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Microorganisms Jan 2024The Gram-negative, strictly anaerobic bacterium was first isolated from the rumen in 1953 and is common in the mammalian gastrointestinal tract. Its ability to use... (Review)
Review
The Gram-negative, strictly anaerobic bacterium was first isolated from the rumen in 1953 and is common in the mammalian gastrointestinal tract. Its ability to use either lactate or glucose as its major energy sources for growth has been well documented, although it can also ferment amino acids into ammonia and branched-chain fatty acids, which are growth factors for other bacteria. The ruminal abundance of usually increases in animals fed grain-based diets due to its ability to use lactate (the product of rapid ruminal sugar fermentation), especially at a low ruminal pH (<5.5). has been proposed as a potential dietary probiotic to prevent ruminal acidosis in feedlot cattle and high-producing dairy cows. However, this bacterium has also been associated with milk fat depression (MFD) in dairy cows, although proving a causative role has remained elusive. This review summarizes the unique physiology of this intriguing bacterium and its functional role in the ruminal community as well as its role in the health and productivity of the host animal. In addition to its effects in the rumen, the ability of to produce C-C carboxylic acids-potential precursors for industrial fuel and chemical production-is examined.
PubMed: 38276203
DOI: 10.3390/microorganisms12010219 -
Frontiers in Microbiology 2019is an ecologically important rumen bacterium that metabolizes lactate and relieves rumen acidosis (RA) induced by a high-grain-diet. Understanding the regulatory...
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 RA. was co-cultured with four lactate producers (, , , and ) and a series of substrate starch doses (1, 3, and 9 g/L) were used to induce one normal and two RA models (subacute rumen acidosis, SARA and acute rumen acidosis, ARA) under batch conditions. The associations between bacterial competition and the shift of organic acids' (OA) accumulation patterns in both statics and dynamics manners were investigated in RA models. Furthermore, we examined the effects of substrate lactate concentration and pH on lactate degradation pattern and genes related to the lactate utilizing pathways in the continuous culture. The positive growth of and caused OA accumulation in the SARA model to shift from lactate to butyrate and resulted in pH recovery. Furthermore, both the quantities of substrate lactate and pH had remarkable effects on lactate utilization due to the transcriptional regulation of metabolic genes, and the lactate utilization in was more sensitive to pH changes than to the substrate lactate level. In addition, compared with associations based on statics data, associations discovered from dynamics data showed greater significance and gave additional explanations regarding the relationships between bacterial competition and OA accumulation.
PubMed: 30792704
DOI: 10.3389/fmicb.2019.00162 -
Scientific Reports May 2022This study aimed to evaluate the effects of Saccharomyces cerevisiae and Megasphaera elsdenii as direct fed microbials (DFM) in beef cattle finishing diets to alleviate...
This study aimed to evaluate the effects of Saccharomyces cerevisiae and Megasphaera elsdenii as direct fed microbials (DFM) in beef cattle finishing diets to alleviate acute ruminal lactic acidosis in vitro. A dual-flow continuous culture system was used. Treatments were a Control, no DFM; YM1, S. cerevisiae and M. elsdenii strain 1; YM2, S. cerevisiae and M. elsdenii strain 2; and YMM, S. cerevisiae and half of the doses of M. elsdenii strain 1 and strain 2. Each DFM dose had a concentration of 1 × 10 CFU/mL. Four experimental periods lasted 11 days each. For the non-acidotic days (day 1-8), diet contained 50:50 forage to concentrate ratio. For the challenge days (day 9-11), diet contained 10:90 forage to concentrate ratio. Acute ruminal acidosis was successfully established. No differences in pH, D-, L-, or total lactate were observed among treatments. Propionic acid increased in treatments containing DFM. For N metabolism, the YMM treatment decreased protein degradation and microbial protein synthesis. No treatment effects were observed on NH-N concentration; however, efficiency of N utilization by ruminal bacteria was greater than 80% during the challenge period and NH-N concentration was reduced to approximately 2 mg/dL as the challenge progressed.
Topics: Acidosis; Animal Feed; Animals; Cattle; Diet; Fermentation; Hydrogen-Ion Concentration; Megasphaera elsdenii; Rumen; Saccharomyces cerevisiae
PubMed: 35562415
DOI: 10.1038/s41598-022-11959-2 -
Journal of Clinical Microbiology Jul 1979A case of endocarditis caused by Megasphaera elsdenii is reported. This anaerobic grim-negative coccus has rarely been associated with human infections and has not...
A case of endocarditis caused by Megasphaera elsdenii is reported. This anaerobic grim-negative coccus has rarely been associated with human infections and has not previously been described as a cause of endocarditis.
Topics: Anaerobiosis; Blood; Endocarditis, Bacterial; Fatty Acids; Humans; Male; Middle Aged; Veillonellaceae
PubMed: 500797
DOI: 10.1128/jcm.10.1.72-74.1979 -
Journal of Animal Physiology and Animal... Mar 2019Two consecutive experiments were carried out to determine efficacy of Megasphaera elsdenii inoculation in alleviation of subacute ruminal acidosis (SARA). In the first...
Two consecutive experiments were carried out to determine efficacy of Megasphaera elsdenii inoculation in alleviation of subacute ruminal acidosis (SARA). In the first experiment, SARA was induced by feeding corn- and wheat-based diets (20%, 40%, 60% and 80% of TMR, DM basis) in six ruminally cannulated heifers. Continuous pH was obtained using data loggers embedded in rumen. In corn (80%)- and wheat (60%)-based diets ruminal pH ranged from 5.2 to 5.6 for 7.77 and 5.93 hr. In the second experiment (5 day), M. elsdenii (200 ml; 2.4 x 10 cfu/ml) was inoculated during the first two days. During the SARA induction period, M. elsdenii and S. bovis in rumen liquor were more abundant in wheat-based feeding (7.97 and 8.77) than in corn-based feeding (7.06 and 7.95 per ml, log basis; p < 0.0001 for both). M. elsdenii inoculation increased total volatile fatty acids (VFA) concentration when corn-based diet was fed, whereas it decreased total VFA concentration when wheat-based diet was fed (p < 0.004). There was a decrease in the propionic acid proportion (24.04%-19.08%; p < 0.002), whereas no alteration in lactate and ammonia concentrations was observed. M. elsdenii inoculation increased protozoa count (from 5.39 to 5.55 per ml, log basis; p < 0.009) and decreased S. bovis count (from 9.18 to 7.95 per ml, log basis; p < 0.0001). The results suggest that M. elsdenii inoculation may help prevent SARA depending on dietary grain through altering rumen flora as reflected by a decrease in S. bovis count and an increase in protozoa count.
Topics: Acidosis; Animals; Blood Glucose; Cattle; Cattle Diseases; Hematocrit; Hydrogen-Ion Concentration; Megasphaera elsdenii; Rumen; Stomach Diseases
PubMed: 30588673
DOI: 10.1111/jpn.13034 -
Journal of Bioscience and Bioengineering May 2018Megasphaera elsdenii is able to produce several short-chain fatty acids (SCFAs), such as acetate, propionate, butyrate, and valerate. These SCFAs serve as an energy...
Megasphaera elsdenii is able to produce several short-chain fatty acids (SCFAs), such as acetate, propionate, butyrate, and valerate. These SCFAs serve as an energy source for host animals and play an important role in gut health. In this study, M. elsdenii was isolated from pig feces that had been collected from two farms located in distinct areas of Japan. These M. elsdenii isolates were genotyped, and 7 representative strains were selected. When these 7 strains and M. elsdenii JCM 1772 were cultured with lactate for 24 h, all 7 strains produced valerate as a predominant SCFA. Therefore, the valerate-producing M. elsdenii inhabits a wide area of Japan. In contrast, M. elsdenii JCM 1772 produced acetate, propionate, butyrate, and valerate at similar levels. When the Y2 strain, one of the 7 representative strains, was cultured without lactate, low levels of valerate accumulated. In contrast, in a time course of lactate fermentation by the Y2 strain, lactate was rapidly consumed, and acetate and propionate were produced after 6 h of incubation. Thereafter, acetate and propionate were consumed from 6 to 12 h after the start of the incubation, and valerate and butyrate were produced. In most of the previously described M. elsdenii strains, valerate was not a predominant SCFA. Therefore, the M. elsdenii Y2 strain showed an unique metabolism in which valerate was produced as a primary end product of lactate fermentation.
Topics: Animals; Butyrates; Fatty Acids, Volatile; Feces; Fermentation; Lactic Acid; Megasphaera elsdenii; Pentanoic Acids; Phylogeny; Propionates; Rumen; Swine; Valerates
PubMed: 29331526
DOI: 10.1016/j.jbiosc.2017.12.016 -
Translational Animal Science 2023Our objective was to evaluate the effects of combinations of and as direct-fed microbials (DFM) on ruminal microbiome during an acute acidosis challenge in a...
Our objective was to evaluate the effects of combinations of and as direct-fed microbials (DFM) on ruminal microbiome during an acute acidosis challenge in a continuous culture system. Treatments provided a DFM dose of 1 × 10 colony-forming unit (CFU)/mL, as follows: control (no DFM), YM1 ( and strain 1), YM2 ( and strain 2), and YMM ( and half of the doses of strains 1 and 2). We conducted four experimental periods of 11 d, which consisted of non-acidotic days (1 to 8) and acidotic challenge days (9 to 11) to establish acute ruminal acidosis conditions with a common basal diet containing 12% neutral detergent fiber and 58% starch. Treatments were applied from days 8 to 11, and samples of liquid and solid-associated bacteria were collected on days 9 to 11. Overall, 128 samples were analyzed by amplification of the V4 region of bacterial 16S rRNA, and data were analyzed with R and SAS for alpha and beta diversity, taxa relative abundance, and correlation of taxa abundance with propionate molar proportion. We observed a lower bacterial diversity (Shannon index, = 0.02) when YM1 was added to the diet in comparison to the three other treatments. Moreover, compared to control, addition of YM1 to the diet increased relative abundance of phylum ( = 0.05) and family ( = 0.05) in the solid fraction and tended to increase abundance of family ( = 0.10) and genus ( = 0.09) in the liquid fraction. Correlation analysis indicated a positive association between propionate molar proportion and relative abundance of ( = 0.36, = 0.04) and ( = 0.36, = 0.05) in the solid fraction. The inclusion of YM1 in high-grain diets with a high starch content resulted in greater abundance of bacteria involved in succinate synthesis which may have provided the substrate for the greater propionate synthesis observed.
PubMed: 38023425
DOI: 10.1093/tas/txad123 -
Anaerobe Dec 2017Lactic acid produced by intestinal bacteria is fermented by lactate-utilizing bacteria. In this study, we developed a selective culture medium (KMI medium) for...
Lactic acid produced by intestinal bacteria is fermented by lactate-utilizing bacteria. In this study, we developed a selective culture medium (KMI medium) for Megasphaera elsdenii, a lactate-utilizing bacterium that is abundant in pig intestines. Supplementation of the medium with lactate and beef extract powder was necessary for the preferential growth of M. elsdenii. In addition, we designed a species-specific primer set to detect M. elsdenii. When pig fecal samples were plated on KMI agar medium, approximately 60-100% of the resulting colonies tested positive using the M. elsdenii-specific PCR primers. In fact, nearly all of the large, yellow-white colonies that grew on the KMI agar medium tested positive by PCR with this primer set. The 16S rRNA gene sequences of three representative PCR-positive strains showed strong similarities to that of M. elsdenii ATCC 25940 (98.9-99.2% identity). These three strains were approximately 1.5 μm sized cocci that were primarily arranged in pairs, as was observed for M. elsdenii JCM 1772. The selective KMI medium and species-specific primer set developed in this study are useful for the isolation and detection of M. elsdenii and will be useful in research aimed at increasing our understanding of intestinal short-chain fatty acid metabolism in pigs.
Topics: Animals; Feces; Megasphaera elsdenii; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Swine
PubMed: 28842275
DOI: 10.1016/j.anaerobe.2017.08.013 -
Animal Bioscience Jun 2023This study was conducted to evaluate the use of Megasphaera elsdenii (M. elsdenii) as a probiotic on rumen fermentation, production performance, carcass traits and...
OBJECTIVE
This study was conducted to evaluate the use of Megasphaera elsdenii (M. elsdenii) as a probiotic on rumen fermentation, production performance, carcass traits and health of ruminants by integrating data from various related studies using meta-analysis.
METHODS
A total of 32 studies (consisted of 136 data points) were obtained and integrated into a database. The parameters integrated were fermentation products, rumen microbes, production performance, carcass quality, animal health, blood and urine metabolites. Statistical analysis of the compiled database used a mixed model methodology. Different studies were considered random effects, while M. elsdenii supplementation doses were considered fixed effects. p-values and the Akaike information criterion were employed as model statistics. The model was deemed significant at p<0.05 or had a tendency to be significant when p-value between 0.05〈p〈0.10.
RESULTS
Supplementation with M. elsdenii increased (p<0.05) some proportion of fermented rumen products such as propionate, butyrate, isobutyrate, and valerate, and significantly reduced (p<0.05) lactic acid concentration, acetate proportion, total bacterial population and methane emission. Furthermore, the probiotic supplementation enhanced (p<0.05) livestock production performance, especially in the average daily gain and body condition score. Regarding the carcass quality, hot carcass weight and carcass gain were elevated (p<0.05) due to the M. elsdenii supplementation. Animal health also showed improvement as indicated by the lower (p<0.05) diarrhoea and bloat incidences as well as the liver abscess. However, M. elsdenii supplementation had negligible effects on blood and urine metabolites of ruminants.
CONCLUSION
Supplementation of M. elsdenii is capable of decreasing ruminal lactic acid concentration, enhancing rumen health, elevating some favourable rumen fermentation products, and in turn, increasing production performance of ruminants.
PubMed: 36634661
DOI: 10.5713/ab.22.0258 -
Bioresource Technology Jan 2022Numerous attempts have been made to upscale biohydrogen production via dark fermentation (DF); however, the Achilles' heel of DF, i.e., lactic acid bacteria (LAB)...
Numerous attempts have been made to upscale biohydrogen production via dark fermentation (DF); however, the Achilles' heel of DF, i.e., lactic acid bacteria (LAB) contamination and overgrowth, hinders such upscaling. Key microbes are needed to develop a lactate-driven DF system that can serve as a lactate fermentation platform. In this study, the utility of Megasphaera elsdenii and LAB co-culturing in lactate-driven DF was evaluated. When inoculated simultaneously with LAB or after LAB culture, M. elsdenii achieved a stable hydrogen yield of 0.95-1.49 H-mol/mol-glucose, approximately half that obtained in pure M. elsdenii cultures. Hydrogen production was maintained even at an initial M. elsdenii-to-LAB cell ratio of one-millionth or less. Moreover, M. elsdenii produced hydrogen via lactate-driven DF from unusable sugars such as xylose or cellobiose. Thus, M. elsdenii could be a Game changer instrumental in unlocking the full potential of DF.
Topics: Animals; Fermentation; Hydrogen; Lactic Acid; Lactobacillales; Megasphaera elsdenii; Rumen
PubMed: 34601026
DOI: 10.1016/j.biortech.2021.126076