Airborne enteric micro-organisms and ammonia levels in diaper-changing rooms in kindergartens

Aims: We evaluated risks associated with diaper changing in Finnish kindergartens where children were using either modern disposable paper or reusable cloth diapers. Methods and Results: We determined enteric micro‐organisms and ammonia in diaper‐changing rooms in four kindergartens in autumn and winter in the ambient air. No coliphages were detected in the air. The numbers of faecal coliforms and enterococci in air were typically low regardless of whether the children used either paper or cloth diapers. Ammonia concentrations increased over the background level because of diaper changing. Conclusions: The numbers of bacteria or coliphages are not expected to pose any high air hygiene risks, and increased ammonia air concentrations are unlikely to impair the health of staff or children when diapers are changed in modern kindergartens. However, increased ammonia gas concentrations indicate that some other diaper‐related gas‐phase emissions should be studied to understand better diaper‐related health risks. Significance and Impact of the Study: Modern reusable cloth baby diapers and the modern paper baby diapers used in this study are equally safe with respect to risks from airborne virus, bacteria or ammonia.     

<Emphasis Type="Italic">Candida</Emphasis> — Agent of the diaper dermatitis?

Occurrence of Candida spp. was determined in a population of 60 infants, 1-15-month-old, with diaper dermatitis, admitted to a neonatal intensive care unit in Hospital Saca (Kosice, Slovakia). Specimens were obtained from the perianal, pubic, inguinal, or gluteal areas that showed signs of secondary infection as manifested by erythema, oozing, vesiculopustular lesions, and pus formation. The most frequently isolated species was C. albicans (41), followed by C. parapsilosis (8), C. tropicalis (4), C. pulcherrima (4), C. guilliermondii (2), and C. zeylanoides (1). Other organisms present in the mixed culture from the diaper area were Staphylococcus aureus (6), Escherichia coli (3), and 2 strains of each group B and D streptococci, and Proteus mirabilis. Infants diapered exclusively in disposable diapers showed less rash than those diapered exclusively or sometimes in cloth diapers.     

Isolation of Phytate-Hydrolysing Microbial Strains From Traditional Waste Water of Rice Fermentation and Liquid Cattle Feeds

Traditional fermentation systems employed by rural people of India were initially screened for phytate-hydrolysing microbes on solid medium supplemented with calcium phytate. It was followed by enzyme assay of culture filtrates to differentiate the phytase-producing microbes. Three new microbial genera are added to the list of phytase-producing organisms.     

Production of amino acids by free-living heterotrophic nitrogen-fixing bacteria

Summary Interest of microbial production of amino acids has been increased greatly since development of biotechnological methods. These methods represent a perspective way applied in a future large-scale manufacture of inexpensive amino acids. In this context, the isolation of producing organisms that may be exploited in the desing of alternative methods for the production of amino acids could be of primary importance.In this review we will describe the liberation of amino acids (methionine, lysine, arginine, tryptophane and glutamic acid) byAzotobacter andAzospirillum during growth in culture media with different carbon sources under diazotrophic and adiazotrophic conditions. These organisms may be useful in developing new methods for the industrial production of amino acids.     

Metabolic engineering of Thermobifida fusca for direct aerobic bioconversion of untreated lignocellulosic biomass to 1-propanol

Biofuel production from renewable resources can potentially address lots of social, economic and environmental issues but an efficient production method has yet to be established. Combinations of different starting materials, organisms and target fuels have been explored with the conversion of cellulose to higher alcohols (1-propanol, 1-butanol) being one potential target. In this study we demonstrate the direct conversion of untreated plant biomass to 1-propanol in aerobic growth conditions using an engineered strain of the actinobacterium, Thermobifida fusca. Based upon computational predictions, a bifunctional butyraldehyde/alcohol dehydrogenase was added to T. fusca leading to 1-propanol production during growth on glucose, cellobiose, cellulose, switchgrass and corn stover. The highest 1-propanol titer (0.48 g/L) was achieved for growth on switchgrass. These results represent the first demonstration of direct conversion of untreated lignocellulosic biomass to 1-propanol in an aerobic organism and illustrate the potential utility of T. fusca as an aerobic, cellulolytic bioprocess organism.     

