Genomic Analyses of Pediococcus pentosaceus ST65ACC, a Bacteriocinogenic Strain Isolated from Artisanal Raw-Milk Cheese.

Pediococcus pentosaceus ST65ACC was obtained from a Brazilian artisanal cheese (BAC) and characterized as bacteriocinogenic. This strain presented beneficial properties in previous studies, indicating its potential as a probiotic candidate. In this study, we aimed to carry out a genetic characterization based on whole-genome sequencing (WGS), including taxonomy, biotechnological properties, bacteriocin clusters and safety-related genes. WGS was performed using the Illumina MiSeq platform and the genome was annotated with the Prokaryotic Genome Annotation (Prokka). P. pentosaceus ST65ACC taxonomy was investigated and bacteriocin genes clusters were identified by BAGEL4, metabolic pathways were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) and safety-related genes were checked. P. pentosaceus ST65ACC had a total draft genome size of 1,933,194 bp with a GC content of 37.00%, and encoded 1950 protein coding sequences (CDSs), 6 rRNA, 55 tRNA, 1 tmRNA and no plasmids were detected. The analysis revealed absence of a CRISPR/Cas system, bacteriocin gene clusters for pediocin PA-1/AcH and penocin-A were identified. Genes related to beneficial properties, such as stress adaptation genes and adhesion genes, were identified. Furthermore, genes related to biogenic amines and virulence-related genes were not detected. Genes related to antibiotic resistance were identified, but not in prophage regions. Based on the obtained results, the beneficial potential of P. pentosaceus ST65ACC was confirmed, allowing its characterization as a potential probiotic candidate.

Pediocin PA-1 production by Pediococcus pentosaceus ET34 using non-detoxified hemicellulose hydrolysate obtained from hydrothermal pretreatment of sugarcane bagasse.

Listeria monocytogenes is one of the foodborne pathogens of most concern for food safety. To limit its presence in foods, bacteriocins have been proposed as natural bio-preservatives. Herein, a bacteriocin was produced on hemicellulose hydrolysate of sugarcane bagasse by Pediococcus pentosaceous ET34, whose genome sequencing revealed an operon with 100% similarity to that of pediocin PA-1. ET34 grown on hydrolysate-containing medium led to an increase in the expression of PA-1 genes and a non-optimized purification step sequence resulted in a yield of 0.8 mg·L-1 of pure pediocin (purity > 95%). Culture conditions were optimized according to a central composite design using temperature and hydrolysate % as independent variables and validated in 3-L Erlenmeyers. Finally, a process for scaled-up implementation by sugar-ethanol industry was proposed, considering green chemistry and biorefinery concepts. This work stands up as an approach addressing a future proper sugarcane bagasse valorisation for pediocin production.

Dynamic changes of total acid and bacterial communities during the traditional fermentation of Hong Qu glutinous rice wine

Background: Hong Qu glutinous rice wine (HQGRW) is brewed under non-aseptic fermentation conditions, so it usually has a relatively high total acid content. The aim of this study was to investigate the dynamics of the bacterial communities and total acid during the fermentation of HQGRW and elucidate the correlation between total acid and bacterial communities. Results: The results showed that the period of rapid acid increase during fermentation occurred at the early stage of fermentation. There was a negative response between total acid increase and the rate of increase in alcohol during the early fermentation stage. Bacterial community analysis using high-throughput sequencing technology was found that the dominant bacterial communities changed during the traditional fermentation of HQGRW. Both principal component analysis (PCA) and hierarchical clustering analysis revealed that there was a great difference between the bacterial communities of Hong Qu starter and those identified during the fermentation process. Furthermore, the key bacteria likely to be associated with total acid were identified by Spearman's correlation analysis. Lactobacillus, unclassified Lactobacillaceae, and Pediococcus were found, which can make significant contributions to the total acid development (| r| N 0.6 with FDR adjusted P b 0.05), establishing that these bacteria can associate closely with the total acid of rice wine. Conclusions: This was the first study to investigate the correlation between bacterial communities and total acid during the fermentation of HQGRW. These findings may be helpful in the development of a set of fermentation techniques for controlling total acid.

Use of crude glycerine and microbial inoculants to improve the fermentation process of Tifton 85 haylages.

