In Vitro Activity of Glucosinolates and Their Degradation Products against Brassica-Pathogenic Bacteria and Fungi

Glucosinolates (GSLs) are secondary metabolites found in Brassica vegetables that confer on them resistance against pests and diseases. Both GSLs and glucosinolate hydrolysis products (GHPs) have shown positive effects in reducing soil pathogens. Information about their in vitro biocide effects is scarce, but previous studies have shown sinigrin GSLs and their associated allyl isothiocyanate (AITC) to be soil biocides. The objective of this work was to evaluate the biocide effects of 17 GSLs and GHPs and of leaf methanolic extracts of different GSL-enriched Brassica crops on suppressing in vitro growth of two bacterial (Xanthomonas campestris pv. campestris and Pseudomonas syringae pv. maculicola) and two fungal (Alternaria brassicae and Sclerotinia scletoriorum) Brassica pathogens. GSLs, GHPs, and methanolic leaf extracts inhibited the development of the pathogens tested compared to the control, and the effect was dose dependent. Furthermore, the biocide effects of the different compounds studied were dependent on the species and race of the pathogen. These results indicate that GSLs and their GHPs, as well as extracts of different Brassica species, have potential to inhibit pathogen growth and offer new opportunities to study the use of Brassica crops in biofumigation for the control of multiple diseases.     

Oxalic acid production by Aspergillus niger

Aspergillus niger is able to produce a quite high concentration of oxalic acid using sucrose as carbon and energy source. Operating at pH higher than 6 and an enriched N and P medium is necessary in order to conduct the fermentation towards oxalic acid production. A pH?shift technique, operating at acid pH?in the first two days and then setting pH?to 6, allowed the productivity to slightly increase in shaking flasks cultures up to 3.0?kg/m³?·?d, with a final oxalic acid concentration of 29?kg/m³. When operating at more controlled conditions, in a stirred tank, both productivity and oxalic acid concentration were improved (4.1?kg/m³?·?d and 33.8?kg/m³, respectively). However the main drawback of this fermentation is the low yield attained (about 0.3?kg oxalic acid/kg sucrose) because most of glucose, resulting from the hydrolysis of sucrose by the extracellular enzymes secreted at the beginning of the fermentation, is very quickly oxidised to gluconic acid, a process which is favoured at a pH?close to 6. Milk whey was proved to be a very good substrate as it allows oxalic acid to be produced with a similar productivity (2.5?kg/m³?·?d in shaking flasks) giving excellent yields of almost 0.6?kg oxalic acid/kg lactose.     

Respiratory changes after stereotactic high cervical cord lesions for pain

Stereotactic cordotomy affected forced expiratory volume in 1 sec (FEV1) less than open cordotomy, but 11 of 15 patients had some effect on respiratory functions. Central cord lesions produced a small (9%) fall in values. Of 10 patients with trigeminal lesions 7 had no charge in respiratory function, but 2 had reduction of more 50% associated with transient extremity paresis, attributed to injury to a corticospinal pathway to respiratory neurones.     

Patterns of nucleotide and haplotype diversity at ICAM-1 across global human populations with varying levels of malaria exposure

Malaria is one of the strongest selective pressures in recent human evolution. African populations have been and continue to be at risk for malarial infections. However, few studies have re-sequenced malaria susceptibility loci across geographically and genetically diverse groups in Africa. We examined nucleotide diversity at Intercellular adhesion molecule-1 (ICAM-1), a malaria susceptibility candidate locus, in a number of human populations with a specific focus on diverse African ethnic groups. We used tests of neutrality to assess whether natural selection has impacted this locus and tested whether SNP variation at ICAM-1 is correlated with malaria endemicity. We observe differing patterns of nucleotide and haplotype variation in global populations and higher levels of diversity in Africa. Although we do not observe a deviation from neutrality based on the allele frequency distribution, we do observe several alleles at ICAM-1, including the ICAM-1 ^Kilifi allele, that are correlated with malaria endemicity. We show that the ICAM-1 ^Kilifi allele, which is common in Africa and Asia, exists on distinct haplotype backgrounds and is likely to have arisen more recently in Asia. Our results suggest that correlation analyses of allele frequencies and malaria endemicity may be useful for identifying candidate functional variants that play a role in malaria resistance and susceptibility.     

A simple flow meter for bioreactors applicable to oscillating feed systems

Summary A new simple electronic device for liquid flowrate measurement in laboratory or semipilot scale fermenters is presented. The flow meter is also applicable to pulsing or oscillating flow rates. This system allows either a direct measurement of the flow or implementation on a data acquisition system, if available.