Inhibition of growth,and effects on nutrient uptake of arctic graminoids by leaf extracts — allelopathy or resource competition between plants and microbes?

Previous research has shown that plant extracts, e.g. from boreal dwarf shrubs and trees, can cause reduced growth of neighbouring plants: an effect known as allelopathy. To examine whether arctic and subarctic plants could also be affected by leaching of phytochemicals, we added extracts from the commonly occurring arctic dwarf shrubs Cassiope tetragona and Empetrum hermaphroditum, and from mountain birch, Betula pubescens ssp. tortuosa to three graminoid species, Carex bigelowii, Festuca vivipara and Luzula arcuata, grown in previously sterilized or non-sterilized arctic soils. The graminoids in non-sterilized soil grew more slowly than those in sterilized soil. Excised roots of the plants in non-sterilized soil had higher uptake rate of labelled P than those in sterilized soil, demonstrating larger nutrient deficiency. The difference in growth rate was probably caused by higher nutrient availability for plants in soils in which the microbial biomass was killed after soil sterilization. The dwarf shrub extracts contained low amounts of inorganic N and P and medium high amounts of carbohydrates. Betula extracts contained somewhat higher levels of N and much higher levels of P and carbohydrates. Addition of leaf extracts to the strongly nutrient limited graminoids in non-sterilized soil tended to reduce growth, whereas in the less nutrient limited sterilized soil it caused strong growth decline. Furthermore, the N and P uptake by excised roots of plants grown in both types of soil was high if extracts from the dwarf shrubs (with low P and N concentrations) had been added, whereas the P uptake declined but the N uptake increased after addition of the P-rich Betula extract. In contrast to the adverse extract effects on plants, soil microbial respiration and soil fungal biomass (ergosterol) was generally stimulated, most strongly after addition of the Betula extract. Although we cannot exclude the possibility that the reduced plant growth and the concomitant stimulation of microbial activity were caused by phytochemicals, we believe that this was more likely due to labile carbon in the extracts which stimulated microbial biomass and activity. As a result microbial uptake increased, thereby depleting the plant available pool of N and P, or, for the P-rich Betula extract, depleting soil inorganic N alone, to the extent of reducing plant growth. This chain of events is supported by the negative correlation between plant growth and sugar content in the three added extracts, and the positive correlation between microbial activity, fungal biomass production and sugar content, and are known reactions when labile carbon is added to nutrient deficient soils.     

Identification, cloning and tissue localization of a rainbow trout (Oncorhynchus mykiss) intelectin-like protein that binds bacteria and chitin

Intelectins are a recently identified group of animal lectins involved in innate immune surveillance. This paper describes the primary structure, expression and immunohistochemical localization of a rainbow trout plasma intelectin (RTInt). RTInt exhibited calcium-dependent binding to N-acetylglucosamine (GlcNAc) and mannose conjugated Toyopearl Amino 650 M matrices. When GlcNAc eluates from chromatography matrices were analyzed by reducing 1D PAGE and Western blots, the lectin appeared as approximately 37 kDa and approximately 72 kDa bands. Similar analysis of plasma revealed a single 72 kDa band under reducing conditions. MALDI-TOF MS demonstrated five, approximately 37 kDa isoforms (pI 5.3-6.1) separated by 2D-PAGE. A 975 bp cDNA sequence obtained by RT-PCR from liver and spleen tissue encoded a 325 amino acid secretory protein with homology to human and murine intelectins, which bind bacterial components and are induced during parasitic infections. Gene expression and immunohistochemistry detected RTInt in gill, spleen, hepatic sinusoid, renal interstitium, intestine, skin, swim bladder and within leukocytes. Direct binding assays demonstrated the ability of RTInt to bind relevant bacterial and chitinous targets. These findings suggest that RTInt plays a role in innate immune defense against bacterial and chitinous microbial organisms.     