The increase in haylage production leads to the search for additives that improve its fermentation and nutritional value. This study aimed to assess the effect of adding crude glycerine and microbial additives on losses, fermentation parameters and nutritional value of haylage. The treatments were composed of three doses of crude glycerine (0, 60 and 120 g/kg forage) and three types of inoculation (control (distilled water), SIL (Lactobacillus plantarum 2.6 × 1010 CFU/g and Pediococcus pentosaceus 2.6 × 1010 CFU/g) and INC (Bacillus subtilis 2.0 × 109 CFU/g, Lactobacillus plantarum 8.0 × 109 CFU/g and Pediococcus acidilactici 1.0 × 1010 CFU/g)). A negative linear effect was observed in the fibre fraction contents of the haylages as a function of crude glycerine addition, which contributed to similarly increasing dry matter in vitro digestibility coefficients. The use of inoculants also resulted in haylages with higher digestibility coefficients of 635.1 and 646.8 g/kg dry matter (DM) in the treatments inoculated with INC and SIL, respectively. Fermentation losses were reduced by adding crude glycerine and were not impacted by the microbial inoculants. Higher lactic acid productions were obtained as a function of crude glycerine doses. Acetic acid productions decreased from 29.3 g/kg DM to 19.2 g/kg DM between crude glycerine doses of 0 and 120 g/kg forage, respectively. SIL led to the highest lactic acid productions compared to INC and the control. Crude glycerine improves the fermentation parameters and nutritional value of haylages. However, the microbial inoculants had little impact on the parameters assessed.

Antimicrobial activity of bacteriocin-like inhibitory substance produced by Pediococcus pentosaceus: from shake flasks to bioreactor.

Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria (LAB), which have a large spectrum of action against spoilage bacteria and foodborne pathogens. However, when not entirely characterized, they are alternatively called bacteriocin-like inhibitory substances (BLIS). Pediococcus pentosaceus ATCC 43200 grew and produced BLIS optimally when cultivated anaerobically in bioreactor for 24 h at 30 °C and 200 rpm in De Man, Rogosa and Sharp (MRS) medium supplemented with 1.5% peptone. Under such optimal conditions, the cell mass concentration (3.41 g/L) was 66% higher, the generation time (1.28 h) 38% shorter and the BLIS activity against different indicator strains significantly higher than in MRS medium without any supplement taken as a control, and the exponential phase started 4 h before. The agar diffusion method showed BLIS inhibition halos against LAB strains with diameter in the range 11.0-19.5 mm and specific areas between 377.1 and 2654.6 mm2/mL, while BLIS activity against Listeria strains was better quantified by the liquid medium assay that showed, for the fermented broth without any dilution, 100 and 50% inhibition of Listeria innocua and Listeria seeligeri growth, respectively. These results highlight the potential of P. pentosaceus BLIS as a natural antimicrobial for application in the food industry.

Pediococcus acidolactici and Pediococcus pentosaceus isolated from a rainbow trout ecosystem have probiotic and ABF1 adsorbing/degrading abilities in vitro.

Probiotics are being used in biological control of bacterial pathogens, as an alternative to antibiotics, to improve health and production parameters in fish farming. Fish farming production is severely affected by aflatoxins (AFs), which are a significant problem in aquaculture systems. Aflatoxins exert substantial impact on production, causing disease with high mortality and a gradual decline of reared fish stock quality. Some aspects of aflatoxicosis in fish, particularly its effects on the gastrointestinal tract, have not been well documented. The aim of the present study was to evaluate probiotic properties of lactic acid bacterial (LAB) strains isolated from rainbow trout intestine and feed. Moreover, AFB1-binding and/or degrading abilities were also evaluated to assess their use in the formulation of feed additives. Growth at pH 2, the ability to co-aggregate with bacterial pathogens, inhibition of bacterial pathogens, and determination of the inhibitory mechanism were tested. Aflatoxin B1 (AFB1) adsorption and degradation ability were also tested. All strains were able to maintain viable (107 cells ml-1) at pH 2. Pediococcus acidilactici RC001 and RC008 showed the strongest antimicrobial activity, inhibiting all the pathogens tested. The strains produced antimicrobial compounds of different nature, being affected by different treatments (catalase, NaOH and heating), which indicated that they could be H2O2, organic acids or proteins. All LAB strains tested showed the ability to coaggregate pathogenic bacteria, showing inhibition percentages above 40%. Pediococcus acidilactici RC003 was the one with the highest adsorption capacity and all LAB strains were able to degrade AFB1 with percentages higher than 15%, showing significant differences with respect to the control. The ability of some of the LAB strains isolated in the present work to compete with pathogens, together with stability against bile and gastric pH, reduction of bioavailability and degradation of AFB1, may indicate the potential of LAB for use in rainbow trout culture.

