Effect of wheat distillers dried grains with solubles or sugar beet pulp on prevalence of Salmonella enterica Typhimurium in weaned pigs.

Salmonella enterica Typhimurium (ST) is of concern in the swine industry with relevance for animal health and consumer safety. Nutritional strategies might help to reduce ST infection and transmission. This study examined the potential of wheat (Triticum aestivum) distillers dried grains with solubles (DDGS) and sugar beet (Beta vulgaris) pulp (SBP) to alter intestinal microbial communities and ST shedding using a Trojan model. Weaned pigs (n = 105; 28.5 ± 3.5 d of age) were separated into 3 treatment groups (7 pigs/pen) and fed a wheat-based control diet or the control diet formulated with 15% wheat DDGS or 6% SBP inclusion. Following 12 d of diet adaptation, 2 pigs/pen were inoculated with 2 x 10(9) cfu ST, resistant to novobiocin and nalidixic acid. Fecal swabs were taken from infected pigs and pen-mates (contact pigs) for 9 d following challenge, enriched in nutrient broth for 24 h, and plated on selective media to determine prevalence of ST. The ranges of prevalence of ST in feces were from 90 to 100% in challenged pigs and 74 to 78% in contact pigs. No influence of treatment on rectal temperature and prevalence of ST in contact pigs were observed. Fifteen contact pigs were euthanized per treatment group on 9 and 10 d postchallenge to enumerate in intestinal contents (ileum, cecum, and proximal colon), Lactobacillus spp., Enterobacteriaceae, and Clostridium clusters I, VI, and XVIa by quantitative PCR (qPCR) and to determine ST prevalence by selective culture. No significant effects of diet were observed with respect to ST prevalence in feces, ileum, cecum, colon, and lymph nodes of contact pigs. Compared with the control diet, DGGS and SBP diets showed a trend towards increased (P < 0.1) number of Lactobacillus species in the cecum and colon. Although both wheat DGGS and SBP tended to increase the Lactobacillus spp. neither of the feed ingredients affected ST prevalence.

Properties of Solubilized Microsomal Lipase from Germinating Brassica napus.

Lipase (triacylglycerol acylhydrolase [EC 3.1.1.3.]) was extracted from the microsomal fraction of cotyledons of dark grown seedlings of Canola (Brassica napus L. cv Westar) by treatment with Triton X-100. The enzyme was partially purified by chromatography on Sephacryl S-300 and DEAE Bio-Gel and was stable when stored at -20 degrees C in 50% (v/v) glycerol. The lipase aggregated readily but the distribution of species present in solution could be controlled by nonionic detergents. A species with an apparent M(r) of about 250,000 was obtained by gel filtration chromatography in the presence of 1% (v/v) Triton X-100. Lipase activity was optimal near neutral pH, and the reaction approached maximum velocity at a concentration of 0.5 to 1 millimolar emulsified triolein. The reaction rate responded linearly to temperature up to about 40 degrees C and the hydrolytic process had an activation energy of 18 kilocalories per mole. Microsomal lipase lost about 20% and 80% activity when heat-treated for 1 hour at 40 degrees C and 60 degrees C, respectively. At appropriate concentrations, the detergents Triton X-100, n-octyl-beta-d-glucopyranoside, (3-[(3-cholamidopropyl-O-dimethylammonio]-1-propanesulfonate, cetyl trimethylammonium bromide, and sodium dodecyl sulfate all inhibited lipase activity. n-Octyl-beta-d-glucopyranoside, however, was stimulatory in the 2 to 8 millimolar concentration range. The inhibitory effects of Triton X-100 were reversible.

Expression of an endogenous galactose-binding lectin in the early chick embryo.

The gastrulating chick blastoderm contains lectin activity specific for beta-D-galactoside groups. The galactose-binding lectin isolated by affinity chromatography on rho-aminophenyl-beta-D-lactoside separates into two bands when studied by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. One of these LII has a relative molecular mass of 70 (+/- 2) X 10(3) while the other LI is a polypeptide that migrates with the dye front in 10% gels. We have prepared an antiserum against this lectin preparation and have affinity-purified antibodies against LI. When embryos at stages 3-7 were examined by immunofluorescence using the affinity-purified antibodies, lectin was expressed in cells at the lowest portions of the primitive streak as well as in cells migrating laterally from this region to form the endoderm. Lectin was also expressed by the cells of the extra-embryonic endoderm and the primordial germ cells of the proximal area opaca. In transfers of gradient gels stained with affinity-purified antibodies against LI, this lectin had an approximate molecular weight of 6.5 X 10(3). Our results indicate that this lectin is expressed in areas that are undergoing cell spreading.

