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Golder HM, Denman SE, McSweeney C, Celi P, Lean IJ. Corrigendum to "Effects of feed additives on rumen function and bacterial and archaeal communities during a starch and fructose challenge" (J. Dairy Sci. 106:8787-8808). J Dairy Sci 2024; 107:3336-3346. [PMID: 38637063 DOI: 10.3168/jds.2024-107-5-3336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Heifers (n = 40) were randomly allocated to 5 treatment groups: (1) control (no additives); (2) virginiamycin (VM; 200 mg/d); (3) monensin (MT; 200 mg/d) + tylosin (110 mg/d); (4) monensin (MLY; 220 mg/d) + live yeast (5.0 × 108 cfu/d); (5) sodium bicarbonate (BUF; 200 g/d) + magnesium oxide (30 g/d).
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Affiliation(s)
- H M Golder
- Scibus, Camden, New South Wales, 2570, Australia; Dairy Science Group, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia, 2567
| | - S E Denman
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St. Lucia, QLD 4067, Australia
| | - C McSweeney
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St. Lucia, QLD 4067, Australia
| | - P Celi
- Melbourne School of Land and Environment, The University of Melbourne, Parkville, VIC 3052, Australia
| | - I J Lean
- Scibus, Camden, New South Wales, 2570, Australia; Dairy Science Group, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia, 2567
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Golder HM, Denman SE, McSweeney C, Celi P, Lean IJ. Effects of feed additives on rumen function and bacterial and archaeal communities during a starch and fructose challenge. J Dairy Sci 2023; 106:8787-8808. [PMID: 37678787 DOI: 10.3168/jds.2023-23486] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/18/2023] [Indexed: 09/09/2023]
Abstract
The objective of this study was to improve understandings of the rumen microbial ecosystem during ruminal acidosis and responses to feed additives to improve prudent use strategies for ruminal acidosis control. Rumen bacterial and archaeal community composition (BCC) and its associations with rumen fermentation measures were examined in Holstein heifers fed feed additives and challenged with starch and fructose. Heifers (n = 40) were randomly allocated to 5 treatment groups: (1) control (no additives); (2) virginiamycin (VM; 200 mg/d); (3) monensin (MT; 200 mg/d) + tylosin (110 mg/d); (4) monensin (MLY; 220 mg/d) + live yeast (5.0 × 1012 cfu/d); (5) sodium bicarbonate (BUF; 200 g/d) + magnesium oxide (30 g/d). Heifers were fed twice daily a 62% forage:38% concentrate total mixed ration at 1.25% of body weight (BW) dry matter (DM)/d for a 20-d adaptation period with their additive(s). Fructose (0.1% of BW/d) was added to the ration for the last 10 d of adaptation. On d 21 heifers were challenged once with a ration consisting of 1.0% of BW DM wheat and 0.2% of BW fructose plus their additive(s). A rumen sample was collected from each heifer via stomach tube weekly (d 0, 7, 14) and 5 times over a 3.6 h period at 5, 65, 115, 165, and 215 min after consumption of the challenge ration (d 21) and analyzed for pH, and ammonia, d- and l-lactate, volatile fatty acids (VFA), and histamine concentrations and total bacteria and archaea. The 16S rRNA gene spanning the V4 region was PCR amplified and sequenced. Alpha and β diversity and associations of relative abundances of taxa with rumen fermentation measures were evaluated. Rumen BCC shifted among treatment groups in the adaptation period and across the challenge sampling period, indicating the feed additives had different modes of action. The monensin-containing treatment groups, MT and MLY often had similar relative abundances of rumen bacterial phyla and families. The MLY treatment group was characterized in the challenge period by increased relative abundances of the lactate utilizing genera Anaerovibrio and Megasphaera. The MLY treatment group also had increased diversity of ruminal bacteria which may provide resilience to changes in substrates. The control and BUF treatment groups were most similar in BCC. A redundancy analysis showed the MLY treatment group differed from all other treatment groups and concentrations of histamine and valerate in the rumen were associated with the most variation in the microbiota, 5.3% and 4.8%, respectively. It was evident from the taxa common to all treatment groups that cattle have a core microbiota. Functional redundancy of rumen bacteria which was reflected in the greater sensitivity for the rumen BCC than rumen fermentation measures likely provide resilience to changes in substrate. This functional redundancy of microbes in cattle suggests that there is no single optimal ruminal microbial population and no universally superior feed additive(s). In summary, differences in modes of action suggest the potential for more targeted and improved prudent use of feed additives with no single feed additive(s) providing an optimal BCC in all heifers.