The trade-off between growth rate and yield in microbial communities and the consequences for under-snow soil respiration in a high elevation coniferous forest

Soil microbial respiration is a critical component of the global carbon cycle, but it is uncertain how properties of microbes affect this process. Previous studies have noted a thermodynamic trade-off between the rate and efficiency of growth in heterotrophic organisms. Growth rate and yield determine the biomass-specific respiration rate of growing microbial populations, but these traits have not previously been used to scale from microbial communities to ecosystems. Here we report seasonal variation in microbial growth kinetics and temperature responses (Q₁₀) in a coniferous forest soil, relate these properties to cultured and uncultured soil microbes, and model the effects of shifting growth kinetics on soil heterotrophic respiration (R_h). Soil microbial communities from under-snow had higher growth rates and lower growth yields than the summer and fall communities from exposed soils, causing higher biomass-specific respiration rates. Growth rate and yield were strongly negatively correlated. Based on experiments using specific growth inhibitors, bacteria had higher growth rates and lower yields than fungi, overall, suggesting a more important role for bacteria in determining R_h. The dominant bacteria from laboratory-incubated soil differed seasonally: faster-growing, cold-adapted Janthinobacterium species dominated in winter and slower-growing, mesophilic Burkholderia and Variovorax species dominated in summer. Modeled R_h was sensitive to microbial kinetics and Q₁₀: a sixfold lower annual R_h resulted from using kinetic parameters from summer versus winter communities. Under the most realistic scenario using seasonally changing communities, the model estimated R_h at 22.67 mol m⁻² year⁻¹, or 47.0% of annual total ecosystem respiration (R_e) for this forest.     

Evaluation of the co-agglutination test in diagnosis of experimental microsporidiosis

Microsporidiosis is an emerging and opportunistic infection associated with wide range of clinical syndromes in humans. Confirmation of the presence of microsporidia in different samples is laborious, costly and often difficult. The present study was designed to evaluate the utility of the Co-agglutination test (Co-A test) for detection of urinary, fecal and circulating microsporidial antigens in experimentally infected mice. One hundred and twenty male Swiss albino mice were divided into non infected control and infected experimental groups which were further subdivided into two equal subgroups; immunosuppressed and immunocompetent. Microsporidial spores were isolated from human stools and identified to be Encephalitozoon intestinalis by the molecular methods. They were used to infect each subgroup of mice, then their urine, stools and sera were collected at the 1st, 3rd, 5th, 7th and 9th days post-infection (PI). Co-A test, using prepared hyperimmune serum, was used to detect antigens in all samples collected. The cross reactivity of microsporidial hyperimmune sera with antigens of Cyclospora cyatenensis and Cryptosporidium parvum was investigated by Co-A test. The results showed that Co-A test was effective in detecting microsporidial antigen in stool of immunosuppressed infected mice from the 1st day PI, and in urine and serum from the 3rd day PI till the end of the study. In the immunocompetent subgroup, Co-A test detected microsporidial antigens in stool, serum and urine of mice from the 1st day, 3rd day and the 5th day PI, respectively till the end of the study, without cross reactivity with C. cyatenensis or C. parvum in both subgroups. Co-A test proved to be simple and suitable tool for detecting microsporidial antigen in different specimens and did not need sophisticated equipment. It is very practical under field or rural conditions and in poorly equipped clinical laboratories.     

On the performances of noise filters in the restoration of oscillatory behavior in continuous yeast cultures

Continuous flow microbial fermentations under industrial conditions are subject to the influx of noise, mainly through the feed stream. Noise upsets the normal deterministic behavior. For continuous cultures of Saccharomyces cerevisiae exhibiting oscillatory responses, four kinds of commonly used noise filters, three algorithmic and one neural, have been compared for their ability to restore noise-free oscillations. An auto-associative neural filter was the best, similar to earlier observations for other organisms under non-oscillatory conditions. This enhances the general applicability of neural filters for industrial scale fermentations.     

Recruitment and growth in Aconitum septentrionale and Actaea spicata in relation to microbial soil communities manipulated by additions of glucose and nutrients

Sowing experiments were used to study seedling recruitment, growth and biomass allocation patterns in the perennial forest herbs Aconitum septentrionale and Actaea spicata in relation to the microbial soil community. Glucose and nutrients were added every second week over a 3-year period to manipulate soil microbial activity and nutrient availability. The glucose was added (400 g glucose m⁻² yr⁻¹) to reduce the nutrient availability to the plants by increasing soil microbial demands. A full nutrient solution was used to increase the nutrient availability. The experiments were performed in a deciduous forest and in an open field in South East Norway, and our study is based on a consecutive sampling of whole plants with intact root systems to be able to estimate growth and allocation patterns. Both species recruited best in the forest while their growth in the open field was ca. 100 times larger than in the forest. Shoot:root ratios were surprisingly similar in the forest and the open field sites and were only marginally affected by the glucose and nutrient treatments. However, the shoot:root ratios were characterised by highly significant seasonal variations. This was the case for both species and indicates that the shoot:root ratios were under strong ontogenetic control. Recruitment was negatively affected by glucose additions, in particular in the open field. Growth was significantly and negatively affected by glucose additions in the forest. Nutrient additions gave, as expected, a significant increase in growth. The failure of seedling recruitment and inferior growth following glucose additions support the assumption that the soil microbial community is an important determinant of plant recruitment and growth.     

