Effects of the acid-tolerant engineered bacterial strain Megasphaera elsdenii H6F32 on ruminal pH and the lactic acid concentration of simulated rumen acidosis in vitro
The aim of this study was to examine the effects of the acid-tolerant engineered bacterial strain Megasphaera elsdenii H6F32 (M. elsdenii H6F32) on ruminal pH and the lactic acid concentrations in simulated rumen acidosis conditions in vitro. A mixed culture of ruminal bacteria, buffer, and primarily degradable substrates was inoculated with equal numbers of M. elsdenii H6 or M. elsdenii H6F32. The pH and lactic acid concentrations in the mixed culture were determined at 0, 2, 4, 6, 8, 10, 12, 14, 16, and 18 h of incubation. Acid-tolerant M. elsdenii H6F32 reduced the accumulation of lactic acid and increased the pH value. These results indicate that acid-tolerant M. elsdenii H6F32 could be a potential candidate for preventing rumen acidosis.
Abstract The objectives were: (a) to select the most effective lactate-utilizing Megasphaera elsdenii ( Me ) isolates (strains) from mixed rumen cultures (Phase 1) and (b) to determine in vivo the efficacy of the two most promising isolates from Phase 1 to control ruminal acidosis (Phase 2). In Phase 1 batch cultures of nine strains of lactate-utilizing Me were isolated and compared with the Me type strain ATCC 25940 and a membrane-filtered supernatant of a centrifuged culture (Control). Culture...
In vitro fermentations containing a mixed culture of ruminal bacteria (ruminal fluid from a hay-fed steer), buffer, and primarily rapidly degradable substrates (starch, glucose, cellulose, cellobiose, and trypticase) were inoculated with an overnight culture of Megasphaera elsdenii B159. Triplicate flasks were either uninoculated or inoculated to obtain a final concentration of 8.7×10 5 and 8.7×10 6 colony forming units of M. elsdenii per milliliter of culture fluid. Inoculation with M. elsdenii...
#2Limin Kung(UD: University of Delaware)H-Index: 29
Abstract Using a purified diet and a mixed culture of ruminal microorganisms, we studied the in vitro effects of a sulfur-containing peptide (A10255) and monensin on ruminal VFA and lactic acid concentrations. After 22h of fermentation, total VFA concentration was greater in cultures with A10255 and monensin (2.5ppm each) than in untreated controls (84.1, 91.9, and 65.2m M for cultures with A10255, monensin, and control, respectively). The molar proportions of propionate were more than 40% great...
Since Megasphaera elsdenii ferments a variable part of dl-lactate to butyrate, measurement of the percentage of dl-lactate fermented to propionate via the acrylate pathway in rumen contents will underestimate the participation of M. elsdenii in the dl-lactate fermentation. The percentage of dl-[2-13C]lactate fermented via the acrylate pathway and the percentage of dl-lactate fermented to butyrate can be measured with 13C-FT (Fourier transform)-nuclear magnetic resonance. On the average, the cont...
#1Theresa Orton(University of Veterinary Medicine Vienna)H-Index: 1
#2Karl Rohn(University of Veterinary Medicine Vienna)H-Index: 21
Last. Melanie Brede(University of Veterinary Medicine Vienna)H-Index: 1
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Subacute rumen acidosis (SARA) is a common problem in dairy cattle. High-concentrate rations lead to an accumulation of short-chain fatty acids (SCFA) in the rumen and a subsequent decrease in ruminal pH. As SARA impairs animal welfare and productivity, numerous in vivo studies are focusing on evaluation of prevention strategies. In vitro models can support this research and reduce animal numbers and experimental costs. We used different diets and buffer compositions to induce SARA in the rumen ...
Intake in sugar-rich diets can be limited either via rumen fill or excessive rumen fermentation and source of non-fibre carbohydrate (NFC) in the diet can affect both factors. The aim of the current study was to quantify the effect of partially replacing ground maize (GM) with steam-rolled maize (SRM) or pelleted citrus pulp (PCP) at two concentrate levels in sugarcane-based diets on digestibility, rumen ecosystem and metabolism of Nellore steers. Six rumen-cannulated steers were assigned to a 6...
