scholarly journals Pressure Transducer Method for Measuring Gas Production by Microorganisms

1974 ◽  
Vol 27 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Judd R. Wilkins
Keyword(s):  
Pressure Transducer ◽  
Gas Production

Pre-incubation of microbes for use in the Pressure Transducer Technique (PTT) of feed evaluation - effect of basal feed composition

1996 ◽  
Vol 1996 ◽  
pp. 220-220
Author(s):  
D M Harris
Keyword(s):  
Pressure Transducer ◽  
Phase 1 ◽  
Barley Grain ◽  
Gas Production ◽  
Lag Phase ◽  
Feed Composition ◽  
Grass Silage ◽  
High Starch ◽  
Effect Of The Composition ◽  
High Cellulose

The use of the Pressure Transducer Technique (PTT) to evaluate feed degradation as described by Theodorou et al (1994) recognises the presence of a lag phase (1-2h) after introducing the microbial innocula to the feed under investigation. Previous work has shown that this can be reduced by incubating the microbes with a basal feed for 24h prior to the addition of a test feed. This work considered the effect of the composition of this basal feed.Four basal mixtures, Grass silage/conc(G), Hay/cone (H), Maize silage/conc: (M), Whole crop wheat/caustic wheat/cone (W) were prepared plus two mixtures based on purified nutrients to give high Starch (St) and high Cellulose (Ce) contents. 20ml strained, homogenised bovine rumen liquor was added to bottles containing 180ml of media and 1.5g DM of each basal mixture. After 24h of vented incubation at 39°C 1g DM of test feed, (either barley grain or straw both milled to 1 mm) was added and gas production measured at decreasing frequencies over the next 72h. Cumulative gas production at 72h were calculated (Table 1).

A comparison of the in vitro fermentation of four feeds by inocula from bovine rumen digesta and equine caecal digesta, using the pressure transducer technique

1996 ◽  
Vol 1996 ◽  
pp. 224-224
Author(s):  
R.S. Lowman ◽  
M.K. Theodorou ◽  
A.C. Longland ◽  
D. Cuddeford
Keyword(s):  
Pressure Transducer ◽  
Gas Production ◽  
In Vitro Fermentation ◽  
Bovine Rumen ◽  
Mesh Screen ◽  
Beet Pulp ◽  
Hind Gut ◽  
Pass Through ◽  
Naked Oats

It is generally believed that ruminants are better able to degrade highly fibrous feeds than equines. To determine if this is due to differences between the microflora of the rumen and the equine hind-gut, oatfeed (OF), naked oats (NO), soya hulls (SH) and unmolassed sugar beet pulp (SB) were incubated with inocula prepared from bovine rumen digesta or equine caecal digesta.OF, NO, SH, and SB were ground to pass through a 1 mm mesh screen and incubated for 72 hours, at 39°C with inocula prepared from either rumen (R) or caecal (C) digesta. Rumen digesta was obtained from three hay-fed, ruminally - fistulated Hereford x Friesian steers, and caecal digesta from three hay-fed, caecally -fistulated, Welsh-cross ponies. Gas production throughout the incubation was measured using the pressure transducer technique (Theodorou et al, 1994). After the incubation, VFA production was measured and residue weights were calculated for each feedstuff.

Effect of reducing the interval of recording from three to one hour on gas production profiles in the semi-automated technique using a pressure transducer

1999 ◽  
Vol 1999 ◽  
pp. 148-148
Author(s):  
R. M. Mauricio ◽  
F. L. Mould ◽  
E. Owen ◽  
M.S. Dhanoa ◽  
M.K. Theodorou
Keyword(s):  
Mathematical Description ◽  
Pressure Transducer ◽  
Gas Production ◽  
Automated System ◽  
Accurate Description ◽  
Lag Phase ◽  
Automated Technique ◽  
Micro Organisms

Mauricio et al.(1997) reported that faeces as an inoculum in the gas production produced similar results to rumen liquor in terms of total gas production and OM digestibility but a greater initial lag phase was observed. Where a mathematical description is to be used to develop the gas production profiles an accurate description of the lag phase (the period prior to degradation during which multiplication and attachment of the micro-organisms occur) must be obtained. For this to be achieved when a large number of samples are to be examined, measurement of gas production has to be achieved rapidly; this is possible using a semi-automated technique (Mauricio et al., 1998). This study evaluated the effect of recording gas production using a manual (syringe) technique, with a standard 3 h interval, and at 1h and 3 h intervals using a semi-automated system.

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).

The effect of bromoethanesulphonic acid on gas production during an in vitro rumen fermentation

1998 ◽  
Vol 22 ◽  
pp. 193-194
Author(s):  
D. R. Davies ◽  
E. L. Bakewell ◽  
D. K. Leemans ◽  
R. J. Merry
Keyword(s):  
Pressure Transducer ◽  
Rumen Fermentation ◽  
Gas Production ◽  
Production Technique ◽  
Microbial Ecosystem ◽  
Considerable Potential ◽  
Microbial Ecosystems ◽  
Presence And Absence ◽  
In Vitro Rumen Fermentation

Pressure transducer technology to measure gas production from microbial ecosystems has been utilized in a number of ways but predominantly for food evaluation. The approach also has considerable potential to increase our understanding of, and ability to manipulate, the rumen microbial ecosystem, but most research to date has concentrated on measurement of total gas production and not composition. The aim of this study was to extend the scope of the gas production technique to the quantitation of component gases, whilst investigating ruminal gas production in the presence and absence of methanogens.

