Effect of long-term application of animal slurries to grassland on silage quality assessed in laboratory silos

The effect on silage quality of slurry type (pig or cow), rate of application of slurry (50, 100 or 200 m³ ha^?1 year^?1) and use of a bacterial silage inoculant, was assessed on grass from a long-term slurry experiment ensiled in laboratory silos. There was no significant effect of slurry type or the quality of silage made from grass re growths. However, on the basis of ammonia-N, lactate and volatile fatty acid contents, spring (first cut) grass treated with cow slurry in both years of the study produced significantly poorer fermentation (P < 0.001) than silage from grass treated with pig slurry. The quality of silage made from slurry-treated swards compared favourably with that from swards treated with granular fertiliser. Although increasing the rate of slurry application was shown to reduce fermentation quality in most treatments, this was seen as an effect of increasing the total-N content of the herbage rather than of slurry application per se. From a study, in selected treatments, of the bacterial flora at harvest, it was also observed that slurry application had little impact on either the composition or diversity of herbage enter bacteria at harvest, and therefore probably upon subsequent fermentation. No evidence was found for the occurrence of clostridia on herbage from slurry-treated swards. Use of a bacterial inoculant (Ecosyl; ICI plc) improved fermentation quality significantly (P < 0.001) even where high rates of slurry (200 m³ ha^?1 year^?1) had been applied to swards. The high acetate and butyrate contents typical of laboratory silages untreated with additive were not seen in the inoculated silages.     

藏灵菇源酸奶复合菌发酵剂对肠道菌群平衡的作用

目的:探讨藏灵菇源酸奶复合菌发酵剂对实验性高胆固醇血症大鼠调节肠道菌群平衡的作用.方法:根据大鼠血清总胆固醇水平分组.高脂模型组和试验Ⅰ、Ⅱ组饲喂高脂饲料,对照组饲喂基础饲料;试验Ⅰ组灌胃脱脂酸奶复合菌发酵剂,试验Ⅱ组灌胃全脂酸奶复合菌发酵剂,对照组和模型组给予蒸馏水,连续8周.结果:对照组大鼠的粪便中乳杆菌、肠杆菌和产气荚膜梭菌的活菌数量处于平稳状态;4周后高脂模型组大鼠的粪便中乳杆菌的活菌数量极显著低于对照组(p＜0.01),而6周后肠杆菌和产气荚膜梭菌的活菌数量极显著高于对照组(p＜0.01);试验Ⅰ组和试验Ⅱ组大鼠粪便中乳杆菌的活菌数量分别在4周和6周开始极显著高于高脂模型组(p＜0.01),而肠杆菌和产气荚膜梭菌的活菌数量极显著低于高脂模型组(p＜0.01);试验Ⅰ组调节肠道菌群平衡效果优于试验Ⅱ组.结论:藏灵菇源酸奶复合菌发酵剂能够促进高胆固醇血症大鼠肠道有益菌的生长,并抑制有害菌的繁殖,具有明显调节肠道菌群平衡作用.     

LSPR-Based Biosensing Enables the Detection of Antimicrobial Resistance Genes

The development of rapid, simple, and accurate bioassays for the detection of nucleic acids has received increasing demand in recent years. Here, localized surface plasmon resonance (LSPR) spectroscopy for the detection of an antimicrobial resistance gene, sulfhydryl variable β-lactamase (blaSHV), which confers resistance against a broad spectrum of β-lactam antibiotics is used. By performing limit of detection experiments, a 23 nucleotide (nt) long deoxyribonucleic acid (DNA) sequence down to 25 nm was detected, whereby the signal intensity is inversely correlated with sequence length (23, 43, 63, and 100 nt). In addition to endpoint measurements of hybridization events, the setup also allowed to monitor the hybridization events in real-time, and consequently enabled to extract kinetic parameters of the studied binding reaction. Performing LSPR measurements using single nucleotide polymorphism (SNP) variants of blaSHV revealed that these sequences can be distinguished from the fully complementary sequence. The possibility to distinguish such sequences is of utmost importance in clinical environments, as it allows to identify mutations essential for enzyme function and thus, is crucial for the correct treatment with antibiotics. Taken together, this system provides a robust, label-free, and cost-efficient analytical tool for the detection of nucleic acids and will enable the surveillance of antimicrobial resistance determinants.     

Ensiling of Manured Crops—Does Repeated Spreading of Slurry Increase the Hygienic Risk?

