Efficiency of a Lactobacillus plantarum-xylanase combination on growth performances, microflora populations, and nutrient digestibilities of broilers infected with Salmonella Typhimurium

in Poultry Science (2009), 88(8), 1643-1654

Three experiments were performed to assess the ability of a Lactobacillus plantarum probiotic combined with a xylanase to reduce the effects of S. typhimurium infection in broiler chickens from 1- to 30 ... [more ▼]

Three experiments were performed to assess the ability of a Lactobacillus plantarum probiotic combined with a xylanase to reduce the effects of S. typhimurium infection in broiler chickens from 1- to 30- or 42-d-old. Chicks were challenged at 3-d-old with 108 or 105 cfu S. typhimurium/chick. Four diets were studied: a wheat-based diet (C+) supplemented with 0.1 g/kg xylanase (E), or 106 cfu/g or L. plantarum (P), or both (PE). Uninfected chicks fed the C diet were used as negative control (C-). Six or 8 chicks were housed per cage with 9 cages/treatment. Growth performance and feed conversion ratio (FCR) were recorded weekly. In experiment 1, bacterial enumeration in caeca was achieved using the fluorescent in situ hybridization technique. Salmonella enumeration was realized in excreta by microbiological cultures (Exp. 2 and 3). Nutrient digestibilities and AMEn were determined in experiment 3 from d 35 to d 39. Infection with S. typhimurium led to a significant decrease in the daily weight gain (DWG) by 23.6% to 32.8%, whereas FCR was increased by 1.0% to 19.7%. Chickens fed the PE diet showed significantly improved performance in comparison with C+ birds (DWG: +12.5% in Exp. 1; FCR: -2.1-8.6%), and in comparison with the P and E treatments (DWG: +6.3-8.3% in Exp. 1; FCR: -2.7-6.4%). In experiment 3, the FCR was significantly improved by 3% with the PE diet in comparison with C- chickens. The PE combination tended to restore a microflora similar to that of uninfected broilers, whereas the P and E diets had less of an effect on the profile of bacterial communities. At slaughter age, Salmonella contamination was reduced by 2.00 and 1.85 log cfu for the E and PE treatment, respectively. The PE diet significantly reduced the crude fat digestibility by 9.2%, in comparison with the C+ chickens. These results suggest that combination between L. plantarum and a xylanase as feed additive could be effective for reduction of detrimental effect following S. typhimurium infection of broilers. [less ▲]

Insights into the plant defense mechanisms induced by Bacillus lipopeptides.

Poster (2009, July)

Pilot scale biotransformation of vegetal oil into natural green note flavor using sugar beet leaves as sources of hydroperoxide lyase

Poster (2009, June 02)

Natural green note aromas (GLVs) are highly attractive flavors commonly used in the food industry. These are produced in extremely low levels upon physiological stress in plant organs of any sort. This ... [more ▼]

Natural green note aromas (GLVs) are highly attractive flavors commonly used in the food industry. These are produced in extremely low levels upon physiological stress in plant organs of any sort. This weak sporadic presence entails a very expensive extraction step to obtain pure GLVs. Therefore catalytic biotransformations of fatty acid sources, the initial substrate for GLVs, have been developed. Enzymatic defense pathways and particularly the LOX pathway produce the major part of GLVs. Unlike GLV molecules that are emitted in the atmosphere, the enzymes are extractible from the plant material. Thus, a combination of plant enzyme extracts and substrate preparations provides all the ingredients for GLV production. Besides, sugar beet leaves present high levels of hydroperoxide lyase among plant sources and are available in large amounts during three months. In this enzymatic pathway, fatty acids are successively transformed by lipase, lipoxygenase and hydroperoxide lyase into aldehydes and alcohols, final compounds of GLVs pathway. Limiting and problematic steps occur with the action of hydroperoxide lyase, when enzymatic catalysis is followed by an enzyme destabilization. Alternative substrates bind irreversibly to the heme group of the enzyme and end the reaction. This poster briefly describes the development of a complete bioprocess for natural GLV production, from hydrolysis to purification. A high level of biotransformation could be achieved using optimum experimental conditions and a cheap source of plant materials. [less ▲]

Bacillus-based biocontrol of Fusarium disease on tomato cultures in Burundi

Poster (2009, May 19)

Plant growth promotion of tomato under field conditions in Burundi

Poster (2009, April 02)

Effects of hydrogen partial pressure on fermentative biohydrogen production by a newly isolated bacterium of the genus Clostridium

Poster (2009, April 01)

Study of the antifungal activity of lactic acid bacteria isolated from fermented cassava and mill flour

Poster (2009, April)

Survival of Freeze-dried Leuconostoc mesenteroides and Lactobacillus plantarum Related to Their Cellular Fatty Acids Composition during Storage

in Applied Biochemistry and Biotechnology (2009), 157(1), 70-84

Lactic acid bacteria strains Lactobacillus plantarum CWBI-B534 and Leuconostoc ssp. mesenteroïdes (L. mesenteroïdes) Kenya MRog2 were produced in bioreactor, concentrated, with or without cryoprotectants ... [more ▼]

