Temporal and spatial variation in mountain birch foliar enzyme activities during the larval period of <Emphasis Type="Italic">Epirrita autumnata</Emphasis>

Summary. Mountain birches are deciduous trees consisting of several clonal and partly autonomous ramets. Autumnal moth, Epirrita autumnata, is an extremely harmful pest of mountain birches that during outbreak years may cause the death of trees over large areas. During the larval development of E. autumnata, leaf characters and nutritional suitability vary considerably both temporally and spatially among and within mountain birches. Compared to variation between trees, however, the extent of within-tree variation is known for only a limited number of potentially defensive traits. Plant oxidases, polyphenoloxidases (PPOs) and peroxidases (PODs) may play an important part in dictating the suitability of a tree for plant-eating animals, including E. autumnata. In this study, we observed changes in the activities of oxidative and antioxidative enzymes along leaf development during the larval period of E. autumnata. We also estimated the relative amounts of spatial variation among and within trees. Our results show that POD activities were remarkably high during the rapid elongation growth phase of leaves but decreased with leaf maturation. Thus PODs are suggested to take part in leaf elongation growth. Time and within tree variation accounted for the most of variation in POD activities whereas there was no among tree variation. In contrast, the activities of antioxidative CATs, which act as antagonists to PODs, were low in young leaves and increased towards leaf maturation, reflecting an increase in the oxidative status of source leaves. Within tree variation accounted for the most of the variation in CAT activities. The absolute PPO activities decreased along leaf growth due to the dilution effect whereas the specific activity of PPOs, which has been shown to be defensive against E. autumnata larvae, did not vary temporally that might reflect the importance of these enzymes in the defence of birches. Acidic PPOs showed marked within- and among-tree variation, which may impact herbivores performance on certain genotypes and increase larval mobility within the tree canopy.     

Amino acids during development of mountain birch leaves

Summary. The nutritive value of tree foliage for herbivores decreases rapidly with leaf maturation, due in particular to the decline in leaf nitrogen content. Since the amino acid content of plants differs from the need of herbivores for individual amino acids, we examined developmental changes in the contents of amino acids throughout the growth season of mountain birch. The contents of free and protein-bound amino acids, as well as essential and nonessential ones, displayed different patterns with leaf maturation, suggesting that total nitrogen or protein levels are poor predictors of the nutritive status of leaves. The contents of protein-bound amino acids were 100 times higher than those of free amino acids, indicating that the role of free amino acids in nutrition of herbivores is probably less important than that of protein-bound amino acids. Among protein-bound amino acids, both the absolute and the relative contents of two nitrogen-rich essential amino acids, lysine and arginine, decreased during early leaf growth, presumably reducing nitrogen availability in developing leaves. Essential amino acids were mainly positively related to each other, suggesting the co-ordinated regulation of their synthesis. Changes in correlations among individual free amino acids reflected developmental changes in allocation preferences between biosynthesis pathways with leaf growth. Received 31 January 2003; accepted 17 March 2003. R1D=" Correspondence to: Teija Ruuhola, e-mail: teiruu@utu.fi     

Removal of antimony from model solutions,mine effluent,and textile industry wastewater with Mg-rich mineral adsorbents

Environmental Science and Pollution Research - Naturally occurring layered double hydroxide mineral, brucite (BRU), was compared with hydromagnesite (HYD) and a commercial Mg-rich mineral adsorbent...     

Increase in the substrate availability decreases phenoloxidase activity in the autumnal moth, Epirrita autumnata

Both the activity of phenoloxidases and the availability of phenoloxidase substrates are said to regulate melanotic encapsulation in invertebrates. The delayed induced resistance of mountain birches has been shown to increase the immunity of Epirrita autumnata (Geometridae: Lepidoptera), but the mechanism behind the increased immunity is unknown. The increase in the contents of aromatic amino acids as a response to herbivory in plants can in theory be one explanation for this carry-over effect. To test this hypothesis that an increase in the substrate availability increases also the melanotic encapsulation rate and the immunity of E. autumnata, we supplied excess levels of two aromatic amino acids, tyrosine (l-Tyr) and phenylalanine (l-Phe), to the diet of moth larvae. Surprisingly, the supply of both aromatic amino acids down-regulated PO activity, whereas the melanotic encapsulation rate was maintained at an unchanged level. PO activity was traded-off with body size and thus the cost of resistance is a probable explanation for the down-regulation of PO activity in the presence of surplus substrates. Our results suggest that both aromatic amino acids act as substrates of melanin, and an increase in substrate contents allows insects to decrease their PO activity without affecting the encapsulation rate.     