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Affiliation(s)
- H M Golder
- Scibus, Camden, New South Wales, 2570, Australia; Dairy Science Group, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia, 2567.
| | - S E Denman
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St. Lucia, QLD 4067, Australia
| | - C McSweeney
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St. Lucia, QLD 4067, Australia
| | - P Celi
- Melbourne School of Land and Environment, The University of Melbourne, Parkville, VIC 3052, Australia
| | - I J Lean
- Scibus, Camden, New South Wales, 2570, Australia; Dairy Science Group, School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Camden, New South Wales, Australia, 2567
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Golder HM, Denman SE, McSweeney C, Wales WJ, Auldist MJ, Wright MM, Marett LC, Greenwood JS, Hannah MC, Celi P, Bramley E, Lean IJ. Effects of partial mixed rations and supplement amounts on milk production and composition, ruminal fermentation, bacterial communities, and ruminal acidosis. J Dairy Sci 2014; 97:5763-85. [PMID: 24997657 DOI: 10.3168/jds.2014-8049] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 05/16/2014] [Indexed: 11/19/2022]
Abstract
Late-lactation Holstein cows (n=144) that were offered 15kg dry matter (DM)/cow per day of perennial ryegrass to graze were randomized into 24 groups of 6. Each group contained a fistulated cow and groups were allocated to 1 of 3 feeding strategies: (1) control (10 groups): cows were fed crushed wheat grain twice daily in the milking parlor and ryegrass silage at pasture; (2) partial mixed ration (PMR; 10 groups): PMR that was isoenergetic to the control diet and fed twice daily on a feed pad; (3) PMR+canola (4 groups): a proportion of wheat in the PMR was replaced with canola meal to produce more estimated metabolizable protein than other groups. Supplements were fed to the control and PMR cows at 8, 10, 12, 14, or 16kg of DM/d, and to the PMR+canola cows at 14 or 16kg of DM/d. The PMR-fed cows had a lower incidence of ruminal acidosis compared with controls, and ruminal acidosis increased linearly and quadratically with supplement fed. Yield of milk fat was highest in the PMR+canola cows fed 14 or 16kg of total supplement DM/d, followed by the PMR-fed cows, and was lowest in controls fed at these amounts; a similar trend was observed for milk fat percentage. Milk protein yield was higher in the PMR+canola cows fed 14 or 16kg of total supplement DM/d. Milk yield and milk protein percentage were not affected by feeding strategy. Milk, energy-corrected milk, and milk protein yields increased linearly with supplement fed, whereas milk fat percentage decreased. Ruminal butyrate and d-lactate concentrations, acetate-to-propionate ratio, (acetate + butyrate)/propionate, and pH increased in PMR-fed cows compared with controls for all supplement amounts, whereas propionate and valerate concentrations decreased. Ruminal acetate, butyrate, and ammonia concentrations, acetate-to-propionate ratio, (acetate + butyrate)/propionate, and pH linearly decreased with amounts of supplement fed. Ruminal propionate concentration linearly increased and valerate concentration linearly and quadratically increased with supplement feeding amount. The Bacteroidetes and Firmicutes were the dominant bacterial phyla identified. The Prevotellaceae, Ruminococcaceae, and Lachnospiraceae were the dominant bacterial families, regardless of feeding group, and were influenced by feeding strategy, supplement feeding amount, or both. The Veillonellaceae family decreased in relative abundance in PMR-fed cows compared with controls, and the Streptococcaeae and Lactobacillaceae families were present in only minor relative abundances, regardless of feeding group. Despite large among- and within-group variation in bacterial community composition, distinct bacterial communities occurred among feeding strategies, supplement amounts, and sample times and were associated with ruminal fermentation measures. Control cows fed 16kg of DM of total supplement per day had the most distinct ruminal bacterial community composition. Bacterial community composition was most significantly associated with supplement feeding amount and ammonia, butyrate, valerate, and propionate concentrations. Feeding supplements in a PMR reduced the incidence of ruminal acidosis and altered ruminal bacterial communities, regardless of supplement feeding amount, but did not result in increased milk measures compared with isoenergetic control diets component-fed to late-lactation cows.