Last. Hongrong Wang(YZU: Yangzhou University)H-Index: 10
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Background: Megasphaera elsdenii is an ecologically important rumen bacterium that metabolizes lactate and relieves rumen acidosis (RA) induced by a high-grain-diet. Understanding the regulatory mechanisms of the lactate metabolism of this species in RA conditions might contribute to developing dietary strategies to alleviate rumen acidosis. Methods: Megasphaera elsdenii was co-cultured with four lactate producers (Streptococcus bovis, Lactobacilli fermentum, Butyrivibrio fibrisolvens and Seleno...
Abstract This study was aimed to evaluate the potential of lactic acid utilizing bacteria in controlling ruminal acidosis in vitro in sheep and their effect as direct fed microbial in dairy cow nutrition. In first in vitro trial, effects of four isolates of Megasphaera elsdenii (SA1, SA2, SA3 and SA4) that were isolated from rumen of Holstein cows were examined on decrease of lactic acid and control of pH in a mixed culture of sheep rumen microorganisms. Gas production, pH, lactic acid and volat...
The rumen microbiome is fundamental for the productivity and health of dairy cattle and diet is known to influence the rumen microbiota composition. In this study, grape-pomace, a natural source of polyphenols, and copper sulfate were provided as feed supplementation in 15 Holstein-Friesian calves, including 5 controls. After 75 days of supplementation, genomic DNA was extracted from the rumen liquor and prepared for 16S rRNA-gene sequencing to characterize the composition of the rumen microbiot...
Last. Toshinari Maeda(Kyushu Institute of Technology)H-Index: 29
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Abstract The potential utilization of phospholine gum, a by-product of the palm oil industry was evaluated using waste sewage sludge (WSS) as a substrate as well as a microbial source to mimic methane production by enteric fermentation. Ruminant animals release enteric methane through their digestive process. The enteric methane is one of the greenhouse gases that can contribute to global warming and should be prevented. In this study, methane production was remarkably inhibited by adding phosph...
Last. Steven D. Brown(ORNL: Oak Ridge National Laboratory)H-Index: 39
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Microorganisms are key components for plant biomass breakdown within rumen environments. Fibrobacter succinogenes have been identified as being active and dominant cellulolytic members of the rumen. In this study, F. succinogenes type strain S85 was adapted for steady state growth in continuous culture at pH 5.75 and confirmed to grow in the range of pH 5.60–5.65, which is lower than has been reported previously. Wild type and acid tolerant strains digested corn stover with equal efficiency in b...
The aim of this study was to investigate the effects of sugarcane neutral detergent fiber digestibility (NDFD), conservation method, and concentrate level on the ruminal microbial population of steers. Eight ruminal-cannulated Nellore steers were distributed in two contemporary 4 × 4 Latin Square design with a 2 × 2 factorial arrangement of treatments. Experiment 1: diets were formulated with 60% of concentrate level, and two sugarcane genotypes (high or low NDFD) either freshly cut or as silage...
Ruminal acidosis is a prevalent disorder among dairy cows and feedlot cattle, which can significantly impair their health and productivity. This study, involving seven different strains of dairy propionibacteria, represents an in vitro investigation of the feasibility of using these organisms as direct-fed microbials to control lactic acid acumulation in the rumen. Interactions between the propionibacteria, Streptococcus bovis and Megasphaera elsdenii were evaluated in terms of effects on lactic...
Last. Severino Segato(UNIPD: University of Padua)H-Index: 14
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Background The aim of this study was to investigate the effects of two feed supplements on rumen bacterial communities of heifers fed a high grain diet. Six Holstein-Friesian heifers received one of the following dietary treatments according to a Latin square design: no supplement (control, C), 60 g/day of fumarate-malate (organic acid, O) and 100 g/day of polyphenol-essential oil (P). Rumen fluid was analyzed to assess the microbial population using Illumina sequencing and quantitative real tim...
