Effect of diet and probiotic addition on chemical composition of free or particle-associated bacterial populations of the rumen

1998 ◽  
Vol 78 (1) ◽  
pp. 115-120 ◽  
Author(s):  
J. Chiquette ◽  
C. Benchaar

Eight dairy heifers (297 ± 11 kg) fitted with a ruminal cannula were used in this study. The following diets were fed in a replicated, concurrently run 4 × 4 Latin square design: 1) 80% chopped timothy hay + 20% rolled barley (HF); 2) HF + 10 g head d−1 of a mixture of Saccharomyces cerevisiae and Aspergillus oryzae (HF + SA); 3) 50% chopped timothy hay + 47.6% rolled barley and 2.4% soya supplement (HC); 4) HC + SA. Feed was offered every 2 h. A sample of whole rumen contents (liquid and solid) was collected 1 h after the 07:00 h feeding to isolate the bacteria associated with the liquid phase (BAL) and the bacteria adherent to the solid phase (BAS). Organic matter (OM) content of BAS was greater (P ≤ 0.0001) than that of BAL, independently of the type of diet fed and of the presence or absence of the pro-biotic mixture. Oppositely, total nitrogen content (N), expressed as g 100 g−1 OM, was greater (P ≤ 0.0001) in the BAL fraction than in the BAS fraction, the difference in N between the two bacterial fractions being more pronounced with the HF diet (P ≤ 0.05). Organic matter content in both bacterial fractions was greater (P ≤ 0.05) when heifers were fed the HC diet. Addition of probiotic had no effect on OM or N content of each bacterial fraction. Significant differences between amino acid composition of BAL and BAS were observed for 10 out of 16 amino acids studied. For most amino acids, differences in content observed between BAL and BAS were maintained independently of the probiotic supplementation whereas diet affected the relative composition of the bacterial fractions for five amino acids. Finally, addition of probiotics did not affect molar proportions of ruminal volatile fatty acids, which were affected by the diet. Key words: Rumen bacteria, chemical composition, probiotic, amino acid

1991 ◽  
Vol 71 (3) ◽  
pp. 377-387 ◽  
Author(s):  
C. A. Campbell ◽  
R. P. Zentner ◽  
K. E. Bowren ◽  
L. Townley-Smith ◽  
M. Schnitzer

The effects of crop rotation and various cultural practices on soil organic matter and some biochemical characteristics of a heavy-textured, Orthic Black Chernozem with a thick A horizon were determined after 31 yr at Melfort, Saskatchewan. Treatments investigated included: fertilization, cropping frequency, green manuring, and inclusion of grass-legume hay crops in predominantly spring wheat (Triticum aestivum L.) systems. The results showed that neither soil organic C nor N in the top 15 cm of soil, nor hydrolyzable amino acids, nor C mineralized in 14 d at 20 °C were influenced by fertilization. However, the relative molar distribution (RMD) of the amino acids reflected the influence of fertilization and the phase (Rot-yr) of the legume green manure rotation sampled. Some characteristics assessed increased marginally with increasing cropping frequency but differences were less marked than results obtained earlier in a heavy-textured Black Chernozem with a thin A horizon at Indian Head, Saskatchewan. The relationship between soil organic matter or C mineralization versus estimated crop residues, residue C, or residue N returned to the land over the 31-yr period, were not significant in the Melfort soil. This contrasts with our findings for the thin Black soil. We speculate that the lack of soil organic matter response in the Melfort soil was due to its very high organic matter content (about 64 t ha−1C and 6.5 t ha−1N in the top 15 cm). We also hypothesized that the amino acid RMD results, which differed from most of those reported in the literature, may be reflecting the more recent cropping history of the soil. This aspect requires further research into the composition and distribution of the humic materials in this soil. Key words: Amino acids, relative molar distribution, C respiration, green manures, fertilization


2012 ◽  
Vol 9 (8) ◽  
pp. 11655-11704 ◽  
Author(s):  
C. Estop-Aragonés ◽  
K.-H. Knorr ◽  
C. Blodau

