Rhizobioaugmentation of Casuarina glauca with N-fixing actinobacteria Frankia decreases enzymatic activities in wastewater irrigated soil: effects of Frankia on C. glauca growth

The use of wastewater for irrigation in agroforestry is cost-effective for water management. It is well established that rhizospheric microorganisms such as N2-fixing bacteria are able to modulate rhizobioaugmention and to boost phyoremediation process. To date, no study has been conducted to evaluate biological effects of rhizobioaugmentation in Casuarina glauca trees induced by their symbiont N-fixing actinobacteria of the genus Frankia. The objective of the present study was to evaluate the main effects of rhizobioaugmentation on the biological activity in the C. glauca’s rhizosphere and on C. glauca growth in soils irrigated with industrial wastewater. Two Frankia strains (BMG5.22 and BMG5.23) were used in a single or dual inoculations of C. glauca seedlings irrigated with industrial wastewater. Soil enzymes activity related to carbon, phosphorus, sulfur and nitrogen cycling were measured. Results revealed that the BMG5.22 Frankia strain increases significantly the size (dry weight) of C. glauca shoots and roots while dual inoculation increased significantly the root length. Surprisingly, β-glucosidase (BG), cellobiohydrolase (CBH), β-N-acetylglucosaminidase (NAGase), aryl sulfatase (AS), acid phosphatase (AP), alkaline phosphatase (AlP), glycine aminopeptidase (GAP), leucine aminopeptidase (LAP), and peroxidase (PER) activity in the rhizosphere decreased significantly in soils treated with the two strains of symbionts. This suggests no positive correlations between enzymatic activity and C. glauca growth.     

Effects of rs6234/rs6235 and rs6232/rs6234/rs6235 PCSK1 single-nucleotide polymorphism clusters on proprotein convertase 1/3 biosynthesis and activity

Background

Proprotein convertase 1/3 (PC1/3) is one of the endoproteases initiating the proteolytic activation of prohormones and proneuropeptides in the secretory pathway. It is produced as a zymogen that is subsequently modified by activity-determining cleavages at the amino and the carboxyl termini. In human, it is encoded by the PCSK1 locus on chromosome 5. Spontaneous inactivating mutations in its gene have been linked to obesity. Minor alleles of the common non-synonymous single-nucleotide polymorphisms (SNPs) rs6232 (T > C, N221D), rs6234 (G > C, Q665E) and rs6235 (C > G, S690T) have been associated with increased risk of obesity. We have shown that the variations associated with these SNPs are linked on minor PCSK1 alleles.

Goal

In this study, we examined the impact of amino acid substitutions specified by the minor PCSK1 alleles on PC1/3 biosynthesis and prohormone processing activity in cultured cells.

Methods

The common and variant isoforms of PC1/3 were expressed in transfected rat pituitary GH4C1 cells with or without proopiomelanocortin (POMC) as a substrate. Secreted PC1/3- or POMC-related proteins and peptides were analyzed by immunoblotting and immunoprecipitation.

Results

When expressed in GH4C1 cells, the triple-variant PC1/3 underwent significantly more proteolytic processing at the amino and carboxyl termini than the common and double-variant isoforms. However, there was no detectable difference among these isoforms in their ability to process POMC in the transfected cells.

Conclusions

Since truncation of PC1/3 in its C-terminal region reportedly renders the enzyme unstable, we speculate that the accentuated processing of the triple variant in this region may, in vivo, create a subtle deficit of PC1/3 enzymatic activity in endocrine and neuroendocrine cells, causing impaired processing of prohormones and proneuropeptides to their bioactive forms.     

Relationship of childhood protein-energy malnutrition and parasite infections in an urban African setting

Summary A clear understanding of protein-energy malnutrition (PEM), parasite infection and their interactions is essential in formulating health and development policies. We studied the prevalence of PEM indicators and the prevalence and/or intensity of infection in 558 Zairian children aged 4 months to 10 years. Multivariate analyses were used to estimate relationships between PEM indicators and parasitic infection. Stunting was found in 40.3% of children, wasting in 4.9% and kwashiorkor in 5.1%. The risk of stunting was significantly higher in children with Ascaris lumbricoides. The risk of wasting was higher in children with A. lumbricoides or Trichuris trichiura , whereas the risk of kwashiorkor was high with T. trichiura but very reduced in those with A. lumbricoides. Plasmodium infection was not related to nutritional indicators. These relationships highlight important interactions, both synergistic and antagonistic, between nutrition and parasites in central Africa.     

Metal Content in Soil and Black Spruce (<Emphasis Type="Italic">Picea mariana</Emphasis>) Trees in the Sudbury Region (Ontario,Canada): Low Concentration of Arsenic,Cadmium, and Nickel Detected near Smelter Sources

Several studies have reported high metal concentrations in soil within the vicinity of smelters in the Sudbury (Ontario) region. Continued investigation and monitoring of soil and vegetation are essential to the understanding of ecosystem recovery following the reduction of emissions from smelters and the establishment of a reforestation program. The concentrations of Cd, Co, Cu, Fe, Ni, and Zn, found in the present study were within the limits set by Ontario Ministry of Environment and Energy (OMEE) guidelines even in sites within the vicinity of the Falconbridge Smelters. The levels of these elements in black spruce (Picea mariana) tissues were much lower and far below the toxic levels for vegetation. This is the first documented report of metal content in black spruce populations in the Sudbury region.     

Expression of Genes Associated with Nickel Resistance in Red Oak (<Emphasis Type="Italic">Quercus rubra</Emphasis>) Populations from a Metal Contaminated Region

Although many studies have reported mechanisms of resistance to metals in herbaceous species, there is very little information on metal coping strategy in hardwood species such as Quercus rubra. The main objective of this study was to determine the expression of genes associated with nickel resistance in red oak (Q. rubra) populations from metal contaminated and uncontaminated sites in the Northern Ontario. Six genes associated with nickel resistances in model and non-model plants were targeted. Differential expressions of these genes were observed in Q. rubra from all the sites, but association between metal contamination and gene expression was not established. This suggests that the bioavailable amounts of metals found in metal contaminated soils in mining sites in northern Ontario and likely in many mining regions around the world cannot trigger a genetic response in higher plant species.     

Bulevirtide als erster spezifischer Wirkstoff gegen Hepatitis-D-Virusinfektionen – Mechanismus und klinische Wirkung

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Die Blockade des Zelleintritts von Krankheitserregern ist ein geeigneter Ansatz, um Neuinfektionen zu verhindern. Der...