Ethanol production at 45 °C by Kluyveromyces marxianus IMB3 during growth on molasses pre-treated with Amberlite® and non-living biomass

The use of high concentrations of molasses as a fermentation feed-stock for ethanol production is normally precluded by the presence of inhibitory compounds. Use of the thermotolerant, ethanol-producing yeast strain Kluyveromyces marxianus IMB3 in fermentations containing high concentrations of molasses resulted in sub-optimal production of ethanol. The results suggested that this was caused by the presence of inhibitory materials rather than an intolerance to increased concentrations of ethanol. In the current study we describe the pretreatment of molasses preparations with either an Amberlite^® monobed mixed ion-exchange resin or non-living microbial biomass from a local distillery. In the study molasses samples diluted to yield a final sugar concentration of 160?g/l were used as the substrate. Control fermentations using the untreated molasses dilutions yielded a maximum ethanol concentration of 40?g/l, representing 49% of the maximum theoretical yield. Fermentations using molasses samples pre-treated with Amberlite^® or non-living biomass yielded maximum ethanol concentrations of 58 and 54?g/l, representing 71 and 66% of the maximum theoretical yield, respectively. The results suggest that pre-treatment brings about removal of toxic or inhibitory materials from the fermentation feed-stock and we believe that such pre-treatments, particularly using the less expensive non-living biomass preparations may find a role in processes concerned with the commercial production of ethanol from molasses using this microorganism.     

Production of ethanol from molasses at 45 °C using Kluyveromyces marxianus IMB3 immobilized in calcium alginate gels and poly(vinyl alcohol) cryogel

The thermotolerant, ethanol-producing yeast strain Kluyveromyces marxianus IMB3 has been immobilized in calcium alginate gel and poly(vinyl alcohol) cryogel (PVAC) beads. The immobilized preparations were used as biocatalyst in fed-batch reactor systems for prolonged periods. The substrate utilized in each case consisted of sugar cane molasses diluted to yield a sugar load of 140?g/l. During the first cycle the maximum ethanol concentration produced by the alginate system was 57?g/l, representing 80% of the maximum theoretical yield. In the system employing the PVAC-immobilized biocatalyst, ethanol production increased to a maximum of 52–53?g/l, representing 73% of the maximum theoretical yield. In both cases, maximum ethanol concentration was achieved within a 72-hour period. When each system was operated on a fed-batch basis for a prolonged period of time the average ethanol concentrations produced in the alginate- and the PVAC-immobilized systems were 21 and 45?g/l, respectively. The results suggest that the PVAC-based immobilization system may provide a more practical alternative to alginate for the production of ethanol by K. marxianus IMB3 in continuous or semi-continuous fermentation systems.     

Increased expression of costimulatory markers CD134 and CD80 on interleukin-17 producing T cells in patients with systemic lupus erythematosus

Introduction  

There is growing evidence that interleukin 17 (IL-17) producing T cells are involved in the pathogenesis of systemic lupus erythematosus (SLE). Previous studies showed that increased percentages of T-cell subsets expressing the costimulatory molecules CD80 and CD134 are associated with disease activity and renal involvement in SLE. The aim of this study was to investigate the distribution and phenotypical characteristics of IL-17 producing T-cells in SLE, in particular in patients with lupus nephritis, with emphasis on the expression of CD80 and CD134.     

Plant–herbivore interactions in Alaskan arctic tundra change with soil nutrient availability

Herbivores in nutrient‐limited systems such as arctic tundra have been suggested to play a minor role in controlling plant growth simply because they are relatively few in number. However, theory predicts that as net primary productivity (NPP) increases because of greater inputs of nutrients or energy, herbivores may have greater effects on plant growth. This prediction has not been tested in the context of climate warming in arctic tundra, which may increase soil nutrient availability and thus NPP. We examined a long‐term experiment that excluded small and large mammalian herbivores and increased soil nutrients in two arctic Alaskan tundra communities: dry heath (DH) and moist acidic tussock (MAT). In the ninth year of manipulations, we measured weekly growth of three plant species of three growth forms: tussock‐forming graminoid, rhizomatous graminoid, and dwarf deciduous shrub, in each community. All species grew better when fertilized. In DH, this increase in growth was exaggerated when plants were protected from herbivores, confirming that herbivory had a negative effect on plant growth under increased nutrient conditions, but was unimportant under ambient soil conditions. However, in MAT, the importance of herbivory differed among species with fertilization. The tussock‐forming sedge at MAT, Eriophorum vaginatum, grew better and flowered more when fenced under both ambient and amended nutrients compared to plants exposed to herbivores. This species decreases in abundance in long‐term fertilized plots when mammals are present, and our results suggest that herbivory may be accounting for at least some of that loss, in addition to shifts in competitive relationships. Although we only focused on individual plants here rather than the entire community, our results suggest that under the increased soil nutrient conditions expected with continued climate warming in the Arctic, herbivores may become more important in affecting several abundant tundra plant populations, and should not be ignored.     

