The study of the effects of carbon dioxide-induced elevation of hydrogen peroxide toxicity on microbes as a novel tool for water purification

The supercritical concentration of CO₂ (SCCO₂) and a high concentration (3.0%) of molecules of hydrogen peroxide (H₂O₂) are currently being used as antiseptic and antibacterial agents. The fact that low concentrations of CO₂ have an activation effect on functional activity of microbes allows us to predict that CO₂ could elevate the toxic effect of H₂O₂ on cells. To check this hypothesis the dependency of the toxic effect of H₂O₂ on wild type of Escherichia coli K-12 on soluble concentration of CO₂ in culture media was studied. The obtained data show that culture media enriched with CO₂ leads to the increase of toxic effect of H₂O₂ on microbes at both cases when pH is constant and when it changes. So CO₂ in non-supercritical concentration could elevate the toxic effect of H₂O₂ on microbes by the activation of the metabolic processes in microbes. During the experiments we used classical microbiological methods (indirect viable cell counts or counting colony forming units (CFUs)), as well as the method of measuring hydrogen peroxide content in aqueous solution by means of enhanced chemiluminescence method in a peroxidase-luminol-p-iodophenol system. This discovery is concerning to use CO₂/H₂O₂ combination system, which could have implication in the inhibition of growth of microbes in water and the microbiological monitoring of water could provide valuable information for managing the health of exhibition of aqua ecosystems.     

Biodiversity and conservation of insects and other invertebrates

The thematic issue of Biodiversity and Conservation devoted to the biodiversity and conservation of insects and other invertebrates is introduced. The issue comprises 23 original research papers covering diverse habitats from forests to grasslands, ponds and rivers to coasts, and the tropics to boreal regions. Amongst the organisms discussed are ants, bees, beetles, butterflies, crabs, microgastropods, millipedes, spiders, and weevils. Some of the difficulties of conserving the most species-rich groups of eukaryotes, in the face of ignorance as to their identities and positions in ecological processes, are noted and the precautionary principle is seen as a pragmatic and responsible approach.     

The influence of temporal variation on relationships between ecosystem services

A growing literature aims to identify areas of congruence in the provision of multiple ecosystem goods and services. However, little attention has been paid to the effect that temporal variation in the provision of such services may have on understanding of these relationships. Due to a lack of temporally and spatially replicated monitoring surveys, such relationships are often assessed using data from disparate time periods. Utilising temporally replicated data for indices of freshwater quality and agricultural production we demonstrate that through time the biophysical values of ecosystem services may vary in a spatially non-uniform way. This can lead to differing conclusions being reached about the strength of relationships between services, which in turn has implications for the prioritisation of areas for management of multiple services. We present this first analysis to illustrate the effect that the use of such temporally disparate datasets may have, and to highlight the need for further research to assess under what circumstances temporal variation of this sort will have the greatest impact.     

Great-granny’s Garden: a living archive and a sensory garden

Since 2003, the Botanical Garden in Oslo has been involved in a project coordinated by the Norwegian Genetic Resource Centre. The wide range of work supervised by this centre includes conservation of ornamental plants. Our garden has been responsible for the registration and collecting of ornamentals in Southeast-Norway and has a special responsibility for the conservation of Paeonia species and cultivars. As a result of the project, Great-granny’s Garden was opened to the public in 2008. It has two objectives. Firstly, it shall be a living archive of Norway’s horticultural heritage. Although proven hardy, easy to grow, and long-lived, old varieties of traditional ornamentals are rapidly disappearing. We aim to keep these old-fashioned varieties for sustainable use in future horticulture and encourage people to use them in present day gardening, both in new gardens and in the restoration of old ones. Secondly, the garden is designed as a sensory garden for people with dementia, in cooperation with Oslo’s Resource Centre for Dementia and Psychiatric Care of the Elderly. It is enclosed by a picked fence and by shrubs, offers rest on several benches, and has a paved and easy to follow round-walk among traditional garden elements and plants with a lush variety of colours, forms, and scents. A sensory garden stimulates many senses, evokes pleasant emotions, brings out long-forgotten memories, and stimulates communication. Sensory gardens are therefore considered an important tool in the therapy of dementia.     

Non-native and translocated fish species in Serbia and their impact on the native ichthyofauna

A total of 22 fish species have been introduced into the inland waters of Serbia, either intentionally or accidentally. This paper provides a summary of data concerning time and reason of introduction, mode of expansion, degree of acclimatization, impact on native fish and estimated area of recent distribution. Four of the non-native fish species currently occupy more than 51% of Serbian territory while 5 of them occupy between 21–50% of territory. This paper reviews impacts of introduced freshwater fish in Serbia based on collected data.     

