Navegando por Autor "Mantovani, Hilário C."
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Item Bovicin HC5 inhibits wasteful amino acid degradation by mixed ruminal bacteria in vitro(FEMS Microbiology Letters, 2009-03-01) Lima, Janaína R.; Ribon, Andréa de O. Barros; Russell, James B.; Mantovani, Hilário C.Streptococcus bovis HC5 produces a broad spectrum lantibiotic (bovicin HC5) that inhibits pure cultures of hyper ammonia-producing bacteria (HAB). Experiments were preformed to see if: (1) S. bovis HC5 cells could inhibit the deamination of amino acids by mixed ruminal bacteria taken directly from a cow, (2) semi-purified bovicin was as effective as S. bovis HC5 cells, and 3) semi-purified and the feed additive monensin were affecting the same types of ammonia-producing ruminal bacteria. Because purified and semi-purified bovicin HC5 was as effective as S. bovis HC5 cells, it appeared that bovicin HC5 was penetrating the cell membranes of HAB before it could be degraded by peptidases and proteinases. Mixed ruminal bacteria that were successively transferred and enriched nine times with trypticase did not become significantly more resistant to either bovicin HC5 (50 AU mL−1) or monensin (5 μM), and amplified rDNA restriction analysis indicated that bovicin HC5 and monensin appeared to be selecting against the same types of bacteria.Item Chemical composition and nutrient degradability in elephant grass silage inoculated with Streptococcus bovisisolated from the rumen(Anais da Academia Brasileira de Ciências, 2013-04-08) Ferreira, Daniele J.; Zanine, Anderson M.; Lana, Rogério P.; Ribeiro, Marinaldo D.; Alves, Guilherme R.; Mantovani, Hilário C.The objective of the present study was to assess the chemical and bromatological composition and in situ degradability of elephant grass silages inoculated with Streptococcus bovisisolated from cattle rumen. A complete randomized design was used with four treatments and six replications: elephant grass silage, elephant grass silage inoculated with 106 CFU/g Streptococcus bovisJB1 strains; elephant grass silage inoculated with 106 CFU/gStreptococcus bovis HC5 strains; elephant grass silage inoculated with 106 CFU/g Enterococcus faeciumwith six replications each. The pH and ammoniacal nitrogen values were lower (P<0.05) for the silages inoculated with Streptococcus bovis JB1 and HC5, respectively. The silage inoculated withStreptococcus bovis had a higher crude protein content (P<0.05) and there were no differences for the fiber contents in the silage. The (a)soluble fraction degradability, especially in the silages inoculated with Streptococcus bovis JB1 and HC5, had higher values, 30.77 and 29.97%, for dry matter and 31.01 and 36.66% for crude protein, respectively. Inoculation with Streptococcus bovis improved the fermentation profile, protein value and rumen degradability of the nutrients.Item Compositional and structural dynamics of the ruminal microbiota in dairy heifers and its relationship to methane production(Journal of the Science of Food and Agriculture, 2019-01-15) Cunha, Camila S.; Marcondes, Marcos I.; Veloso, Cristina M.; Mantovani, Hilário C.; Pereira, Luiz Gustavo R.; Tomich, Thierry R.; Dill- McFarland, Kimberly A.; Suen, GarretHeifers emit more enteric methane (CH4) than adult cows and these emissions tend to decrease per unit feed intake as they age. However, common mitigation strategies like expensive high‐quality feeds are not economically feasible for these pre‐production animals. Given its direct role in CH4 production, altering the rumen microbiota is another potential avenue for reducing CH4 production by ruminants. However, to identify effective microbial targets, a better understanding of the rumen microbiota and its relationship to CH4 production across heifer development is needed. Here, we investigate the relationship between rumen bacterial, archaeal, and fungal communities as well as CH4 emissions and a number of production traits in prepubertal (PP), pubertal (PB), and pregnant heifers (PG). Overall, PG heifers emitted the most CH4, followed by PB and PP heifers. The bacterial genus Acetobacter and the archaeal genus Methanobrevibacter were positively associated, while Eubacterium and Methanosphaera were negatively associated with raw CH4 production by heifers. When corrected for dietary intake, both Eubacterium and Methanosphaera remained negatively associated with CH4 production. We suggest that Eubacterium and Methanosphaera represent likely targets for CH4 mitigation efforts in heifers as they were negatively associated with CH4 production and not significantly associated with production traits.Item Distribution and genetic diversity of bacteriocin gene clusters in rumen microbial