Greater shrub dominance alters breeding habitat and food resources for migratory songbirds in Alaskan arctic tundra

Climate warming is affecting the Arctic in multiple ways, including via increased dominance of deciduous shrubs. Although many studies have focused on how this vegetation shift is altering nutrient cycling and energy balance, few have explicitly considered effects on tundra fauna, such as the millions of migratory songbirds that breed in northern regions every year. To understand how increasing deciduous shrub dominance may alter breeding songbird habitat, we quantified vegetation and arthropod community characteristics in both graminoid and shrub dominated tundra. We combined measurements of preferred nest site characteristics for Lapland longspurs (Calcarius lapponicus) and Gambel's White‐crowned sparrows (Zonotrichia leucophrys gambelii) with modeled predictions for the distribution of plant community types in the Alaskan arctic foothills region for the year 2050. Lapland longspur nests were found in sedge‐dominated tussock tundra where shrub height does not exceed 20 cm, whereas White‐crowned sparrows nested only under shrubs between 20 cm and 1 m in height, with no preference for shrub species. Shrub canopies had higher canopy‐dwelling arthropod availability (i.e. small flies and spiders) but lower ground‐dwelling arthropod availability (i.e. large spiders and beetles). Since flies are the birds' preferred prey, increasing shrubs may result in a net enhancement in preferred prey availability. Acknowledging the coarse resolution of existing tundra vegetation models, we predict that by 2050 there will be a northward shift in current White‐crowned sparrow habitat range and a 20–60% increase in their preferred habitat extent, while Lapland longspur habitat extent will be equivalently reduced. Our findings can be used to make first approximations of future habitat change for species with similar nesting requirements. However, we contend that as exemplified by this study's findings, existing tundra modeling tools cannot yet simulate the fine‐scale habitat characteristics that are critical to accurately predicting future habitat extent for many wildlife species.     

CCR2 receptor antagonists: optimization of biaryl sulfonamides to increase activity in whole blood

A series of biarylsulfonamides was identified as hCCR2 receptor antagonist but suffered from high plasma protein binding resulting in a >100 fold shift in activity in a functional GTPγS assay run in tandem in the presence and absence of human serum albumin. Introduction of an aryl amide with ethylenediamine linker led to compounds with reduced shifts and improved activity in whole blood.     

Baseline predictors of response and discontinuation of tumor necrosis factor-alpha blocking therapy in ankylosing spondylitis: a prospective longitudinal observational cohort study

Introduction  

Identifying ankylosing spondylitis (AS) patients who are likely to benefit from tumor necrosis factor-alpha (TNF-α) blocking therapy is important, especially in view of the costs and potential side effects of these agents. Recently, the AS Disease Activity Score (ASDAS) has been developed to assess both subjective and objective aspects of AS disease activity. However, data about the predictive value of the ASDAS with respect to clinical response to TNF-α blocking therapy are lacking. The aim of the present study was to identify baseline predictors of response and discontinuation of TNF-α blocking therapy in AS patients in daily clinical practice.     

Advanced glycation endproducts are increased in rheumatoid arthritis patients with controlled disease

Introduction  

Advanced glycation end products (AGEs) are produced and can accumulate during chronic inflammation, as might be present in patients with rheumatoid arthritis (RA). AGEs are involved in the development of cardiovascular disease. The aim of this study is to evaluate whether AGEs are increased in patients with long-standing RA and whether AGE accumulation is related to disease activity, disease severity and measures of (premature) atherosclerosis, such as endothelial activation, endothelial dysfunction and intima media thickness (IMT).     

Expression of collier in the premandibular segment of myriapods: support for the traditional Atelocerata concept or a case of convergence?

Background  

A recent study on expression and function of the ortholog of the Drosophila collier (col) gene in various arthropods including insects, crustaceans and chelicerates suggested a de novo function of col in the development of the appendage-less intercalary segment of insects. However, this assumption was made on the background of the now widely-accepted Pancrustacea hypothesis that hexapods represent an in-group of the crustaceans. It was therefore assumed that the expression of col in myriapods would reflect the ancestral state like in crustaceans and chelicerates, i.e. absence from the premandibular/intercalary segment and hence no function in its formation.