Stimulating Effects of Sucrose and Inulin on Growth, Lactate, and Bacteriocin Productions by Pediococcus pentosaceus.

Sucrose and inulin, when combined with glucose, behaved as stimulating agents of bacteriocin production by Pediococcus pentosaceus ATCC 43200. When such microbial strain was grown in glucose-based Man, Rogosa, and Sharpe (MRS) medium, without any additional supplement, it showed higher maximum cell concentration (2.68 ± 1.10 g/L) and longer generation time (2.17 ± 0.02 h), but lower specific growth rate (0.32 ± 0.01 h-1) than in the same medium supplemented with 1.0% of both ingredients (2.53 ± 1.10 g/L, 1.60 ± 0.05 h and 0.43 ± 0.02 h-1, respectively). Glucose replacement by sucrose or inulin almost completely suppressed growth, hence confirming that it is the preferred carbon source for this strain. Qualitatively, similar results were observed for lactate production, which was 59.8% higher in glucose-based medium. Enterococcus and Listeria strains were sensitive to bacteriocin, whose antimicrobial effect after 8 h increased from 120.25 ± 0.35 to 144.00 ± 1.41 or 171.00 ± 1.41 AU/mL when sucrose or inulin was added to the glucose-based MRS medium. Sucrose and inulin were also able to speed up P. pentosaceus growth in the exponential phase.

Pediococcus spp.: An important genus of lactic acid bacteria and pediocin producers.

Probiotics have gained increasing attention due to several health benefits related to the human digestive and immune systems. Pediococcus spp. are lactic acid bacteria (LAB) that are widely described as probiotics and characterized as coccus-shaped bacteria (arranged in tetrads), Gram-positive, non-motile, non-spore forming, catalase-negative, and facultative anaerobes. There are many Pediococcus strains that produce pediocin, an effective antilisterial bacteriocin. Pediocins are small, cationic molecules consisting of a conserved hydrophilic N-terminal portion containing the YGNGV motif and an amphiphilic or hydrophobic C-terminal variable portion. A number of studies have been developed with Pediococcus isolated from multiple biological niches to conduct fermentation processes for pediocin or Pediococcus cell production. This review gathers the most significant information about the cultivation, mode of action, and variability of bacteriocins produced by Pediococcus spp., emphasizing their applications in the areas of food and clinical practice. This updated panorama assists in delimiting the challenges that still need to be overcome for pediocin use to be approved for human consumption and the food industry.

Biodiversity and technological potential of lactic acid bacteria isolated from spontaneously fermented amaranth sourdough.

UNLABELLED: Spontaneous fermented sourdoughs prepared from amaranth flour were investigated for the presence of autochthonous lactic acid bacteria (LAB) predominating microbiota. The doughs were fermented with daily backslopping on a laboratory scale at 30°C for 10 days. LAB counts ranged from 2·60 to 8·54 log CFU g(-1) with a pH declined from 6·2 to 3·8 throughout fermentation. The combined use of randomly amplified polymorphic DNA (RAPD)-PCR analysis and sequence analysis of 16S rRNA was applied for LAB intraspecies differentiation and taxonomic identification, respectively. Enterococcus, Pediococcus and Lactobacillus species were present in amaranth sourdoughs (AS). After the first refreshment step, Lactobacillus plantarum dominated AS until the end of fermentation. In coincidence, when DGGE analysis was performed, the occurrence of a progressive change in bacterial communities allowed the selection of Lact. plantarum as a dominant species. Moreover, technological, functional and safety characteristics of representative RAPD-biotypes were investigated. Lact. plantarum CRL1898 was selected as a potential candidate for gluten-free amaranth sourdough starter. SIGNIFICANCE AND IMPACT OF THE STUDY: Nowadays, there is an increasing interest in ancient noncereal gluten-free (GF) crops such as amaranth, due to their reported nutritional and health benefits. However, the use of these grains is still limited to traditional foods and bread making processes that are not yet well standardized. Results on the dynamics of autochthonous lactic acid bacteria (LAB) microbiota during laboratory spontaneous amaranth sourdoughs (AS) fermentation will contribute to overcome challenges for GF-fermented products development. In addition, knowledge about LAB diversity involving Enterococcus, Pediococcus and Lactobacillus species, with Lactobacillus plantarum predominating during AS fermentation, and their technological and functional properties provides the basis for the selection of autochthonous strains as starters cultures for novel gluten-free bakery products with enhanced nutritional, sensory and/or safety quality.

