Activity-dependent labeling of oxygenase enzymes in a trichloroethene-contaminated groundwater site

A variety of naturally occurring bacteria produce enzymes that cometabolically degrade trichloroethene (TCE), including organisms with aerobic oxygenases. Groundwater contaminated with TCE was collected from the aerobic region of the Test Area North site of the Idaho National Laboratory. Samples were evaluated with enzyme activity probes, and resulted in measurable detection of toluene oxygenase activity (6-79% of the total microbial cells). Wells from both inside and outside contaminated plume showed activity. Toluene oxygenase-specific PCR primers determined that toluene-degrading genes were present in all groundwater samples evaluated. In addition, bacterial isolates were obtained and possessed toluene oxygenase enzymes, demonstrated activity, and were dominated by the phylotype Pseudomonas. This study demonstrated, through the use of enzymatic probes and oxygenase gene identification, that indigenous microorganisms at a contaminated site were cometabolically active. Documentation such as this can be used to substantiate observations of natural attenuation of TCE-contaminated groundwater plumes.     

Some bacteriological aspects of poultry litter used as feed supplement in rabbit diets

An investigation was carried out to determine the microbial load in poultry litter used as feed supplement in rabbit diets. Before heat treatment by deep stacking the poultry litter, samples of the litter were collected to assay for microbial load at the Microbiology Laboratory of the Rivers State University of Science and Technology, Port Harcourt, Nigeria. Results obtained showed that before heat-treating the poultry litter, Escherichia coli, Salmonella, Mycobacterium, Clostridium and Staphylococcus were isolated at 41, 37, 37, 41 and 42°C, respectively. The results obtained also indicate that no pathogen was isolated after heat treatment of between 40 and 55°C for 21 days. This study justifies the suitability of using poultry litter as a feed supplement.     

Deep stacking poultry litter as feed ingredient in livestock production

The compelling need to harness the potentials of the numerous agro-industrial by-products and the so-called “wastes” as part replacement for the more expensive conventional feed ingredients have been seriously expressed. This need has arisen mainly from the increasing demand and supply deficit of conventional feed resources with a concomitant sharp rise in their cost prices. The net effect of increased unit cost of the conventional feed resources is increased cost of the compounded rations, which by extension gives rise to increased cost of meat and animal products. It then becomes highly imperative that other sources for rapid livestock output to meet the growing human demands for animal protein foods are sourced. Such other sources should be cheap and nutritionally adequate for feeding animals with the aim of lowering the cost of producing meat. One of such measure is the recycling of poultry litter as part replacement for soya bean in livestock nutrition. Poultry litter is the by-product of poultry production, which should be managed in an environmentally friendly manner. As observed in this study, poultry litter contains 20% crude protein, 621.41 ME kcal kg^?1, and substantial amounts of minerals that could be exploited in feeding livestock. This study has explored the possibility of including poultry litter in diets in view of its contents.     

Is dew water potable? Chemical and biological analyses of dew water in Ajaccio (Corsica Island, France)

To determine to what extent dew water is potable without further treatment, a thorough set of chemical and biological analyses were performed on 10 samples of dew water collected on a large scale radiative collector (29.83 m2) in Ajaccio (Corsica Island, France), between 21 May 2002 and 5 Mar. 2003. Samples were collected following four protocols according to the dew volume amount and 48 parameters (ions, minerals, and bacteria) were analyzed and compared to French and European Union legislation and also World Health Organization (WHO) recommendations. Aluminum and Fe were the main pollutants whose concentrations were significantly larger than recommended. Their presence is due to local deposition of aerosols coming from the Sahara (a characteristic of the Mediterranean basin). A large number of biologically cultivable microorganisms were found, together with bacteria typical of fecal contamination. For dew water to be potable with respect to present legislation at the Ajaccio site, it should be disinfected and treated for turbidity.     

Chemical characterization of fatty acids,alkanes, n-diols and alkyl esters produced by a mixed culture of Trichoderma koningii and Penicillium janthinellum grown aerobically on undecanoic acid,potatoe dextrose and their mixture

Little is known about the mixed fungal synthesis of high-value aliphatics derived from the metabolism of simple and complex carbon substrates. Trichoderma koningii and Penicillium janthinellum were fed with undecanoic acid (UDA), potatoe dextrose broth (PDB), and their mixture. Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) together with ¹H and ¹³C Nuclear Magnetic Resonance (NMR) characterized CHCl₃ soluble aliphatics in the fungal cell culture. Data from NMR and Py-FIMS analysis were complementary to each other. On average, the mixed fungal species produced mostly fatty acids (28% of total ion intensity, TII) > alkanes (2% of TII) > n-diols (2% of TII) > and alkyl esters (0.8% of TII) when fed with UDA, PDB or UDA+PDB. The cell culture accumulated aliphatics extracellularly, although most of the identified compounds accumulated intracellularly. The mixed fungal culture produced high-value chemicals from the metabolic conversion of simple and complex carbon substrates.     

