Factors Influencing Geosmin Production by a Streptomycete and their Relevance to the Occurrence of Earthy Taints in Reservoirs

1983 ◽  
Vol 15 (6-7) ◽  
pp. 191-198 ◽  
Author(s):  
S Wood ◽  
S T Williams ◽  
W R White ◽  
F Jones
Keyword(s):  
Water Mass ◽  
Plant Debris ◽  
Water Supplies ◽  
Biological Origin ◽  
Factors Influencing ◽  
Run Off ◽  
High Concentrations

Water Authorities in the U.K. receive complaints about taste and odours of chemical and biological origin in water supplies. Earthy flavours associated with actinomycetes, cyanobacteria and/or combinations of these are most prevalent. The study area consisted of five large open reservoirs, four of which have sporadic flavour problems. The possible sources of odourous metabolites were studied (water mass, sediment, plant debris, soil run-off). The water mass required high concentrations of nutrients before actinomycetes produced geosmin; such were not reached in the reservoirs. Sediment yielded geosmin after exposure to air for four weeks and plant debris was found to support geosmin production. The soil surrounding the reservoir supports geosmin production and may contaminate the water by run-off or seepage through the reservoir walls.

675. The carbon dioxide content of New Zealand Cheddar cheese

1957 ◽  
Vol 24 (2) ◽  
pp. 235-241 ◽  
Author(s):  
P. S. Robertson
Keyword(s):  
Carbon Dioxide ◽  
New Zealand ◽  
Carbon Dioxide Concentration ◽  
Cheddar Cheese ◽  
Carbon Dioxide Content ◽  
Single Strain ◽  
Open Texture ◽  
Factors Influencing ◽  
High Concentrations ◽  
Lower Temperature

Some of the factors influencing the concentration of carbon dioxide found in New Zealand Cheddar cheese have been investigated.1. Cheeses made with the use of commercial starters (containing betacocci) are characterized by a rapid increase in their carbon dioxide content during the 2 weeks following manufacture.2. Cheeses made with the use of single strain starters do not change in carbon dioxide content in the first 2 weeks following manufacture, but may ultimately contain as much carbon dioxide as commercial starter cheeses.3. High concentrations of carbon dioxide within a cheese result in an open texture, especially when the carbon dioxide is formed shortly after manufacture.4. The loss of carbon dioxide to the atmosphere is demonstrated by the existence of a carbon dioxide concentration gradient within the cheese.5. Storage of cheese at a lower temperature than is usual results in retarded carbon dioxide formation.

Factors influencing tartrate uptake by Penicillium charlesii

1968 ◽  
Vol 14 (5) ◽  
pp. 579-585 ◽  
Author(s):  
K. P. Klatt ◽  
J. E. Gander
Keyword(s):  
Spore Germination ◽  
Glucose Concentration ◽  
Factors Influencing ◽  
High Concentrations

The uptake of tartrate by P. charlesii has been studied for cultures that were either aerated by shaking or were kept stationary. Stationary cultures were permeable to tartrate when high concentrations of NH4+ (above 36 mM) and glucose (278 mM) were present. Manganous ion (10−5 M) was required for the uptake of tartrate by stationary cultures containing high concentrations of NH4+. Both stationary and shake cultures were able to remove tartrate from the medium when the glucose concentration was reduced below 278 mM; the process was then no longer dependent upon the presence of Mn2+. The influence of changes in the concentrations of glucose and NH4+ was not related to the biochemical events of spore germination.

Factors influencing the run off of mercury from small watersheds in Sweden

1991 ◽  
Vol 24 (4) ◽  
pp. 2200-2204 ◽  
Author(s):  
Kjell Johansson ◽  
Åke Iverfeldt
Keyword(s):  
Small Watersheds ◽  
Factors Influencing ◽  
Run Off

scholarly journals Sediment Carbon Variations in the Venice Lagoon and Other Transitional Water Systems of the Northern Adriatic Sea

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3430
Author(s):  
Adriano Sfriso ◽  
Alessandro Buosi ◽  
Yari Tomio ◽  
Abdul-Salam Juhmani ◽  
Stefania Chiesa ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Anthropogenic Impacts ◽  
Venice Lagoon ◽  
Total Carbon ◽  
Central Basin ◽  
Northern Adriatic Sea ◽  
Biological Origin ◽  
Northern Adriatic ◽  
High Concentrations ◽  
Shell Fragments

