The effect of previous microbial experience on the gas production profiles in the Gas Pressure Transducer system.

1993 ◽  
Vol 1993 ◽  
pp. 170-170
Author(s):  
A T Chamberlain
Keyword(s):  
Microbial Population ◽  
Fish Meal ◽  
Spring Barley ◽  
Nutrient Release ◽  
Sole Source ◽  
Barley Grain ◽  
Gas Production ◽  
Set Up ◽  
Kinetics Of ◽  
Feed Samples

A technique involving the measurement of the gas production from the microbial fermentation of a specified substrate in sealed conditions has recently been proposed as a method of assessing the fermentation kinetics of tropical feeds (Theodorou et al, 1992). In this technique the feed under test is the sole source of nutrients to the microbes and therefore it is possible that the nutrient release profile may have an influence on the microbial population leading to a modified gas production profile. The objective of this study was to investigate the effect of previous microbial experience on gas production.One gram air dried feed samples were placed with 95 ml of modified van Soest media and 5 ml of strained rumen liquor in 150 ml serum bottles and sealed under anaerobic conditions. The rumen liquor was obtained from fistulated yearling wethers fed a maintenance diet of 0.9 good hay: 0.1 commercial 16% CP compound feed). Four replicates of fish meal (FM) and eight of spring barley grain (SPB) were set up together with control blanks.

The use of the Gas Pressure Transducer Technique for the assessment of the ruminal degradation of the dry matter of protein supplements.

1993 ◽  
Vol 1993 ◽  
pp. 169-169
Author(s):  
A T Chamberlain
Keyword(s):  
Dry Matter ◽  
Gas Production ◽  
Production Volume ◽  
Protein Supplements ◽  
Ruminal Degradation ◽  
Bean Meal ◽  
Soya Bean Meal ◽  
Set Up ◽  
Kinetics Of ◽  
Feed Samples

A technique involving the measurement of the gas production from the microbial fermentation of a specified substrate in sealed conditions has recently been proposed as a method of assessing the fermentation kinetics of tropical feeds (Theodorou et al, 1992). The objective of this work was to determine if such a technique could be used to assess the dry matter degradability of protein supplements.1g air dried feed samples were placed with 95 ml of modified van Soest media and 5 ml of strained rumen liquor in 150 ml serum bottles and sealed under anaerobic conditions. Five replicates of soya bean meal (SBM), fish meal (FM), rape seed meal (RSM) and winter beans (WB) were set up together with control blanks that lacked the test feed. Bottles were incubated at 39.5°C for a 96 hour period and gas production volume measured at regular intervals. Cumulative gas production was corrected for the blanks and sample dry matter and plotted against time.

The effect of the length of the priming period on fermentation characteristics using the pressure transducer technique

1998 ◽  
Vol 22 ◽  
pp. 217-217
Author(s):  
D. M. Harris ◽  
D. E. Beever
Keyword(s):  
Kinetic Data ◽  
Pressure Transducer ◽  
Microbial Population ◽  
Basal Diet ◽  
Barley Grain ◽  
Gas Production ◽  
Donor Animal ◽  
Grass Silage

The pressure transducer technique of Theodorou et al. (1984) is becoming of increasing importance in food evaluation. The main advantage over end-point procedures is the collection of kinetic data on a food. Previously such data were only obtained by sequential sacrifice or in situ techniques. Earlier work (Harris, 1996) showed that kinetics in the early stages of the incubation may not accurately simulate the processes occurring in vivo and this led to the use of a priming technique when the microbial innocula is acclimatized for 24 h to a priming food similar to the basal diet of the donor animal. This work investigates the effect of the length of priming on fermentation characteristics of two foods.Samples of barley grain and straw were ground through a 1-mm screen and a priming food of grass silage and concentrates prepared according to the method of Harris (1996). Gas production was determined from the barley grain and straw using bovine rumen liquor after exposing the microbial population to the priming food for 0 (unprimed), 6, 12, or 24 h. Gas volumes were recorded manually and the blank corrected volumes fitted to the equation of France et al. (1993).

Protein fermentation characteristics in rumen fluid determined with the gas production technique

2009 ◽  
Vol 2009 ◽  
pp. 192-192
Author(s):  
J W Cone ◽  
M A M Rodrigues
Keyword(s):  
Rumen Fluid ◽  
Gas Production ◽  
Limiting Factor ◽  
Production Technique ◽  
High Input ◽  
Fermentable Carbohydrates ◽  
Kinetics Of ◽  
Feed Samples ◽  
Microbial Mass

The gas production technique was developed to determine the fermentation kinetics of organic matter in rumen fluid. However, the gas production technique can be adapted for the determination of protein fermentation characteristics. To do that the buffer must be N-free. All the N coming with the rumen fluid must be incorporated into microbial mass. This can be done by supplying the buffered rumen fluid with an excess of fast fermentable carbohydrates. To prevent a too high input of N from the rumen fluid the rumen fluid can be diluted further compared to the standard 3 times (Cone et al., 1996). This makes N the limiting factor for fermentation and the obtained gas production profiles reflect the availability of N from the feed samples. The aim of the present study was to investigate if the adapted gas production technique is suitable to determine differences in protein availability in rumen fluid. The fermentation characteristics of N of 19 feed samples were determined using the adapted gas production technique. The amount of sample incubated, was that sufficient to provide 15 mg N. The results were compared with data of N degradation obtained with the nylon bag technique.

