Low-pH and aluminum (Al) stresses are the major constraints that limit crop yield in acidic soils. Grafting vegetable elite cultivars onto appropriate rootstocks may represent an effective tool to improve crop tolerance to acidity and Al toxicity. Two greenhouse hydroponic experiments were performed to evaluate growth, yield, biomass production, chlorophyll index, electrolyte leakage, mineral c...

BACKGROUND The product yield and titers of biological processes involving the conversion of biomass to desirable chemicals can be limited by environmental stresses encountered by the microbial hosts used for the bioconversion. One of these main stresses is growth inhibition due to exposure to low pH conditions. In order to circumvent this problem, understanding the biological mechanisms involve...

The objective of this study was to determine the effect of acid adaptation conditions on heat resistance of E. coli O157: H7 932. E. coli O157: H7 was adapted to acid by exposing the cells to pH 4.5 (2h), pH 5.0 (1 h), and pH 5.5 (1 h) in tryptic soy broth. D and z values of the acid adapted and control cultures at 54 degrees C, 56 degrees C, and 58 degrees C were determined in E buffer. The he...

We recently reported the identification by in vitro selection of 10MD5, a deoxyribozyme that requires both Mn2+ and Zn2+ to hydrolyze a single-stranded DNA substrate with formation of 5′-phosphate and 3′-hydroxyl termini. DNA cleavage by 10MD5 proceeds with kobs=2.7 h(−1) and rate enhancement of 10(12) over the uncatalyzed P−O hydrolysis reaction. 10MD5 has a very sharp pH optimum near 7.5, wit...

GlnR-mediated repression of the GlnR regulon at acidic pH is required for optimal acid tolerance in Streptococcus mutans, the etiologic agent for dental caries. Unlike most streptococci, the GlnR regulon is also regulated by newly identified PmrA (SMUGS5_RS05810) at the transcriptional level in S. mutans GS5. Results from gel mobility shift assays confirmed that both GlnR and PmrA recognized th...

Exposure of Saccharomyces cerevisiae to alkaline pH provokes a stress condition that generates a compensatory reaction. In the present study we examined a possible role for the PKA (protein kinase A) pathway in this response. Phenotypic analysis revealed that mutations that activate the PKA pathway (ira1 ira2, bcy1) tend to cause sensitivity to alkaline pH, whereas its deactivation enhances tol...

Abstract As climate changes, maintenance of yield stability requires efficient selection for drought tolerance. Drought-tolerant cultivars have been successfully but slowly bred by yield-based in arid environments. Marker-assisted accelerates breeding is less effective polygenic traits. Therefore, we investigated a based on phenotypic markers derived from automatic phenotyping systems. Our tria...

Salmonellosis is one of the main causes of foodborne illnesses worldwide, with outbreaks predominately linked to contamination of eggs and raw egg products, such as mayonnaise. This review explores previous studies that have investigated Salmonella control mechanisms utilized in the production of raw egg mayonnaise and other food products. Apart from the use of pasteurized eggs, the main contro...

The commonly accepted hypothesis explaining the mechanism of action of pyrazinamide (PZA) is based on the assumption that PZA-susceptible Mycobacterium tuberculosis strains produce pyrazinamidase, which hydrolyzes PZA to the antibacterial moiety pyrazinoic acid (POA). It is not clear whether POA has specific antimicrobial activity or the inhibition of growth caused by POA is due to its ability ...

Functional coupling of calcium- and alkaline responsive signalling occurs in multiple fungi to afford efficient cation homeostasis. Host microenvironments exert alkaline stress and potentially toxic concentrations of Ca2+ , such that highly conserved regulators of both calcium- (Crz) and pH- (PacC/Rim101) responsive signalling are crucial for fungal pathogenicity. Drugs targeting calcineurin ar...