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Affiliation(s)
- H M Golder
- The Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; SBScibus, Camden, New South Wales, Australia 2570.
| | - S E Denman
- CSIRO Animal, Food and Health Services, Queensland Bioscience Precinct, St. Lucia, Queensland, Australia 4067
| | - C McSweeney
- CSIRO Animal, Food and Health Services, Queensland Bioscience Precinct, St. Lucia, Queensland, Australia 4067
| | - W J Wales
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - M J Auldist
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - M M Wright
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - L C Marett
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - J S Greenwood
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - M C Hannah
- Farming Systems Research Division, Department of Environment and Primary Industries, Ellinbank, Victoria, Australia 3821
| | - P Celi
- The Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; Melbourne School of Land and Environment, The University of Melbourne, Parkville, Victoria, Australia 3010
| | - E Bramley
- School of Veterinary and Biomedical Sciences, Murdoch University, Murdoch, Western Australia 6150
| | - I J Lean
- The Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; SBScibus, Camden, New South Wales, Australia 2570
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Golder HM, Denman SE, McSweeney C, Celi P, Lean IJ. Ruminal bacterial community shifts in grain-, sugar-, and histidine-challenged dairy heifers. J Dairy Sci 2014; 97:5131-50. [PMID: 24881800 DOI: 10.3168/jds.2014-8003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/10/2014] [Indexed: 11/19/2022]
Abstract
Ruminal bacterial community composition (BCC) and its associations with ruminal fermentation measures were studied in dairy heifers challenged with combinations of grain, fructose, and histidine in a partial factorial study. Holstein-Friesian heifers (n=30) were randomly allocated to 5 triticale grain-based treatment groups: (1) control (no grain), (2) grain [fed at a dry matter intake (DMI) of 1.2% of body weight (BW)], (3) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI), (4) grain (1.2% of BW DMI) + histidine (6g/head), and (5) grain (0.8% of BW DMI) + fructose (0.4% of BW DMI) + histidine (6g/head). Ruminal fluid was collected using a stomach tube 5, 115, and 215min after consumption of the rations and bacterial 16S ribosomal DNA sequence data was analyzed to characterize bacteria. Large variation among heifers and distinct BCC were evident in a between-group constrained principal components analysis. Bacterial composition in the fructose-fed heifers was positively related to total lactate and butyrate concentrations. Bacterial composition was positively associated with ruminal ammonia, valerate, and histamine concentrations in the grain-fed heifers. The predominant phyla were the Firmicutes (57.6% of total recovered sequences), Bacteroidetes (32.0%), and candidate phylum TM7 (4.0%). Prevotella was the dominant genus. In general, grain or histidine or their interactions with time had minimal effects on the relative abundance of bacterial phyla and families. Fructose increased and decreased the relative abundance of the Firmicutes and Proteobacteria phyla over time, respectively, and decreased the abundance of the Prevotellaceae family over time. The relative abundance of the Streptococcaceae and Veillonellaceae families was increased in the fructose-fed heifers and these heifers over time. A total of 31 operational taxonomic units differed among treatment groups in the 3.6h sampling period, Streptococcus bovis was observed in fructose fed animals. The TM7 candidate phylum had an increased abundance of sequence reads by over 2.5 fold due to the introduction of histidine into the diet. Rapid changes in BCC can occur in a short period after a single substrate challenge and the nature of these changes may influence ruminal acidosis risk and differ from those in cattle exposed to substrate challenges over a longer time period.
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Affiliation(s)
- H M Golder
- Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; SBScibus, Camden, New South Wales, Australia 2570.