Biological control of AFB1-producing Aspergillus section Flavi strains isolated from brewer's grains, alternative feed intended for swine production in Argentina.

The aim of the present study was to investigate the inhibitory activity of lactic acid bacteria (LAB) isolated from brewer's grains on Aspergillus section Flavi growth and aflatoxin B1 production. The Aspergillus strains tested were inhibited by all the LAB strains assayed. The isolates Lactobacillus brevis B20, P. pentosaceus B86, Lactococcus lactis subsp. lactis B87, L. brevis B131, and Lactobacillus sp. B144 completely suppressed the fungal growth and reduced aflatoxin B1 production. In conclusion, LAB isolated from brewer's grains show a high inhibitory activity on fungal growth and aflatoxin biosynthesis by Aspergillus flavus and Aspergillus parasiticus. Further studies must be conducted to evaluate the success of in vitro assays under food environment conditions and to elucidate the antifungal mechanism of these strains.

Characterization of the phenolic fraction from Argentine wine and its effect on viability and polysaccharide production of Pediococcus pentosaceus.

OBJECTIVES: To qualitatively and quantitatively characterize a low molecular weight phenolic fraction (LMF) of Malbec wine from Cafayate, Argentina, and evaluate its effect on viability and exopolysaccharide production of Pediococcus pentosaceus 12p, a wine spoilage bacterium. RESULTS: The phenolic compounds detected were, in general, comparable to data previously reported but hydroxycinnamic acids were detected at higher concentrations than determined in other studies. Addition of LMF at identical concentrations present in wine or a four times concentrated LMF mixture to a synthetic wine-like medium produced a diminution in bacterial viability and exopolysaccharide production in the supernatant culture. Transmission electron microscopy revealed damage of bacterial cell integrity after 96 h of incubation only in the presence of four times concentrated LMF. CONCLUSION: This is the first time a low molecular weight phenolic fraction has been characterized in Cafayate wine and it has demonstrated a marked antimicrobial effect on an exopolysaccharide-producing wine spoilage bacterium.

In vitro determination of volatile compound development during starter culture-controlled fermentation of Cucurbitaceae cotyledons.

The effects of Lactobacillus plantarum UFLA CH3, Pediococcus acidilactici UFLA BFFCX 27.1, and Torulaspora delbrueckii UFLA FFT2.4 inoculation on the volatile compound profile of fermentation of Cucumeropsis mannii cotyledons were investigated. Different microbial associations were used as starters. All associations displayed the ability to ferment the cotyledons as judged by lowering the pH from 6.4 to 4.4-5 within 24h and increasing organic acids such as lactate and acetate. The population of lactic acid bacteria (LAB) and yeasts increased during fermentation. In the fermentation performed without inoculation (control), the LAB and yeast populations were lower than those in inoculated assays at the beginning, but they reached similar populations after 48 h. The Enterobacteriaceae population decreased during the fermentation, and they were not detected at 48 h in the L. plantarum UFLA CH3 and P. acidilactici UFLA BFFCX 27.1 (LP+PA) and L. plantarum UFLA CH3, P. acidilactici UFLA BFFCX 27.1, and T. delbrueckii UFLA FFT2.4 (LP+PA+TD) samples. The assays inoculated with the yeast T. delbrueckii UFLA FFT2.4 exhibited the majority of volatile compounds (13 compounds) characterized by pleasant notes. The LP+PA+TD association seemed to be appropriate to ferment C. mannii cotyledons. It was able to control the Enterobacteriaceae population, and achieved high concentrations of esters and low concentrations of aldehydes and ketones.

