignocellulosic materials that are the most abundant plant biomass in the world have the potential to become sustainable sources of the produced value added products. Tea processing waste (TPW) is a good lignocellulosic source to produce the value added products from fermentable sugars (FSs). Therefore, the present study is undertaken to produce FSs by using ultrasound‐assisted dilute acid (UADA) and dilute acid (DA) hydrolysis of TPW followed by enzymatic hydrolysis. UADA hydrolysis of TPW was optimized by response surface methodology (RSM) at maximum power (900 W) for 2 h. The optimum conditions were determined as 50°C, 1:6 (w/v) solid:liquid ratio, and 1% (w/v) DA concentration, which yielded 20.34 g/L FS concentration. Furthermore, its DA hydrolysis was also optimized by using RSM for comparison and the optimized conditions were found as 120°C, 1:8 solid:liquid ratio, and 1% acid concentration, which produced 25.3 g/L FS yield. Even though the produced sugars with UADA hydrolysis are slightly less, but it can provide significant cost saving due to the lower temperature requirement and less liquid consumption. Besides, enzymatic hydrolysis applied after pretreatments of TPW were very more economic than the conventional enzymatic hydrolysis in the literature due to shorter time requiring. In conclusion, ultrasound‐assisted is a promising technology that can be successfully applied for hydrolysis of biomass and can be an alternative to the other hydrolysis procedures and also TPW can be considered as suitable carbon source for the production of value‐added products like biofuels, organic acids, and polysaccharides. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:393–403, 2016     

Precambrian–Cambrian boundary interval occurrence and form of the enigmatic tubular body fossil Shaanxilithes ningqiangensis from the Lesser Himalaya of India

The affinity of the Ediacaran fossil Shaanxilithes ningqiangensis and putatively related forms has long been enigmatic; over the past few decades, interpretations ranging from trace fossils to algae to metazoans of uncertain phylogenetic placement have been proposed. Combined morphological and geochemical evidence from a new occurrence of S. ningqiangensis in the Krol and Tal groups of the Lesser Himalaya of India indicates that S. ningqiangensis is not a trace fossil, but rather an organic‐walled tubular body fossil of unknown taxonomic affinity. Specimens consist of compressed organic cylindrical structures, characterized by extended, overlapping or fragmented iterated units. Where specimens intersect, overlapping rather than branching or intraplanar crossing is observed. Lithologic comparisons and sequence stratigraphic data all suggest a late Ediacaran age for the uppermost Krol Group and basalmost Tal Group. By extending the biogeographical distribution of S. ningqiangensis, hitherto confined to the Ediacaran of China and potentially Siberia, to the Precambrian–Cambrian boundary interval of India, this new occurrence of S. ningqiangensis expands the biostratigraphic utility of this enigmatic fossil to the inter‐regional and intercontinental scale. Moreover, study of these new and exceptionally preserved samples may help to significantly constrain the long‐debated problem of Shaanxilithes' affinity, elucidating its ‘problematic’ status and shedding new light upon the ecology and taphonomy of one of the most significant intervals in early life history.     

Intra- and extra-cellular flux distributions of TCA and glyoxalate cycle and vancomycin production of <Emphasis Type="Italic">Amycolatopsis orientalis</Emphasis> grown in different glycerol concentration

The relationship between tricarboxylic acid (TCA) and glyoxalate cycle and the effect of their metabolites levels on the vancomycin production of Amycolatopsis orientalis were investigated in different concentration of glycerol (2.5–20 g/l). Intracellular glycerol levels increased with respect to increases in glycerol concentrations of the growth medium. Extracellular glycerol levels decreased slowly up to 24 h while uptake rates were increased during 36–48^th h for 10 and 15 g/l and during 36–60^th h at 20 g/l of glycerol. Intracellular citrate, α-ketoglutarate, fumarate levels increased up to 10 g/l glycerol concentration. However, intracellular succinate and malate levels were increased up to 15 g/l glycerol. Extracellular citrate, α-ketoglutarate, succinate and malate levels increased with respect to increases in glycerol concentration. The highest α-ketoglutarate dehydrogenase activity was determined at 15 g/l glycerol. Isocitrate lyase activity showed a positive correlation with the increases in glycerol concentration of the growth medium. Vancomycin production increased with the increases in glycerol concentration from 5 to 10 g/l. These results showed that A. orientalis grown in glycerol containing medium used glyoxalate shunt actively instead of TCA cycle which supports precursors of many amino acid which are effective on the antibiotic production.     

Acoustic rhinometry in humans: accuracy of nasal passage area estimates, and ability to quantify paranasal sinus volume and ostium size.

A comprehensive study that compared acoustic rhinometry (AR) data to computed tomography (CT) data was performed to evaluate the accuracy of AR measurements in estimating nasal passage area and to assess its ability of quantifying paranasal sinus volume and ostium size in live humans. Twenty nasal passages of 10 healthy adults were examined by using AR and CT. Actual cross-sectional areas of the nasal cavity, sinus ostia sizes, and maxillary and frontal sinus volumes were determined from CT sections perpendicular to the curved acoustic axis of the nasal passage. Nasal cavity volume (from nostril to choana) calculated from the AR-derived area-distance curve was compared with that from the CT-derived area-distance curve. AR measurements were also done on pipe models that featured a side branch (Helmholtz resonator of constant volume but two different neck diameters) simulating a paranasal sinus. In the anterior nasal cavity, there was good agreement between the cross-sectional areas determined by AR and CT. However, posterior to the sinus ostia, AR overestimated cross-sectional area. The difference between AR nasal volume and CT nasal volume was much smaller than the combined volume of the maxillary and frontal sinuses. The results suggest that AR measurements of the healthy adult nasal cavity are reasonably accurate to the level of the paranasal sinus ostia. Beyond this point, AR overestimates cross-sectional area and provides no quantitative data for sinus volume or ostium size. The effects of paranasal sinuses and acoustic resonances in the nasal cavity are not accounted for in the present AR algorithms.