| | - S E Denman
- CSIRO Animal, Food and Health Services, Queensland Bioscience Precinct, St. Lucia, Queensland, Australia 4067
| | - C McSweeney
- CSIRO Animal, Food and Health Services, Queensland Bioscience Precinct, St. Lucia, Queensland, Australia 4067
| | - P Celi
- Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; Melbourne School of Land and Environment, The University of Melbourne, Parkville, Victoria, Australia 3052
| | - I J Lean
- Dairy Science Group, Faculty of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia 2570; SBScibus, Camden, New South Wales, Australia 2570
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Davis CK, Denman SE, Sly LI, McSweeney CS. Development of a colorimetric colony-screening assay for detection of defluorination by micro-organisms. Lett Appl Microbiol 2011; 53:417-23. [PMID: 21767280 DOI: 10.1111/j.1472-765x.2011.03123.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS To develop a colorimetric colony-screening assay to facilitate the isolation of micro-organisms capable of defluorination. METHODS AND RESULTS A metal-dye chelate, zirconium-xylenol orange was used to detect fluoride ions released from a fluorinated substrate through microbial metabolism. Depolymerised zirconium reagent gave the greatest visual contrast for the presence of fluoride compared to more polymerised forms of zirconium reagent. The sensitivity of the assay was greatest when the molar ratio of depolymerised zirconium to xylenol orange was 1:2. Using depolymerised zirconium and xylenol orange (150 and 300 nmol l(-1) respectively), the assay could detect a fluoride application spot (5 mmol l(-1)) containing 50 nmoles of fluoride ions. Most media constituents were well tolerated by the assay, although phosphate ions needed to be restricted to 0.1 g l(-1) and some proteins digest to between 1 and 5 g l(-1). A microbial enrichment culture growing on solidified medium containing 20 mmol l(-1) fluoroacetate was screened using the assay, and defluorinating bacteria belonging to the genus Burkholderia isolated. CONCLUSIONS A method was developed that is sensitive, rapid and reliable for detecting defluorination by micro-organisms growing on solidified medium. SIGNIFICANCE AND IMPACT OF THE STUDY This method can be used to facilitate the isolation of micro-organisms capable of defluorination.
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Affiliation(s)
- C K Davis
- CSIRO Livestock Industries, Queensland Bioscience Precinct, St Lucia, Qld, Australia
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Pope PB, Smith W, Denman SE, Tringe SG, Barry K, Hugenholtz P, McSweeney CS, McHardy AC, Morrison M. Isolation of Succinivibrionaceae Implicated in Low Methane Emissions from Tammar Wallabies. Science 2011; 333:646-8. [DOI: 10.1126/science.1205760] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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de Wet SC, Denman SE, Sly L, McSweeney CS. An improved method for RNA extraction from carcass samples for detection of viable Escherichia coli O157:H7 by reverse-transcriptase polymerase chain reaction. Lett Appl Microbiol 2009; 47:399-404. [PMID: 19146528 DOI: 10.1111/j.1472-765x.2008.02462.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS To develop a rapid RNA extraction procedure for maximizing bacterial RNA yield from carcass samples with low abundance of Escherichia coli O157:H7 without pre-enrichment. METHODS AND RESULTS Nontarget bacterial cells were added to the sample prior to RNA extraction, facilitating the co-precipitation of target RNA along with nontarget RNA and thus enhancing the recovery. This method was developed using a serial dilution of log phase target cells (E. coli O157:H7), combined with a high number of nontarget cells (E. coli K12). Cells were lysed by a bead beating method followed by RNA purification using a commercial kit. A reverse-transcriptase PCR assay for the detection of rfbE gene in E. coli O157:H7 was used to demonstrate that the procedure increased the recovery of amplifiable RNA target with a detection limit of approximately 63 CFU ml(-1) in cultures and 27.5 CFU ml(-1) in carcass liquor. CONCLUSIONS An RNA extraction procedure was developed to detect low numbers (<30 viable cells ml(-1)) of E. coli O157:H7 in carcass liquor without pre-enrichment. SIGNIFICANCE AND IMPACT OF THE STUDY This method could be applied for the detection of E. coli O157:H7 in low abundance on carcasses where rapid detection and early intervention is essential for safety in the livestock industry.
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Affiliation(s)
- S C de Wet
- Queensland Bioscience Precinct, CSIRO Livestock Industries, 306 Carmody Road, St Lucia, Qld 4067, Australia.
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Guo YQ, Liu JX, Lu Y, Zhu WY, Denman SE, McSweeney CS. Effect of tea saponin on methanogenesis, microbial community structure and expression of mcrA gene, in cultures of rumen micro-organisms. Lett Appl Microbiol 2009; 47:421-6. [PMID: 19146532 DOI: 10.1111/j.1472-765x.2008.02459.x] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
AIMS To determine the in-vitro effect and mode of action of tea saponin on the rumen microbial community and methane production. METHODS AND RESULTS Saponin extracted from tea seeds was added to (1) an in-vitro fermentation inoculated with rumen fluid and (2) a pure culture of Methanobrevibacter ruminantium. Methane production and expression of the methyl coenzyme-M reductase subunit A (mcrA) were monitored in both cultures. Abundance of methanogens, protozoa, rumen fungi and cellulolytic bacteria were quantified using real-time PCR, and bacterial diversity was observed using denaturing gradient gel electrophoresis. Addition of tea saponin significantly reduced methane production and mcrA gene expression in the ruminal fermentation but not with the pure culture of M. ruminantium. The abundance of protozoa and fungi were significantly decreased 50% and 79% respectively but methanogen numbers were not affected, and Fibrobacter succinogenes increased by 41%. Bacterial diversity was similar in cultures with or without tea saponin. CONCLUSIONS Tea saponin appeared to reduce methane production by inhibiting protozoa and presumably lowering methanogenic activity of protozoal-associated methanogens. SIGNIFICANCE AND IMPACT OF THE STUDY Tea saponin may be useful as a supplement to indirectly inhibit methane production in ruminants without a deleterious effect on rumen function.
