Pediococcus acidilactici isolated from the rumen of lambs with rumen acidosis, 16S rRNA identification and sensibility to monensin and lasalocid.

A lactic-acid producing bacterium was isolated from the rumen of lambs with rumen acidosis. The cells were gram-positive, nonmotile, nonsporing, catalase negative spherical, 1.5-2.0 µm in diameter, and occur in pairs and tetrads. Analysis of 16S ribosomal RNA indicated that the rumen bacterium was a strain of Pediococcus acidilactici with 99% of nucleotide homology. This bacterium was sensible to monensin and lasalocid at the unique dose tested of 300 ppm. The concentration of lactic acid and DM degradation decreased (P<0.05) when monensin or lasalocid were added to the culture media after 24, 48 and 72 h of incubation. In contrast, total VFA concentration and pH were higher (P<0.05) in the culture media added with the ionophores. Up to now S. bovis is considered the main ruminal bacterium related with rumen acidosis, but the importance of P. acidilactici should be also reconsidered in experimental studies focused on the control rumen acidosis.

Molecular identification and characterization of wine yeasts isolated from Tenerife (Canary Island, Spain).

AIMS: The present study was aimed at the identification, differentiation and characterization of indigenous yeasts isolated from Tenerife vineyards (viticulture region that has never been characterized before). Microbiota were studied from 14 samples taken during fermentations carried out in the 2002 vintage, from 11 wineries belonging to five wine regions on Tenerife Island. METHODS AND RESULTS: Yeasts' strains were identified and characterized through restriction analysis of the 5.8S-internal transcribed spacer region and the mitochondrial DNA. At the beginning of alcoholic fermentation, 26 yeast species were found, where 14 species were present in significant frequencies in only one sample. Likewise, the Saccharomyces cerevisiae strains isolated are very specific, as they were only present in one wine region. CONCLUSIONS: There were isolated specific yeasts from each region on Tenerife Island. The founded yeasts may be responsible for distinctive and interesting properties of the studied wines. SIGNIFICANCE AND IMPACT OF THE STUDY: This study forms part of an extensive taxonomic survey within the ecological framework of vineyards in Tenerife. This investigation is an essential step towards the preservation and exploitation of the hidden oenological potential of the untapped wealth of yeast biodiversity in the grape growing regions of this island. The results obtained demonstrate the value of using molecular genetic methods in taxonomic and ecological surveys. The results also shed some light on the ecology and oenological potential of S. cerevisiae strains isolated from this unique environment.

Effect of exogenous fibrolytic enzyme on ruminal fermentation and digestibility of alfalfa and rye-grass hay fed to lambs.

This experiment was carried out to study the effect of a directly fed exogenous fibrolytic enzyme on intake and digestion of DM, OM, protein, NDF, ADF, and hemicellulose of alfalfa and ryegrass hay by sheep. Four diets were randomly assigned to four ruminally cannulated lambs using a 4 x 4 Latin square design, repeated in time, with a factorial arrangement (2 x 2) of diets: 1) alfalfa hay; 2) alfalfa hay + exogenous fibrolytic enzymes (enzyme); 3) ryegrass hay; and 4) ryegrass hay + enzyme. Lambs consumed more DM and OM from alfalfa than from ryegrass hay (P < 0.001). The ADF intake was not different between the hays, but NDF intake was lower for alfalfa (P < 0.001). For both hays, the enzyme increased intake of DM (P < 0.01), as well as OM and CP (P < 0.05); however, NDF and ADF intake were not changed. Alfalfa hay had higher apparent digestibility of DM, OM, and CP (P < 0.001), but lower digestibility for NDF, ADF, and hemicellulose. The enzyme increased apparent digestibility of CP, hemicellulose (P < 0.05), and NDF (P < 0.10) for alfalfa. Also, for both hays, the enzyme improved N balance because lambs retained more N (P < 0.05). The enzyme increased (P < 0.05) total VFA concentration (3 and 6 h) for both hays. Results from this trial indicate that directly fed exogenous fibrolytic enzymes may change ruminal fermentation, intake, and digestibility of forages with different nutritive value.

The effects of chemical treatment of whole canola seed on lipid and protein digestion by steers.

Five Angus x Simmental steers (average BW 259 kg) cannulated in the rumen, proximal duodenum, and terminal ileum were fed five diets in a 5 x 5 Latin square design. Experimental periods were 14 d in length, with 10 d of diet adaptation and 4 d of sample collection. The basal diet contained (percentage of diet DM) ammoniated corn cobs (50%), alfalfa hay (22%), cornstarch grits (13%), corn (6.7%), cane molasses (5%), and urea (1.25%). Three canola seed-containing diets and a diet containing Ca salts of long-chain fatty acids (Ca-LCFA) were formulated by replacing cornstarch grits from the basal diet with the test feedstuffs. Whole canola seed untreated, crushed, or treated with a caustic alkaline solution and an oxidant were included at 10% of diet DM. The Ca-LCFA diet contained (percentage of diet DM) canola meal (5%) and Megalac (5%). Diets containing untreated, crushed, and treated canola seed and Ca-LCFA contained, on average, 5.6% more total fatty acids than the basal diet. Steers were fed 5.3 kg DM/d (2.05% of initial BW) in 12 equal portions (every 2 h). Ruminal fermentation characteristics and digestibilities of OM, GE, N, NDF, and ADF were unaffected (P > .05) by diet. Biohydrogenation of total 18-carbon unsaturated fatty acids was greater (P < .05) for steers fed the crushed canola seed-containing diet (72.0%) than for steers fed the untreated (27.9%) and treated (38.6%) canola seed-containing diets. Digestibility of total 18-carbon fatty acids in the small intestine was greater for steers fed the crushed canola seed (58.9% of duodenal flow) rather than the untreated canola seed (28.4% of duodenal flow) and intermediate for steers fed the treated canola seed (47.0% of duodenal flow). Chemical treatment of whole canola seed may be a viable method for the postruminal delivery of intestinally available unsaturated fatty acids to ruminants.

High serum prolactin levels in asymptomatic HIV-infected patients and in patients with acquired immunodeficiency syndrome.

Prolactin (PRL) is an immunostimulatory hormone that is increased in serum of patients with systemic lupus erythematosus (SLE). On the other hand, SLE and AIDS patients share some clinical and immunologic manifestations and probably share similar pathogenic factors and etiology. Based on the above, we decided to investigate the serum PRL levels in 22 asymptomatic HIV-infected patients, 32 patients with AIDS, 9 seronegative homosexual men, and 66 healthy controls. Antibodies to HIV were determined by a micro-ELISA system and by HIV-1 Western blot. Serum PRL was assayed by monoclonal antibodies. Serum PRL levels in the control group were 5.07 +/- 1.36 ng/ml and in the seronegative homosexual men were 5.81 +/- 1.45 ng/ml. Serum PRL levels in asymptomatic HIV-infected patients were 9.22 +/- 3.3 ng/ml and in AIDS patients were 10.26 +/- 2.5 ng/ml (P < 0.01 and P < 0.001, respectively, for both groups when compared to healthy controls). The difference between seronegative homosexual men and AIDS patients was P < 0.05. In the present study we found that serum PRL levels in AIDS patients are higher than in seronegative homosexual men and healthy controls; these results are in agreement with a previous published report. Since PRL is related to lymphocyte activation and lymphoproliferation, the finding may have monitoring, prognostic, and therapeutic implications.