Capturing Old-Growth Values for Use in Forest Decision-Making

Old-growth forests have declined significantly across the world. Decisions related to old growth are often mired in challenges of value diversity, conflict, data gaps, and resource pressures. This article describes old-growth values of citizens and groups in Nova Scotia, Canada, for integration in sustainable forest management (SFM) decision-making. The study is based on data from 76 research subjects who participated in nine field trips to forest stands. Research subjects were drawn from Aboriginal groups, environmental organizations, forestry professionals, and rural and urban publics. Diaries, group discussions, and rating sheets were used to elicit information during the field trips. Findings show that different elicitation techniques can influence the articulation of intensity with which some values are held. In addition, certain values are more often associated with old-growth than with other forest-age classes. Some values associated with old-growth are considered more important than others, and some silvicultural treatments are perceived to compromise old-growth values more than others. Demographic characteristics, such as constituency group, gender, and age, are shown to influence value priorities. Ideas on how to incorporate old-growth values into SFM decision-making are highlighted.     

Latest developments in post-mortem foetal imaging

A sustained decline in parental consent rates for perinatal autopsies has driven the development of less-invasive methods for death investigation. A wide variety of imaging modalities have been developed for this purpose and include post-mortem whole body magnetic resonance imaging (MRI), ultrasound, computed tomography (CT) and micro-focus CT techniques. These are also vital for “minimally invasive” methods, which include potential for tissue sampling, such as image guidance for targeted biopsies and laparoscopic-assisted techniques. In this article, we address the range of imaging techniques currently in clinical practice and those under development. Significant advances in high-field MRI and micro-focus CT imaging show particular promise for smaller and earlier gestation foetuses. We also review how MRI biomarkers such as diffusion-weighted imaging and organ volumetric analysis may aid diagnosis and image interpretation in the absence of autopsy data. Three-dimensional printing and augmented reality may help make imaging findings more accessible to parents, colleagues and trainees.     

Habituation in the green frog, Rana clamitans

Habituation and its role in the dear enemy effect was investigated in a population of green frogs, Rana clamitans. Green frogs have a prolonged breeding season, and males defend territories centered around suitable oviposition sites. We tested the prediction that male green frogs will habituate to broadcasts of synthetic conspecific stimuli. Our results indicate that male green frogs can discriminate familiar from unfamiliar stimuli. We suggest that habituation helps to mediate the territorial interactions between male green frogs. Strangers present a greater threat than familiar neighbors. By habituating to the advertisement vocalizations of their near neighbors, males avoid costly interactions with individuals that are not a major threat to their territories. Received: 20 July 1998 / Accepted after revision: 6 September 1998     

Alum split applications strengthened phosphorus fixation and phosphate sorption in high legacy phosphorus calcareous soil

High phosphorus (P) saturation arising from historic P inputs to protected vegetable fields (PVFs) drives high P mobilisation to waterbodies. Amendment of soils with alum has shown potential in terms of fixing labile P and protecting water quality. The present 15 month pot experiment investigated P stabilisation across single alum application (Alum-1 treatment, 20 g alum/kg soil incorporated into soil before the maize was sown), alum split applications (Alum-4 treatment, 5 g alum/kg soil incorporated into soil before each crop was sown i.e. 4 × 5 g/kg) and soil only treatment (Control). Results showed that the Alum-1 treatment caused the strongest stabilisation of soil labile P after maize plant removal, whereas the P stabilisation effect was gradually weakened due to the transformation of soil non-labile P to labile P and the reduced active Al³⁺ in soil solution. For the Alum-4 treatment, soil labile P decreased gradually with each crop planting and was lower than the Alum-1 treatment at the end of the final crop removal, without any impairment on plant growth. The better P stabilisation at the end of Alum-4 treatment was closely correlated with a progressive supply of Al³⁺ and a gradual decrease of pH, which resulted in higher contents of poorly-crystalline Al, Fe and exchangeable Ca. These aspects were conducive to increasing the soil P stabilisation and phosphate sorption. In terms of management, growers in continuous cropping systems could utilise split alum applications as a strategy to alleviate P losses in high-P enriched calcareous soil.     

Biogenic volatile organic compounds as a potential stimulator for organic contaminant degradation by soil microorganisms

The effects of monoterpenes on the degradation of ¹⁴C-2,4-dichlorophenol (DCP) were investigated in soils collected from areas surrounding monoterpene and non-monoterpene-emitting vegetation. Indigenous microorganisms degraded ¹⁴C-2,4-DCP to ¹⁴CO₂, after 1 d contact time. Degradation was enhanced by prior exposure of the soils to 2,4-DCP for 32 d, increasing extents of mineralisation up to 60%. Monoterpene amendments further enhanced 2,4-DCP degradation, but only following pre-exposure to both 2,4-DCP and monoterpene, with total 2,4-DCP mineralisation extents of up to 71%. Degradation was greatest at the higher monoterpene concentrations (≥1 μg kg⁻¹). Total mineralisation extents were similar between concentrations, but higher than the control and the 0.1 μg kg⁻¹ amendment, indicating that increases in monoterpene concentration has a diminishing enhancing effect. We suggest that monoterpenes can stimulate the biodegradation of 2,4-DCP by indigenous soil microorganisms and that monoterpene amendment in soils is an effective strategy for removing organic contaminants.