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Affiliation(s)
- Y Q Guo
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, Zhejiang University, Hangzhou, China
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Abstract
AIM To develop an automated ribosomal intergenic spacer region analysis (ARISA) method for the detection of anaerobic rumen fungi and also to demonstrate utility of the technique to monitor colonization and persistence of fungi, and diet-induced changes in community structure. METHODS AND RESULTS The method could discriminate between three genera of anaerobic rumen fungal isolates, representing Orpinomyces, Piromyces and Neocallimastix species. Changes in anaerobic fungal composition were observed between animals fed a high-fibre diet compared with a grain-based diet. ARISA analysis of rumen samples from animals on grain showed a decrease in fungal diversity with a dominance of Orpinomyces and Piromyces spp. Clustering analysis of ARISA profile patterns grouped animals based on diet. A single strain of Orpinomyces was dosed into a cow and was detectable within the rumen fungal population for several weeks afterwards. CONCLUSIONS The ARISA technique was capable of discriminating between pure cultures at the genus level. Diet composition has a significant influence on the diversity of anaerobic fungi in the rumen and the method can be used to monitor introduced strains. SIGNIFICANCE AND IMPACT OF THE STUDY Through the use of ARISA analysis, a better understanding of the effect of diets on rumen anaerobic fungi populations is provided.
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Affiliation(s)
- S E Denman
- CSIRO Livestock Industries, Queensland Bioscience Precinct, Brisbane, Queensland, Australia
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McSweeney CS, Denman SE. Effect of sulfur supplements on cellulolytic rumen micro-organisms and microbial protein synthesis in cattle fed a high fibre diet. J Appl Microbiol 2008; 103:1757-65. [PMID: 17953586 DOI: 10.1111/j.1365-2672.2007.03408.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To examine the effect of sulfur-containing compounds on the growth of anaerobic rumen fungi and the fibrolytic rumen bacteria Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogenes in pure culture and within the cattle rumen. METHODS AND RESULTS The effect of two reduced sulfur compounds, 3-mercaptopropionic acid (MPA) or 3-mercapto-1-propanesulfonic acid as the sole S source on growth of pure fibroyltic fungal and bacterial cultures showed that these compounds were capable of sustaining growth. An in vivo trial was then conducted to determine the effect of sulfur supplements (MPA and sodium sulfate) on microbial population dynamics in cattle fed the roughage Dichanthium aristatum. Real-time PCR showed significant increases in fibrolytic bacterial and fungal populations when cattle were supplemented with these compounds. Sulfate supplementation leads to an increase in dry matter intake without a change in whole tract dry matter digestibility. CONCLUSIONS Supplementation of low S-containing diets with either sodium sulfate or MPA stimulates microbial growth with an increase in rumen microbial protein supply to the animal. SIGNIFICANCE AND IMPACT OF THE STUDY Through the use of real-time PCR monitoring, a better understanding of the effect of S supplementation on discrete microbial populations within the rumen is provided.
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Affiliation(s)
- C S McSweeney
- CSIRO Livestock Industries, Queensland Bioscience Precinct, St Lucia, QLD, Australia.
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Gough JM, Conlan LL, Denman SE, Krause DO, Smith WJM, Williamson MA, McSweeney CS. Screening of bacteria from the cattle gastrointestinal tract for inhibitory activity against enterohemorrhagic Escherichia coli O157:H7, O111:H-, and O26:H11. J Food Prot 2006; 69:2843-50. [PMID: 17186648 DOI: 10.4315/0362-028x-69.12.2843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A quick and reproducible microgel plate assay was adapted to screen bacteria from cattle gastrointestinal tracts for production of compounds inhibitory to the growth of three enterohemorrhagic Escherichia coli (EHEC) serotypes: O157:H7, O111:H-, and O26:H11. The inhibitory activity of 309 bacteria, isolated on several agar media, was assessed by a microgel assay performed in 96-well microtiter plates. Fifty-three isolates secreted inhibitory compounds with a molecular weight of less than 1,000. In 12 isolates, the inhibitory activity was attributable to compounds other than lactic or acetic acid. These compounds were highly heat tolerant, with varying sensitivity to digestion by proteolytic enzymes. The inhibitory isolates were identified as lactic acid-producing bacteria on the basis of a combination of analyses, including 16S-rDNA restriction fragment length polymorphisms, 16S-rDNA gene sequences, and fermentation end products. The lactic acid bacteria of ruminants may contain antibacterial compounds not yet described. Naturally occurring populations of lactic acid bacteria may have potential as probiotics, to reduce the carriage of EHEC in the gastrointestinal tract of ruminants.
