Achieving energy neutrality in wastewater treatment plants through energy savings and enhancing renewable energy production

Wastewater treatment plants (WWTPs) consume high amounts of energy which is mostly purchased from the grid. During the past years, many ongoing measures have taken place to analyze the possible solutions for both reducing the energy consumption and increasing the renewable energy production in the plants. This review contains all possible aspects which may assist to move towards energy neutrality in WWTPs. The sources of energy in wastewater were introduced and different indicators to express the energy consumption were discussed with examples of the operating WWTPs worldwide. Furthermore, the pathways for energy consumption reductions were reviewed including the operational strategies and the novel technological upgrades of the wastewater treatment processes. Then the methods of recovering the potential energy hidden in wastewater were described along with application of renewable energies in WWTPs. The available assessment methods, which may help in analyzing and comparing WWTPs in terms of energy and greenhouse gas emissions were introduced. Eventually, successful case studies on energy self-sufficiency of WWTPs were listed and the innovative projects in this area were presented.     

Effects of phenotype, sex, and diet on plasma lipids in LA/N-cp rats

The LA/N-corpulent (cp) rat is a recently developed congenic strain which exhibits obesity. The effects of phenotype and sex on serum and lipoprotein lipid content were examined in LA/N-cp rats fed either a control or an atherogenic diet high in saturated fat and protein. Obese rats were pair-fed to equivalent lean animals. Results from this study indicate that sex, phenotype, and diet exert significant effects on plasma and lipoprotein cholesterol content. Plasma cholesterol levels were higher in obese compared with lean rats, females than in males, and rats consuming the atherogenic diet compared with the control diet. Plasma and lipoprotein triglyceride levels were significantly increased only in obese compared with lean animals. The increased plasma cholesterol and triglyceride was observed primarily in the chylomicron and very low density lipoprotein fractions. Increased levels of plasma cholesterol were not a result of increased dietary cholesterol absorption or increased liver cholesterol biosynthesis. These data suggest that LA/N-cp rats can serve as a unique rodent model for the study of the interrelationships between hyperlipidemia, obesity, and coronary heart disease.     

Serological characteristics within the genus Desulfovibrio

Antisera were prepared against one strain each of Desulfovibrio desulfuricans, D. vulgaris and D. salexigens. The antisera were tested for cross reactivity against 36 heterologous Desulfovibrio strains by both agglutination titration and by double immunodiffusion precipitin plates.Generally no cross-reaction was demonstrated by agglutination even between heterologous strains of the same species, suggesting that the surface antigens of Desulfovibrio are highly specific. In immunodiffusion plates a single apparently genus-specific surface antigen could be shown to be present in all but two of the strains tested. Although other common precipitin bands showed the presence of some antigens common between heterologous strains these appeared to be randomly distributed among the strains tested, with the exception of one band shown to be generally specific to strains of D. salexigens. With this exception no other precipitin band could be shown to be consistently specific to any other species, nor consistently common to more than one species.     

Real-time RT-PCR expression analysis of chitinase and endoglucanase genes in the three-way interaction between the biocontrol strain Clonostachys rosea IK726, Botrytis cinerea and strawberry

Clonostachys rosea is a well-known biocontrol agent against Botrytis cinerea, the causal agent of gray mold in strawberry. The activity of cell wall-degrading enzymes might play a significant role for successful biocontrol by C. rosea. The expression pattern of four chitinases, and two endoglucanase genes from C. rosea strain IK726 was analyzed using real-time RT-PCR in vitro and in strawberry leaves during interaction with B. cinerea. Specific primers were designed for beta-tubulin genes from C. rosea and B. cinerea, respectively, and a gene encoding a DNA-binding protein (DBP) from strawberry, allowing in situ activity assessment of each fungus in vitro and during their interaction on strawberry leaves. Growth of B. cinerea was inhibited in all pathogen-antagonist interactions while the activity of IK726 was slightly increased. In all in vitro interactions, four of the six genes were upregulated while no change in expression of two endochitinases was measured. In strawberry leaves, the chitinase genes were upregulated 2-12-fold, except one of the endochitinases, whereas no change in expression of the two endoglucanases was measured. The results suggest that three out of four chitinase genes of IK726 are involved in biocontrol on leaves. This is the first example of monitoring of expression of chitinolytic genes in interactions between biocontrol agents and pathogens in plant material.     

