Effect of pH on lipid accumulation by an oleaginous yeast:Rhodotorula glutinis IIP-30

Maximum lipid production (66% w/w dry wt) inRhodotorula glutinis IIP-30 utilizing glucose in a fed-batch fermentation under N-limiting conditions at 30°C, was at pH 4. At pH 3, 5 and 6, the lipid contents were 12%, 48% and 44%, respectively. There was only a small change in the fatty acid profile over the pH range examined, although the ergosterol content decreased by a third as the pH increased.     

Development of a water hyacinth based vermireactor using an epigeic earthworm Eisenia foetida

The aim of this work was to investigate the potential of water hyacinth (WH) spiked with cow dung (CD) into vermicompost. Five vermireactors containing WH and CD in different ratios, were run under laboratory conditions for 147 days. The maximum worm growth was recorded in CD alone. Worms grew and reproduced favourably in 25% WH+75% CD feed mixture. Greater proportion of WH in feed mixture significantly affected the biomass gain, hatchling numbers and numbers of cocoons produced during experiments. In all the vermireactors, there was significant decrease in pH, TOC and C:N ratio, but increase in TKN, TK and TAP at the end. The heavy metals content in the vermicomposts was lower than initial feed mixtures. The results indicated that WH could be potentially useful as raw substrate in vermicomposting if mixed with up to 25% in cow dung (on dry weight basis).     

Production, purification and characterization of thermostable phytase from thermophilic fungus Thermomyces lanuginosus TL-7

Ten different strains of Thermomyces lanuginosus, isolated from composting soils were found to produce phytase when grown on PSM medium. The wild type strain CM was found to produce maximum amount ofphytase (4.33 units/g DW substrate). Culturing T. lanuginosus strain CM on medium containing wheat bran and optimizing other culture conditions (carbon source, media type, nitrogen source, level of nitrogen, temperature, pH, inoculum age, inoculum level and moisture), increased the phytase yield to 13.26 units/g substrate. This culture was further subjected to UV mutagenesis for developing phytase hyperproducing mutants. The mutant (TL-7) showed 2.29-fold increase in phytase activity as compared to the parental strain. Employing Box-Behnken factor factorial design of response surface methodology resulted in optimized phytase production (32.19 units/g of substrate) by mutant TL-7. A simple two-step purification (40.75-folds) ofphytase from mutant TL-7 was achieved by anion exchange and gel filtration chromatography. The purified phytase (approximately 54 kDa) was characterized to be optimally active at pH 5.0 and temperature 70 degrees C, though the enzyme showed approximately 70% activity over a wide pH and temperature range (2.0-10.0 and 30-90 degrees C, respectively). The phytase showed broad substrate specificity with activity against sodium phytate, ADP and riboflavin phosphate. The phytase from T. lanuginosus was thermoacidstable as it showed up to 70% residual activity after exposure to 70 degrees C at pH 3.0 for 120 min. The enzyme showed Km 4.55 microM and Vmax 0.833 microM/min/mg against sodium phytate as substrate.     

Pentoxifylline attenuates cardiac dysfunction and reduces TNF-alpha level in ischemic-reperfused heart

Although pentoxifylline (PTXF), a phosphodiesterase inhibitor, has been reported to exert beneficial effects in cardiac bypass surgery, its effect and mechanisms against ischemia-reperfusion (I/R) injury in heart are poorly understood. Because I/R is known to increase the level of tumor necrosis factor (TNF)-alpha in myocardium and PTXF has been shown to depress the production of TNF-alpha in failing heart, this study examined the hypothesis that PTXF may attenuate cardiac dysfunction and reduce TNF-alpha content in I/R heart. For this purpose, isolated rat hearts were subjected to global ischemia for 30 min followed by reperfusion for 2-30 min. Although cardiac dysfunction due to ischemia was not affected, the recovery of heart function upon reperfusion was markedly improved by PTXF treatment. This cardioprotective effect of PTXF was dose dependent; maximal effect was seen at a concentration of 125 microM. TNF-alpha, nuclear factor-kappaB (NF-kappaB), and phosphorylated NF-kappaB contents were decreased in ischemic heart but were markedly increased within 2 min of starting reperfusion. The ratio of cytosolic-to-homogenate NF-kappaB was decreased, whereas the ratio of particulate-to-homogenate NF-kappaB was increased in I/R hearts. These changes in TNF-alpha and NF-kappaB protein contents as well as in NF-kappaB redistribution due to I/R were significantly attenuated by PTXF treatment. The results of this study indicate that the cardioprotective effects of PTXF against I/R injury may be due to reductions in the activation of NF-kappaB and the production of TNF-alpha content.     

Sarcoplasmic reticulum Ca2+ transport and gene expression in congestive heart failure are modified by imidapril treatment

