Protease, peptidase and esterase activities by lactobacilli and yeast isolates from Feta cheese brine

Aims: The study of peptidase, esterase and caseinolytic activity of Lactobacillus paracasei subsp. paracasei, Debaryomyces hansenii and Sacchromyces cerevisiae isolates from Feta cheese brine. Methods and Results: Cell-free extracts from four strains of Lact. paracasei subsp. paracasei, four strains of D. hansenii and three strains of S. cerevisiae, isolated from Feta cheese brine were tested for their proteolytic and esterase enzyme activities. Lactobacillus paracasei subsp. paracasei strains had intracellular aminopeptidase, dipeptidyl aminopeptidase, dipeptidase, endopeptidase and carboxypeptidase activities. Esterases were detected in three of four strains of lactobacilli and their activities were smaller with higher molecular weight fatty acids. The strains of yeasts did not exhibit endopeptidase as well as dipeptidase activities except on Pro-Leu. Their intracellular proteolytic activity was higher than that of lactobacilli. Esterases from yeasts preferentially degraded short chain fatty acids. Lactobacilli degraded preferentially beta-casein. Caseinolytic activity of yeasts was higher than that of lactobacilli. Conclusions: The results suggest that Lact. paracasei subsp. paracasei and yeasts may contribute to the development of flavour in Feta cheese. Significance and impact of the Study: Selected strains could be used as adjunct starters to make high quality Feta cheese.

Regulation of cell cycle and stress responses to hydrostatic pressure in fission yeast

We have investigated the cellular responses to hydrostatic pressure by using the fission yeast Schizosaccharomyces pombe as a model system. Exposure to sublethal levels of hydrostatic pressure resulted in G2 cell cycle delay. This delay resulted from Cdc2 tyrosine-15 (Y-15) phosphorylation, and it was abrogated by simultaneous disruption of the Cdc2 kinase regulators Cdc25 and Wee1. However, cell cycle delay was independent of the DNA damage, cytokinesis, and cell size checkpoints, suggesting a novel mechanism of Cdc2-Y15 phosphorylation in response to hydrostatic pressure. Spc1/Sty1 mitogen-activated protein (MAP) kinase, a conserved member of the eukaryotic stress-activated p38, mitogen-activated protein (MAP) kinase family, was rapidly activated after pressure stress, and it was required for cell cycle recovery under these conditions, in part through promoting polo kinase (Plo1) phosphorylation on serine 402. Moreover, the Spc1 MAP kinase pathway played a key role in maintaining cell viability under hydrostatic pressure stress through the bZip transcription factor, Atf1. Further analysis revealed that prestressing cells with heat increased barotolerance, suggesting adaptational cross-talk between these stress responses. These findings provide new insight into eukaryotic homeostasis after exposure to pressure stress.

A specific group of genes respond to cold dehydration stress in cut Alstroemeria flowers whereas ambient dehydration stress accelerates developmental senescence expression patterns

Petal development and senescence entails a normally irreversible process. It starts with petal expansion and pigment production, and ends with nutrient remobilization and ultimately cell death. In many species this is accompanied by petal abscission. Post-harvest stress is an important factor in limiting petal longevity in cut flowers and accelerates some of the processes of senescence such as petal wilting and abscission. However, some of the effects of moderate stress in young flowers are reversible with appropriate treatments. Transcriptomic studies have shown that distinct gene sets are expressed during petal development and senescence. Despite this, the overlap in gene expression between developmental and stress-induced senescence in petals has not been fully investigated in any species. Here a custom-made cDNA microarray from Alstroemeria petals was used to investigate the overlap in gene expression between developmental changes (bud to first sign of senescence) and typical post-harvest stress treatments. Young flowers were stressed by cold or ambient temperatures without water followed by a recovery and rehydration period. Stressed flowers were still at the bud stage after stress treatments. Microarray analysis showed that ambient dehydration stress accelerates many of the changes in gene expression patterns that would normally occur during developmental senescence. However, a higher proportion of gene expression changes in response to cold stress were specific to this stimulus and not senescence related. The expression of 21 transcription factors was characterized, showing that overlapping sets of regulatory genes are activated during developmental senescence and by different stresses.