genomes(Applied and Environmental Microbiology, 2015-08-02) Azevedo, Analice C.; Bento, Cláudia B. P.; Ruiz, Jeronimo C.; Queiroz, Marisa V.; Mantovani, Hilário C.Some species of ruminal bacteria are known to produce antimicrobial peptides, but the screening procedures have mostly been based on in vitro assays using standardized methods. Recent sequencing efforts have made available the genome sequences of hundreds of ruminal microorganisms. In this work, we performed genome mining of the complete and partial genome sequences of 224 ruminal bacteria and 5 ruminal archaea to determine the distribution and diversity of bacteriocin gene clusters. A total of 46 bacteriocin gene clusters were identified in 33 strains of ruminal bacteria. Twenty gene clusters were related to lanthipeptide biosynthesis, while 11 gene clusters were associated with sactipeptide production, 7 gene clusters were associated with class II bacteriocin production, and 8 gene clusters were associated with class III bacteriocin production. The frequency of strains whose genomes encode putative antimicrobial peptide precursors was 14.4%. Clusters related to the production of sactipeptides were identified for the first time among ruminal bacteria. BLAST analysis indicated that the majority of the gene clusters (88%) encoding putative lanthipeptides contained all the essential genes required for lanthipeptide biosynthesis. Most strains of Streptococcus (66.6%) harbored complete lanthipeptide gene clusters, in addition to an open reading frame encoding a putative class II bacteriocin. Albusin B-like proteins were found in 100% of the Ruminococcus albus strains screened in this study. The in silico analysis provided evidence of novel biosynthetic gene clusters in bacterial species not previously related to bacteriocin production, suggesting that the rumen microbiota represents an underexplored source of antimicrobial peptides.Item Draft genome sequence of Streptococcus equinus (Streptococcus bovis) HC5, a lantibiotic producer from the bovine rumen(Genome Announcements, 2015-03-05) Azevedo, Analice C.; Bento, Cláudia B. P.; Ruiz, Jeronimo C.; Queiroz, Marisa V.; Mantovani, Hilário C.Streptococcus equinus (Streptococcus bovis) HC5 is a bacteriocinogenic lactic acid bacterium with simple growth requirements. The draft genome sequence of S. equinus HC5 consists of 1,846,241 bp, with a G+C content of 37.04%. In silico analysis indicated that S. equinus HC5 might be useful to control bacteria that are detrimental to livestock animals.Item Effect of pre- weaning diet on the ruminal archaeal, bacterial, and fungal communities of dairy calves(Frontiers in Microbiology, 2017-08) Dias, Juliana; Marcondes, Marcos I.; Noronha, Melline F.; Resende, Rafael T.; Machado, Fernanda S.; Mantovani, Hilário C.; Dill- McFarland, Kimberly A.; Suen, GarretAt birth, calves display an underdeveloped rumen that eventually matures into a fully functional rumen as a result of solid food intake and microbial activity. However, little is known regarding the gradual impact of pre-weaning diet on the establishment of the rumen microbiota. Here, we employed next-generation sequencing to investigate the effects of the inclusion of starter concentrate (M: milk-fed vs. MC: milk plus starter concentrate fed) on archaeal, bacterial and anaerobic fungal communities in the rumens of 45 crossbred dairy calves across pre-weaning development (7, 28, 49, and 63 days). Our results show that archaeal, bacterial, and fungal taxa commonly found in the mature rumen were already established in the rumens of calves at 7 days old, regardless of diet. This confirms that microbiota colonization occurs in the absence of solid substrate. However, diet did significantly impact some microbial taxa. In the bacterial community, feeding starter concentrate promoted greater diversity of bacterial taxa known to degrade readily fermentable carbohydrates in the rumen (e.g., Megasphaera, Sharpea, and Succinivribrio). Shifts in the ruminal bacterial community also correlated to changes in fermentation patterns that favored the colonization of Methanosphaera sp. A4 in the rumen of MC calves. In contrast, M calves displayed a bacterial community dominated by taxa able to utilize milk nutrients (e.g., Lactobacillus, Bacteroides, and Parabacteroides). In both diet groups, the dominance of these milk-associated taxa decreased with age, suggesting that diet and age simultaneously drive changes in the structure and abundance of bacterial communities in the developing rumen. Changes in the composition and abundance of archaeal communities were attributed exclusively to diet, with more highly abundant Methanosphaera and less abundant Methanobrevibacter in MC calves. Finally, the