The effect of increasing substrate concentration on the gas production profiles of pure maize starch and milled, high temperature dried grass

1996 ◽  
Vol 1996 ◽  
pp. 222-222
Author(s):  
J. A. Huntington ◽  
D. I. Givens
Keyword(s):  
Substrate Concentration ◽  
Linear Response ◽  
Pressure Transducer ◽  
Rumen Fluid ◽  
Lag Time ◽  
Enzymic Activity ◽  
Gas Production ◽  
Maize Starch ◽  
Data Logger ◽  
Manual Pressure

Theodorou et al. (1994) using a manual pressure transducer technique observed a linear response to substrate concentration (cone.) in gas production (GP; ml absolute) whilst lag time and rate of GP values remained constant. This experiment investigated the effect of increasing the cone, of maize starch (S) and milled (1mm) dried grass (DG) on the GP profile using an automated GP technique (Cone 1994).Either 0.1, 0.25, 0.5, 1.0 or 2.0 g of S or DG were weighed into 250 ml bottles and pre-soaked with anaerobic buffer (85 ml). The bottles were connected to a data logger/pressure tranducer unit and gassed with carbon dioxide. Incubation (39°C) started ∽16 h later when strained rumen fluid was injected into each bottle (15 ml) and a data logger initiated. When GP had ceased the final pH of each bottle was measured and 25 ml of 1M H3PO4 added to stop further enzymic activity. DG bottles were filtered to determine organic matter (OM) residue and hence OM degraded (OMD).

A comparison between two in vitro gas production techniques to study fermentation profiles of three foodstuffs

1998 ◽  
Vol 22 ◽  
pp. 207-208
Author(s):  
R. S. Lowman ◽  
N. S. Jessop ◽  
M. K. Theodorou ◽  
M. Herrero ◽  
D. Cuddeford
Keyword(s):  
Pressure Transducer ◽  
Rumen Fluid ◽  
Gas Production ◽  
In Vitro Gas Production ◽  
Production Techniques ◽  
Gas Tight ◽  
Gas Volume ◽  
Kinetics Of ◽  
Made In

Following the development of the Menke technique in 1979, the measurement of gas production in vitro has become increasingly popular for investigating the kinetics of rumen fermentation. The aim of this study was to compare the gas production profiles for three foods using two in vitro gas production techniques; the Menke et al. (1979) technique (MT) and the pressure transducer technique (PTT) (Theodorou et al., 1994). Both techniques involve recording gas production throughout the incubation of a food sample with rumen fluid. The MT incubations are made in gas-tight syringes where the volume of gas produced causes the plunger to move up the syringe barrel. The PTT involves measuring gas production in fermentation bottles using a pressure transducer and syringe assembly to measure the pressure and corresponding gas volume. As the medium to rumen fluid ratios also differ between techniques; 2:1 in the Menke technique and 9:1 in the PTT, both ratios were investigated in this study.

Gas production in vitro from either unprocessed, micronised or extruded maize, peas, wheat, naked oats and barley using equine faeces as the source of inocula

1999 ◽  
Vol 1999 ◽  
pp. 137-137
Author(s):  
B M L McLean ◽  
J J Hyslop ◽  
A C Longland ◽  
D Cuddeford ◽  
T Hollands
Keyword(s):  
Incubation Period ◽  
Batch Culture ◽  
Pressure Transducer ◽  
Culture Technique ◽  
Gas Production ◽  
Grass Hay ◽  
Physical Processing ◽  
Ad Libitum ◽  
Naked Oats

A wide variety of starch based feeds are available for inclusion in equine diets. These feeds may be subjected to physical processing (micronisation or extrusion) prior to inclusion. This experiment evaluates a range of starch based feedstuffs using an in vitro batch culture technique.A total of 15 feedstuffs were incubated in vitro with an inocula prepared from freshly voided faeces which was collected from six ponies fed grass hay ad libitum. The feeds were five starch based feedstuffs; i.e: maize (M), peas (P), wheat (W), naked oats (NO) or barley (Ba) in one of three physically processed forms i.e: unprocessed (Unp), micronised (Mic) or extruded (Ext). All feeds were ground through a 1.0mm screen prior to incubation. Cumulative gas production (GP) was measured using the pressure transducer technique of Theodorou et al (1994) throughout a 72 h incubation period.

Relationship between in vitro gas production and in vivo energy digestibility in growing pigs

1996 ◽  
Vol 1996 ◽  
pp. 142-142
Author(s):  
A.C. Longland ◽  
S.P. Bray ◽  
A.E. Brooks ◽  
M.K. Theodorou ◽  
A.G. Low
Keyword(s):  
Pressure Transducer ◽  
Nutritive Value ◽  
Rumen Fluid ◽  
Gas Production ◽  
Growing Pigs ◽  
Digestible Energy ◽  
In Vitro Gas Production

In vitro methods which can be used to predict the nutritive value of feedstuflfs for livestock are attractive in terms of both speed and economy. The in vitro pressure transducer technique (PTT) whereby the gas evolved during the in vitro fermentation of feedstuffs in rumen fluid is quantified by a pressure transducer, has been used to predict the nutritive value of ruminant feedstuffs. Here the potential for the PTT in predicting the digestible energy contents of eight feedstuffs varying in non-starch polysaccharide (NSP) content fed to growing pigs, was investigated.

Sign in / Sign up

Export Citation Format

Share Document