Genetic analysis of heat tolerance at anthesis in rice

Genetic analysis of heat tolerance will help breeders produce rice (Oryza sativa L.) varieties adapted to future climates. An F6 population of 181 recombinant inbred lines of Bala (tolerant) × Azucena (susceptible) was screened for heat tolerance at anthesis by measuring spikelet fertility at 30°C (control) and 38°C (high temperature) in experiments conducted in the Philippines and the United Kingdom. The parents varied significantly for absolute spikelet fertility under control (79–87%) and at high temperature (2.9–47.1%), and for relative spikelet fertility (high temperature/control) at high temperature (3.7–54.9%). There was no correlation between spikelet fertility in control and high-temperature conditions and no common quantitative trait loci (QTLs) were identified. Two QTLs for spikelet fertility under control conditions were identified on chromosomes 2 and 4. Eight QTLs for spikelet fertility under high-temperature conditions were identified on chromosomes 1, 2, 3, 8, 10, and 11. The most significant heat-responsive QTL, contributed by Bala and explaining up to 18% of the phenotypic variation, was identified on chromosome 1 (38.35 mega base pairs on the rice physical genome map). This QTL was also found to influence plant height, explaining 36.6% of the phenotypic variation. A comparison with other studies of abiotic (drought, cold, salinity) stresses showed QTLs at similar positions on chromosomes 1, 3, 8, and 10, suggesting common underlying stress-responsive regions of the genome.

Effect of dietary supplementation with selenium-enriched yeast or sodium selenite on selenium tissue distribution and meat quality in commercial-line turkeys

The objective of this study was to determine the concentration of total selenium (Se) and proportions of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in the tissues of female turkeys offered diets containing graded additions of selenized-enriched yeast (SY), or sodium selenite (SS). Oxidative stability and tissue glutathione peroxidase (GSH-Px) activity of breast and thigh muscle were assessed at 0 and 10 days post mortem. A total of 216 female turkey poults were enrolled in the study. A total of 24 birds were euthanized at the start of the study and samples of blood, breast, thigh, heart, liver, kidney and gizzard were collected for determination of total Se. Remaining birds were blocked by live weight and randomly allocated to one of four dietary treatments(n548 birds/treatment) that differed either in Se source (SY v. SS) or dose (Con [0.2 mg/kg total Se], SY-L and SS-L [0.3mg/kg total Se as SY and SS, respectively] and SY-H [0.45mg total Se/kg]). Following 42 and 84 days of treatment 24 birds per treatment were euthanized and samples of blood, breast, thigh, heart, liver, kidney and gizzard were retained for determination of total Se and the proportion of total Se comprised as SeMet or SeCys. Whole blood GSH-Px activity was determined at each time point. Tissue GSH-Px activity and thiobarbituric acid reactive substances were determined in breast and thigh tissue at the end of the study. There were responses (P,0.001) in all tissues to the graded addition of dietary Se, although rates of accumulation were highest in birds offered SY. There were notable differences between tissue types and treatments in the distribution of SeMet and SeCys, and the activity of tissue and erythrocyte GSH-Px (P,0.05). SeCys was the predominant form of Se in visceral tissue and SeMet the predominant form in breast tissue. SeCys contents were greater in thigh when compared with breast tissue. Muscle tissue GSH-Px activities mirrored SeCys contents. Despite treatment differences in tissue GSH-Px activity, there were no effects of treatment on any meat quality parameter.

