Dry weight measurement of microbial biomass and measurement variability analysis

1992 ◽  
Vol 6 (3) ◽  
pp. 207-212 ◽  
Author(s):  
K. M. Stone ◽  
F. W. Roche ◽  
N. F. Thornhill
Keyword(s):  
Microbial Biomass ◽  
Dry Weight ◽  
Measurement Variability ◽  
Variability Analysis ◽  
Weight Measurement

scholarly journals CMM Measurement Variability Analysis: A Comparison Between Two Metrological Laboratories Measuring Three Industrial Workpieces

2008 ◽  
Author(s):  
Francesco Aggogeri ◽  
Emanuele Barini ◽  
Raffaello Levi
Keyword(s):  
Task Environment ◽  
Reliable Measurement ◽  
Measurement Variability ◽  
Workpiece Surface ◽  
Measurement Systems ◽  
Variability Analysis ◽  
Linear Dimensions ◽  
Number Of Factors ◽  
Remedial Actions ◽  
Control Procedures

Quality may be defined as a set of requirements a system should satisfy in order to meet customer’s needs. Control of these requirements assures satisfaction of relevant standards, and consequently the performance levels of a manufacturing/transactional stream. In this context it is fundamental to define control procedures and reliable measurement systems adequate for adopting improvement action as soon as anomalies and dysfunctions are detected. This paper deals with a study of measurement variability occurring during practical exploitation of CMMs (Coordinate Measuring Machines). These measurement systems are designed to probe selected points of workpiece surface, and compare the relevant coordinates or derived quantities with specified values; capability and versatility of CMMs justify their widespread use in industry. Evaluation of CMM measurement variability is however often awkward owing to a number of factors, such as e.g. measurement task, environment, operator and measurement procedures. A round robin exercise involving two industrial laboratories was planned in order to address these issues. Three typical machine tool parts were circulated among participants, who were asked to measure linear dimensions as well as tolerances at specified locations, according to an agreed upon schedule. Results of measurements, performed by experienced CMM industrial users, were analyzed in order to bring out discrepancies, and suggest remedial actions in the light of information gathered. Several factors involving metrological as well as other aspects were observed to cause major discrepancies, yielding in turn information on where to look for potential sources of trouble. Conclusions were drawn in terms of operating procedure, leading to improved information on origin and components of variability.

scholarly journals Dehydrogenase activity in topsoil at windthrow plots in Tatra National Park

2017 ◽  
Vol 63 (2-3) ◽  
pp. 91-96 ◽  
Author(s):  
Peter Hanajík ◽  
Jana Gáfriková ◽  
Milan Zvarík
Keyword(s):  
Microbial Biomass ◽  
Carbon Content ◽  
Dehydrogenase Activity ◽  
National Park ◽  
Dry Weight ◽  
Soil Samples ◽  
Control Plot ◽  
Microbial Biomass C ◽  
Wood Debris ◽  
Tatra National Park

AbstractThe aim of the study was to compare the effect of windthrow treatments established after the windstorm in 2004 on the activity of enzyme dehydrogenase (DHA) in forest topsoils. We also focused on the effect of the recent windthrow (May 2014) on the DHA in topsoil. Soil samples were collected in July 2014 from four sites in the Tatra National Park: EXT - tree trunks and wood debris extracted after the windstorm in 2004, NEX - area left for self-regeneration after the windstorm in 2004, REX - tree trunks and wood debris extracted after the windstorm (May 2014), REN - Norway spruce stand set as a control plot. We measured pH, dry weight %, soil organic matter (SOM), carbon content in microbial biomass (Cblo) and DHA. Dehydrogenase activity at studied plots was the lowest at the EXT plot and the highest values were measured at the REN plot. DHA at NEX was similar to REN suggesting comparable ecological conditions at these plots comparing to EXT. Carbon content in microbial biomass at plots reflected intensity of dehydrogenase activity in sequence EXT < REX < NEX < REN.

Infrared Measurement Variability Analysis.

1980 ◽  
Author(s):  
N. K. Matthis ◽  
T. J. Morin ◽  
W. E. Thompson
Keyword(s):  
Measurement Variability ◽  
Variability Analysis ◽  
Infrared Measurement

Measurement variability analysis for fermentation process assays

1995 ◽  
Vol 13 (5) ◽  
pp. 239-243 ◽  
Author(s):  
M. Dehghani ◽  
M. Bulmer ◽  
M. E. Gregory ◽  
N. F. Thornhill
Keyword(s):  
Fermentation Process ◽  
Measurement Variability ◽  
Variability Analysis

The relative contribution of plant residues and fertilizer to the phosphorus nutrition of wheat in a pasture cereal system