Effects of Cd2+ exposure on key life history traits and activities of four metabolic enzymes in Helicoverpa armigera (Lepidopteran: Noctuidae)

Cadmium (Cd) is a toxic non-essential element accumulated easily in living organisms due to its non-biodegradable nature. A slight increase in Cd levels will threaten the health of terrestrial and aquatic organisms. Therefore, Cd contamination and its effects on the ecosystems and organisms have become a major topic of eco-toxicological research. The present study investigated the eco-toxicological effects of Cd-supplemented diet on some life history traits and specific enzyme activities of carboxylesterase (CarE), glutathione S-transferase (GST), acetylcholinesterase (AChE) and cytochrome P450 monooxygenases (P450s) in the cotton bollworm, Helicoverpa armigera. The results showed that Cd significantly decreased larval survival, pupation and emergence, and reduced body mass of the sixth instar larvae, pupae, adult moths and female fecundity. Cd-supplemented diet also delayed the development of larvae and pupae and shortened the life span of the cotton bollworm moth. In addition, dietary Cd inhibited the activities of GST, CarE and P450, but increased AChE activity of the sixth instar larvae. We concluded that life history traits and metabolic enzymes are sensitive to Cd stress in the cotton bollworm. These parameters are potential biomarkers for monitoring environmental stress in Lepidopteran insect pests.     

Concentrations and Diversity of Microbes from Four Local Bioaerosol Emission Sources in Finland

ABSTRACT

Microbial particles can readily be released into the air from different types of man-made sources such as waste operations. Microbiological emissions from different biological sources and their dispersion may be an issue of concern for area planning and for nearby residents. This study was designed to determine the concentrations and diversity of microbiological emissions from four different man-made source environments: waste center with composting windrows, sewage treatment plant, farming environment, and cattle manure spreading. Samples of airborne particles were collected onto polyvinyl chloride filters at three distances along the prevailing downwind direction, from each source environment during a period of approximately 1 week. These samples were analyzed for 13 species or assay groups of fungi, bacterial genus Streptomyces, and Gram-positive and -negative bacteria using quantitative polymerase chain reaction (PCR). Samples for determining the concentrations of viable fungi and bacteria were collected from all environments using a six-stage impactor. The results show that there were variations in the microbial diversity between the source environments. Specifically, composting was a major source for the fungal genera Aspergillus and Penicillium, particularly for Aspergillus fumigatus, and for the bacterial genus Streptomyces. Although the microbial concentrations in the sewage treatment plant area were significantly higher than those at 50 or 200 m distance from the plant area, in the farming environment or cattle manure spreading area, no significant difference was observed between different distances from the source. In summary, elevated concentrations of microbes that differ from background can only be detected within a few hundred meters from the source. This finding, reported earlier for culturable bacteria and fungi, could thus be confirmed using molecular methods that cover both culturable and nonculturable microbial material.

IMPLICATIONS Concentrations and diversity of airborne microbes increase due to particle emissions from different biological waste treatment applications. However, these emissions cannot be separated from the background concentrations after more than a few hundred meters from the source. As part of a risk assessment, it may be necessary to confirm the behavior of microbial emissions from a specific source. Quantitative PCR is a useful tool for estimating total concentrations of different microbial species or groups as it detects both culturable and nonculturable microbial material.     

