This study was aimed to perform a screening of Lactobacillus buchneri strains from maize silage and use them as inoculant in maize and sugarcane silages. In all, 151 lactic acid bacteria (LAB) strains were isolated from whole‐plant maize silage, and their identification was based on the sequence analysis of 16S rDNA. In total, 15 strains were categorized to the L. buchneri group and eight of these were selected based on growth rate and fermentation pattern. The selected strains were evaluated on fermentation and aerobic stability of maize and sugarcane silages. For maize, the inoculated silages had lower pH and higher LAB population, but lower acetic acid concentration in comparison with the untreated control silage. For sugarcane silage, the strains 56.1, 56.4 and 40788 resulted in highest dry‐matter (DM) content and lowest DM losses. However, only the strain 40788 showed lowest counts of yeasts and moulds. Sugarcane silages inoculated with the strains 56.9, 56.26 and the untreated control silage showed highest concentrations of lactic acid and ethanol, besides the great DM losses. Even so, for both crops, the aerobic stability was not affected by inoculation. After air exposure, all silages increased temperature and had high population of yeast and moulds. Nevertheless, the strains 56.1 and 56.4 are promising for use as a silage inoculant.

The effects of new strains of lactic acid bacteria on alfalfa silage fermentation were evaluated. The experiment was performed using a completely randomized design (with three replicates) based on a 6 × 6 factorial assay with 6 inoculants (I): Control (CTRL), Commercial inoculant (CI), Lactobacillus pentosus 14.7SE (LPE), Lactobacillus plantarum 3.7E (LP), Pediococcus pentosaceus 14.15SE (PP), and Lactobacillus plantarum 3.7E + Pediococcus pentosaceus 14.15SE (LP + PP), and six fermentation periods (P): 1, 3, 7, 14, 28 and 56 days. Alfalfa was wilted for 6 h in the field, which increased the dry matter content to 368 g/kg as fed. The CP and yeast population decreased during the fermentation process. Silage inoculated with the PP strain had the lowest pH values beginning at 14 d of fermentation and the lowest acetic acid concentration on the last day of fermentation. New strains more efficiently regulated enterobacteria and mold populations at days 56 and 28, respectively. Silages inoculated with the PP strain had a higher coefficient of in vitro dry matter digestibility than LP silages. All of the tested novel strains resulted in positive effects on at least one chemical property of the silage during the fermentation process. However, the adding of P . pentosaceus can be indicated as the better for silage quality considering the tested treatments in the present study.

Listeria 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.

The first part of the study aimed to isolate, characterize, and identify wild lactic acid bacteria (LAB) strains from alfalfa silage produced in a tropical area. LAB strains were isolated from alfalfa silage ensiled for 1, 3, 7, 14, 28, and 56 days (d) and were identified by sequencing the 16S rRNA gene. The second part aimed to investigate the effects of wild LAB strains on the nutritive and fermentative characteristics of alfalfa silage. This trial was conducted according to a completely randomized design in a 4 × 2 factorial scheme [four inoculants (I) × two harvests (H)], (n = 4). The inoculants were: (1) no inoculant (CTRL), (2) Lactobacillus pentosus (AV 14.17); (3) L. pentosus + Lactobacillus brevis + Pediococcus acidilactici (Combo); and (4) commercial inoculant (CI). Alfalfa forage (7 kg) was ensiled in 10 L buckets and opened after 90 d. Seventy-seven strains were isolated. Pediococcus, Lactobacillus, and Weissella represented 52.0, 24.7, and 20.8% of the isolates, respectively. For the first harvest, Combo, CI, and all inoculated silages showed lower acid detergent fiber ADF, neutral detergent fiber (NDF), and ammonia nitrogen (NH3-N), respectively. Silage fermented with AV14.17 presented greater residual water-soluble carbohydrate (WSC) in the second harvest and showed the lowest pH in both harvests. AV14.17 strain has potential as an inoculant for alfalfa silage production.

Background: Sugarcane silage has been increasing as a feed in the tropics by dairy farmers. However, sugarcane normally had high yeast population that leads to intense alcoholic fermentation and excessive Dry-Matter (DM) loss during ensilage and after air exposure, as well. There are several patents that have recently shown the benefits of applying Lactobacillus buchneri in forage preservation. Objective: This study aimed to investigate the changes in pH, DM, Water-Soluble Carbohydrates (WSC) and fermentation end product concentrations that occur in sugarcane silage with or without inoculation with L. buchneri after 45 days of ensiling. Methods: Sugarcane plants were harvested with approximately 16 months of growth and chopped at 2 cm. Four strains of wild L. buchneri (56.1, 56.4, 56.9 and 56.26) and the commercial inoculant “Lalsil Cana” were evaluated. For all treatments, the theoretical application rate was 1.0 × 106 colony- forming units (cfu) per g of fresh weight. Data from the silo openings were analysed as a completely randomized design, with four replicates per treatment (inoculants). Results: The treatment with L. buchneri affected the DM content, pH, Lactic Acid Bacteria (LAB) population, DM recovery, and concentrations of WSC, lactic acid, acetic acid and ethanol of sugarcane silage after 45 days of ensiling. Yeasts and molds populations and the concentrations of propionic and butyric acids were not affected by the treatments. Conclusion: Lactobacillus buchneri 56.1 and 56.4 are considered the most suitable strains for improving the fermentation of sugarcane silage and thus are potential inoculants for silage production. At present, we are preparing the patent application.

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