The effect of head-space pressure on gas production profiles

1998 ◽  
Vol 22 ◽  
pp. 205-206
Author(s):  
R. S. Lowman ◽  
A. E. Brooks ◽  
M. K. Theodorou ◽  
M. S. Dhanoa ◽  
D. Cuddeford
Keyword(s):  
Pressure Transducer ◽  
Culture Medium ◽  
Microbial Population ◽  
Volume Measurement ◽  
Gas Production ◽  
Head Space ◽  
Manual Pressure ◽  
Production Techniques ◽  
Kinetics Of

In vitro gas production techniques are becoming increasingly popular as tools to investigate the food quality for ruminant and monogastric herbivores. They are attractive due to their ability to measure the kinetics of digestion associated with the gut microbial fermentation of foodstuffs. It is therefore important to know and understand what factors affect the volume of gas produced, particularly as they relate to repeatability within or between laboratories. In studies involving gas pressure and volume measurement, the chemical composition of the culture medium, the nature of the microbial population and the type and amount of substrate available for fermentation all have a significant influence on gas accumulation. In this study, the manual pressure transducer technique (PTT) of Theodorou et al. (1994) was used to investigate the effect of head-space pressure on the resultant gas production profiles.

Continuous Quantitative Monitoring of Mural, Platelet-Dependent, Thrombus Kinetics in the Crushed Rat Femoral Vein

1991 ◽  
Vol 65 (04) ◽  
pp. 425-431 ◽  
Author(s):  
F Stockmans ◽  
H Deckmyn ◽  
J Gruwez ◽  
J Vermylen ◽  
R Acland
Keyword(s):  
Thrombus Formation ◽  
Femoral Vein ◽  
Maximum Size ◽  
Digital Analysis ◽  
Video Recordings ◽  
Quantitative Monitoring ◽  
Set Up ◽  
Kinetics Of ◽  
Quantitative Nature

SummaryA new in vivo method to study the size and dynamics of a growing mural thrombus was set up in the rat femoral vein. The method uses a standardized crush injury to induce a thrombus, and a newly developed transilluminator combined with digital analysis of video recordings. Thrombi in this model formed rapidly, reaching a maximum size 391 ± 35 sec following injury, after which they degraded with a half-life of 197 ± 31 sec. Histological examination indicated that the thrombi consisted mainly of platelets. The quantitative nature of the transillumination technique was demonstrated by simultaneous measurement of the incorporation of 111In labeled platelets into the thrombus. Thrombus formation, studied at 30 min interval in both femoral veins, showed satisfactory reproducibility overall and within a given animalWith this method we were able to induce a thrombus using a clinically relevant injury and to monitor continuously and reproducibly the kinetics of thrombus formation in a vessel of clinically and surgically relevant size

Modelling of impregnation of γ-alumina with cobalt and molybdenum salts. CoCl2-(NH4)2MoO4-γ-Al2O3 (aluminate type) system

1987 ◽  
Vol 52 (3) ◽  
pp. 663-671 ◽  
Author(s):  
Jiří Hanika ◽  
Vladimír Janoušek ◽  
Karel Sporka
Keyword(s):  
Effective Diffusion ◽  
Type System ◽  
Catalyst Particle ◽  
Ammonium Molybdate ◽  
Active Components ◽  
Model Set ◽  
Cobalt Dichloride ◽  
Set Up ◽  
Electron Microanalysis ◽  
Kinetics Of

Adsorption data for the impregnation of alumina with an aqueous solution of cobalt dichloride and ammonium molybdate were treated in terms of the Langmuir adsorption isotherm and compared with a mathematical model set up to describe the kinetics of simultaneous impregnation of a support by two components. The effective diffusion coefficients of the two components at 25 °C in a cylindrical particle of alumina were obtained. The validity of the model used was verified qualitatively by comparing the numerical results with the experimental time dependent concentration profiles of the active components in a catalyst particle, measured by electron microanalysis technique.

scholarly journals Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2246
Author(s):  
Georgia Charalampous ◽  
Efsevia Fragkou ◽  
Konstantinos A. Kormas ◽  
Alexandre B. De Menezes ◽  
Paraskevi N. Polymenakou ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Oil Spills ◽  
Eastern Mediterranean ◽  
Sole Source ◽  
Eastern Mediterranean Sea ◽  
Deep Waters ◽  
Degradation Rates ◽  
Polycyclic Aromatic ◽  
Set Up