Influence of arbuscular-mycorrhizal fungi, Rhizobium meliloti strains and PGPR inoculation on the growth of Medicago arborea used as model legume for re-vegetation and biological reactivation in a semi-arid mediterranean area

Medicago arborea can be used for re-vegetationpurposes under semiarid conditions. These woody legumes have the ability toforman association with arbuscular mycorrhizal (AM) fungi and rhizobial bacteria,which can be maximised by microorganisms producing certain stimulatingmetabolites acting as plant growth promoting rhizobacteria (PGPR). The effectsof single and combined inoculations using microorganisms with different andinteractive metabolic capacities, namely three Glomusspecies, two Rhizobium meliloti strains (a wild type, WTand its genetically modified derivative GM) and a plant growth promotingrhizobacterium, (PGPR), were evaluated. All three inoculated AM fungi affectedMedicago growth in different ways. Differences weremaintained when soil was co-inoculated with each of the rhizobial strains (WTorGM) and the PGPR. Mycorrhizal fungi were effective in all cases, but the PGPRonly affected plant growth specific microbial situations. PGPR increased growthof G. mosseae-colonised plants associated withRhizobium WT strain by 36% and those infected byG. deserticola when associated with the rhizobial GMstrainby 40%. The most efficient microbial treatments involved mycorrhizalinoculation, which was an indication of the AM dependency of this plantspecies.Moreover, PGPR inoculation was only effective when associated with specificmycorrhizal endophytes (G. mosseae plus WT andG.deserticola plus GM rhizobial strain). The reduced root/shoot (R/S)ratio resulting from PGPR inoculation, was an indication of more effective rootfunction in treated plants. AM colonisation and nodule formation wereunaffectedby the type of AM fungus or bacteria (rhizobial strain and/or PGPR). AM fromnatural soil were less infective and effective than those from the collection.The results supported the existence of selective microbial interactionsaffecting plant performance. The indigenous AM fungi appeared to be ineffectiveand M. arborea behaved as though it was highly dependentonAM colonisation, which implied that it must have a mycorrhizal association toreach maximum growth in the stressed conditions tested. Optimum growth ofmycorrhizal M. arborea plants was associated with specificmicrobial groups, accounting for a 355% increase in growth overnodulatedcontrol plants. The beneficial effect of PGPR in increasing the growth of awoody legume, such as M. arborea under stress, was onlyobserved with co-inoculation of specific AM endophytes. As a result of theinteraction, only shoot biomass was enhanced, but not as a consequence ofenhancing of the colonising abilities of the endophytes. The growthstimulation,occurring as a consequence of selected microbial groups, may be critical anddecisive for the successful establishment of plants under Mediterraneanclimaticand soil conditions.     

Life cycle assessment of bio-based products: a disposable diaper case study

Purpose

In this study, a life cycle assessment of a bioplastic based diaper was performed. The product has several innovative elements, due to the implementation of eco-design principles, such as: (1) introduction of biopolymers (namely polylactic acid (PLA) and Mater-bi®), (2) relevant reduction of petrochemical plastics, and (3) minimization of energy consumptions and use of renewable energy in manufacturing. The aim of the study is to evaluate the environmental benefits gained through eco-innovation, while identifying further areas of improvement.

Methods

The bio-based diaper has been evaluated using a “cradle-to-gate” analysis. The functional unit is one diaper, assuming an average size among the different commercial options. A case study of an enterprise in Italy (WIP S.p.A) was carried out to collect as much reliable primary data as possible. In order to highlight potential areas of improvement and to compare the environmental performance of the product, a sensitivity analysis based on three different impact assessment methods (adopting ReCiPe 2008, IMPACT 2002+ and Cumulative Energy Demand (CED)) and a comparison with a standard commercial diaper were performed. Finally, three possible end-of-life scenarios including composting of WIP diaper were hypothesized and tested.