Abstract. Climate change induced drying and flooding may alter the redox conditions of organic matter decomposition in peat soils. The seasonal and intermittent changes in pore water solutes (NO3−, Fe2+, SO42−, H2S, acetate) and dissolved soil gases (CO2, O2, CH4, H2) under natural water table fluctuations were compared to the response under a reinforced drying and flooding in fen peats. Oxygen penetration during dryings led to CO2 and CH4 degassing and to a regeneration of dissolved electron acceptors (NO3−, Fe3+ and SO42−). Drying intensity controlled the extent of the electron acceptor regeneration. Iron was rapidly reduced and sulfate pools ~ 1 mmol L−1 depleted upon rewetting and CH4 did not substantially accumulate until sulfate levels declined to ~ 100 μmoll−1. The post-rewetting recovery of soil methane concentrations to levels ~ 80 μmoll−1 needed 40–50 days after natural drought. This recovery was prolonged after experimentally reinforced drought. A greater regeneration of electron acceptors during drying was not related to prolonged methanogenesis suppression after rewetting. Peat compaction, solid phase content of reactive iron and total reduced inorganic sulfur and organic matter content controlled oxygen penetration, the regeneration of electron acceptors and the recovery of CH4 production, respectively. Methane production was maintained despite moderate water table decline of 20 cm in denser peats. Flooding led to accumulation of acetate and H2, promoted CH4 production and strengthened the co-occurrence of iron and sulfate reduction and methanogenesis. Mass balances during drying and flooding indicated that an important fraction of the electron flow must have been used for the generation and consumption of electron acceptors in the solid phase or other mechanisms. In contrast to flooding, dry-wet cycles negatively affect methane production on a seasonal scale but this impact might strongly depend on drying intensity and on the peat matrix, whose structure and physical properties influence moisture content.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Abiodun D. Ogunniyi ◽  
Catherine E. Dandie ◽  
Sergio Ferro ◽  
Barbara Hall ◽  
Barbara Drigo ◽  
...  

AbstractThere is increasing demand for safe and effective sanitizers for irrigation water disinfection to prevent transmission of foodborne pathogens to fresh produce. Here we compared the efficacy of pH-neutral electrolyzed oxidizing water (EOW), sodium hypochlorite (NaClO) and chlorine dioxide (ClO2) against single and mixed populations of E. coli, Listeria and Salmonella under a range of pH and organic matter content. EOW treatment of the mixed bacterial suspension resulted in a dose-dependent (<1 mg/L free chlorine), rapid (<2 min) and effective (4–6 Log10) reduction of the microbial load in water devoid of organic matter under the range of pH conditions tested (pH, 6.0, 7.0, 8.4 and 9.2). The efficacy of EOW containing 5 mg/L free chlorine was unaffected by increasing organic matter, and compared favourably with equivalent concentrations of NaClO and ClO2. EOW at 20 mg/L free chlorine was more effective than NaClO and ClO2 in reducing bacterial populations in the presence of high (20–100 mg/L) dissolved organic carbon, and no regrowth or metabolic activity was observed for EOW-treated bacteria at this concentration upon reculturing in rich media. Thus, EOW is as effective or more effective than other common chlorine-based sanitizers for pathogen reduction in contaminated water. EOW’s other characteristics, such as neutral pH and ease of handling, indicate its suitability for fresh produce sanitation.


1972 ◽  
Vol 79 (3) ◽  
pp. 541-542 ◽  
Author(s):  
F. D. DeB. Hovell ◽  
E. R. Ørskov

The conventional method for the determination of the organic matter content of diets and faeces is by ashing the sample at 550 °C (A.O.A.C, 1965)Organic matter (O.M.) = dry matter (D.M.)–ash.If the sample contains calcium carbonate, then some of this carbonate will be converted to oxide (Vogel, 1951) and the weight of carbon dioxide evolved will be calculated as organic matter. The amount of carbonate converted will be dependent upon the temperature at which the sample is ashed and the duration of the ashing process. We have found (Ørskov, Hovell & Allen, 1966; Hovell & Greenhalgh, 1972) that when calcium salts of volatile fatty acids are included in diets given to sheep, most of the calcium is excreted in the faeces as carbonate, and since apparent digestibility is the difference between the amounts of nutrient ingested and excreted, the estimation of the apparent digestibility of organic matter will be in error if no correction is made for the high calcium carbonate content of the faeces. For example, a diet which contained 9·2% of calcium acetate had a true organic matterapparent digestibility of 86·8%. Had no correction been made this would have been estimated as 84·9%.


Pedosphere ◽  
2021 ◽  
Vol 31 (6) ◽  
pp. 903-911
Author(s):  
Carlo ANGELETTI ◽  
Elga MONACI ◽  
Beatrice GIANNETTA ◽  
Serena POLVERIGIANI ◽  
Costantino VISCHETTI

2014 ◽  
Vol 6 (1) ◽  
pp. 33-38
Author(s):  
Gabriella Rétháti ◽  
Adrienn Vejzer ◽  
Barbara Simon ◽  
Ramadan Benjared ◽  
György Füleky