The concentrations of inorganic, organic and total carbon, and some sedimentary parameters (sediment density, fines, pH, and shell fragments), have been analyzed in surface sediments of the Venice Lagoon since 1987. Environmental scenarios, characterized by different anthropogenic impacts, have been considered, especially in the central basin where more information is available. Data collected in 2009 in the lagoons and ponds of Po Delta, in Comacchio Valleys and Pialassa della Baiona have been also considered and analyzed together with those recorded in the whole Venice Lagoon in 2011. The results show a strong correlation of the inorganic carbon (Cinorg) with the carbonatic or siliceous origins of the sediments and changes of both Cinorg and organic carbon (Corg) according to different anthropogenic impacts, especially eutrophication and clam-fishing activities. Higher sediment density, grain-size, and pH were associated to good-high ecological conditions and the higher presence of inorganic carbon of biological origin (shell fragments and calcified macroalgal fragments). Conversely, Corg, which is associated to eutrophic conditions, was strongly affected by the sediment disturbance and the presence of high concentrations of bivalves which enhance its consumption.

Measurement of Isocitric Dehydrogenase Activity in Body Fluids

1959 ◽  
Vol 5 (6) ◽  
pp. 509-518 ◽  
Author(s):  
George N Bowers
Keyword(s):  
Standard Deviation ◽  
Dehydrogenase Activity ◽  
Substrate Inhibition ◽  
Body Fluids ◽  
Isocitric Dehydrogenase ◽  
Factors Influencing ◽  
Activity Curve ◽  
High Concentrations ◽  
Healthy Males

Abstract 1. Factors influencing the isocitric dehydrogenase (ICD) activity of serum were studied. Substrate inhibition by high concentrations of isocitrate was observed. 2. The temperature-activity curve of serum ICD was determined. The importance of controlling the temperature of the reaction was stressed. 3. Using this information, a method of measuring the ICD activity in 0.2 ml. of serum is described. 4. The range of ICD activity in 50 healthy males was 30 to 192 units with a mean of 90 units and a standard deviation of ± 34.3 units.

The influence of calcium on phytase efficacy in non-ruminant animals

2016 ◽  
Vol 56 (8) ◽  
pp. 1345 ◽  
Author(s):  
C. L. Walk
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Binding Sites ◽  
Nutrient Digestibility ◽  
Factors Influencing ◽  
Ruminant Animals ◽  
Ph Conditions ◽  
The Difference ◽  
High Concentrations ◽  
Book Values

High dietary calcium (Ca) can negatively influence growth performance and reduce phosphorus, protein and amino acid digestibility in broilers and pigs. In addition, high dietary Ca will precipitate with phytate at pH conditions within the small intestine. Previous research reported that high dietary Ca significantly reduced phytase efficacy through precipitation with or competition for binding sites on the phytate molecule. However, microbial phytases are active at pH ranges where phytate is soluble and hydrolyse phytate rapidly to reduce the likelihood of phytate precipitating with Ca, suggesting the effect of dietary Ca on the efficacy of these phytases may be reduced. Even with such phytases there may still be problems observed due to particularly high concentrations of dietary Ca, which can occur as a result of a reduction in Ca not being applied in the presence of a phytase and/or if Ca concentrations in the diet exceed expectations. For example, when total Ca was analysed in 795 broiler and pig diets, on average, there was 0.22% more Ca present than expected. This means that if a diet was formulated to contain 0.80% total Ca, the analysed value could be as high as 1.02%, almost 25% above the expected dietary Ca concentration. The discrepancy between the expected and analysed total Ca may have implications on chemical and physical properties within the gastrointestinal tract, dietary phytate solubility, nutrient digestibility and phytase efficacy. The present paper aims to highlight factors influencing the effect of Ca on phytase efficacy, encompassing the differences among published book values for total Ca content of ingredients, the difference between Ca sources and their affinity for phytate, and finally how these factors influence the Ca to P ratio and thus phytase efficacy.

Maintenance of Iron Meromixis by Iron Redeposition in a Rapidly Flushed Monimolimnion

1980 ◽  
Vol 37 (8) ◽  
pp. 1303-1313 ◽  
Author(s):  
P. Campbell ◽  
T. Torgersen
Keyword(s):  
Organic Matter ◽  
Residence Time ◽  
Deep Water ◽  
Lake Water ◽  
Redox Reactions ◽  
Water Mass ◽  
Experimental Lakes Area ◽  
Water Renewal ◽  
Renewal Time ◽  
High Concentrations

