The surface-localised α-enolase of Mycoplasma suis is an adhesion protein

Mycoplasma suis belongs to the haemotrophic mycoplasmas which colonise red blood cells of a wide range of vertebrates. Adhesion to red blood cells is the crucial step in the unique lifecycle of M. suis. Due to the lack of a cultivation system, identification of adhesion structures has been difficult. So far, only one adhesion protein, i.e. MSG1 was identified. In order to determine further adhesion molecules of M. suis, we screened genomic M. suis libraries and performed Southern blot hybridisation analyses of genomic M. suis DNA. The α-enolase of M. suis was identified and analysed genetically and functionally. The encoding gene has 1623 bp in size. The deduced amino acid sequence showed an overall identity of 59.6-65.1% to α-enolases of other pathogenic mycoplasmas. The 540 aa M. suis α-enolase displays a size extension of about 90 aa in comparison to α-enolases of other mycoplasmas. Recombinant α-enolase expressed in Escherichia coli demonstrated immunogenicity in experimentally infected pigs. Immunoblot, confocal laser scanning microscopy and immune electron microscopy analysis using antibodies against recombinant α-enolase, indicate the membrane and surface localisation of native α-enolase in M. suis, though no typical signal sequences exist. Furthermore, we showed that recombinant α-enolase binds to porcine erythrocyte lysate in a dose-dependent manner. E. coli transformants which express α-enolase on their surface acquire the ability to adhere to porcine red blood cells. In conclusion, our observations indicate that α-enolase could be involved in the adhesion of M. suis to porcine red blood cells.     

Regional impacts of abolishing direct payments: An integrated analysis in four European regions

The direct payment system of the Common Agricultural Policy (CAP) provides income transfers to European farmers. Recently, several countries including England and Sweden have advocated the elimination of direct payments after 2013. The extent to which an elimination of direct payments would affect the land use dynamics in Europe including impacts on structural change and the environment has not been addressed in the existing literature. In this paper, we combine participatory methods, to analyze regional preferences for functions and effects of agriculture, and farm-level modeling, to assess the impacts of such a policy change on farm structures and land use intensities in four European regions located in Germany, Denmark, Italy and Poland, each with different socio-economic and biophysical characteristics. In each region, the entire farm population consisting of different farm types with different production orientations and land management types was modeled under the presence and absence of direct payments using a combination of agent-based and bio-economic modeling. We found that the initial characteristics of the regions, such as the historical farm structure and regional site conditions, greatly influence the impact of direct support elimination and cause regionally different development trends. The results for the four regions were summarized in four specific storylines that emphasize how much the diversity of European regions matters for future policy decisions. An explicitly regional focus is, therefore, argued to be crucial to complement future policy analysis.     

Changes in oil content,lipid class and fatty acid composition of the microalga Chaetoceros calcitrans over different phases of batch culture

The diatom Chaetoceros calcitrans is a microalgal species used as food for larva in aquaculture for many species worldwide. Chaetoceros calcitrans is an important source of omega 3 long chain (C ≥ 20) polyunsaturated fatty acids (n‐3 LC PUFA), chiefly eicosapentaenoic acid (EPA, 20:5n‐3). This article reports lipid content, lipid class composition and fatty acid profiles of each lipid class during the growth cycle of batch cultures of C. calcitrans. Total lipid content and the concentration of neutral lipid were highest in the late stationary growth phase (day 12). However, the amount of EPA was highest during the logarithmic growth phase (1.24 pg/cell on day 4). EPA was initially concentrated in the glycolipid fraction, but this fraction decreased during logarithmic growth, coinciding with the increase in neutral lipid. Docosahexaenoic acid (22:6n‐3, DHA) (0.91 pg/cell) was reported as a major fatty acid (>10 mg/100 g) in all lipid classes on day 1. DHA was depleted quickly from the neutral lipid and glycolipid classes, but at a slower rate from the polar lipid fraction. This work confirms that C. calcitrans is a good source of lipid, in particular EPA, for larval and adult filter feeders in aquaculture.     