This study was designed to test the hypothesis that blockade of the renin-angiotensin system improves cardiac function in congestive heart failure by preventing changes in gene expression of sarcoplasmic reticulum (SR) proteins. We employed rats with myocardial infarction (MI) to examine effects of an angiotensin-converting enzyme inhibitor, imidapril, on SR Ca(2+) transport, protein content, and gene expression. Imidapril (1 mg.kg(-1).day(-1)) was given for 4 wk starting 3 wk after coronary artery occlusion. Infarcted rats exhibited a fourfold increase in left ventricular end-diastolic pressure, whereas rates of pressure development and decay were decreased by 60 and 55%, respectively. SR Ca(2+) uptake and Ca(2+) pump ATPase, as well as Ca(2+) release and ryanodine receptor binding activities, were depressed in the failing hearts; protein content and mRNA levels for Ca(2+) pump ATPase, phospholamban, and ryanodine receptor were also decreased by approximately 55-65%. Imidapril treatment of infarcted animals improved cardiac performance and attenuated alterations in SR Ca(2+) pump and Ca(2+) release activities. Changes in protein content and mRNA levels for SR Ca(2+) pump ATPase, phospholamban, and ryanodine receptor were also prevented by imidapril treatment. Beneficial effects of imidapril on cardiac function and SR Ca(2+) transport were not only seen at different intervals of MI but were also simulated by another angiotensin-converting enzyme inhibitor, enalapril, and an ANG II receptor antagonist, losartan. These results suggest that blockade of the renin-angiotensin system may increase the abundance of mRNA for SR proteins and, thus, may prevent the depression in SR Ca(2+) transport and improve cardiac function in congestive heart failure due to MI.     

Sorghum straw for xylanase hyper-production by Thermomyces lanuginosus (D2W3) under solid-state fermentation

This paper reports the production of very high levels of cellulase free xylanase and associated hemicellulases by an indigenous thermophilic isolate of Thermomyces lanuginosus (D(2)W(3)) using solid-state fermentation. Sorghum straw, an inexpensive and abundant source of carbon supported maximal xylanase activity (11,855 units/g dry substrate). Culturing T. lanuginosus D(2)W(3) on sorghum straw and optimizing other culture conditions (media types, particle size of carbon source, inoculum level, inoculum age and additives), yielded increased levels of xylanase (39,726 units/g dry substrate). Further optimization of enzyme production was carried out using Box-Behnken design of experiments with three independent variables (inoculum level, glycerol and ammonium sulphate concentrations) which resulted in very high levels of xylanase, 48,000+/-1774 units/g dry substrate, and 2.6+/-0.2, 13.4+/-0.56, 68+/-1.7, 1.4+/-0.08, 1.2+/-0.05 (units/g dry substrate) of beta-xylosidase, alpha-galactosidase, pectinase, beta-mannosidase and alpha-L-arabinofuranosidase, respectively.     

Short-term zinc deficiency in diet induces increased oxidative stress in testes and epididymis of rats

In order to determine the effects of Zinc deficient diet on oxidative stress in testis and epididymis, various parameters viz: total proteins, lipid peroxidation, hydroperoxides, antioxidant capacity and enzymatic activities are evaluated in rats fed on zinc deficient diet for 2, 4 and 6 weeks. Total proteins, water and lipid solouble antioxidant capacity decreased while lipid peroxidation (TBARS) and hydroperoxides concentration increased in testes, caput and cauda epididymis except in 2ZD (testes) where hydroperoxides revealed a significant decrease. GSH decreased in testes and caput and cauda epididymis. GPx and gamma-GT activities increased in testes and caput and cauda epididymis of zinc deficient rats. Further, GST increased in testes but exhibited decreases after 2 and 4 weeks and an increase after 6 weeks in caput and cauda epididymis of zinc deficient rats. GR activities decreased in testes but it increased in caput and cauda epididymis of zinc deficient rats. Thus, zinc deprivation results in increased sensitivity to oxidative stress. All these may have been as a consequence of increased ROS generation and/or decreased zinc dependent antioxidant processes.     

Pharmacological basis of different targets for the treatment of atherosclerosis

The development of atherosclerotic plaque is a highly regulated and complex process which occurs as a result of structural and functional alterations in endothelial cells, smooth muscle cells (SMCs), monocytes/macrophages, T-lymphocytes and platelets. The plaque formation in the coronary arteries or rupture of the plaque in the peripheral vasculature in latter stages of atherosclerosis triggers the onset of acute ischemic events involving myocardium. Although lipid lowering with statins has been established as an important therapy for the treatment of atherosclerosis, partially beneficial effects of statins beyond decreasing lipid levels has shifted the focus to develop newer drugs that can affect directly the process of atherosclerosis. Blockade of renin angiotensin system, augmentation of nitric oxide availability, reduction of Ca(2+) influx, prevention of oxidative stress as well as attenuation of inflammation, platelet activation and SMC proliferation have been recognized as targets for drug treatment to control the development, progression and management of atherosclerosis. A major challenge for future drug development is to formulate a combination therapy affecting different targets to improve the treatment of atherosclerosis.     

Masting by Betula-species; applying the resource budget model to north European data sets

Masting, the intermittent production of large crops of flowers by a plant population, is a common feature among trees in boreal and temperate forests. The pollen of many broadleaved trees causes allergic diseases, which are major causes of increasing health-care costs in industrialised countries. As the prevalence and severity of allergic diseases are connected with the concentrations of airborne pollen, an universal model predicting the intensity of the coming flowering would be a valuable tool for pollen information services, and ultimately for allergic people and allergologists. We investigated whether a resource budget model created in Japan explains the fluctuations in the annual pollen sums of Betula-species in north European data sets (10–12 years at 4 sites, 20 years at 10 sites). Using the shorter data sets, the model explained 76–92% of the annual fluctuations at five study sites. Using the 20-year data set, the percentage for southern Finland was much lower, only 48%, compared with the 85% of the 12-year data set. The annual pollen sums have been higher during the 1990s than in the 1980s, which may explain the ineffectiveness of the model, while applied to the 20-year data set. Our results support the resource budget model: the masting of birch species is regulated by weather factors together with the system of resource allocation among years. The model can serve pollen information service. However, only the 10 most recent years should be used to avoid interference from trends in changing vegetation and/or climate.