Results and discussion

Contribution analysis suggested that sourcing and production of raw materials used in WIP diaper manufacturing contributed most significantly to the potential environmental impacts. Adopting ReCiPe method, pulp, and sodium polyacrylate present the highest environmental burdens in WIP diaper system. Applying IMPACT2002+ method, PLA relative contribution to the toxicity increases, due to the generation of the electricity used in corn production and in PLA production phases. For both methods, impacts related to energy consumption of the WIP diapers’ production process look to be negligible. WIP diaper performance has room for improvement, since critical points were detected in the life cycle stages of raw materials used. However, the results of the normalization step, according to ReCiPe method, state that WIP diapers can bring environmental benefits, compared to standard ones. Moreover, if composting end-of-life scenario is included in the assessment, there is a significant improvement in WIP diaper environmental performance compared to a standard diaper.

Conclusions

Integrating eco-innovation and eco-design principles in the production of the bio-based diaper leads to a better environmental profile, compared to the standard one. Nevertheless, there are several areas of concerns to be considered in order to further improve its environmental performance. So far, the possible improvements identified from the case study are: (1) the selection of biopolymers suppliers with better production systems from an environmental point of view, (2) the reduction of distances along the supply chain, and (3) the implementation of composting procedures for the end of life. In conclusion, the introduction of biopolymers in diaper composition could lead them to be preferable compared to standard diapers, but criticisms arise, which need to be solved, to avoid the risk of burdens shifting.     

Ecological studies on the plants of fagaceae V. Growth in the sapling stage and minimal participation of reserve materials in the formation of annual new shoots of the evergreenQuercus glauca thunb

The growth in the sapling stage and participation of reserve materials in the formation of annual new shoots were studied in the evergreen treeQuercus glauca. The growth and some allometric relationship were analyzed for 1-to 4-year-oldQ. glauca plants. Each individual was felled at the foot, or all the leaves were removed at the end of the growth season (December). Sprouts were formed on the remaining stump and new shoots were formed from winter buds under dark or light conditions. The dry weight of each plant part was measured before and afte,, the formation of these new shoots. The amount of reserve materials in each plant part was estimated from the difference in allometric relatationships before and after the formation of new shoots. Although the results showed that a small amount of reserve material existed in roots, the participation of reserve materials in the formation of annual new shoots was negligible inQ. glauca growing under usual conditions, and substrates for the formation of new shoots were derived from the products of photosynthesis in old leaves and developing new leaves. Some of the growth characteristics ofQ. glauca were compared with those of the deciduous speciesQuercus variabilis to explain ecological behavior of the two species in warmtemperate secondary forests.     

Effect of organic soil amendments on the incidence of stalk rot of maize

Five organic materials, Calopogonium sp. leaves, rice straw, mixed wood saw dust of Terminalia sp. Triplochyton sp. and Kaya sp., fresh guinea grass and poultry manure were added to soil with a recent history of high stalk rot of maize caused by Macrophomina phaseolina and Fusarium moniliforme. The two stalk rot organisms reacted differently to the organic amendments. All the amendments produced significantly less Fusarium stalk rot disease than the unamended control. Amendment of soil with fresh Calopogonium leaves was almost ineffective in controlling the incidence of Macrophomina phaseolina. Organic amendment with poultry manure increased the disease casued by M. phaseolina. The other amendments appeared to be equally effective in checking the disease. Increased microbial population due to amendment may play some role in disease suppression.     

Synthesis of L-asparaginase bySerratia marcescens (Nima)

The production of L-asparaginase by two mutants ofSerratia marcescens grown on 14 different media was studied. The enzyme content increased from trace levels to 2.4 international units per ml when the organisms were grown in glycerol-peptone yeast extract medium. Glucose was the best carbon source under aerobic conditions. The enzyme content increased when L-asparagine was present in the growth medium.     