A retrospective study on the prevalence of primary cataracts in two pedigrees from the German population of English Cocker Spaniels

Objective  Two pedigrees from the German English Cocker Spaniel population are presented to illustrate the familial occurrence of primary cataract (CAT) in single- and multicolored English Cocker Spaniels. The aim was to characterize similarities and differences in the prevalence and formation of CAT in these separately bred color variants of English Cocker Spaniels.
Materials  The study was based on the veterinary records for presumed inherited eye diseases of 1232 English Cocker Spaniels which were provided by the German panel of the European Eye Scheme for diagnosis of inherited eye diseases in animals (DOK, < http://www.dok-vet.de >). Data included information on 615 single-colored and 617 multicolored English Cocker Spaniels.
Results  CAT was diagnosed in 92 (14.96%) of the single-colored and 34 (5.51%) of the multicolored English Cocker Spaniels. The pedigree of the single-colored English Cocker Spaniels included 40 ophthalmologically examined dogs with 18 unaffected and 22 affected dogs. The pedigree of the multicolored English Cocker Spaniels contained 16 ophthalmologically examined dogs with 11 unaffected and five affected dogs.
Conclusions  In both color variants of the English Cocker Spaniels different forms of primary CAT with respect to location within the lens occurred among close relatives. Appearance of CAT was very heterogeneous without obvious sex differences. The sample pedigrees do not support the assumption of familial segregation of specific forms of primary CAT in English Cocker Spaniels.     

Using a multi-stakeholder approach to increase value for traditional agroforestry systems: the case of baobab (Adansonia digitata L.) in Kilifi,Kenya

Agroforestry Systems - The baobab tree (Adansonia digitata L.) is an integral component of many dryland farming systems in sub-Sahara Africa. Such traditional agroforestry systems can foster a...     

Soil tillage and herbicide applications in pea: arbuscular mycorrhizal fungi,plant growth and nutrient concentration respond differently

ABSTRACT

We conducted a field- and pot experiment with peas to investigate the impact of soil tillage and herbicide applications on arbuscular mycorrhizal fungi (AMF), plant growth, phosphorus concentrations, C:N ratio in plants and yield. The field study was carried out in a long-term soil tillage experiment where four tillage treatments have been compared. Field soil from the experimental plots were used for the pot experiment. AMF were not affected by herbicide (MCPB) application, neither in the field nor in the pot experiments. However, AMF root colonization was enhanced by reduced tillage, minimum tillage and no-tillage practices, compared to conventional tillage. In the pot experiment, plant growth and nodulation of pea roots was negatively affected by the high herbicide dosage. In the field experiment neither tillage nor herbicide treatment exert specific effects on root growth parameters, phosphorus concentrations, C:N ratio and plant dry matter. This work demonstrates that an appropriate herbicide usage coupled with conservation soil tillage techniques can favour AMF root colonization and benefit plant growth.

Abbreviations: AMF: arbuscular mycorrhizal fungi; CT: conventional tillage; RT: reduced tillage; MT: minimum tillage; NT: no tillage; P: Phosphorus; C:N ratio: carbon:nitrogen ratio     

Methane dynamics of landfill cover soils and aspects of their classification

The methane dynamics of soils covering a landfill in Oldenburg, Lower Saxony, was investigated in 1996. The methane concentration was often < 20 nmol (dry g)^?1 within the cover layer and up to 9950 nmol (dry g)^?1 within the refuse body. The methane production rates correlated positively with the methane concentrations and were mostly < 10 nmol (dry g)^?1 d^?1 within the cover layer and up to 1090 nmol (dry g)^_1 d^_1 within the refuse body. The methane oxidation rates varied between 38.0–2310 nmol (dry g)^?1 d^?1. The methane emission rates showed values of up to 574 mol m^?2 h^?1, but in two cases no emission of methane was found. The data indicate that the methano-genesis of the deep refuse layers did not substantially affect the methane behaviour of the upper soil sections. It is likely that the emission of methane from landfills can be reduced by thick well aerated cover layers. The term “Reduktosol” for landfill soils is critically discussed.     

Development of a 13C-glycocholic acid blood test to assess bacterial metabolic activity of the small intestine in canines

The objectives of this study were to establish optimal doses of 13C-glycocolic acid (GCA) for use in a GCA blood test as a marker for canine small intestinal bacterial metabolic activity. Four doses of GCA were administered orally to 8 healthy dogs. Blood samples were collected at various time points up to 480 min. The percent dose/min of 13C administered as GCA (PCD) and cumulative PCD (CUMPCD) were determined by fractional mass spectrometry. No dog showed any clinically obvious side effects. Doses of 1 and 2 mg/kg of bodyweight (BW) led to a significant increase in PCD and CUMPCD (P < 0.001). The mean CUMPCD was significantly higher for the 1 mg/kg BW dose compared with the 2 and 4 mg/kg BW doses (P < 0.05). Administration of 1 mg/kg BW of 13C-glycocholic acid led to an increase in CUMPCD over baseline in gas extracted from blood samples and appears to be the best parameter to evaluate for future clinical studies.