Lactic acid bacteria strains Lactobacillus plantarum CWBI-B534 and Leuconostoc ssp. mesenteroïdes (L. mesenteroïdes) Kenya MRog2 were produced in bioreactor, concentrated, with or without cryoprotectants. In general, viable population did not change significantly after freeze-drying (p>0.05). In most cases, viable population for cells added with cryoprotectants was significantly lower than those without (p<0.05). Cellular fatty acids (CFAs) from the two strains in this study were analyzed before and after freeze-drying. Six CFAs were identified, namely, palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1), linoleic (C18:2), and linolenic (C18:3) acids were identified. Four of them, C16:0, C16:1, C18:0, and C18:1, make up more than 94% or 93% of the fatty acids in L. mesenteroides and L. plantarum, respectively, with another one, namely, C18:3, making a smaller (on average 5–6%, respectively) contribution. The C18:2 contributed very small percentages (on average≤1%) to the total in each strain. C16:0 had the highest proportion at most points relative to other fatty acids. Moisture content and water activity (a w) increased significantly during the storage period. It was observed that C16:1/C16:0, C18:0/C16:0 and C18:1/C16:0 ratios for freeze-dried L. mesenteroides or L. plantarum, with or without cryoprotectants, did not change significantly during the storage period. According to the packaging mode and storage temperatures, C18:2/C16:0 and C18:3/C16:0 ratios for freeze-dried L. mesenteroides and L. plantarum with or without cryoprotectants decreased as the storage time increased. However, a higher C18:2/C16:0 or C18:3/C16:0 ratio for L. mesenteroides and L. plantarum was noted in the freeze-dried powder held at 4 °C or under vacuum and in dark than at 20 °C or in the presence of oxygen and light [less ▲]

The role of the specific immune response on cecal colonization of slow-growing broiler chickens reared on litter contaminated by Campylobacter jejuni

Conference (2009)

The aim of this experiment was to study the relation between the specific immune response and infection of slow-growing broiler chickens reared on straw litter contaminated by Campylobacter jejuni. The 11 ... [more ▼]

The aim of this experiment was to study the relation between the specific immune response and infection of slow-growing broiler chickens reared on straw litter contaminated by Campylobacter jejuni. The 11-weeks experiment was carried out in a 45 m2 broiler house with 500 chickens from 1 day of age, which had access to an open-air range. Litter contamination was performed before the setting up of the chicks by rearing campylobacter-positive cocks. These birds were also used to contaminate the open-air range during one week before the exit of the chickens, at 5 weeks of age. Blood samples were taken weekly on 20 chickens for anti-campylobacter IgG quantitative measurements on serum. Chickens were then euthanized and cecal contents and bile were collected for Campylobacter enumeration and anti-campylobacter IgA quantification, respectively. A high serum anti-campylobacter IgG titer of 110.13 was measured in one-day-old chicks. The IgG antibodies level significantly decreased to 5.60 at 28 days of age which coincided with the onset of Campylobacter infection in the flock. A significant reduction of the cecal colonization from 11 weeks of age was correlated with the increase in biliary IgA titers. These results suggest that the 2-3 week’s delay generally observed in poultry production before flock infection by Campylobacter may be, at least partly, explained by the protective effect of maternal antibodies. The increase of secretory immune response as bird age may help to limit Campylobacter population in the chicken gut. [less ▲]

Enzymatic interesterification of anhydrous milk fat with rapeseed and/or linseed oil: oxidative stability

in Journal of Agricultural and Food Chemistry (2009), 57(15), 6787-6794

Blends of anhydrous milkfat (AMF) and linseed oil (70/30), and AMF, rapeseed oil (RO) and linseed oil (LO), 70/20/10, were submitted to enzymatic interesterification. The oxidative stability of the blends ... [more ▼]

Blends of anhydrous milkfat (AMF) and linseed oil (70/30), and AMF, rapeseed oil (RO) and linseed oil (LO), 70/20/10, were submitted to enzymatic interesterification. The oxidative stability of the blends, the interesterified (IE) blends and IE blends with 50 ppm -tocopherol added as antioxidant were studied. Samples were stored in open flasks at 60°C, 25°C and 4°C, and periodically submitted to peroxide, p-anisidine, TBA value determination and UV measurement at 232 and 268 nm. The analysis of volatile compounds was carried out by SPME for the samples stored at 60°C. Peroxides appeared to be the only significant oxidation products after 12 weeks storage at 4°C. As expected, the binary blends (BB) were more sensitive to oxidation than the ternary blends (TB). The BB were associated with increased volatile emission compared to TB. Interesterification led to variable effects on the oxidation of fat mixtures, depending on composition and temperature (beneficial effect on BB, at both 25°C and 60°C, and a rather neutral effect on TB). The IE blends exhibited higher volatile release prior to ageing. A pro-oxidant effect of -tocopherol addition was observed at 25°C on both BB and TB. At 60°C, an antioxidant effect was observed on TB. [less ▲]