Characterization of the exopolysaccharide produced by Salipiger mucosus A3, a halophilic species belonging to the Alphaproteobacteria, isolated on the Spanish Mediterranean seaboard

We have studied the exopolysaccharide produced by the type strain of Salipiger mucosus, a species of halophilic, EPS-producing (exopolysaccharide-producing) bacterium belonging to the Alphaproteobacteria. The strain, isolated on the Mediterranean seaboard, produced a polysaccharide, mainly during its exponential growth phase but also to a lesser extent during the stationary phase. Culture parameters influenced bacterial growth and EPS production. Yield was always directly related to the quantity of biomass in the culture. The polymer is a heteropolysaccharide with a molecular mass of 250 kDa and its components are glucose (19.7%, w/w), mannose (34%, w/w), galactose (32.9%, w/w) and fucose (13.4%, w/w). Fucose and fucose-rich oligosaccharides have applications in the fields of medicine and cosmetics. The chemical or enzymatic hydrolysis of fucose-rich polysaccharides offers a new efficient way to process fucose. The exopolysaccharide in question produces a solution of very low viscosity that shows pseudoplastic behavior and emulsifying activity on several hydrophobic substrates. It also has a high capacity for binding cations and incorporating considerable quantities of sulfates, this latter feature being very unusual in bacterial polysaccharides.     

Study of the variability of the response to inbreeding for meat production in Merino sheep

Inbreeding is known to affect metric traits. Reduction of additive genetic variance, as well as phenotypic values are its most significant deleterious effects. Yet the emergence of disorders due to recessive gene action constitutes another important aspect. Despite the fact that some effect of inbreeding can be positively used in selection schemes (T oro 1993), breeders are aware of the deleterious effects and try to avoid them. This is particularly true when the selection nucleus and the related population are of small size. Several authors (H agger 1991; V errier et al. 1993; W ray and G oddard 1994) have stressed that the application of sophisticated methods of selection, particularly BLUP-based techniques (H enderson 1973) is to be reconsidered in the light of inbreeding effects. Comparisons of selection methods should therefore account for inbreeding depression (T oro and P jrez -E nciso 1990; Q uinton et al. 1992). Other authors believe that inbreeding depression is not so important, at least in the meat production industry (G ama and S mith 1993) for traits with high heritabilities. Nevertheless, the net effect of inbreeding in a selection programme will depend on the magnitude of the selection response relative to the depression due to the accumulated inbreeding. Depending on whether genetic gain and inbreeding depression compensate for each other, the level of inbreeding of the animals may need to be accounted for in the selection process (K eller et al. 1989; R oehe et al. 1993; K lieve et al. 1994; B risbane and G ibson 1995). On the other hand, the response to inbreeding is not the same for all animals. There is an important range of variation for the estimates of inbreeding depression reported in the literature (e.g. L amberson and T homas 1984). Differences in such a response with respect to identifiable sources of variation should be examined. The objective of this work was to study the relationship between the depression due to inbreeding and litter size of ewes and weights of lambs; and to identify sources of a possible differential response to inbreeding between animals coming from different genetic line, sex, or type of birth.     

Prolonged emersion of Solea senegalensis,Kaup 1858, for its application in transport

This study aimed to determine the maximum time of emersion of Senegalese sole (Solea senegalensis) specimens to form the basis for a dry sole transport procedure. For this purpose, 56 specimens (922.33 ± 29.52 g body weight) were individually placed in polystyrene boxes on a wet cloth, maintaining constant temperature (15°C) during emersion trial. Specimens (n = 7 per group) were sampled for plasma, and mortality was monitored at different points (0, 2, 6, 12, 20, 28, 36 and 44 h of emersion), and several stress (cortisol, glucose and lactate) and metabolic (triglycerides, proteins and amino acids) parameters were assessed. After sampling, each experimental group was placed in recovery tanks for the assessment of delayed mortality and feeding performance after emersion trial. Transport periods longer than 28 h produced high stress level indicated by (i) significant increase in circulating cortisol and lactate and (ii) glucose reserves mobilization. These alterations originated physiological problems during the emersion trial that induced mortality as well as problems for recovering correct feeding performance of specimens. These results suggested that at 15°C for S. senegalensis specimens (around 900 g body weight), a waterless transport is possible without direct or delayed mortality up to 28 h.     

Characterization of an infectious pancreatic necrosis (IPN) virus carrier cell culture with resistance to superinfection with heterologous viruses

A state of persistence of a non susceptible fish cell line with infectious pancreatic necrosis virus (IPNV) was established in vitro by experimental infection. The persistently infected culture showed sustained production of infectious virus and could be continuously passaged for months. A distinct feature of this culture is that only a very small fraction of the cells harbours virus replication, in contrast to other reported IPNV-persistently infected cells from salmonid fish, where nearly all the cells express viral antigens. In spite of the small number of detectable IPNV-infected cells, the carrier culture shows resistance to superinfection with homologous as well as heterologous viruses. Temperature shift-up experiments indicate that viral interference is due to continuous replication of IPNV in the culture. Quantitation of Mx gene expression suggested that the interference phenomenon could be mediated by the activation of the interferon (IFN) system. However, conditioned medium from the IPNV-infected cell cultures only marginally protected other cells against VHSV infection, indicating that other type I IFN-independent mechanism may be underlying the resistance of the persistently infected culture to infection with heterologous viruses. Our study defines a novel in vitro model of IPNV persistence and contributes to the understanding of the widespread distribution of aquabirnaviruses in marine and fresh water environments by establishing a carrier state in non susceptible fish species.     