The influence of cattle slurry applied to a silage crop was studied in three successive years. Each year, 40 t slurry ha^-1 were applied in two equal applications. Unfertilised and mineral-fertilised field plots were used as controls. Before spreading, the slurry was contaminated with spores of Clostridium tyrobutyricum (10³–10⁴ g^-1 FM). The fields were harvested two times a year, the yields were measured and the chemical composition and bacterial content of the crop were determined. The fresh material was chopped, ensiled without additives, and stored for 100 days before opening. The bacterial content of the soil surface and available N, P and K in soil were measured. Slurry did not seem to have any significance in a short-term perspective. Yield increase as an effect of slurry application was slight and inconsistent in comparison with the yield from unfertilised plots. The number of Clostridium or Bacillus spores in the soil surface was not significantly affected by the slurry application, nor was the number of detrimental organisms in harvested crop at ensiling. Nonetheless, in three of the four silages in which clostridial spores were estimated, numbers were higher in silage made from slurry-treated crops. © 1997 SCI.     

Microbial acidification,alcoholization, and aroma production during spontaneous lambic beer production

Acidic beers, such as Belgian lambic beers and American and other coolship ales, are becoming increasingly popular worldwide thanks to their refreshing acidity and fruity notes. The traditional fermentation used to produce them does not apply pure yeast cultures but relies on spontaneous, environmental inoculation. The fermentation and maturation process is carried out in wooden barrels and can take up to three years. It is characterized by different microbial species belonging to the enterobacteria, acetic acid bacteria, lactic acid bacteria, and yeasts. This review provides an introduction to the technology and four fermentation strategies of beer production, followed by the microbiology of acidic beer production, focusing on the main microorganisms present during the long process used for the production of Belgian lambic beers. © 2018 Society of Chemical Industry     

The numbers of epiphytic bacteria on grass at ensilage on commercial farms

The numbers of lactic acid bacteria and enterobacteria on herbage at the silage pit on commercial farms in Durham and Northumberland were determined in 1987 and 1988. The mean number of lactic acid bacteria were higher (P <0.01) in 1987 (second silage cut) than in 1988 (first silage cut); mean values were 5.46 and 4.85 log₁₀ colony-forming units g^?1 herbage, respectively, when enumerated on MRS agar. In 1988, when Rogosa agar was used to enumerate the lactic acid bacteria in addition to MRS agar, the numbers of lactic acid bacteria recovered were substantially less than on MRS agar. These results are discussed in relation to epiphytic lactic acid bacteria numbers reported in the literature and to recommended application rates of inoculant-type silage additives. The epiphytic enterobacteria did not differ in numbers between years and had a mean value of 4.76 log₁₀ colonyforming units g^?1 herbage.     

大蒜对干发酵香肠中肠道菌的抑制作用研究

本文以植物乳杆菌6003作为乳酸菌发酵剂，以大肠菌O139和鼠伤寒沙门氏菌代表肠道菌，添加于模拟干发酵香肠肉汤中。通过不同浓度的大蒜对模拟肉汤影响研究，表明0．05％大蒜和0．1％大蒜即分别能有效延缓模拟肉汤中鼠伤寒沙门氏菌的增殖及大肠菌O139的增殖。l％的大蒜能完全阻止二种肠道菌在发酵期间的增殖。1％浓度大蒜对乳酸菌发酵剂没有抑制作用。     

食盐与大蒜发酵泡菜品质的对比分析

以大白菜为原料,研究不同浓度的食盐与不同质量分数的大蒜在发酵泡菜中生化指标（pH,可滴定酸,亚硝酸盐）,微生物指标（细菌总量,乳酸菌,肠杆菌）,感官评价（颜色,香气,滋味,质地）的相似点与差异性。结果表明：6种泡菜第10d后都具有较高的安全性,大蒜与食盐具有相似的抑菌效果,5％大蒜与4％的食盐在发酵的过程中各种指标变化相当,其中5％大蒜的感官评价最高。     

Influence of farmyard manure on the quality of grass silage

The influence of adding small aggregates (5 g) of farmyard manure (FYM) and/or a bacteria suspension (BS), containing Escherichia coli, and spores of Bacillus cereus and Clostridium tyrobutyricum, to silage was studied in two successive years. Direct cut (approximately 200 g DM kg⁻¹), precision-chopped grass herbage was ensiled in 1·6 l experimental silos. At ensiling the BS was either well distributed in the crop or added directly to 5 g of grass or FYM, which was placed in the centre of the green material when the silos were filled. Silage was further treated with formic acid (4 kg t⁻¹ FM), or an inoculant of lactic acid bacteria (10⁶ cfu g⁻¹ FM), and compared with no additive. Only minor influences on silage quality resulted from the addition of BS, although the number of clostridial spores increased slightly. Silages given additions of small aggregates of FYM were of poor quality. The inferior silage with a high number of clostridial spores (⩾3·9 cfu g⁻¹) and a high concentration of butyric acid (⩾2·8 g kg⁻¹) was found in the immediate vicinity of the addition. Application of silage additives did not improve silage quality. The poor quality of ‘FYM-silages’ could not solely be explained by the high number of organisms, but other factors in the manure and/or crops may contribute to the poor silage fermentation. © 1997 SCI.