Hepatic mechanisms of the Walnut antidiabetic effect in mice

The present study was designed to explore the mechanism of action of walnut (the seed of Juglans regia) leaf and ridge on hepatic glucose metabolism in diabetic mice. Experimental diabetes was induced by intravenous administration of streptozotocin (60 mg/kg)and confirmed with an increase of blood glucose, 90–100% of the control, 72 hours later. Isolated extracts from walnut leaf and ridges were administered in a single effective dose of 400 mg/kg orally. Firstly, blood glucose was determined every 1 hour until 5 hours post administration of extracts. In the second experiment, the liver was surgically removed, 2 hours post treatment of diabetic animals with extracts, homogenized and used for measurement of key enzymes of glycogenolysis (glycogen phosphorylase, GP) and gluconeogenesis (phosphoenolpyruvate carboxykinase, PEPCK). Treatment by both leaf and ridge extracts decreased blood glucose and liver PEPCK activity and increased blood insulin and liver GP activity. It is concluded that walnut is able to lower blood glucose through inhibition of hepatic gluconeogenesis and secretion of pancreatic insulin.     

Microbial transformation of hydrocortisone by Acremonium strictum PTCC 5282

The ability of a genus of cephalosporium-like fungus isolated from soil, Acremonium strictum PTCC 5282, for hydrocortisone biotransformation has been investigated. This potential had not been previously examined. The fermentation yielded 11beta,17beta-dihydroxyandrost-4-en-3-one, 11beta,17alpha,20beta,21-tetrahydroxypregn-4-en-3-one and 21-acetoxy-11beta,17alpha,20-trihydroxypregn-4-en-3-one. Each microbial metabolite was purified and characterized using spectroscopic methods.     

Establishment and in vitro differentiation of a new embryonic stem cell line from human blastocyst

Embryonic stem cells have the ability to remain undifferentiated and proliferate indefinitely in vitro while maintaining the potential to differentiate into derivatives of all three embryonic germ layers. These cells have, therefore, potential for in vitro differentiation studies, gene function, and so on. The aim of this study was to produce a human embryonic stem cell line. An inner cell mass of a human blastocyst was separated and cultured on mouse embryonic fibroblasts in embryonic stem cell medium with related additives. The established line was evaluated by morphology; passaging; freezing and thawing; alkaline phosphatase; Oct-4 expression; anti-surface markers including Tra-1-60 and Tra-1-81; and karyotype and spontaneous differentiation. Differentiated cardiomyocytes and neurons were evaluated by transmission electron microscopy and immunocytochemistry. Here, we report the derivation of a new embryonic stem cell line (Royan H1) from a human blastocyst that remains undifferentiated in morphology during continuous passaging for more than 30 passages, maintains a normal XX karyotype, is viable after freezing and thawing, and expresses alkaline phosphatase, Oct-4, Tra-1-60, and Tra-1-81. These cells remain undifferentiated when grown on mouse embryonic fibroblast feeder layers in the presence or absence of recombinant human leukemia inhibitory factor. Royan H1 cells can differentiate in vitro in the absence of feeder cells and can produce embryoid bodies that can further differentiate into beating cardiomyocytes as well as neurons. These results define Royan H1 cells as a new human embryonic stem cell line.     

Electrochemical studies of DNA immobilization onto the azide-terminated monolayers and its interaction with taxol

A surface modification procedure for the creation of self-assembled monolayers (SAMs) that can be used as a scaffold for double-stranded DNA (dsDNA) incorporation onto the gold surfaces is described. The SAMs of an azidohexane thiol derivative were prepared on the Au electrode and then used for the immobilization of dsDNA. The electrochemical characteristics of dsDNA onto the SAM-modified gold electrode were investigated by cyclic voltammetry and electrochemical impedance spectroscopy, and the surface concentration of dsDNA onto the SAMs surface was estimated. The interaction of dsDNA with the anticancer drug, taxol (paclitaxel), was also studied on the surface of DNA/SAM/Au electrode. The observed decrease in the guanine oxidation peak current was used to monitor the interaction of taxol with DNA. The resulting Langmuir isotherm for taxol binding to DNA at the modified electrode was used to evaluate the binding constant of taxol-DNA. The results obtained supported the groove binding interaction of taxol with DNA. The modified electrode was used as a sensitive sensor for quantification of taxol in human serum sample.