Silagem de milheto (Pennisetum americanum) com inclusão de grãos de sorgo e inoculação microbiana / Sorghum inclusion and microbial inoculation in millet silage (Pennisetum americanum)

Objetivou-se avaliar a qualidade de silagens de milheto, confeccionadas com o uso de aditivos, por meio da avaliação de pH, composição química e digestibilidade in vitro da matéria seca (DIVMS). Os tratamentos consistiram em milheto: com ou sem grãos de sorgo e com ou sem inoculante, em esquema fatorial (2x2). Teores de matéria seca (MS), proteína bruta (PB) e DIVMS aumentaram com a inclusão de sorgo. O pH das silagens com sorgo e inoculadas foi menor que o das silagens de milheto controle. O teor de nitrogênio insolúvel em detergente ácido (NIDA) e de fibra em detergente ácido (FDA) foi menor para a silagem com sorgo. A inoculação não influenciou a MS (23,76%) e DIVMS (48,90%). Houve interação entre inclusão de sorgo e inoculante para fibra em detergente neutro (FDN). A adição de grão de sorgo melhora as características da silagem, resultado de melhor conservação. O uso de inoculante reduz o pH, inibindo fermentações indesejáveis e proporcionando maiores teores de PB...(AU)

The objective of this study was to evaluate the quality of millet silage produced with additives by evaluating pH, chemical composition and in vitro dry matter digestibility (IVDMD). The treatments consisted of millet with or without sorghum grains and with or without microbial inoculant in a factorial scheme (2x2). Dry matter content, crude protein content and IVDMD increased with sorghum inclusion. The pH of silage containing sorghum and microbial inoculant was lower than that of control millet silage. Acid detergent insoluble nitrogen and acid detergent fiber content were lower in silage containing sorghum. Microbial inoculation did not influence dry matter (23.76%) or IVDMD (48.9%). There was an interaction between sorghum inclusion and microbial inoculant for neutral detergent fiber. The addition of sorghum grain and microbial inoculant improves silage characteristics as a result of better preservation. The use of microbial inoculant reduces pH, inhibiting undesirable fermentation and increasing crude protein content...(AU)

Silagem de milheto (Pennisetum americanum) com inclusão de grãos de sorgo e inoculação microbiana / Sorghum inclusion and microbial inoculation in millet silage (Pennisetum americanum)

Objetivou-se avaliar a qualidade de silagens de milheto, confeccionadas com o uso de aditivos, por meio da avaliação de pH, composição química e digestibilidade in vitro da matéria seca (DIVMS). Os tratamentos consistiram em milheto: com ou sem grãos de sorgo e com ou sem inoculante, em esquema fatorial (2x2). Teores de matéria seca (MS), proteína bruta (PB) e DIVMS aumentaram com a inclusão de sorgo. O pH das silagens com sorgo e inoculadas foi menor que o das silagens de milheto controle. O teor de nitrogênio insolúvel em detergente ácido (NIDA) e de fibra em detergente ácido (FDA) foi menor para a silagem com sorgo. A inoculação não influenciou a MS (23,76%) e DIVMS (48,90%). Houve interação entre inclusão de sorgo e inoculante para fibra em detergente neutro (FDN). A adição de grão de sorgo melhora as características da silagem, resultado de melhor conservação. O uso de inoculante reduz o pH, inibindo fermentações indesejáveis e proporcionando maiores teores de PB...

The objective of this study was to evaluate the quality of millet silage produced with additives by evaluating pH, chemical composition and in vitro dry matter digestibility (IVDMD). The treatments consisted of millet with or without sorghum grains and with or without microbial inoculant in a factorial scheme (2x2). Dry matter content, crude protein content and IVDMD increased with sorghum inclusion. The pH of silage containing sorghum and microbial inoculant was lower than that of control millet silage. Acid detergent insoluble nitrogen and acid detergent fiber content were lower in silage containing sorghum. Microbial inoculation did not influence dry matter (23.76%) or IVDMD (48.9%). There was an interaction between sorghum inclusion and microbial inoculant for neutral detergent fiber. The addition of sorghum grain and microbial inoculant improves silage characteristics as a result of better preservation. The use of microbial inoculant reduces pH, inhibiting undesirable fermentation and increasing crude protein content...