Intestinal iron absorption during suckling in mammals

The maintenance of appropriate iron levels is important for mammalian health, particularly during the rapid growth period following birth. Too little iron can lead to irreversible damage to the developing central nervous system and too much iron at this point can have adverse long term consequences, possibly due to excessive free radical production. In order to maintain iron levels, intestinal iron absorption is very efficient in young mammals, such that almost all of the iron in breast milk is utilized. However this high level of absorption is unable to be down regulated in response to excess iron as it can be in adults, implying that different regulatory processes are involved during suckling. Various mechanisms have been proposed to explain this high absorption, including enhanced expression of the proteins involved in iron absorption in adults (particularly DMT1 and ferroportin), non-specific uptake via pinocytosis, and the uptake of lactoferrin bound iron by the lactoferrin receptor. However, at present the precise mechanism is unclear. It is possible that all of these components contribute to the high intestinal iron absorption seen during suckling, or a novel, as yet undescribed, mechanism could be involved. This review summarises the evidence for and against each of the mechanisms described above and highlights how little is known about iron homeostasis in this vital stage of development.     

<Emphasis Type=Italic>Pseudomonas</Emphasis> siderophores in the sputum of patients with cystic fibrosis

The lungs of patients with cystic fibrosis become chronically infected with the bacterium Pseudomonas aeruginosa, which heralds progressive lung damage and a decline in health. Iron is a crucial micronutrient for bacteria and its acquisition is a key factor in infection. P. aeruginosa can acquire this element by secreting pyoverdine and pyochelin, iron-chelating compounds (siderophores) that scavenge iron and deliver it to the bacteria. Siderophore-mediated iron uptake is generally considered a key factor in the ability of P. aeruginosa to cause infection. We have investigated the amounts of pyoverdine in 148 sputum samples from 36 cystic fibrosis patients (30 infected with P. aeruginosa and 6 as negative controls). Pyoverdine was present in 93 samples in concentrations between 0.30 and 51 μM (median 4.6 μM) and there was a strong association between the amount of pyoverdine and the number of P. aeruginosa present. However, pyoverdine was not present, or below the limits of detection (~0.3 μM), in 21 sputum samples that contained P. aeruginosa. Pyochelin was also absent, or below the limits of detection (~1 μM), in samples from P. aeruginosa-infected patients with little or no detectable pyoverdine. Our data show that pyoverdine is an important iron-scavenging molecule for P. aeruginosa in many cystic fibrosis patients, but other P. aeruginosa iron-uptake systems must be active in some patients to satisfy the bacterial need for iron.     

A macronutrient optimization platform for micropropagation and acclimatization: using turmeric (<Emphasis Type=Italic>Curcuma longa</Emphasis> L.) as a model plant

Tissue culture medium is often overlooked as a factor in plant biotechnology. Most work uses Murashige and Skoog (MS; Physiol Plant in 15:473–497, 1962) inorganic medium formulation, which is not likely optimal for many of the plant systems where it is used. This current study of macronutrient factors simultaneously altered media volume and amount of tissue (plants per vessel), sucrose, nitrogen (as NO₃⁻ and NH₄⁺ ions), and K⁺ in a d-optimal design space with only 55 experimental units (including five true replicates). Meso- and micro-nutrient concentrations were lowered (5% of MS) to determine which elements were most critical to plantlet quality. Plantlet quality was quantified by multiplication in the laboratory and survival and growth in the greenhouse. Plantlets grown at the lowest plant density, the lowest macronutrient concentration (20 mM), and equi-molar proportions of NH₄⁺/K⁺ resulted in the best multiplication ratio and 100% greenhouse survival. Multiplication ratio in vitro and survival in the greenhouse were well correlated with one another. Laboratory dry mass, media use, sucrose use, and the uptake of the macronutrients NO₃⁻, NH₄⁺, and K⁺ were not well correlated with plantlet quality. Plantlets with the greatest uptake of P, Ca, Mg, and Mn had the best multiplication in the laboratory and on subsequent transfer, acclimatized and grew fastest in the greenhouse. Phosphorus was shown to be most depleted in media. This work demonstrates a platform to simultaneously optimize several nutritive components of tissue culture media to produce plantlets that perform well in both laboratory and greenhouse environments. Plant quality was related with factors outside the macronutrient design, and this platform indicated where to expand the experimental space. Fixed, flat-screen presentations revealed less of the response surface than interactive profiles driven by the reader.     

Alumina-doped alginate gel as a cell carrier for ethanol production in a packed-bed bioreactor

Alumina-doped alginate gel (AEC) was developed as a new type of cell carrier to be used in ethanol fermentation. The presence of the alumina particles in alginate gel not only improved the porous structure of the carrier, but also provided many advantageous characteristics including good mechanical strength, high stability, and high immobilization yield. The attachment of alumina particles and yeast cells by electrostatic attraction was shown to promote cell growth and increase ethanol productivity. The AEC carrier was found to be more effective for the immobilization of Saccharomyces cerevisiae M30 than the conventional Ca-alginate bead. Ethanol productivities of 1.4 and 7.9 ∼ 12.6 g/(L/h) were obtained using the AEC cultures in batch and continuous modes of operation, respectively, with an ethanol yield of 43.9 ∼ 46.7% and an immobilized yield of 81.4 ∼ 84.5%. Ethanol fermentation in a continuous packed-bed reactor using the AEC carrier was stable for > 30 days.