Soil Research ◽  
1986 ◽  
Vol 24 (4) ◽  
pp. 517 ◽  
Author(s):  
MJ Mclaughlin ◽  
AM Alston
Keyword(s):  
Microbial Biomass ◽  
Wheat Plant ◽  
Dry Weight ◽  
Plant Residues ◽  
Soil Microbial ◽  
Relative Contribution ◽  
Medicago Trunculata ◽  
Microbial P ◽  
32P Uptake ◽  
Total P

Wheat plants (Triticum aestivum cv. Warigal) here grown in a solonised brown soil (Calcixerollic xerochrept) which had been previously cropped to medic (Medicago trunculata cv. Paraggio). The 33P-labelled medic residues and 32P-labelled monocalcium phosphate were added to the soil in factorial combination. Amounts of 31P, 32P and 33P in the wheat plants and in the soil microbial biomass were determined. Addition of residues depressed wheat dry weight, 31P and 32P uptake, while simultaneously increasing amounts of 31P and 32P incorporated into the microbial biomass. Addition of fertiliser had no effect on the proportion of plant P taken up from the residues, but significantly increased the proportion of microbial P derived from this source. The 31P held in the microbial biomass was significantly increased by both residue and fertiliser P addition, with the former having the larger effect. Of the total P applied to the soil, medic residues contributed approximately one-quarter of that supplied by the fertiliser. Of the total P in the wheat plant, medic residues supplied approximately one-fifth of that supplied by the fertiliser.

Pools and composition of soils in the alpine zone of the Tatra Mountains

Biologia ◽  
2006 ◽  
Vol 61 (18) ◽  
Author(s):  
Jiří Kopáček ◽  
Jiří Kaňa ◽  
Hana Šantrůčková
Keyword(s):  
Microbial Biomass ◽  
Base Cations ◽  
Dry Weight ◽  
Biochemical Properties ◽  
Exchange Capacity ◽  
Tatra Mountains ◽  
Organic C ◽  
Molar Ratios ◽  
Alpine Zone ◽  
The Tatra Mountains

AbstractThe basic physical, chemical, and biochemical properties of mountain soils were determined in alpine-zone meadow and moraine areas of the Tatra Mountains (Slovakia, Poland) in 2000–2001. The amount of soil (dry weight soil < 2 mm) varied from 38 to 255 kg m−2 (average of 121 kg m−2) in alpine meadows and averaged 13 kg m−2 in moraine areas. Concentration of organic C was the parameter that most strongly and positively correlated with N, P, S, effective cation exchange capacity (CEC), exchangeable base cations, exchangeable acidity, and all biochemical parameters (C, N, and P in microbial biomass and C mineralisation rates). The relationship between C and P was less straightforward due to inorganic P forms associated with Fe and Al oxides. The average pools of C, N, P, and S, were respectively 696, 41, 2.9, and 1.9 mol m−2 (i.e., 84, 5.7, 0.91 and 0.61 t ha−1) in meadow soils, and 38, 2.1, 0.45 and 0.12 mol m−2 (i.e., 4.5, 0.30, 0.14 and 0.04 t ha−1) in moraine areas. Soil pH was generally low, with the lowest pHH 2 O values (3.8–4.9) in the A-horizons. Average pools of CEC were 12 and 0.7 eq m−2 in meadows and moraine areas, respectively. The base saturation (BS) was 4–45% (12% on average) of CEC, and was primarily based on Ca2+ and K+ (∼40% and ∼22% of BS, respectively). C:N molar ratios (14–20) were only slightly lower than those observed in the alpine Tatra Mountain zone ∼40 years ago. Concentrations of C, N, and P in soil microbial biomass were high (on average 1.6, 3.4, and 25% of total C, N, and P concentrations), suggesting high microbial activity in alpine soils.

scholarly journals Methods for elucidating microbial biomass

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Nidhi Saxena
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Standing Crop ◽  
Bacterial Biomass ◽  
Dry Weight ◽  
Trophic Levels ◽  
Total Microbial Biomass ◽  
Ecological Parameter ◽  
Living Material ◽  
Living Organisms

<p>The microbial biomass of soil is defined as the part of the organic matter in the soil that constitutes living organisms smaller than the 5-10 mm<sup>3. </sup>It is generally expressed in the milligrams of carbon per kilogram of soil or micrograms of carbons per gram of dry weight of soil. Typical biomass carbon ranges from 1 to 5% of soil organic matter. Biomass literally means “mass of living material” and can be expressed in units of weight (grams) or units of energy (calories or joules). Biomass is an important ecological parameter as it represents the quantity of energy being stored in a particular segment of biological community.             </p>               Measurement of biomass is used to determine standing crop of a population and transfer of energy between trophic levels within an ecosystem. A measure of the total microbial biomass in soil is often required when studying productivity or fertility of soils. Sometimes the biomass of specific parts of the microbiota is required-for example fungal biomass versus bacterial biomass.

