Biodiesel Co-Product (BCP) Decreases Soil Nitrogen (N) Losses to Groundwater.

This study compares a traditional agricultural approach to minimise N pollution of groundwater (incorporation of crop residues) with applications of small amounts of biodiesel co-product (BCP) to arable soils. Loss of N from soil to the aqueous phase was shown to be greatly reduced in the laboratory, mainly by decreasing concentrations of dissolved nitrate-N. Increases in soil microbial biomass occurred within 4 days of BCP application-indicating rapid adaptation of the soil microbial community. Increases in biomass-N suggest that microbes were partly mechanistic in the immobilisation of N in soil. Straw, meadow-grass and BCP were subsequently incorporated into experimental soil mesocosms of depth equal to plough layer (23 cm), and placed in an exposed netted tunnel to simulate field conditions. Leachate was collected after rainfall between the autumn of 2009 and spring of 2010. Treatment with BCP resulted in less total-N transferred from soil to water over the entire period, with 32.1, 18.9, 13.2 and 4.2 mg N kg-1 soil leached cumulatively from the control, grass, straw and BCP treatments, respectively. More than 99 % of nitrate leaching was prevented using BCP. Accordingly, soils provided with crop residues or BCP showed statistically significant increases in soil N and C compared to the control (no incorporation). Microbial biomass, indicated by soil ATP concentration, was also highest for soils given BCP (p < 0.05). These results indicate that field-scale incorporation of BCP may be an effective method to reduce nitrogen loss from agricultural soils, prevent nitrate pollution of groundwater and augment the soil microbial biomass.

A comparison of two colorimetric assays, based upon Lowry and Bradford techniques, to estimate total protein in soil extracts.

Soil extracts usually contain large quantities of dissolved humified organic material, typically reflected by high polyphenolic content. Since polyphenols seriously confound quantification of extracted protein, minimising this interference is important to ensure measurements are representative. Although the Bradford colorimetric assay is used routinely in soil science for rapid quantification protein in soil-extracts, it has several limitations. We therefore investigated an alternative colorimetric technique based on the Lowry assay (frequently used to measure protein and humic substances as distinct pools in microbial biofilms). The accuracies of both the Bradford assay and a modified Lowry microplate method were compared in factorial combination. Protein was quantified in soil-extracts (extracted with citrate), including standard additions of model protein (BSA) and polyphenol (Sigma H1675-2). Using the Lowry microplate assay described, no interfering effects of citrate were detected even with concentrations up to 5 times greater than are typically used to extract soil protein. Moreover, the Bradford assay was found to be highly susceptible to two simultaneous and confounding artefacts: 1) the colour development due to added protein was greatly inhibited by polyphenol concentration, and 2) substantial colour development was caused directly by the polyphenol addition. In contrast, the Lowry method enabled distinction between colour development from protein and non-protein origin, providing a more accurate quantitative analysis. These results suggest that the modified-Lowry method is a more suitable measure of extract protein (defined by standard equivalents) because it is less confounded by the high polyphenolic content which is so typical of soil extracts.

Hyperhomocysteinemia in L-dopa treated Parkinson's disease patients: effect of cobalamin and folate administration.

Homocysteine (Hcy) is a risk factor for vascular diseases, cognitive impairment and dementia. L-dopa treatment may represent an acquired cause of hyperhomocysteinemia (HHcy), as evidenced by studies in rats as well as in Parkinson's disease (PD) patients. Folate and cobalamin status also seems to influence the effects of L-dopa on plasma Hcy levels; therefore B-vitamins supplementation has been proposed to reduce the HHcy in L-dopa treated PD patients. Plasma Hcy, folate, and cobalamin levels were evaluated in 20 PD patients treated with L-dopa in the baseline condition and following a 5-week period of treatment with cobalamin and folate; results were compared with 35 controls. Analysis of data revealed that Hcy levels were higher in L-dopa treated PD patients when compared with age- and sex-matched controls and that supplementation of the diet with cobalamin and folate is effective in reducing Hcy concentrations; these findings may have important implications in the treatment of PD patients who are potentially at risk for vascular diseases and cognitive impairment or dementia.

Plasma homocysteine levels in Parkinson's disease: role of antiparkinsonian medications.

Elevated plasma homocysteine (Hcy) concentrations have been reported in L-dopa treated Parkinson's disease (PD) patients, suggesting that L-dopa treatment is an acquired cause of hyperhomocysteinemia. Aim of this study is to evaluate the effects of different antiparkinsonian drugs on Hcy concentrations. We compared Hcy, B(12) and folate levels in 45 PD patients (15 treated with dopamine-agonists, 15 with L-dopa and 15 with L-dopa plus a catechol-O-methyltransferase-inhibitor (COMT-I) and in 15 controls. Analysis of data revealed that L-dopa administration significantly increases Hcy concentrations and that the addition of COMT-I effectively reduces the homocysteinemia.

[Report on Citrobacter strains having antigenic relationship with "E. coli", and their characteristics (author's transl)]. / Sul reperto e su alcune caratteristiche di stipiti di citrobacter antigenicamente correlati con "E. coli".

During a research done on the diffusion of enteropathogenic E. coli in a children's community, 24 strains of Citrobacter have been isolated. By agglutination and agar-gel diffusion techniques, they looked to have some somatic antigens in common with those serogroups of enteropathogenic E. coli. The results were as follows: 14 strains were correlated with the serogroup O111; 9 strains with the serogroup O125 and 1 strain with the serogroup O55. The isolation of these strains has been made at the same period when we have found out the E. coli of homologous serogroups, even if they didn't belong to the same subjects. The colicine typing and sensibility to antibiotics tests made both on Citrobacter strains and on E. coli ones of homologous serogroups haven't pointed out other characteristics of identity. Furthermore, antigenic relationships between the 24 strains of Citrobacter and different serogroups of Salmonella have been demonstrated, that is: the strains containing the somatic antigen O111 were correlated with the serogroup O35; the strains having the somatic antigen O125, with the serogroup O6, 14, 24 and the strain containing the somatic antigen O55, with the serogroup O50. The presence of these strains in normal subjects only, gives a further witness that their role in enteric infections remains to be demonstrated.