Anaerobic digestion of autoclaved and untreated food waste

Anaerobic digestion of autoclaved (160 °C, 6.2 bar) and untreated source segregated food waste (FW) was compared over 473 days in semi-continuously fed mesophilic reactors with trace elements supplementation, at organic loading rates (OLRs) of 2, 3, 4 and 6 kg volatile solids (VS)/m³ d. Methane yields at all OLR were 5–10% higher for untreated FW (maximum 0.483 ± 0.013 m³ CH₄/kg VS at 3 kg VS/m³ d) than autoclaved FW (maximum 0.439 ± 0.020 m³ CH₄/kg VS at 4 kg VS/m³ d). The residual methane potential of both digestates at all OLRs was less than 0.110 m³ CH₄/kg VS, indicating efficient methanation in all cases. Use of acclimated inoculum allowed very rapid increases in OLR. Reactors fed on autoclaved FW showed lower ammonium and hydrogen sulphide concentrations, probably due to reduced protein hydrolysis as a result of formation of Maillard compounds. In the current study this reduced biodegradability appears to outweigh any benefit due to thermal hydrolysis of ligno-cellulosic components.     

Eco-efficiency in contaminated land management in Finland – Barriers and development needs

In Finland the number of potentially contaminated sites totals ca. 20?000. The annual costs of remediation are 60–70 million euros. Excavation combined with disposal or off-site treatment is the most common soil remediation method. To define which factors make contaminated land management (CLM) eco-efficient and to study whether eco-efficiency has been considered in CLM decisions we carried out a literature survey, two stakeholder seminars, thematic interviews and a questionnaire study on economic instruments. Generally speaking, eco-efficiency means gaining environmental benefits with fewer resources. To assess its realization in CLM, it is necessary to have a more specific definition. In our study, we arrived at a list of several qualifications for eco-efficiency. It was also shown that eco-efficiency has hardly been a real issue in the selection of remediation techniques or generally, in the decision-making concerning contaminated sites. The existing policy instruments seem to be insufficient to promote eco-efficiency in CLM. Several concrete barriers to eco-efficiency also came up, urgency and lack of money being the most important. The scarcity of the use of in situ remediation methods and the difficulties involved in recycling slightly contaminated or treated soil were considered to be major problems. Insufficient site studies, inadequate or unsuitable methods for risk assessment and cost evaluation, and deficient and mistimed risk communication can also hinder the realization of eco-efficiency. Hence, there is a need to promote the use of more eco-efficient remediation techniques and to develop CLM policy instruments, guidelines, and participatory processes and methods to assess the eco-efficiency of CLM options.     

Value in sustainability: the process industry perspective

The most important driver for management is successful business that increases its value to shareholders. The adoption of environmentally responsible business practices can open up an additional range of opportunities for companies, for example by improving material efficiency. The choice to improve environmental performance of a company tends to also improve its financial performance. In this paper, our aim is to study the value of sustainability in process and mining industry from the perspective of interest groups such as investors, customers and the public, by using case examples. Interviews and workshops were employed to investigate whether or not investors and customers are interested in sustainability in the process and mining industries. We also illustrate how easy it can be to jeopardize corporate reputation through. The present situation and challenges faced in bringing sustainability into everyday business practices are summarized and proposals made concerning ways to achieve increased sustainability.     

Effects of moisture damage and renovation on microbial conditions and pupils' health in two schools--a longitudinal analysis of five years

Airborne microbes and pupils' symptoms were monitored in a moisture-damaged (index) school and a reference school for five consecutive years. These surveys were carried out in two separate years before the renovation of the index school, during the renovation, and one and two years after the renovation. Microbial concentrations were higher in the index school than those in the reference school before and during renovation, but afterwards, the levels decreased to the level of the reference school. The effect of remediation was seen as an altered mycobiota in the index school. Year-to-year variation of microbial concentrations, probably due to climatic factors, caused a peak in both schools but their difference remained. Several symptoms were more prevalent in the moisture-damaged school than in the reference school, but the differences disappeared during the renovations. These results emphasize the importance of using a reference building in assessing the microbial conditions of a moisture damaged building. Furthermore, microbial concentrations reflected well the technical condition of the construction, but the reported symptoms of the occupants did not strictly follow the timely fluctuation in microbial conditions.