Co-culture fermentation of peanut-soy milk for the development of a novel functional beverage.

Most of the commercial probiotic products are dairy-based, and the development of non-dairy probiotic products could be an alternative for new functional products. The peanut-soy milk (PSM(1)) was inoculated with six different lactic acid bacteria (LAB), including probiotic strains and yeasts and fermentation was accomplished for 24h at 37 °C and afterwards, another 24h at ±4 °C. The Pediococcus acidilactici (UFLA BFFCX 27.1), Lactococcus lactis (CCT 0360), Lactobacillus rhamnosus (LR 32) probiotic LAB, and the Lactobacillus delbrueckii subsp. bulgaricus (LB 340) yogurt starter culture reached cell concentrations of about 8.3log CFU/mL during fermentation. However, these strains were not able to acidify the substrate when inoculated as pure culture. The Lactobacillus acidophilus (LACA 4) probiotic produced significant amounts of lactic acid (3.35 g/L) and rapidly lowered the pH (4.6). Saccharomyces cerevisiae (UFLA YFFBM 18.03) did not completely consume the available sugars in PSM and consequently produced low amounts of ethanol (0.24 g/L). In pure culture, S. cerevisiae (UFLA YFFBM 18.03), L. rhamnosus (LR 32), L. acidophilus (LACA 4), and P. acidilactici (UFLA BFFCX 27.1) promoted the increase of total amino acids (48.02%, 47.32%, 46.21% and, 44.07%, respectively). However, when in co-cultured, the strains consumed the free amino acids favoring their growth, and reaching the population of 8log CFU/mL in PSM. Lactic acid production increased, and 12 h was required to reach a pH value of 4.3. In general, the strains were more efficient in the use of available carbohydrates and release of metabolites in co-cultured than in single culture fermentations. An average of 58% and 78% of available carbohydrates was consumed when single and co-cultures were evaluated, respectively. Higher lactic acid contents were found in a binary culture of P. acidilactici (UFLA BFFCX 27.1) and L. acidophilus (LACA 4), and by co-culture of P. acidilactici (UFLA BFFCX 27.1), L. acidophilus (LACA 4) and S. cerevisiae (UFLA YFFBM 18.03) (9.03 and 8.51 g/L, respectively). The final content of ethanol was 0.03% (v/v) or less, which classified the final beverage as non-alcoholic.

Effect of regrowth interval and a microbial inoculant on the fermentation profile and dry matter recovery of guinea grass silages.

The objectives of this study were to characterize and quantify the microbial populations in guinea grass (Panicum maximum Jacq. cultivar Mombasa) harvested at different regrowth intervals (35, 45, 55, and 65 d). The chemical composition and fermentation profile of silages (after 60 d) with or without the addition of a microbial inoculant were also analyzed. Before ensiling, samples of the plants were used for the isolation and identification of lactic acid bacteria (LAB) in the epiphytic microbiota. A 4 × 2 factorial arrangement of treatments (4 regrowth intervals × with/without inoculant) was used in a completely randomized design with 3 replications. Based on the morphological and biochemical characteristics and the carbohydrate fermentation profile, Lactobacillus plantarum was found to be the predominant specie of LAB in guinea grass forage. Linear increases were detected in the dry matter (DM) content and concentrations of neutral detergent fiber, acid detergent fiber, acid detergent insoluble nitrogen, and DM recovery as well as linear reductions in the concentrations of crude protein and NH3-N with regrowth interval. Additionally, linear reductions for gas and effluent losses in silages were detected with increasing regrowth interval. These results demonstrate that guinea grass plants harvested after 55 d of regrowth contain a LAB population sufficiently large to ensure good fermentation and increase the DM recovery. The use of microbial inoculant further enhanced the fermentation of guinea grass at all stages of regrowth by improving the DM recovery.