Acyl lipids, pigments, and gramine in developing leaves of barley and its virescens mutant.

Changes in acyl lipids and pigments during leaf development in a virescens barley mutant (M) and the normal (N) were studied. Apical 3-cm leaf segments were extracted with chloroform-methanol, the extracts were purified on Sephadex G-25 columns, and the polar lipids were separated on two-dimensional-thin layer chromatography silica gel plates. The pigment remaining on the Sephadex column was identified as flavonoids and a zone on the TLC plates which did not correspond to the usual standards was identified as gramine. Quantification of acyl lipids by either polar head group analysis or fatty acid analysis using heptadecanoate as an internal standard gave similar results. The per cent of the total lipid extract quantified for the M between 4 and 8 days ranged from 46 to 65% and that for the N ranged from 60 to 68%. Of these, acyl lipids represented 37 to 48% in the M and 43 to 50% in the N. By 8 days, mono- and digalacto-syldiglyceride (MG and DG) accounted for 45 and 25% of the total acyl lipid of both the M and N. For the period of study here, this represented a 4-fold increase in MG and a 2.5-fold increase in DG in the M but only a 1.8-fold increase for MG and DG in the N. These increases were closely correlated with the increases in chlorophyll. Chlorophyll increased sharply between 4 and 6 days for the N, whereas, in the M, it rose from 7 to 50% relative to the normal by 8 days. The proportions of the various fatty acids were unique for the lipid classes. The only major quantitative change for a fatty acid was for hexadecanoate in phosphatidylglycerol which increased from 5% at 4 days to 25 to 30% by 8 days. Relative to the N, the carotenoid content of the M increased from 14 to 50% between 4 and 8 days. In both the M and N, the increase in beta-carotene and chlorophyll were closely correlated.

Acetyl coenzyme a carboxylase activity in developing seedlings and chloroplasts of barley and its virescens mutant.

Acetyl coenzyme A (CoA) carboxylase activity of whole tissue homogenates and chloroplast preparations was analyzed as the acetyl-CoA-dependent incorporation of [(14)C]bicarbonate into an acid-stable product. The absolute requirement for ATP and MgCl(2), the complete inhibition with avidin, and end-product analysis were consistent with the presence of acetyl-CoA carboxylase activity. Little difference was found between the mutant and normal tissue homogenates from the 1- to 3-day growth stages, during which period both showed a 3-fold increase. However, by 4 days, the activity of the mutant exceeded that of the normal. Fractionation studies showed that the enzyme was a soluble protein present in the stromal fraction of chloroplasts. The biotin content was also highest in the stroma, although it was found in the lamellar fraction as well. For both the mutant and the normal, the highest acetyl-CoA carboxylase activities were obtained in the stromal preparations from 4-day seedlings (54 and 31 nmoles per milligram protein per minute for the mutant and the normal, respectively) with a progressive decline by 6 and 8 days. The difference between the mutant and the normal was not due to the accumulation of an inhibitor in the normal.

Lipids in rye seedlings in relation to vernalization.

Increasing the chilling time from 1 to 8 weeks decreased the time to heading of winter rye (Secale cereale var. Sangaste) to approximate that of the spring variety (Prolific). On a dry weight basis, the total phospholipid content of the embryos was higher in Sangaste but declined in both varieties during chilling. The proportions of the individual phospholipid components were similar for both varieties and showed similar responses during the 8-week chilling period. Phosphatidylcholine declined and phosphatidic acid increased in both varieties during the treatment.During the initial 3 weeks, an increased accumulation of linolenic acid and a corresponding decline in linoleic acid occurred for all the lipid components and then remained relatively stable. The glycolipids were more unsaturated than the phospholipids; however, the amount of linolenate was approximately doubled in both during the treatment. In general, the fatty acid content of the respective lipid classes were similar for both varieties.