Abstract Organic matter input into soils is essential regarding agricultural, environmental and soil science aspects as well. However, the application of the pyrolysed forms of biochars and materials with different organic matter content gained more attention in order to decrease the emission of the green house gases (CO2, N2O) from the soil. During pyrolysis, the materials containing high organic matter (biomass-originated organic matter) are heated in oxygen-free (or limited amount of oxygen) environment. As a result, the solid phase, which remains after eliminating the gases and liquid phase, is more stable compared to the original product, it cannot be mineralized easily in the soil and its utilization is more beneficial in terms of climatic aspects. Furthermore, it can improve soil structure and it can retain soil moisture and cations in the topsoil for long periods of time, which is very important for plants. In our experiment, the effects of biochar and bone char were examined on soils by zinc adsorption experiments. Based on our experiments, we concluded that the pyrolysis products can have significant Zn adsorption capacity compared to the soil. Bone ash can adsorb more Zn than the charcoal product. The Zn adsorption capacity of soils treated by pyrolysis products can be described by Langmuir adsorption isotherms. However, based on the amount of pyrolysis products, one or two term Langmuir isotherm fits well on the experiment data, which depends on the time the pyrolysis product has spent in the soil.


2010 ◽  
Vol 62 (10) ◽  
pp. 2294-2300 ◽  
Author(s):  
T. Mato ◽  
M. Ben ◽  
C. Kennes ◽  
M. C. Veiga

Fibreboard production is one of the most important industrial activities in Galicia (Spain). Great amounts of wastewater are generated, with properties depending on the type of wood, treatment process, final product and water reusing, among others. These effluents are characterized by a high chemical oxygen demand (COD), low pH and nutrients limitation. Aerobic and anaerobic processes have been used for their treatment. Presently, bioplastics production (mainly polyhydroxyalkanoates or PHA) from wastewaters with mixed cultures is being studied. Substrate requirements for these processes are a high organic matter content and low nutrient concentration. Therefore, wood mill effluents could be a suitable feedstock. PHA production from wastewaters is carried out in three steps. First, complex organic matter is converted into volatile fatty acids (VFA) through acidogenic fermentation. Then, VFA are used as substrate in an aerobic sequencing batch reactor (SBR), in which the enrichement of PHA producing bacteria from a mixed culture is favoured. Finally, the sludge from the SBR is fed with a pulse containing high VFA concentrations, resulting in PHA accumulation inside the cells. In this work, the possibility of applying this process to wood mill effluents is proposed. An acidification percentage of 37% and a storage yield (YSTO) of 0.23 Cmmol/Cmmol were obtained.


2013 ◽  
Vol 10 (1) ◽  
pp. 421-436 ◽  
Author(s):  
C. Estop-Aragonés ◽  
K.-H. Knorr ◽  
C. Blodau

Abstract. Climate change induced drying and flooding may alter the redox conditions of organic matter decomposition in peat soils. The seasonal and intermittent changes in pore water solutes (NO3−, Fe2+, SO42−, H2S, acetate) and dissolved soil gases (CO2, O2, CH4, H2) under natural water table fluctuations were compared to the response under a reinforced drying and flooding in fen peats. Oxygen penetration during dryings led to CO2 and CH4 degassing and to a regeneration of dissolved electron acceptors (NO3−, Fe3+ and SO42−). Drying intensity controlled the extent of the electron acceptor regeneration. Iron was rapidly reduced and sulfate pools ~ 1 mM depleted upon rewetting and CH4 did not substantially accumulate until sulfate levels declined to ~ 100 μmol L−1. The post-rewetting recovery of soil methane concentrations to levels ~ 80 μmol L−1 needed 40–50 days after natural drought. This recovery was prolonged after experimentally reinforced drought. A greater regeneration of electron acceptors during drying was not related to prolonged methanogenesis suppression after rewetting. Peat compaction, solid phase content of reactive iron and total reduced inorganic sulfur and organic matter content controlled oxygen penetration, the regeneration of electron acceptors and the recovery of CH4 production, respectively. Methane production was maintained despite moderate water table decline of 20 cm in denser peats. Flooding led to accumulation of acetate and H2, promoted CH4 production and strengthened the co-occurrence of iron and sulfate reduction and methanogenesis. Mass balances during drying and flooding indicated that an important fraction of the electron flow must have been used for the generation and consumption of electron acceptors in the solid phase or other mechanisms. In contrast to flooding, dry-wet cycles negatively affect methane production on a seasonal scale, but this impact might strongly depend on drying intensity and on the peat matrix, of which structure and physical properties influence moisture content.


Author(s):  

The formation of the chemical composition of the Bureya water reservoir in the first years of its operation is described. The reservoir filling-in with water stage by stage gradually balanced different levels of concentration of mineral and organic substances and stabilized water mineral composition by the sixth year of reservoir filling-in.


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