Water mass ages determined by the 3H–3He method gave a water renewal time of 2.5 ± 1 yr for the monimolimnion of softwater iron meromictic Lake 120. The water renewal time of the monimolimnion is less than, or equal to, the renewal time of the whole lake. The monimolimnion of Lake 120 was, therefore, not found to be a stratum of "perennially stagnant deep water." The rates of supply to, and degradation of, organic matter in the monimolimnion are responsible, in the first place, for the low redox potential necessary to establish the high concentrations of soluble Fe2+ observed (up to 4.2 mmol∙L−1). However, it was found that the major key to maintenance of high monimolimnetic concentrations of Fe, i.e. maintenance of iron meromixis, is recycling of Fe at the chemocline by an [Formula: see text] "Ferrous Wheel." Up to 90% recycling of iron between chemocline and monimolimnion results in an iron residence time of [Formula: see text] for the whole lake (greater than 4 times the whole lake water renewal time).Key words: meromixis, iron recycling, 3H–3He water ages, water renewal times, chemical budgets, sediment funneling, redox reactions, Experimental Lakes Area (ELA).

Industrial and Agricultural Chemicals

PEDIATRICS ◽  
1974 ◽  
Vol 53 (5) ◽  
pp. 843-844
Author(s):  
S. Hope Sandifer
Keyword(s):  
South Carolina ◽  
Environmental Protection Agency ◽  
Small Sample Size ◽  
The United States ◽  
Small Sample ◽  
Adult Males ◽  
Community Studies ◽  
Water Supplies ◽  
Intermittent Exposure ◽  
High Concentrations

The alert practitioner should know the types of pollution created by agriculture and industry in his area. In agriculture, two important pollutants are nitrates and pesticides (which include insecticides, herbicides, fungicides, rodenticides, and defoliants). Pediatricians are well aware of methemoglobmnemia due to excessive nitrates in water. Nitrates in water supplies are of increasing concern because of runoff from feed lots and incremental use of fertilizers. Tolerance levels of nitrate in municipal water supplies are established, and pediatricians should insist that these standards be enforced in their community. With regard to pesticides, the Environmental Protection Agency has funded 13 community studies throughout the United States. The purpose is to monitor the health of pesticide workers compared with suitable controls. To date no significant health effects have been demonstrated. Most studies have been made on adult males because of their occupational exposure to pesticides. The groups under surveillance include workers who manufacture pesticides, pest-control operators who spray daily, and farmers who have intermittent exposure to high concentrations of pesticides. We are seeking the effects, if any, in the most heavily exposed persons before trying to determine the effects of smaller doses. This approach suffers the problem of small sample size (several thousand instead of hundreds of thousands of exposed persons). Our studies and those of others have shown that DDT in the sera of blacks is about two to three times that of whites.1-3 We had assumed that this difference was due to environmental exposure, but recent studies in Charleston, South Carolina, have suggested a genetic factor.

scholarly journals Thermodynamic and Kinetic Aspects on the Biosorption of Cadmium by Low Cost Materials: A Review

2006 ◽  
Vol 3 (6) ◽  
pp. 400 ◽  
Author(s):  
Pablo Lodeiro ◽  
Roberto Herrero ◽  
Manuel E. Sastre de Vicente
Keyword(s):  
Low Cost ◽  
Kinetic Studies ◽  
Chemical Precipitation ◽  
Point Of View ◽  
Biological Origin ◽  
Biosorption Process ◽  
Low Concentrations ◽  
Passive Adsorption ◽  
High Concentrations

Environmental Context. The toxicity of cadmium in waters can be decreased by using a wide variety of low-cost biomaterials. A number of such investigations are reviewed here and the models used to describe the process of biosorption discussed. Fundamental investigations that probe the thermodynamics and kinetics of the biosorption process are essential for a strong understanding of all biosorption processes. Areas that still need addressing are highlighted, in particular with regard to cadmium biosorption, some models for which are ready to be tested in pilot plants. Abstract. Cadmium is internationally recognized as an important pollutant in the environment, and different methods for its removal from wastewaters (chemical precipitation being the most commonly used) have been reported in the literature. Those methods are in most cases oriented to situations with high concentrations of the pollutant. Thus, alternative removal and recovery methods are being considered for removing very low concentrations of cadmium. These methods are all based on biosorption, the passive adsorption and sequestration of metals by several natural materials of biological origin. In this review we have considered the biosorption of cadmium onto biomaterials from a physicochemical, thermodynamic, and kinetic perspective. The thermodynamic perspective is based on the characterization of the interactions of the binding sites of the biosorbents with cadmium species in aqueous solution. Traditionally, this approach has been quantified using different kinds of isotherms. In addition, the description is completed by taking into account electrostatic effects, and the influence of pH and ionic strength, which are associated with the negative charge developed, in most cases, by the biomaterial. The other point of view in this review is the kinetic one, which is necessary for a full physicochemical description of the sorbate–biosorbent system. Consequently, an updated description of the various approaches commonly employed in kinetic studies in biosorption has been carried out.

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