Influence of solids retention time on membrane fouling: characterization of extracellular polymeric substances and soluble microbial products

The objective of this study was to investigate the influence of solids retention time (SRT) on membrane fouling and the characteristics of biomacromolecules. Four identical laboratory-scale membrane bioreactors (MBRs) were operated with SRTs for 10, 20, 40 and 80 days. The results indicated that membrane fouling occurred faster and more readily under short SRTs. Fouling resistance was the primary source of filtration resistance. The modified fouling index (MFI) results suggested that the more ready fouling at short SRTs could be attributed to higher concentrations of soluble microbial products (SMP). Fourier transform infrared (FTIR) spectra indicated that the SRT had a weak influence on the functional groups of the total extracellular polymeric substances (TEPS) and SMP. However, the MBR under a short SRT had more low-molecular-weight (MW) compounds (<1 kDa) and fewer high-MW compounds (>100 kDa). Aromatic protein and tryptophan protein-like substances were the dominant groups in the TEPS and SMP, respectively.     

Synthesis of Some O-Alkyl O-(2-Methoxycarbonylphenyl) N-Substituted Phosphoramidates as Fungicides

The reaction between the amino group and the carbonyl group is important in food quality control. Furthermore, advanced glycation end products from foods are considered to relate to aging and diabetes. Thus, it is important to control this reaction. In this study, we investigated the effects of salt concentration on the rates of browning reaction of amino acid, peptides, and proteins. A high concentration of sodium chloride retarded the reaction rate of Glc with amino acids as measured with the absorbance at 470 nm, but did not change the browning rate of Glc with peptides. On the other hand, sodium chloride retarded the browning reaction rate of proteins as measured with polymerization degree or by the loss of Lys. It is hoped that the results of this study will be applied in the control of amino-carbonyl reaction rates in the food industry.     

Structure of an early native‐like intermediate of β2‐microglobulin amyloidogenesis

To investigate early intermediates of β2‐microglobulin (β2m) amyloidogenesis, we solved the structure of β2m containing the amyloidogenic Pro32Gly mutation by X‐ray crystallography. One nanobody (Nb24) that efficiently blocks fibril elongation was used as a chaperone to co‐crystallize the Pro32Gly β2m monomer under physiological conditions. The complex of P32G β2m with Nb24 reveals a trans peptide bond at position 32 of this amyloidogenic variant, whereas Pro32 adopts the cis conformation in the wild‐type monomer, indicating that the cis to trans isomerization at Pro32 plays a critical role in the early onset of β2m amyloid formation.     

Incorporating trnH-psbA to the core DNA barcodes improves significantly species discrimination within?southern African Combretaceae

Recent studies indicate that the discriminatory power of the core DNA barcodes (rbcLa + matK) for land plants may have been overestimated since their performance have been tested only on few closely related species. In this study we focused mainly on how the addition of complementary barcodes (nrITS and trnH-psbA) to the core barcodes will affect the performance of the core barcodes in discriminating closely related species from family to section levels. In general, we found that the core barcodes performed poorly compared to the various combinations tested. Using multiple criteria, we finally advocated for the use of the core + trnH-psbA as potential DNA barcode for the family Combretaceae at least in southern Africa. Our results also indicate that the success of DNA barcoding in discriminating closely related species may be related to evolutionary and possibly the biogeographic histories of the taxonomic group tested.     

Pharmacological and nutritional agents promoting browning of white adipose tissue

The role of brown adipose tissue in the regulation of energy balance and maintenance of body weight is well known in rodents. Recently, interest in this tissue has re-emerged due to the realization of active brown-like adipose tissue in adult humans and inducible brown-like adipocytes in white adipose tissue depots in response to appropriate stimuli (“browning process”). Brown-like adipocytes that appear in white fat depots have been called “brite” (from brown-in-white) or “beige” adipocytes and have characteristics similar to brown adipocytes, in particular the capacity for uncoupled respiration. There is controversy as to the origin of these brite/beige adipocytes, but regardless of this, induction of the browning of white fat represents an attractive potential strategy for the management and treatment of obesity and related complications. Here, the different physiological, pharmacological and dietary determinants that have been linked to white-to-brown fat remodeling and the molecular mechanisms involved are reviewed in detail. In the light of available data, interesting therapeutic perspectives can be expected from the use of specific drugs or food compounds able to induce a program of brown fat differentiation including uncoupling protein 1 expression and enhancing oxidative metabolism in white adipose cells. However, additional research is needed, mainly focused on the physiological relevance of browning and its dietary control, where the use of ferrets and other non-rodent animal models with a more similar adipose tissue organization and metabolism to humans could be of much help. This article is part of a Special Issue entitled Brown and White Fat: From Signaling to Disease.     

Influence of environmental factors on content and composition of essential oil from common juniper ripe berry cones (Juniperus communis L.)

Abstract

The present study evaluated the influence of some environmental factors on the quantity and composition of essential oil (EO) in ripe berry cones of Juniperus communis L. The berry cones were collected from juniper shrubs growing wild at five localities of north-east Slovakia during the years 2012–2014. The EO yield ranged from 0.4 to 1.9%, depending on the locality and year. In the EO, eight monoterpenes (α-pinene, β-pinene, β-myrcene, sabinene, limonene, terpinene-4-ol, borneol, bornylacetate) and one sesquiterpene (β-caryophyllene) were identified. The dominant component was the monoterpene α-pinene, ranging from 31.0 to 49.0%. The amount and composition of the EO was affected by soil composition (content of humus and pH) and topographic environmental factors, including air temperature and precipitation. According to the composition of the EO, the studied juniper shrubs belong to the α-pinene chemotype.     

In vitro effects of bisphenol A on the quality parameters,oxidative stress,DNA integrity and adenosine triphosphate content in sterlet (Acipenser ruthenus) spermatozoa

Among endocrine disruptors, the xenoestrogen bisphenol A (BPA) deserves particular attention due to widespread human exposure. Besides hormonal effects, BPA has been suspected to be responsible for adverse effect on reproductive ability of various species. In the present study the effect of BPA on the quality parameters, oxidative stress, the DNA integrity and intracellular ATP content of sterlet (Acipenser ruthenus) spermatozoa were investigated in vitro. Fish spermatozoa were exposed to concentrations of BPA possibly occurring in nature (0.5, 1.75, 2.5, 5 and 10 μg/L) for 2 h. Results revealed that BPA significantly decreased spermatozoa motility and velocity of spermatozoa at concentration of BPA 2.5–10 μg/L. Significant positive correlation (r = 0.713, P < 0.05) was found between percent motile spermatozoa and ATP content. Oxidative stress was observed at concentrations 1.75–10 μg/L, as reflected by significantly higher levels of protein and lipid oxidation and superoxide dismutase activity. Intracellular ATP content of spermatozoa decreased with increasing concentrations of BPA. A dramatic increase in DNA fragmentation expressed as percent tail DNA (2.2% ± 0.46) and Olive tail moment (0.37 ± 0.09 arbitrary units) was recorded at concentrations of 1.75 μg/L and above. The present study confirms that concentrations of BPA that can be encountered in nature are capable to induce oxidative stress, leading to impaired sperm quality, DNA fragmentation and intracellular ATP content.     

Contribution of genetic and epigenetic mechanisms to Wnt pathway activity in prevalent skeletal disorders

We reported previously that the expression of Wnt-related genes is lower in osteoporotic hip fractures than in osteoarthritis. We aimed to confirm those results by analyzing β-catenin levels and explored potential genetic and epigenetic mechanisms involved.