Destruction of Aspergillus versicolor,Penicillium chrysogenum,Stachybotrys chartarum,and Cladosporium cladosporioides spores using chemical oxidation treatment process

The survival of aqueous suspensions of Penicillium chrysogenum, Stachybotrys chartarum, Aspergillus versicolor, and Cladosporium cladosporioides spores was evaluated using various combinations of hydrogen peroxide and Fe²⁺ as catalyst. Spore concentrations of 10⁶–10⁷ colony forming units per milliliter (CFU/mL) were suspended in water and treated with initial hydrogen peroxide and iron concentrations ranging from 0.05 to 10 percent and 100 to 200 ppm, respectively. After four hours of reaction time, samples were plated on agar plates, and the viable fraction of spores was determined by the number of colonies formed. Hydrogen peroxide concentrations above 50,000 ppm resulted in greater than 6‐log₁₀ reduction of viable spores for both catalyzed and noncatalyzed reactions. Iron had a strong catalytic effect when added to solutions with hydrogen peroxide concentration above 5,000 ppm and resulted in two to three orders of magnitude greater reduction compared to hydrogen peroxide alone. Additional samples taken after 24 hours of reaction time showed that the effect of the addition of 100 and 200 ppm of Fe²⁺ catalyst was mostly kinetic, and noncatalyzed hydrogen peroxide had sporicidal effects similar to catalyzed hydrogen peroxide. This study identified initial reagent concentrations of hydrogen peroxide and Fe²⁺ that accomplish a 6‐log₁₀ reduction of viable mold spores within reaction times of 4 and 24 hours. © 2007 Wiley Periodicals, Inc.     

Sustainable Development and Strategic Thinking

From an economic point of view, the industrial economy is efficient to overcome situations of a scarcity of goods. From a technological point of view, the resource efficiency of the manufacturing processes of the industrial economy has been permanently improved during the last 200 years. In addition, cleaner processes have been developed. However, from an ecologic point of view, an increasing world population with increasing consumption has produced a ＂global footprint＂ which approaches the carrying capacity of the planet. A circular economy and its high-value spin-offs-a lake economy and a performance or functional service economy-can fulfil customers＇ needs with considerably less resource consumption, less environmental impairment in production and considerably less end-of-life product waste, especially in situations of affluence, when a considerable stock of physical goods and infrastructures exists. Also, in situations of a scarcity of natural resources, both energy and materials, often characterised by rapidly rising resource prices, the economic actors of a circular economy have a high competitive advantage over the actors of the industrial economy, due to much lower procurement costs for materials and energy. From a social point of view, a circular economy increases the number of skilled jobs in regional enterprises. However, the shift from a linear manufacturing economy to a circular or service economy means a change in economic thinking from flow （throughput） management to stock （asset） management： in a manufacturing economy with largely unsaturated markets, total wealth increases through accumulation as resource throughput （flow） is transformed into a higher stock of goods of better quality （but in a manufacturing economy with largely saturated markets, wealth represented by the stock of goods will no longer increase）; in a circular or service economy, total wealth increases through a smart management of existing physical assets （stock） that are adapted to changes in both technology and customer demand. This second approach not only applies to physical capital but equally to social capital, such as health and education and green GDP. To measure the social wealth of a population, it is not the amount of money spent on schools and hospitals that matters, butif this expenditure has led to a better education of the students, and a better health of the people.     

Geochemical characteristics of surficial sediments in a tropical estuary, south-west India

Geochemical characteristics of surficial sediments in the Panangad region of Cochin estuary, the largest brackish-water humid ecosystem in the south-west coast of India, were analysed. Temporal variations in nutrient stoichiometry, seasonal characteristics of redox elements Fe and S, and the phosphorus geochemistry were employed for the purpose. The stoichiometric analysis pointed towards autochthonous origin of organic matter, possibility of nitrogen limitation, and allochthonous modification of redox conditions. Seasonal variations were not statistically significant for all the geochemical parameters, whereas significant spatial variations were observed with lower values at sandy stations, suggesting that the texture of the sediments is the main factor influencing the sediment geochemistry. Significant inter-relations between the geochemical parameters also suggest a common control mechanism. Based on these geochemical characteristics, the study region can be effectively categorized into two distinct zones, viz. (1) erosion and transportation and (2) deposition zones.     

Effect of periphyton grazing by Hydrobia ulvae on the growth of Zostera noltii on a tidal flat in the Dutch Wadden Sea

The decrease of the intertidal seagrass Zostera noltii in the Dutch Wadden Sea may have been the result of enhanced periphyton load due to eutrophication. Decrease of this seagrass species coincided with an increase in the mudsnail Hydrobia ulvae. Feeding of this mudsnail on periphyton may have partly counteracted an increase of periphyton biomass. Exclosure experiments on seagrass stands in the Dutch Wadden Sea in 1987 showed that density of periphyton on leaves of Z. noltii decreased significantly with increasing density of grazers. An increased density of mudsnails significantly enhanced the density and biomass of seagrass, in particular of the below ground parts. Since this seagrass species survives winter in temperate climate zones mainly by means of rhizomes, grazing may also influence the seagrass dynamics in the long term. Results of the experiment were in agreement with field observations on coinciding low densities of mudsnails and high densities of fouling of seagrass stands on the tidal flats of western Wadden Sea in the late 1970s.     

Grower reported pesticide poisonings among Florida citrus fieldworkers

In a 1981 survey of 436 Florida citrus growers, 27 pesticide related poisoning incidents were reported that were to have taken place within one year of the interview date. From these reports it is possible to estimate that there are 376 citrus fieldworker related poisonings per year in Florida. This number of estimated poisonings may be developed into an incidence rate of 113 fieldworker poisonings per 10,000 fieldworkers.     

Rock phosphate solubilizing and cellulolytic actinomycete isolates of earthworm casts

Four microbial isolates, OP2, OP3, OP6, and OP7, of earthworm casts ofPontoscolex corethrurus were found to be acid tolerant actinomycetes and efficient rock phosphate (RP) solubilizers that could grow fast on NH₄Cl-enriched or N-free carboxymethyl cellulose or glucose as sole carbon source. CMC (carboxymethyl cellulose) induced production of extracellular cellulase enzyme and the production of reducing sugar in all the isolates. RP solubilizing power was observed to be inversely related to glucose consumption. The most efficient RP solubilizer was found to consume the least glucose. Growth was faster on cellulose than on glucose media. N-free CMC induced greater glucose production than NH₄Cl-enriched CMC medium. Both CMC and glucose media were acidified by all the isolates, however, RP solubilizing power decreased with acidification. Solubilization power was greatest with isolate OP7, which also produced the greatest amount of reducing sugar per gram CMC. Both RP solubilizing power and the cellulolytic efficiency varied among isolates. A minimum of 631 μg P/0.1 g RP and a maximum of 951.4 μg P/0.1 g RP was recorded.