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Affiliation(s)
- J M Gough
- Commonwealth Scientific and Industrial Research Organisation (C.S.I.R.O.) Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St. Lucia, Queensland 4067, Australia
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McSweeney CS, Denman SE, Wright ADG, Yu Z. Application of Recent DNA/RNA-based Techniques in Rumen Ecology. Asian Australas J Anim Sci 2006. [DOI: 10.5713/ajas.2007.283] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Al-Ajmi D, Padmanabha J, Denman SE, Gilbert RA, Al Jassim RAM, McSweeney CS. Evaluation of a PCR detection method for Escherichia coli O157:H7/H- bovine faecal samples. Lett Appl Microbiol 2006; 42:386-91. [PMID: 16599993 DOI: 10.1111/j.1472-765x.2005.01850.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS Combinations of PCR primer sets were evaluated to establish a multiplex PCR method to specifically detect Escherichia coli O157:H7 genes in bovine faecal samples. METHODS AND RESULTS A multiplex PCR method combining three primer sets for the E. coli O157:H7 genes rfbE, uidA and E. coli H7 fliC was developed and tested for sensitivity and specificity with pure cultures of 27 E. coli serotype O157 strains, 88 non-O157 E. coli strains, predominantly bovine in origin and five bacterial strains other than E. coli. The PCR method was very specific in the detection of E. coli O157:H7 and O157:H- strains, and the detection limit in seeded bovine faecal samples was <10 CFU g(-1) faeces, following an 18-h enrichment at 37 degrees C, and could be performed using crude DNA extracts as template. CONCLUSIONS A new multiplex PCR method was developed to detect E. coli O157:H7 and O157:H-, and was shown to be highly specific and sensitive for these strains both in pure culture and in crude DNA extracts prepared from inoculated bovine faecal samples. SIGNIFICANCE AND IMPACT OF THE STUDY This new multiplex PCR method is suitable for the rapid detection of E. coli O157:H7 and O157:H- genes in ruminant faecal samples.
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Affiliation(s)
- D Al-Ajmi
- School of Animal Studies, University of Queensland, Gatton, Qld, Australia
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Xue GP, Denman SE, Glassop D, Johnson JS, Dierens LM, Gobius KS, Aylward JH. Modification of a xylanase cDNA isolated from an anaerobic fungus Neocallimastix patriciarum for high-level expression in Escherichia coli. J Biotechnol 1995; 38:269-77. [PMID: 7765876 DOI: 10.1016/0168-1656(94)00133-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A Neocallimastix patriciarum xylanase cDNA with the core coding sequence essentially identical to xynA was isolated and modified for high-level expression in Escherichia coli. The xylanase cDNA was truncated into individual catalytic domains, which were modified at the N-terminus. These modified xylanases were synthesised as non-fusion proteins under the control of the tac promoter. High-level expression was obtained with the modified domain II construct, accounting for approx. 25% of total cellular protein. However, with the same vector and expression cassette, expression levels of constructs containing domain I or domains I and II fused in tandem were very low. RNA analysis revealed that the striking difference in expression levels of these three constructs was not due to transcription efficiency, but was mainly related to transcript stability. Further analysis of the domain II construct revealed that the high-level expression of the domain II xylanase was largely attributed to the presence of a favourable N-terminal coding sequence, as mutation at the N-terminus of the domain II dramatically reduced the expression level. The modified domain II xylanase produced in E. coli had a specific activity of 1229 U mg-1 protein at pH 7 and 50 degrees C without purification. The availability of a recombinant fungal xylanase with high specific activity and in high yield offers a potentially attractive source of xylanase for industrial applications.
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Affiliation(s)
- G P Xue
- CSIRO Division of Tropical Crops and Pastures, St. Lucia, Qld, Australia
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