scholarly journals Degradation of Phthalate and Di-(2-Ethylhexyl)phthalate by Indigenous and Inoculated Microorganisms in Sludge-Amended Soil

1998 ◽  
Vol 64 (12) ◽  
pp. 4711-4719 ◽  
Author(s):  
Peter Roslev ◽  
Peter L. Madsen ◽  
Jesper B. Thyme ◽  
Kaj Henriksen
Keyword(s):  
Microbial Biomass ◽  
Late Phase ◽  
Fractional Power ◽  
Dry Weight ◽  
Second Phase ◽  
First Order ◽  
Ethylhexyl Phthalate ◽  
Radiotracer Techniques ◽  
Amended Soil

ABSTRACT The metabolism of phthalic acid (PA) and di-(2-ethylhexyl)phthalate (DEHP) in sludge-amended agricultural soil was studied with radiotracer techniques. The initial rates of metabolism of PA and DEHP (4.1 nmol/g [dry weight]) were estimated to be 731.8 and 25.6 pmol/g (dry weight) per day, respectively. Indigenous microorganisms assimilated 28 and 17% of the carbon in [14C]PA and [14C]DEHP, respectively, into microbial biomass. The rates of DEHP metabolism were much greater in sludge assays without soil than in assays with sludge-amended soil. Mineralization of [14C]DEHP to 14CO2 increased fourfold after inoculation of sludge and soil samples with DEHP-degrading strain SDE 2. The elevated mineralization potential was maintained for more than 27 days. Experiments performed with strain SDE 2 suggested that the bioavailability and mineralization of DEHP decreased substantially in the presence of soil and sludge components. The microorganisms metabolizing PA and DEHP in sludge and sludge-amended soil were characterized by substrate-specific radiolabelling, followed by analysis of 14C-labelled phospholipid ester-linked fatty acids (14C-PLFAs). This assay provided a radioactive fingerprint of the organisms actively metabolizing [14C]PA and [14C]DEHP. The14C-PLFA fingerprints showed that organisms with different PLFA compositions metabolized PA and DEHP in sludge-amended soil. In contrast, microorganisms with comparable 14C-PLFA fingerprints were found to dominate DEHP metabolism in sludge and sludge-amended soil. Our results suggested that indigenous sludge microorganisms dominated DEHP degradation in sludge-amended soil. Mineralization of DEHP and PA followed complex kinetics that could not be described by simple first-order equations. The initial mineralization activity was described by an exponential function; this was followed by a second phase that was described best by a fractional power function. In the initial phase, the half times for PA and DEHP in sludge-amended soil were 2 and 58 days, respectively. In the late phase of incubation, the apparent half times for PA and DEHP increased to 15 and 147 days, respectively. In the second phase (after more than 28 days), the half time for DEHP was 2.9 times longer in sludge-amended soil assays than in sludge assays without soil. Experiments with radiolabelled DEHP degraders suggested that a significant fraction of the 14CO2 produced in long-term degradation assays may have originated from turnover of labelled microbial biomass rather than mineralization of [14C]PA or [14C]DEHP. It was estimated that a significant amount of DEHP with poor biodegradability and extractability remains in sludge-amended soil for extended periods of time despite the presence of microorganisms capable of degrading the compound (e.g., more than 40% of the DEHP added is not mineralized after 1 year).

Effects of the Initial Rice Bran Concentration on the Production of Lactobacillus casei as Digestive Bio-regulator

2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Siti Marsilawati Mohamed Esivan ◽  
Roslina Rashid ◽  
Nor Azrini Nadiha Azmi ◽  
Nor Athirah Zaharudin ◽  
Norasikin Othman
Keyword(s):  
Rice Bran ◽  
Substrate Concentration ◽  
Lactobacillus Casei ◽  
Dry Weight ◽  
Weight Measurement ◽  
Initial Substrate ◽  
The World ◽  
Live Bacteria ◽  
The Cost ◽  
Initial Substrate Concentration

Digestive bio-regulator or probiotic is defined as live bacteria with clinically documented health effects in humans and animals. Nowadays, there is increasing interest in probiotics from all over the world. However, the cost of producing probiotics products is still high. To reduce the cost, there is a need to study the usage of agro waste as an inexpensive substrate. The viability of the cell was counted in colony unit per mL (CFU/mL) and the growth was measured using dry weight measurement (g/mL). The sugar concentration was measured using glucose analyzer. At initial substrate concentration of 20% (w/v) and at incubation time of 10hr, the viability cell was 3 x 108 CFU/mL and cell dry weight was 0.0076 g/mL. From the results of this study, it is found that when the initial substrate concentration increased, the viability and growth of Lactobacillus casei increased.

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