Soluble and bound phenolic compounds in different Bolivian purple corn ( Zea mays L.) cultivars

In nine Bolivian purple corn ( Zea mays L.) varieties the content of phenolic compounds as well as the anthocyanin composition has been determined. The phenotypes under investigation included four red and five blue varieties (Kulli, Ayzuma, Paru, Tuimuru, Oke, Huaca Songo, Colorado, Huillcaparu, and Checchi). In purple corn, phenolic compounds were highly concentrated in cell walls. Thus, simultaneous determination of soluble and bound-form phenolics is essential for analysis, extraction, and quantification. The present study reports the determination of soluble and insoluble-bound fraction of phenolic compounds by HPLC-DAD and HPLC-ESI-MS(n) in Bolivian purple corn varieties. Enzymatic, thermal, and alkaline hydrolyses were used to obtain the cell wall-linked phenolic compounds. Ferulic acid values ranged from 132.9 to 298.4 mg/100 g, and p-coumaric acid contents varied between 251.8 and 607.5 mg/100 g dry weight (DW), respectively, and were identified as the main nonanthocyanin phenolics. The total content of phenolic compounds ranged from 311.0 to 817.6 mg gallic acid equivalents (GAE)/100 g DW, and the percentage contribution of bound to total phenolics varied from 62.1 to 86.6%. The total monomeric anthocyanin content ranged from 1.9 to 71.7 mg cyanidin-3-glucoside equivalents/100 g DW. Anthocyanin profiles are almost the same among the different samples. Differences are observed only in the relative percentage of each anthocyanin. Cyanidin-3-glucoside and its malonated derivative were detected as major anthocyanins. Several dimalonylated monoglucosides of cyanidin, peonidin, and pelargonidin were present as minor constituents.     

Mouse barley awn (Hordeum murinum) migration induced cystolithiasis in 2 male dogs

Two male dogs were presented with cystic uroliths composed of magnesium ammonium phosphate (struvite). Each had an atypical nidus, a mouse barley awn (Hordeum murinum). To our knowledge, this is the first report of grass awns located in the bladder lumen of dogs. The composition of uroliths and the pathophysiology of grass awn migration to the urinary bladder are discussed.     

Cytoprotective effect of hydroxytyrosyl alkyl ether derivatives after oral administration to rats in a model of glucose-oxygen deprivation in brain slices

This study was designed to determine whether the oral administration of hydroxytyrosol (HT) alkyl ether derivatives has a neuroprotective effect in rats. The animals were treated for 7 days with HT or ethyl, butyl, hexyl, octyl, and dodecyl HT ether. A method of in vitro hypoxia-reoxygenation in brain slices was used. Hexyl, octyl, and dodecyl HT derivatives reduced brain cell death (LDH efflux). Lipid peroxidation and nitrite concentrations were inhibited most by hexyl, octyl, and dodecyl derivatives. Concentrations of 3-nitrotyrosine were reduced by HT butyl, hexyl, octyl, and dodecyl ether derivatives. Interleukin-1β was significantly reduced in brain slices from rats treated with all HT ether derivatives. LDH efflux showed a linear correlation with brain concentrations of lipid peroxides, nitrites plus nitrates, and interleukin 1β. The reduction in oxidative and nitrosative stress and decreased production of pro-inflammatory interleukins may be the basis for the observed neuroprotective effects.     

Organic or conventional dairy farming in northern Spain: Impacts on cow reproductive performance

Organic farming has traditionally given preference to indigenous breeds that are well adapted to local conditions; however, current trends towards increased yields may produce less robust animals with potentially low fertility. The Holstein‐Friesian breed dominates dairy sector, although there is a general concern that these cows may not be well adapted to organic systems. This study aims to evaluate the reproductive performance of organic dairy herds in northern Spain, by comparing organically reared Holstein‐Friesian with their counterparts reared on conventional farms and also with other organically reared breeds and crosses. Reproductive parameters were obtained for individual cows on organic, conventional pasture‐based and conventional zero‐grazing farms. The reproductive performance of Holstein‐Friesian cows was slightly better in organic systems than in pasture‐based conventional systems, but not than in zero‐grazing conventional systems. The comparison of reproductive performance of Holstein‐Friesian from organic and conventional systems and with other organically reared breeds and crosses enabled us to demonstrate that it is not the organic system that constrains the reproductive performance of Holstein‐Friesian, but that the manifestation of oestrus is less marked than in other breeds. Breeding selection considering reproductive traits and appropriate management of oestrous detection would improve the reproductive performance of Holstein‐Friesian cows.