fungal community was dominated by members of the genus SK3 and Caecomyces. Relative anaerobic fungal abundances did not change significantly in response to diet or age, likely due to high inter-animal variation and the low fiber content of starter concentrate. This study provides new insights into the colonization of archaea, bacteria, and anaerobic fungi communities in pre-ruminant calves that may be useful in designing strategies to promote colonization of target communities to improve functional development.Item Effects of the oral administration of viable and heat-killed Streptococcus bovis HC5 cells to pre-sensitized BALB/c mice(Plos One, 2012-10-29) Paiva, Aline D.; Fernandes, Kenner M.; Dias, Roberto S.; Rocha, Alípio S.; Oliveira, Leandro L. de; Neves, Clóvis A.; Paula, Sérgio O. de; Mantovani, Hilário C.Antimicrobial peptides have been suggested as an alternative to classical antibiotics in livestock production and bacteriocin-producing bacteria could be added to animal feeds to deliver bacteriocins in the gastrointestinal (GI) tract of ruminant and monogastric animals. In this study, viable (V) and heat-killed (HK) Streptococcus bovis HC5 cells were orally administered to pre-sensitized mice in order to assess the effects of a bacteriocin-producing bacteria on histological parameters and the immune response of the GI tract of monogastric animals. The administration of V and HK S. bovis HC5 cells during 58 days to BALB/c mice did not affect weight gain, but an increase in gut permeability was detected in animals receiving the HK cells. Viable and heat killed cells caused similar morphological alterations in the GI tract of the animals, but the most prominent effects were detected in the small intestine. The oral administration of S. bovis HC5 also influenced cytokine production in the small intestine, and the immune-mediated activity differed between V and HK cells. The relative expression of IL-12 and INF-γ was significantly higher in the small intestine of mice treated with V cells, while an increase in IL-5, IL-13 and TNF-α expression was only detected in mice treated with HK cells. Considering that even under a condition of severe challenge (pre-sensitization followed by daily exposure to the same bacterial immunogen) the general health of the animals was maintained, it appears that oral administration of S. bovis HC5 cells could be a useful route to deliver bacteriocin in the GI tract of livestock animals.Item Evaluation of the length of adaptation period for changeover and crossover nutritional experiments with cattle fed tropical forage-based diets(Animal Feed Science and Technology, 2016-12) Machado, Marcelo G.; Detmann, Edenio; Mantovani, Hilário C.; Valadares Filho, Sebastião C.; Bento, Cláudia B.P.; Marcondes, Marcos I.; Assunção, Amanda S.It was evaluated the impact of the diet switch on nutritional characteristics and bacterial community composition in cattle fed tropical forage-based diet aiming to establish the minimal length of the adaptation period that could be applied to changeover or crossover design protocols. Twelve rumen-cannulated crossbreed (B. taurus × B. indicus) bovines were used in this experiment (four young bulls, four steers, and four heifers). The experiment lasted 60 days and two diet switches were done at d 21 and d 41. Four diet sequences were evaluated (one animal of each category per sequence): sugarcane-corn silage-sugarcane, corn silage-sugarcane-corn silage, high-low-high concentrate diets, and low-high-low concentrate diets. All diets were adjusted to 110 g crude protein/kg dry matter by using urea. Four groups of variables were evaluated along experimental days: voluntary intake characteristics, fecal excretion and composition, ruminal digesta compostion, and ruminal fermentation profile. The pattern of the groups along time was interpreted through a non-hierarchical clustering procedure and the stabilization of each group of characteristics was achieved within 9–13, 9–14, 6–13, and 4–11 days after diet switch, respectively. The diversity of the liquid-associated rumen bacterial community was also evaluated by using PCR-DGGE in the young bulls from 6 days before to 20 days after the second diet switch. The pattern of microbial diversity was evaluated through a clustering procedure using the unweight pair group method with arithmetic mean. The bacterial community in the liquid phase stabilized within 3–9 days after diet switch. From the results of this experiment, among all obtained times to adapt intake, fecal and digesta composition, and ruminal fermentation and microbial diversity, a 14-days adaptation period is recommended for changeover and crossover experiments with cattle fed tropical forage-based