Effects of simple and disposable chicken cages for experimental Eimeria infections

During experimental Eimeria infections in chickens, facilities are often contaminated by fecal oocysts known to be highly resistant to both chemical and enzymatic treatments. Thus, studies using experimental Eimeria infections have been limited due to the difficulty of complete elimination of residual oocysts from both cages and facilities. To overcome this limitation, simple, inexpensive, and disposable cages were constructed from cardboard boxes and tested during experimental Eimeria maxima infections. The cages were used in animal rooms with only a 1.7% evidence of coccidia contamination between adjacent cages. No significant differences in fecal oocyst output and body weight gain were noted between animals housed in disposable cages and animals housed in wire control cages. This cage design is a useful means for preventing oocyst contamination during experimental conditions, suggesting that this disposable cage design could be used for other avian infectious disease studies.     

Physiological significance and bioenergetic aspects of glucose dehydrogenase

The regulation of the PQQ-linked glucose dehydrogenase in different organisms is reviewed. It is concluded that this enzyme functions as an auxiliary energy-generating mechanism, because it is maximally synthesized under conditions of energy stress. It is now definitively established that the oxidation of glucose to gluconate generates metabolically useful energy. The magnitude of the contribution of the oxidation of glucose to gluconate via this enzyme to the growth yield of organisms such asAcinetobacter calcoaceticus is not yet clear.     

硬化地表对不同树种土壤微生物群落结构和功能的影响

城市硬化地表可减少土壤有机物输入,并改变土壤理化性质,由此可能影响土壤微生物群落结构和功能,但目前国内外相关研究较少。为研究不同树种下土壤微生物群落对硬化地表的响应,设置透水硬化地表(Pervious pavement, P)、不透水硬化地表(Impervious pavement, IP)和自然地表(Control, C)3个处理水平的地表类型,并栽种北方常见的常绿针叶树油松(pine,Pinus tabulaeformis)和落叶阔叶树白蜡(ash,Fraxinus chinensis)。采用氯仿熏蒸浸提法、磷脂脂肪酸法(PLFA)及BIOLOG培养法分别测定了土壤微生物量、群落结构和功能多样性。结果表明:(1)与自然地表(C)相比,硬化地表下土壤微生物生物量碳、氮含量显著降低(P0.05),土壤微生物群落组成和群落功能多样性发生了改变。透水和不透水硬化地表下土壤微生物细菌、真菌数量降低,真菌/细菌(fungi/bacteria, F/B)、cy/pre(环丙基脂肪酸/前体结构cyclopropyl fatty acid/monoenoic precursors)和sat/mono(一般饱和脂肪酸/单不饱和脂肪酸normal saturated fatty acid/monounsaturated fatty acid)等环境压力指标均显著升高(P0.05),且土壤微生物cy/pre值在不透水硬化地表下显著高于透水硬化地表下,表明不透水硬化地表下土壤环境压力更大;不透水硬化地表下土壤微生物对糖类、氨基酸类、羧酸类、胺类和聚合物的利用显著降低(P0.05),微生物群落功能丰富度及多样性指数显著降低(P0.05)。(2)土壤微生物群落结构和功能多样性在不同树种间存在一定差异。油松树下土壤微生物真菌、丛枝菌根真菌(arbuscular mycorrhizal fungi, AMF)和F/B值在透水和不透水硬化地表下均显著降低(P0.05),而白蜡树下只在透水硬化地表下显著降低(P0.05);硬化地表使土壤微生物对糖类、氨基酸类和聚合物的利用强度在油松和白蜡树下表现出显著差异。硬化地表对土壤微生物的影响将进一步影响城市绿地的养分循环、树木生境和生态系统服务功能。     

Simple growth chambers for culturing microalgae with precision at different temperatures and irradiance

Profiles describing the relationships between growth, irradiance and temperature are important in the evaluation of microalgae and cyanobacteria for biomass production, as well as for their general characterization. To get correct results culturing chambers with plane parallel optical faces are needed. Only these give a defined light climate in the culture, but such devices are not found commercially. We here describe the testing of thermostated growth chambers with 200-mL culture volumes, easily constructed from disposable 144-mm diameter plastic Petri dishes. Their properties were examined by growing Spirulina platensis concurrently in 15 parallel cultures under identical conditions of illumination and temperature, showing efficient and reproducible growth between them. The chambers are naturally also very suitable for growing microalgae in general. This revised version was published online in August 2006 with corrections to the Cover Date.