Flight to quality? An investigation of the attributes of sold properties in hot and cold markets

This paper uses sales transaction data in order to examine whether flight from risk phenomena took place in the US office property investment market during the financial crisis of 2007-2009. The effect of the crisis on the pricing of property quality attributes, mainly summarized by the class category of each building, is investigated. In addition, the paper examines how turnover levels were affected by the market downturn and whether there were significant variations between different real estate quality types. The results of the hedonic regression models suggest that the price spread between Class, A, B and C grew significantly during the downturn. We also find that property attributes such as size, height and age are priced significantly different in ‘hot’ and ‘cold’ markets.

The solar influence on the probability of relatively cold UK winters in the future

Recent research has suggested that relatively cold UK winters are more common when solar activity is low (Lockwood et al 2010 Environ. Res. Lett. 5 024001). Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century (Lockwood 2010 Proc. R. Soc. A 466 303–29) and records of past solar variations inferred from cosmogenic isotopes (Abreu et al 2008 Geophys. Res. Lett. 35 L20109) and geomagnetic activity data (Lockwood et al 2009 Astrophys. J. 700 937–44) suggest that the current grand solar maximum is coming to an end and hence that solar activity can be expected to continue to decline. Combining cosmogenic isotope data with the long record of temperatures measured in central England, we estimate how solar change could influence the probability in the future of further UK winters that are cold, relative to the hemispheric mean temperature, if all other factors remain constant. Global warming is taken into account only through the detrending using mean hemispheric temperatures. We show that some predictive skill may be obtained by including the solar effect.

Simulating dynamic crop growth with an adapted land surface model – JULES-SUCROS: model development and validation

The increasing demand for ecosystem services, in conjunction with climate change, is expected to signif- icantly alter terrestrial ecosystems. In order to evaluate the sustainability of land and water resources, there is a need for a better understanding of the relationships between crop production, land surface characteristics and the energy and water cycles. These relationships are analysed using the Joint UK Land Environment Simulator (JULES). JULES includes the full hydrological cycle and vegetation effects on the energy, water, and carbon fluxes. However, this model currently only simulates land surface processes in natural ecosystems. An adapted version of JULES for agricultural ecosystems, called JULES-SUCROS has therefore been developed. In addition to overall model improvements, JULES-SUCROS includes a dynamic crop growth structure that fully fits within and builds upon the biogeochemical modelling framework for natural vegetation. Specific agro-ecosystem features such as the development of yield-bearing organs and the phenological cycle from sowing till harvest have been included in the model. This paper describes the structure of JULES-SUCROS and evaluates the fluxes simulated with this model against FLUXNET measurements at 6 European sites. We show that JULES-SUCROS significantly improves the correlation between simulated and observed fluxes over cropland and captures well the spatial and temporal vari- ability of the growth conditions in Europe. Simulations with JULES-SUCROS highlight the importance of vegetation structure and phenology, and the impact they have on land–atmosphere interactions.

Building a left coast: the legacy of the California Popular Front and the challenge to Cold War liberalism in the post-world war two era

The Cold War in the late 1940s blunted attempts by the Truman administration to extend the scope of government in areas such as health care and civil rights. In California, the combined weakness of the Democratic Party in electoral politics and the importance of fellow travelers and communists in state liberal politics made the problem of how to advance the left at a time of heightened Cold War tensions particularly acute. Yet by the early 1960s a new generation of liberal politicians had gained political power in the Golden State and was constructing a greatly expanded welfare system as a way of cementing their hold on power. In this article I argue that the New Politics of the 1970s, shaped nationally by Vietnam and by the social upheavals of the 1960s over questions of race, gender, sexuality, and economic rights, possessed particular power in California because many activists drew on the longer-term experiences of a liberal politics receptive to earlier anti-Cold War struggles. A desire to use political involvement as a form of social networking had given California a strong Popular Front, and in some respects the power of new liberalism was an offspring of those earlier battles.

NATO's security discourse after the Cold War: representing the West

This book provides a critical investigation into the discursive processes through which the North Atlantic Treaty Organisation (NATO)reproduced a geopolitical order after the end of the Cold War and the demise of its constitutive enemy, the Soviet Union.