diets.Item Genome analysis reveals insights of the endophytic Bacillus toyonensis BAC3151 as a potentially novel agent for biocontrol of plant pathogens(World Journal of Microbiology and Biotechnology, 2017-09-25) Lopes, Ralf; Cerdeira, Louise; Tavares, Grace S.; Ruiz, Jeronimo C.; Blom, Jochen; Horácio, Elvira C. A.; Mantovani, Hilário C.; Queiroz, Marisa Vieira deDiseases caused by phytopathogenic microorganisms account for enormous losses for agribusiness. Although Bacillus species are recognized as being antimicrobial producers and some may provide benefits to plants, the association between Bacillus toyonensis and plants has not been studied. In this study, the whole-genome sequenced endophytic B. toyonensis BAC3151, which has demonstrated antimicrobial activity and quorum sensing inhibition of phytopathogenic bacteria, was investigated for its potential for the production of compounds for biocontrol of plant pathogens. Four whole-genome sequenced B. toyonensis strains shared 3811 protein-coding DNA sequences (CDSs), while strain-specific CDSs, such as biosynthetic gene clusters of antimicrobials, were associated with specific chromosomal regions and mobile genetic elements of the strains. B. toyonensis strains had a higher frequency of putative bacteriocins gene clusters than that of Bacillus species traditionally used for the production of antimicrobials. In addition, gene clusters potentially involved in the production of novel bacteriocins were found in BAC3151, as well as biosynthetic genes of several other compounds, including non-ribosomal peptides, N-acyl homoserine lactonase and chitinases, revealing a genetic repertoire for antimicrobial synthesis greater than that of other Bacillus strains that have demonstrated effective activity against phytopathogens. This study showed for the first time that B. toyonensis has potential to produce various antimicrobials, and the analyses performed indicated that the endophytic strain BAC3151 can be useful for the development of new strategies to control microbial diseases in plants that are responsible for large damages in agricultural crops.Item Inhibition of Listeria monocytogenes by a lactic acid bacterium isolated from Italian salami(Food Microbiology, 2005-07-18) Carvalho, Ana Andréa Teixeira de; Paula, Rosinéa Aparecida de; Mantovani, Hilário C.; Moraes, Célia Alencar deListeria monocytogenes is an opportunistic psychrotroph foodborne pathogen that has been used as a model organism to study the efficacy of many different preservation methods. This work aimed to test the antilisterial activity of lactic acid bacteria isolated from Italian salami and study the development of resistance. Isolates were obtained from naturally fermented Italian salami and cultures that retained activity in the supernatants after pH neutralization and catalase treatment were further characterized. The isolate showing highest inhibitory activity (PD 6.9) was tested for sensibility to proteases, heat and pH. To evaluate if resistance developed, sensitive strains were transferred with sub-lethal doses of the partially purified inhibitory substance and then inoculated into media containing higher doses of the extract. Isolate PD 6.9 inhibited several L. monocytogenes strains obtained from different origins and retained its activity over a wide range of pH and temperature. When increasing concentrations (10–100 AU ml−1) of the partially purified inhibitory substance were added to culture media, growth of L. monocytogenes did not occur even after 12 h of incubation. Cultures of Listeria that were transferred with sub-lethal doses (10 AU ml−1) of the partially purified inhibitory substance could resist higher doses of the extract (50 AU ml−1), but were inhibited when the concentration was further increased (100 AU ml−1). These results indicate that isolate PD 6.9 could potentially be used as a bioprotective culture for salami fermentation.Item Lack of AHL-based quorum sensing in Pseudomonas fluorescens isolated from milk(Brazilian Journal of Microbiology, 2014-10-09) Vanetti, Maria C.D.; Martins, Maurilio L.; Pinto, Uelinton, M.; Riedel, Kathrin; Mantovani, Hilário C.; Araújo, Elza F. deNumerous bacteria coordinate gene expression in response to small signalling molecules in many cases known as acylhomoserine lactones (AHLs), which accumulate as a function of cell density in a process known as quorum sensing. This work aimed to determine if phenotypes that are important to define microbial activity in foods such as biofilm formation, swarming motility and proteolytic activity of two Pseudomonas fluorescens strains, isolated from refrigerated raw milk, are influenced by AHL molecules. The tested P. fluorescens strains did not produce