Principais micro-organismos contaminantes no processo de fabricação de cerveja em microcervejaria / Contaminant micro-organisms in the brewing process microbrewery

A cerveja é uma das bebidas mais consumidas no Brasil e no mundo. O Brasil enquadra-se no 4° lugar do ranking em produção mundial de cerveja, produzindo cerca de 10,34 bilhões de litros por ano. Porém, uma nova modalidade de produção vem despertando interesse econômico em investidores de pequeno a médio porte, os quais produzem a cerveja nas denominadas microcervejarias (cerca de 2% da produção total do país). Junto com seu desenvolvimento, cresce também a preocupação com a qualidade durante seu processamento, despertando para o real perigo da contaminação microbiológica que acarreta em perdas econômicas pela baixa qualidade da cerveja produzida. O presente artigo tem como objetivo fazer uma abordagem no que se refere aos principais micro-organismos envolvidos no processo de fabricação de microcervejarias. Dentre eles estão os principais envolvidos: bactérias do grupo dos Lactobacillos e Pediococcus. (AU)

The beer is one of the most widely consumed beverages in Brazil and worldwide. The Brazil fits the 4th place ranking in global beer production, producing about 10.34 billion gallons per year. However, a new mode of production is economical interest to investors in small to medium size which produce beer in so-called micro breweries (about 2% of total production in the country). Along with its development, so does the concern for quality during processing, real awakening to the danger of microbiological contamination which results in economic losses for the low quality of the beer produced. This article aims to make an approach with regard to the main microorganisms involved in the manufacture of micro breweries. Among them are the principals involved: the group of Lactobacilli bacteria. (AU)

Silagens de milho inoculadas microbiologicamente em diferentes estádios de maturidade: perdas fermentativas, composição bromatológica e digestibilidade in vitro / Corn silage inoculated with lactic acid bacteria in different maturity stages: fermentative losses, chemical composition and in vitro digestibility

Objetivou-se com este estudo avaliar as perdas fermentativas, composição bromatológica e digestibilidade in vitro da matéria orgânica de silagens de milho produzidas em diferentes estádios de maturidade, inoculadas microbiologicamente. Aplicaram-se dois inoculantes comerciais nas silagens produzidas nos estádios SLL, 1/3 LL, 1/2 LL, 2/3 LL e CN, permanecendo ainda um tratamento sem inoculação (silagem controle), configurando um esquema fatorial 3x5. A inoculação com BAL resultou em menores perdas fermentativas (P=0,0348), ao passo que silagens produzidas com plantas mais secas também apresentam menores perdas de MS (P<0,01). A inoculação das silagens resultou em maiores concentrações de PB nas silagens produzidas nos estádios SLL, 2/3 LL e CN (P=0,0033). O uso do inoculante Maize All® resultou em menor concentração de FDN (P=0,0140) no estádio CN e acréscimo dos coeficientes de DIVMO quando as plantas foram colhidas com 2/3 LL e CN (P=0,0006). As perdas fermentativas diminuem devido à utilização dos inoculantes bacterianos e também em silagens produzidas com plantas mais secas. A aplicação de bactérias ácido-láticas (inoculante Maize All®) em silagens de milho produzidas com plantas em estádio de maturidade mais avançado melhora a composição química e digestibilidade in vitro.(AU)

The aim of this study was to evaluate the fermentative losses, chemical composition and in vitro organic matter digestibility of corn silages produced in different maturity stages microbiologically inoculated. Two commercial inoculants were applied in the silages produced in stages SLL, 1/3 LL, 1/2 LL, 2/3 LL and CN, remaining an uninoculated treatment (control silage), illustrating a factorial scheme 3 x 5. The lactic acid bacteria (LAB) inoculation resulted in lower fermentative losses (P=0.0348), whereas silages produced with dried plants present lower DM losses (P<0.01). Because of inoculant application, there was higher concentrations of CP in the silages produced in stages SLL, 2/3 LL and CN (P=0.0033) and concentration lower of NDF (P=0.0140) in CN stage because of the Maize All® inoculant. This inoculant provided increase in the IVOMD coefficients when the plants were harvested with 2/3 LL and CN (P= 0.0006). Fermentative losses decreased because of the use of microbial inoculants, and this fact it is also observed in silages produced with dried plants. Application of lactic acid bacteria (Maize All® inoculant) in corn silages produced with plants harvested in more advanced stages of maturity improve the chemical composition and in vitro digestibility.(AU)

Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements.

The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 10(9) CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 10(10) CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection.