scholarly journals Effects of Methanogenic Inhibitors on Methane Production and Abundances of Methanogens and Cellulolytic Bacteria inIn VitroRuminal Cultures

2011 ◽  
Vol 77 (8) ◽  
pp. 2634-2639 ◽  
Author(s):  
Zhenming Zhou ◽  
Qingxiang Meng ◽  
Zhongtang Yu
Keyword(s):  
Methane Production ◽  
Volatile Fatty Acids ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Cellulolytic Bacteria ◽  
Bacterial Populations ◽  
Content Type ◽  
Specific Pcr ◽  
Methanogen Population ◽  
Propynoic Acid

ABSTRACTThe objective of this study was to systematically evaluate and compare the effects of select antimethanogen compounds on methane production, feed digestion and fermentation, and populations of ruminal bacteria and methanogens usingin vitrocultures. Seven compounds, including 2-bromoethanesulphonate (BES), propynoic acid (PA), nitroethane (NE), ethyltrans-2-butenoate (ETB), 2-nitroethanol (2NEOH), sodium nitrate (SN), and ethyl-2-butynote (EB), were tested at a final concentration of 12 mM. Ground alfalfa hay was included as the only substrate to simulate daily forage intake. Compared to no-inhibitor controls, PA, 2NEOH, and SN greatly reduced the production of methane (70 to 99%), volatile fatty acids (VFAs; 46 to 66%), acetate (30 to 60%), and propionate (79 to 82%), with 2NEOH reducing the most. EB reduced methane production by 23% without a significant effect on total VFAs, acetate, or propionate. BES significantly reduced the propionate concentration but not the production of methane, total VFAs, or acetate. ETB or NE had no significant effect on any of the above-mentioned measurements. Specific quantitative-PCR (qPCR) assays showed that none of the inhibitors significantly affected total bacterial populations but that they did reduce theFibrobacter succinogenespopulation. SN reduced theRuminococcus albuspopulation, while PA and 2NEOH increased the populations of bothR. albusandRuminococcus flavefaciens. Archaeon-specific PCR-denaturing gradient gel electrophoresis (DGGE) showed that all the inhibitors affected the methanogen population structure, while archaeon-specific qPCR revealed a significant decrease in methanogen population in all treatments. These results showed that EB, ETB, NE, and BES can effectively reduce the total population of methanogens but that they reduce methane production to a lesser extent. The results may guide futureinvivostudies to develop effective mitigation of methane emission from ruminants.

scholarly journals Effects of Essential Oils on Methane Production and Fermentation by, and Abundance and Diversity of, Rumen Microbial Populations

2012 ◽  
Vol 78 (12) ◽  
pp. 4271-4280 ◽  
Author(s):  
Amlan K. Patra ◽  
Zhongtang Yu
Keyword(s):  
Essential Oils ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Diversity Index ◽  
Neutral Detergent Fiber ◽  
Dependent Manner ◽  
Cellulolytic Bacteria ◽  
Content Type ◽  
Wiener Diversity Index

ABSTRACTFive essential oils (EOs), namely, clove oil (CLO), eucalyptus oil (EUO), garlic oil (GAO), origanum oil (ORO), and peppermint oil (PEO), were testedin vitroat 3 different doses (0.25, 0.50, and 1.0 g/liter) for their effect on methane production, fermentation, and select groups of ruminal microbes, including total bacteria, cellulolytic bacteria, archaea, and protozoa. All the EOs significantly reduced methane production with increasing doses, with reductions by 34.4%, 17.6%, 42.3%, 87%, and 25.7% for CLO, EUO, GAO, ORO, and PEO, respectively, at 1.0 g/liter compared with the control. However, apparent degradability of dry matter and neutral detergent fiber also decreased linearly with increasing doses by all EOs except GAO. The concentrations of total volatile fatty acids were not affected by GAO, EUO, or PEO but altered linearly and quadratically by CLO and ORO, respectively. All the EOs also differed in altering the molar proportions of acetate, propionate, and butyrate. As determined by quantitative real-time PCR, all the EOs decreased the abundance of archaea, protozoa, and major cellulolytic bacteria (i.e.,Fibrobacter succinogenes,Ruminococcus flavefaciens, andR. albus) linearly with increasing EO doses. On the basis of denaturing gradient gel electrophoresis analysis, different EOs changed the composition of both archaeal and bacterial communities to different extents. The Shannon-Wiener diversity index (H′) was reduced for archaea by all EOs in a dose-dependent manner but increased for bacteria at low and medium doses (0.25 and 0.50 g/liter) for all EOs except ORO. Due to the adverse effects on feed digestion and fermentation at high doses, a single EO may not effectively and practically mitigate methane emission from ruminants unless used at low doses in combinations with other antimethanogenic compounds.

scholarly journals Profiles of Odd- and Branched-Chain Fatty Acids and Their Correlations With Rumen Fermentation Parameters, Microbial Protein Synthesis and Bacterial Populations Based on Pure Carbohydrate Incubation in Vitro

2020 ◽  
Author(s):  
Hangshu Xin ◽  
Xin Liu ◽  
Xin Jiang ◽  
Chunlong Liu ◽  
Shuzhi Zhang ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Cellulolytic Bacteria ◽  
Bacterial Populations ◽  
Branched Chain Fatty Acids ◽  
Degrading Bacteria ◽  
Branched Chain ◽  
Fermentation Parameters ◽  
Chain Fatty Acids

Abstract Background: The objectives of this study were to evaluate the profiles of odd- and branched-chain fatty acids (OBCFA; including C15:0, iso-C15:0, anteiso-C15:0, iso-C16:0, C17:0, iso-C17:0 and anteiso-C17:0) during pure carbohydrates incubation in vitro and whether they correlated with ruminal fermentation parameters, microbial crude protein (MCP) synthesis, and bacterial populations. The pure substrates containing five different ratios of fiber and starch (F:S; 0:100, 25:75, 50:50, 75:25 and 100:0) were incubated for 6 h, 12 h, 18 h and 24 h. Results: Except iso-C17:0, OBCFA concentrations were interacted by F:S and incubation time. The highest concentration of total OBCFA was found in the fermented mixture after 24 h of incubation when the F:S = 0:100; while the lowest level was 1.65 mg/g DM produced after 6 h of incubation with F:S = 50:50. The concentrations of total volatile fatty acids (TVFA) and MCP remarkably decreased linearly as the inclusion of fiber in the substrates increased, as expected. The proportions of investigated cellulolytic bacteria in our study were increased linearly (or linearly and quadratically) while those of R. amylophilus and S. bovis were decreased as fiber inclusion increased. The correlation analysis indicated that iso-C16:0 concentration might have potential as a marker of productions of TVFA and MCP with ρ being 0.78 and 0.82 respectively. Compared to starch degrading bacteria, cellulolytic bacteria had more correlations with OBCFA profiles, and the strongest association was found on the population of R. flavefaciens with C15:0 concentration (ρ = 0.70). Conclusions: Our study shows there might be scope for iso-C16:0 to predict rumen productions of VFA and MCP. Notedly, this is the first paper reporting linkage of OBCFA with rumen function based on pure carbohydrate in vitro incubation, which would avoid confounding interference from dietary protein and fat presence. However, more in-depth experiments are needed to substantiate the current findings.

scholarly journals Pomegranate seed oil rich in conjugated linolenic acids reduces in vitro methane production

1970 ◽  
Vol 46 (3) ◽  
pp. 325-335
Author(s):  
E. Maleki ◽  
G.Y. Meng ◽  
M. Faseleh Jahromi ◽  
R. Jorfi ◽  
A. Khoddami ◽  
...  
Keyword(s):  
Methane Production ◽  
Volatile Fatty Acids ◽  
Seed Oil ◽  
Control Diet ◽  
Nutrient Utilization ◽  
Gas Production ◽  
Metabolizable Energy ◽  
Ruminal Fermentation ◽  
Ch4 Production

The objective of this study was to determine the effect of pomegranate (Punica granatum L.) seed oil (PSO) on gas and methane (CH4) production, ruminal fermentation and microbial populations under in vitro conditions. Three treatments consisting of a control diet containing 10 mg tallow (CON); the control diet with 5 mg PSO + 5 mg tallow (MPSO) and the control diet containing 10 mg PSO (HPSO) were compared. Ten mg of the experimental fat/oil samples were inserted into a gas-tight 100 mL plastic syringe containing 30 mL of an incubation inoculum and 250 mg of a basic substrate of a hay/concentrate (1/1, w/w) mixture. In vitro gas production was recorded over 0, 2, 4, 6, 8, 10, 12 and 24 h of incubation. After 24 hours, incubation was stopped, and methane production, pH, volatile fatty acids (VFAs) and microbial counts were measured in the inoculant. Gas production at 4, 6, 8, 10, 12 and 24 h incubation, metabolizable energy and in vitro organic matter disappearance increased linearly and quadratically as level of PSO increased. Furthermore, the 10 mg PSO (HPSO) decreased CH4 production by 21.0% compared with the control (CON) group. There were no significant differences in total and individual VFA concentrations between different levels of PSO, except for butyric acid. After 24 h of incubation, methanogenesis decreased in the HPSO compared with the MPSO and CON treatments. In addition, total bacteria and protozoa counts increased with rising PSO levels, while population methanogenesis declined significantly. These results suggested that PSO could reduce methane emissions, which might be beneficial to nutrient utilization and growth in ruminants.

scholarly journals Modelling the impact of the macroalgae Asparagopsis taxiformis on rumen microbial fermentation

2020 ◽  
Author(s):  
Rafael Muñoz-Tamayo ◽  
Juana C. Chagas ◽  
Mohammad Ramin ◽  
Sophie J. Krizsan
Keyword(s):  
Methane Production ◽  
Volatile Fatty Acids ◽  
Mean Squared Error ◽  
Microbial Fermentation ◽  
Model Structure ◽  
Red Macroalgae ◽  
Asparagopsis Taxiformis ◽  
The Impact

AbstractBackgroundThe red macroalgae Asparagopsis taxiformis is a potent natural supplement for reducing methane production from cattle. A. taxiformis contains several anti-methanogenic compounds including bromoform that inhibits directly methanogenesis. The positive and adverse effects of A. taxiformis on the rumen microbiota are dose-dependent and operate in a dynamic fashion. It is therefore key to characterize the dynamic response of the rumen microbial fermentation for identifying optimal conditions on the use of A. taxiformis as a dietary supplement for methane mitigation. Accordingly, the objective of this work was to model the effect of A. taxiformis supplementation on the rumen microbial fermentation under in vitro conditions. We adapted a published mathematical model of rumen microbial fermentation to account for A. taxiformis supplementation. We modelled the impact of A. taxiformis on the fermentation and methane production by two mechanisms, namely (i) direct inhibition of the growth rate of methanogenesis by bromoform and (ii) hydrogen control on sugars utilization and on the flux distribution towards volatile fatty acids production. We calibrated our model using a multi-experiment estimation approach that integrated experimental data with six macroalgae supplementation levels from a published in vitro study assessing the dose-response impact of A. taxiformis on rumen fermentation.Resultsour model captured satisfactorily the effect of A. taxiformis on the dynamic profile of rumen microbial fermentation for the six supplementation levels of A. taxiformis with an average determination coefficient of 0.88 and an average coefficient of variation of the root mean squared error of 15.2% for acetate, butyrate, propionate, ammonia and methane.Conclusionsour results indicated the potential of our model as prediction tool for assessing the impact of additives such as seaweeds on the rumen microbial fermentation and methane production in vitro. Additional dynamic data on hydrogen and bromoform are required to validate our model structure and look for model structure improvements. We are working on model extensions to account for in vivo conditions. We expect this model development can be useful to help the design of sustainable nutritional strategies promoting healthy rumen function and low environmental footprint.

scholarly journals Horizontal Spread of Rhodococcus equi Macrolide Resistance Plasmid pRErm46 across Environmental Actinobacteria

2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Sonsiray Álvarez-Narváez ◽  
Steeve Giguère ◽  
Londa J. Berghaus ◽  
Cody Dailey ◽  
José A. Vázquez-Boland
Keyword(s):  
Bacterial Species ◽  
Low Frequency ◽  
Rhodococcus Equi ◽  
Macrolide Resistance ◽  
Conjugative Plasmid ◽  
Bacterial Populations ◽  
Prolonged Incubation ◽  
Content Type ◽  
Host Restriction

ABSTRACT Conjugation is one of the main mechanisms involved in the spread and maintenance of antibiotic resistance in bacterial populations. We recently showed that the emerging macrolide resistance in the soilborne equine and zoonotic pathogen Rhodococcus equi is conferred by the erm(46) gene carried on the 87-kb conjugative plasmid pRErm46. Here, we investigated the conjugal transferability of pRErm46 to 14 representative bacteria likely encountered by R. equi in the environmental habitat. In vitro mating experiments demonstrated conjugation to different members of the genus Rhodococcus as well as to Nocardia and Arthrobacter spp. at frequencies ranging from ∼10−2 to 10−6. pRErm46 transfer was also observed in mating experiments in soil and horse manure, albeit at a low frequency and after prolonged incubation at 22 to 30°C (environmental temperatures), not 37°C. All transconjugants were able to transfer pRErm46 back to R. equi. Conjugation could not be detected with Mycobacterium or Corynebacterium spp. or several members of the more distant phylum Firmicutes such as Enterococcus, Streptococcus, or Staphylococcus. Thus, the pRErm46 host range appears to span several actinobacterial orders with certain host restriction within the Corynebacteriales. All bacterial species that acquired pRErm46 expressed increased macrolide resistance with no significant deleterious impact on fitness, except in the case of Rhodococcus rhodnii. Our results indicate that actinobacterial members of the environmental microbiota can both acquire and transmit the R. equi pRErm46 plasmid and thus potentially contribute to the maintenance and spread of erm(46)-mediated macrolide resistance in equine farms. IMPORTANCE This study demonstrates the efficient horizontal transfer of the Rhodococcus equi conjugative plasmid pRErm46, recently identified as the cause of the emerging macrolide resistance among equine isolates of this pathogen, to and from different environmental Actinobacteria, including a variety of rhodococci as well as Nocardia and Arthrobacter spp. The reported data support the notion that environmental microbiotas may act as reservoirs for the endemic maintenance of antimicrobial resistance in an antibiotic pressurized farm habitat.

scholarly journals In VitroCulture of Previously Uncultured Oral Bacterial Phylotypes

2015 ◽  
Vol 81 (24) ◽  
pp. 8307-8314 ◽  
Author(s):  
Hayley Thompson ◽  
Alexandra Rybalka ◽  
Rebecca Moazzez ◽  
Floyd E. Dewhirst ◽  
William G. Wade
Keyword(s):  
Culture Media ◽  
Pcr Primers ◽  
Oral Bacteria ◽  
Subgingival Plaque ◽  
Community Studies ◽  
Shotgun Metagenomics ◽  
Content Type ◽  
Specific Pcr ◽  
Proteose Peptone

ABSTRACTAround a third of oral bacteria cannot be grown using conventional bacteriological culture media. Community profiling targeting 16S rRNA and shotgun metagenomics methods have proved valuable in revealing the complexity of the oral bacterial community. Studies investigating the role of oral bacteria in health and disease require phenotypic characterizations that are possible only with live cultures. The aim of this study was to develop novel culture media and use anin vitrobiofilm model to culture previously uncultured oral bacteria. Subgingival plaque samples collected from subjects with periodontitis were cultured on complex mucin-containing agar plates supplemented with proteose peptone (PPA), beef extract (BEA), or Gelysate (GA) as well as on fastidious anaerobe agar plus 5% horse blood (FAA).In vitrobiofilms inoculated with the subgingival plaque samples and proteose peptone broth (PPB) as the growth medium were established using the Calgary biofilm device. Specific PCR primers were designed and validated for the previously uncultivated oral taxaBacteroidetesbacteria HOT 365 and HOT 281,Lachnospiraceaebacteria HOT 100 and HOT 500, andClostridialesbacterium HOT 093. All agar media were able to support the growth of 10 reference strains of oral bacteria. One previously uncultivated phylotype,Actinomycessp. HOT 525, was cultivated on FAA. Of 93 previously uncultivated phylotypes found in the inocula, 26 were detected inin vitro-cultivated biofilms.Lachnospiraceaebacterium HOT 500 was successfully cultured from biofilm material harvested from PPA plates in coculture withParvimonas micraorVeillonella dispar/parvulaafter colony hybridization-directed enrichment. The establishment ofin vitrobiofilms from oral inocula enables the cultivation of previously uncultured oral bacteria and provides source material for isolation in coculture.

scholarly journals Effects of Geraniol and Camphene on in Vitro Rumen Fermentation and Methane Production

2017 ◽  
Vol 48 (2) ◽  
pp. 63-69
Author(s):  
M. Joch ◽  
V. Kudrna ◽  
B. Hučko
Keyword(s):  
Methane Emission ◽  
Methane Production ◽  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Positive Control ◽  
Rumen Fermentation ◽  
Dry Matter Digestibility

AbstractThe objective of this study was to determine the effects of geraniol and camphene at three dosages (300, 600, and 900 mg l-1) on rumen microbial fermentation and methane emission in in vitro batch culture of rumen fluid supplied with a 60 : 40 forage : concentrate substrate (16.2% crude protein, 33.1% neutral detergent fibre). The ionophore antibiotic monensin (8 mg/l) was used as positive control. Compared to control, geraniol significantly (P < 0.05) reduced methane production with increasing doses, with reductions by 10.2, 66.9, and 97.9%. However, total volatile fatty acids (VFA) production and in vitro dry matter digestibility were also reduced (P < 0.05) by all doses of geraniol. Camphene demonstrated weak and unpromising effects on rumen fermentation. Camphene did not decrease (P > 0.05) methane production and slightly decreased (P < 0.05) VFA production. Due to the strong antimethanogenic effect of geraniol a careful selection of dose and combination with other antimethanogenic compounds may be effective in mitigating methane emission from ruminants. However, if a reduction in total VFA production and dry matter digestibility persisted in vivo, geraniol would have a negative effect on animal productivity.

scholarly journals Burkholderia Species Are Major Inhabitants of White Lupin Cluster Roots

2011 ◽  
Vol 77 (21) ◽  
pp. 7715-7720 ◽  
Author(s):  
Laure Weisskopf ◽  
Stefanie Heller ◽  
Leo Eberl
Keyword(s):  
Burkholderia Cepacia ◽  
Carbon Sources ◽  
White Lupin ◽  
Cluster Roots ◽  
Bacterial Populations ◽  
Content Type ◽  
Significant Enrichment ◽  
Branched Structure ◽  
Successful Colonization

ABSTRACTThe formation of cluster roots by plants represents a highly efficient strategy for acquisition of sparingly available phosphate. This particular root type is characterized by a densely branched structure and high exudation of organic acids and protons, which are likely to influence the resident bacterial community. Until now, the identity of the bacterial populations living in cluster roots has not been investigated. We applied cultivation-dependent and cultivation-independent methods to characterize the dominant bacterial genera inhabiting the growing cluster roots of white lupin. We observed a high relative abundance ofBurkholderiaspecies (up to 58% of all isolated strains and 44% of all retrieved 16S rRNA sequences) and a significant enrichment with increasing cluster root age. Most of the sequences retrieved clustered together with known plant- or fungus-associatedBurkholderiaspecies, while only one of 98 sequences was affiliated with theBurkholderia cepaciacomplex.In vitroassays revealed thatBurkholderiastrains were much more tolerant to low pH than non-Burkholderiastrains. Moreover, many strains produced large amounts of siderophores and were able to utilize citrate and oxalate as carbon sources. These features seem to represent important traits for the successful colonization and maintenance ofBurkholderiaspecies in white lupin cluster roots.

scholarly journals Influence of diets supplemented with naturally protected or unprotected eucalyptus oil on methane production and lactating buffalo productivity

2021 ◽  
Author(s):  
Fawzy Mohamed Abo-Donia ◽  
Mohamed Youssif Elaref ◽  
Abd El-Moniem Ali Sayed Mahgoub ◽  
Tarek Abd El Wahab Ahmed Deraz ◽  
Usama Aboelez Nayel
Keyword(s):  
Acetic Acid ◽  
Methane Production ◽  
Milk Fat ◽  
Corn Silage ◽  
Control Group ◽  
Cellulolytic Bacteria ◽  
Feed Conversion ◽  
Feed Mixture ◽  
Eucalyptus Oil

Abstract This study was designed to investigate the influence of naturally protected eucalyptus oil supplementation in a form of leaves (EUL) or mature seed capsules (EUS) compared to crude eucalyptus oil (EUO). The control group (G1) received a diet containing concentrate feed mixture, fresh berseem, rice straw, and corn silage. Whereas the G2, G3, and G4 animals have a diet supplemented with 200 g/head/day of EUL or EUS or 4 mL/head/day EUO, respectively. Supplementation of EUL or EUS increased NH3-N, SCFA’s, and concentrations of acetic acid in-vitro. Bacterial total count, protozoa, and cellulolytic bacteria increased (P < 0.05) with EUL and EUS supplementation. Methane production dropped (P < 0.05) with EUS, EUL, and EUO supplementation. Milk fat decreased (P < 0.05) with EUO supplementation, while an adverse trend was shown for lactose. No differences in feed conversion were found among EUS, EUL, and EUO. Blood total protein, albumin, and urea increased (P < 0.05) with supplementation of EUL or EUS compared to EUO. EUO supplementation yielded increased (P < 0.05) AST, ALT, glucose, and creatinine. Supplementation with EUL, EUS, or EUO decreased (P < 0.05) DM, OM, and CP digestibility. While digestibility of EE with supplementation by EUL, EUS, or EUO was higher (P < 0.05). The digestion coefficient of NDF and ADF decreased (P < 0.05) with supplemental EUL, EUS, or EUO compared to the G1 diet. Feeding EUS increased the values of TDN and DCP compared to EUL, which increased than EUO. Our results confirm that the naturally protected form of leaves or seeds mitigates the undesirable effects of directly supplementing crude eucalyptus oil.

scholarly journals Influence of diets supplemented with naturally protected or unprotected eucalyptus oil on methane production and lactating buffalo productivity

2021 ◽  
Author(s):  
Fawzy Mohamed Abo-Donia ◽  
Mohamed Youssif Elaref ◽  
Abd El-Moniem Ali Sayed Mahgoub ◽  
Tarek Abd El Wahab Ahmed Deraz ◽  
Usama Aboelez Nayel
Keyword(s):  
Methane Production ◽  
Milk Fat ◽  
Control Diet ◽  
Basal Diet ◽  
Control Group ◽  
Cellulolytic Bacteria ◽  
Feed Conversion ◽  
Negative Effects ◽  
Eucalyptus Oil

Abstract This study aimed to investigate the effects of naturally protected eucalyptus oil supplementation in a form of leaves (EUL) or mature seed capsules (EUS) compared to crude eucalyptus oil (EUO). The control group (G1) received the basal diet consisting of concentrate feed mixture, fresh berseem, rice straw, and corn silage. The G2, G3, and G4 animals were fed the basal diet with a supplement of 200 g/head/day of EUL or EUS or 4 mL EUO, respectively. Supplementation with EUL or EUS increased NH3-N, SCFA, and acetic acid concentrations in-vitro. The total count of bacterial, protozoa and cellulolytic bacteria increased (P < 0.05) with EUL and EUS supplementation. Methane production lowered (P < 0.05) with EUS, EUL, and EUO supplementation. Milk fat decreased (P < 0.05) with EUO supplementation, while an adverse trend was shown for lactose. No differences in feed conversion were found among EUS, EUL, and EUO. Total protein, albumin, and blood urea increased (P < 0.05) with supplementation of EUL or EUS compared to EUO. EUO supplementation yielded increased (P < 0.05) AST, ALT, glucose, and creatinine. Supplementation with EUL, EUS, or EUO decreased (P < 0.05) DM, OM, and CP digestibility. While digestibility of EE with supplementation by EUL, EUS, or EUO was higher (P < 0.05). Digestibility of NDF and ADF decreased (P < 0.05) with supplemental EUL, EUS, or EUO compared to the control diet. Feeding EUS increased the values of TDN and DCP compared to EUL, which was higher than EUO. Our results confirm that the naturally protected form of leaves or seeds mitigates the negative effects of directly supplementing crude eucalyptus oil.

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