AHL molecules in none of the evaluated media. We found that biofilm formation was dependent on the culture media, but it was not influenced by AHLs. Our results indicate that biofilm formation, swarming motility and proteolytic activity of the tested P. fluorescens strains are not regulated by acyl-homoserine lactones. It is likely that AHL-dependent quorum sensing system is absent from these strainsItem Nutritive value and fermentation quality of palisadegrass and stylo mixed silages(Animal Science Journal, 2018-01-12) Silva, Juliana S. Da; Ribeiro, karina G.; Pereira, Odilon G.; Mantovani, Hilário C.; Cecon, Paulo R.; Pereira, Rosana C.; Silva, Janaina de L.The nutritive value and fermentation quality of palisadegrass (Brachiaria brizantha cv. Xaraes) and stylo (Stylosanthes capitata × S. macrocephala cv. Campo Grande) mixed silages were evaluated. The experiment was analyzed in a factorial scheme (5 × 2) in a completely randomized design using increasing levels of stylo (0, 25, 50, 75 and 100% on a fresh matter basis) on palisadegrass silages, with and without microbial inoculants (MI). With the increased ratio of stylo in mixed silages, dry matter (DM), crude protein (CP), acid detergent fiber (ADF), and lignin content increased in silages. The presence of MI promoted lower DM content, and higher neutral detergent fiber corrected for ash and protein, ADF and lignin content. The acid detergent insoluble nitrogen content and the lactic acid bacteria populations were not affected by treatments. The in vitroDM digestibility was affected by the interaction of levels of the stylo and MI. The pH, NH3-N/total nitrogen and butyric acid concentrations decreased with increasing levels of stylo. Better nutritive value and quality of fermentation was found in the silage containing higher proportions of this stylo mixed with palisadegrass. The microbial inoculant evaluated did not alter the nutritive value or quality of the fermentation of the silages in this experiment.Item Parameterization of ruminal fibre degradation in low-quality tropical forage using Michaelis–Menten kinetics(Livestock Science, 2009-12) Detmann, Edenio; Paulino, Mário F.; Mantovani, Hilário C.; Valadares Filho, Sebastião de C.; Sampaio, Cláudia B.; Souza, Marjorrie A. de; Lazzarini, Ísis; Detmann, Kelly S. C.This work aimed to parameterize the ruminal degradation of neutral detergent fibre (NDF) from low-quality tropical forage using Michaelis–Menten kinetics. The intake, rumen outflow (L), fractional degradation rate (kd), discrete lag (LAG) and effective degradability (ED) of NDF, and the microbial flow of nitrogenous compounds into the small intestine (Nmic) were assessed in two 5 × 5 Latin square experiments by using five Holstein × Zebu heifers cannulated in the rumen. The experiments were carried out sequentially and the treatments were formed by increasing the level of supplementation with nitrogenous compounds. A low-quality signal grass (Brachiaria decumbens) hay was used as roughage. The nitrogen supplement was a mixture of urea, ammonium sulfate and albumin, at the ratios of 4.5:0.5:1.0, respectively. The crude protein contents in the diets ranged from 51.9 to 136.3 g/kg of dry matter. The rumen ammonia nitrogen (RAN) concentration was used as an independent variable. The NDF intake, L and Nmic showed a quadratic pattern (P < 0.05) as a function of RAN concentration, and the critical points (maximum responses) were observed with 15.17, 16.28, and 14.52 mg of RAN/dL of rumen fluid, respectively. On the other hand, ED and LAG presented a linear-response-plateau (P < 0.05) according to the RAN concentration, with break points close to 8 mg/dL for ED (maximum estimate) and LAG (minimum estimate). The RAN concentrations to optimize NDF degradation and intake were defined as 8 and 15 mg/dL, respectively. This difference between estimates appears to be due to a better adequacy of the metabolizable protein:metabolizable energy ratio in the animal metabolism, which increases the animal intake even after the rumen NDF degradation has been optimized. This observation was supported by Nmic pattern. An adapted Michaelis–Menten model was applied to the data, where RAN was the independent variable and kd the dependent variable. The relationship between these variables was found to be significant by using the Hanes–Woolf plot (P < 0.01). Based on this model, the rate of NDF degradation as a function of RAN concentration indicates that fibre degradation in the rumen could be considered a second order process. In this context, the RAN concentration of 8 mg/dL was assumed as the limit where zero order (below limit) and first order (above limit) reactions become predominant for NDF degradation in the rumen.