The diversity and degradation capacity of hydrocarbon-degrading consortia from surface and deep waters of the Eastern Mediterranean Sea were studied in time-series experiments. Microcosms were set up in ONR7a medium at in situ temperatures of 25 °C and 14 °C for the Surface and Deep consortia, respectively, and crude oil as the sole source of carbon. The Deep consortium was additionally investigated at 25 °C to allow the direct comparison of the degradation rates to the Surface consortium. In total, ~50% of the alkanes and ~15% of the polycyclic aromatic hydrocarbons were degraded in all treatments by Day 24. Approximately ~95% of the total biodegradation by the Deep consortium took place within 6 days regardless of temperature, whereas comparable levels of degradation were reached on Day 12 by the Surface consortium. Both consortia were dominated by well-known hydrocarbon-degrading taxa. Temperature played a significant role in shaping the Deep consortia communities with Pseudomonas and Pseudoalteromonas dominating at 25 °C and Alcanivorax at 14 °C. Overall, the Deep consortium showed a higher efficiency for hydrocarbon degradation within the first week following contamination, which is critical in the case of oil spills, and thus merits further investigation for its exploitation in bioremediation technologies tailored to the Eastern Mediterranean Sea.

scholarly journals Preserving Porphyra umbilicalis and Saccharina latissima as Silages for Ruminant Feeding

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1957
Author(s):  
Margarita Novoa-Garrido ◽  
Carlos Navarro Marcos ◽  
María Dolores Carro Travieso ◽  
Eduarda Molina Alcaide ◽  
Mogens Larsen ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Volatile Fatty Acids ◽  
Gas Production ◽  
Saccharina Latissima ◽  
Porphyra Umbilicalis ◽  
In Vitro Gas Production ◽  
Ruminal Degradability ◽  
Kinetics Of

The study analyzed the characteristics, chemical composition, and in vitro gas production kinetics of Porphyra umbilicalis and Saccharina latissima silages. Each seaweed was ensiled in vacuum bags (three bags/silage) following a 2 × 3 factorial design, with two pre-treatments (unwilted or pre-wilted) and three silage types: unwashed seaweed ensiled without additive; seaweed washed and ensiled without additive; and seaweed washed and ensiled with 4 g of formic acid (FAC) per kg seaweed. Silages were kept for 3 months in darkness at 20 °C. Pre-wilting prevented (p < 0.001) effluent formation and reduced (p ≤ 0.038) the production of NH3-N and volatile fatty acids for both seaweeds. Both pre-wilting and washing increased (p < 0.05) the ruminal degradability of P. umbilicalis silages but not of S. latissima silages. The pH of the FAC-treated silages was below 4.0, but ranged from 4.54 to 6.23 in non FAC-treated silages. DL-lactate concentrations were low (≤23.0 g/kg dry matter) and acetate was the predominant fermentation product, indicating a non-lactic fermentation. The estimated ruminal degradability of the P. umbilicalis and S. latissima silages was as average, 59.9 and 86.1% of that for high-quality rye-grass silages, respectively, indicating a medium-low nutritional value of these seaweed silages for ruminants.

scholarly journals How nutrient rich are decaying cocoa pod husks? The kinetics of nutrient leaching

2021 ◽  
Author(s):  
D.-G. J. M. Hougni ◽  
A. G. T. Schut ◽  
L. S. Woittiez ◽  
B. Vanlauwe ◽  
K. E. Giller
Keyword(s):  
Nutrient Release ◽  
Nutrient Content ◽  
Nutrient Leaching ◽  
Intense Rainfall ◽  
Decomposition Rates ◽  
Rainfall Events ◽  
Rainfall Frequency ◽  
Water Saturated ◽  
Kinetics Of ◽  
Cocoa Pod Husks

Abstract Aim Recycling of cocoa pod husks has potential to contribute to mineral nutrition of cocoa. Yet little is known of the nutrient content and nutrient release patterns from the husks. The potassium (K) rich husks are usually left in heaps in cocoa plantations in Africa. We aimed to understand and quantify release patterns of K and other nutrients from husks under varying rainfall regimes and assessed the effects of partial decomposition and inundation on nutrient leaching rates. Methods We incubated chunks of cocoa pod husks to assess decomposition rates and we measured nutrient leaching rates from two sets of husk chunks: one set was placed in tubes that were submitted to simulated scheduled rainfall events while the second set was continuously inundated in beakers. Results Decomposition of husks followed a second-order exponential curve (k: 0.09 day−1; ageing constant: 0.43). Nutrient losses recorded within 25 days were larger and more variable for K (33%) than for other macronutrients released in this order: Mg > Ca ≈ P > N (less than 15%). Potassium leaching was mainly driven by rainfall frequency (P < 0.05) and reinforced by intense rainfall, especially at lower frequency. Under water-saturated conditions, 11% of K was leached out within 48 h from fresh husks compared with 92% from partially decayed husks. Conclusion Some initial decomposition of cocoa pod husks is required to expose K to intense leaching. As decomposition progresses, abundant K losses are to be expected under frequent and/or intense rainfall events.

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