Mutagenic activity of 6-azido deoxyhexoses and azido alcohols in Salmonella typhimurium and its inhibition by a structure-similar carbon source in the medium

6-Azido-6-deoxy (AZd) derivatives of D-glucose, D-mannose, D-altrose, D-allose, L-idose, D-galactose, D-galactonic acid and D-galactitol, 3-azido-1,2-propanediol (azidoglycerol), 3,1-diazido-2-propanol (diazidoglycerol) and (at much higher doses) 2-azidoethanol were mutagenic in Salmonella typhimurium strains TA100 and TA1535. The mutagenic response was similar to that induced by sodium azide, i.e., the azido compounds failed to induce mutations in strain TA98, and mutagenesis was independent of plasmid pKM101, and independent of external activation. The specific mutagenicity (his+ rev/mmole) of AZd-glucose and AZd-galactose was decreased with increasing concentrations of D-glucose or D-galactose in the minimal agar medium and enhanced 100-fold or more when 0.2% citrate rather than 0.2% glucose served as the carbon source in the medium. Similarly, the mutagenic efficiency of azidoglycerol was inhibited by glycerol but not by D-glucose or D-galactose; however, the mutagenicity of sodium azide was not influenced by any of these carbon sources in the medium. The inhibition of the mutagenic action of azido hexoses and azido alcohols by non-azido structural analogs is assumed to reside in competition in transmembrane transport or for the metabolic pathways.     

A two-dimensional proteome reference map of Herbaspirillum seropedicae proteins

Herbaspirillum seropedicae is an endophytic diazotroph associated with economically important crops such as rice, sugarcane, and wheat. Here, we present a 2-D reference map for H. seropedicae. Using MALDI-TOF-MS we identified 205 spots representing 173 different proteins with a calculated average of 1.18 proteins/gene. Seventeen hypothetical or conserved hypothetical ORFs were shown to code for true gene products. These data will support the genome annotation process and provide a basis on which to undertake comparative proteomic studies.     

Associations of physical activity with gut microbiota in pre-adolescent children

[Purpose] To determine whether physical activity (PA), primarily the recommended 60 minutes of moderate-to-vigorous PA, is associated with gut bacterial microbiota in 10-year-old children.[Methods] The Block Physical Activity Screener, which provides minutes/day PA variables, was used to determine whether the child met the PA recommendations. 16S rRNA sequencing was performed on stool samples from the children to profile the composition of their gut bacterial microbiota. Differences in alpha diversity metrics (richness, Pielou’s evenness, and Faith’s phylogenetic diversity) by PA were determined using linear regression, whereas beta diversity (unweighted and weighted UniFrac) relationships were assessed using PERMANOVA. Taxon relative abundance differentials were determined using DESeq2.[Results] The analytic sample included 321 children with both PA and 16S rRNA sequencing data (mean age [SD] =10.2 [0.8] years; 54.2% male; 62.9% African American), where 189 (58.9%) met the PA recommendations. After adjusting for covariates, meeting the PA recommendations as well as minutes/day PA variables were not significantly associated with gut richness, evenness, or diversity (p ≥ 0.19). However, meeting the PA recommendations (weighted UniFrac R² = 0.014, p = 0.001) was significantly associated with distinct gut bacterial composition. These compositional differences were partly characterized by increased abundance of Megamonas and Anaerovorax as well as specific Christensenellaceae_R-7_group taxa in children with higher PA.[Conclusion] Children who met the recommendations of PA had altered gut microbiota compositions. Whether this translates to a reduced risk of obesity or associated metabolic diseases is still unclear.     

Recruitment of TBK1 to cytosol‐invading Salmonella induces WIPI2‐dependent antibacterial autophagy

Mammalian cells deploy autophagy to defend their cytosol against bacterial invaders. Anti‐bacterial autophagy relies on the core autophagy machinery, cargo receptors, and “eat‐me” signals such as galectin‐8 and ubiquitin that label bacteria as autophagy cargo. Anti‐bacterial autophagy also requires the kinase TBK1, whose role in autophagy has remained enigmatic. Here we show that recruitment of WIPI2, itself essential for anti‐bacterial autophagy, is dependent on the localization of catalytically active TBK1 to the vicinity of cytosolic bacteria. Experimental manipulation of TBK1 recruitment revealed that engagement of TBK1 with any of a variety of Salmonella‐associated “eat‐me” signals, including host‐derived glycans and K48‐ and K63‐linked ubiquitin chains, suffices to restrict bacterial proliferation. Promiscuity in recruiting TBK1 via independent signals may buffer TBK1 functionality from potential bacterial antagonism and thus be of evolutionary advantage to the host.     

A radioimmunoprecipitation method in the serodiagnosis of HIV infection: the development of the optimal conditions for its performance and the evaluation of the possibilities for its use

The optimum conditions for using the method of radioimmunoprecipitation (RIP) for the detection of human immunodeficiency virus (HIV) in serum samples have been established. Out of several available cell lines persistently infected with HIV, specially selected line 17 has been chosen. The characteristic feature of this is the high and stable (under the conditions of prolonged cultivation) accumulation of virus-specific proteins in infected cells. The optimum conditions for making the test and its evaluation have also been established. The data of literature on the advantages of the method of RIP over such traditional methods as the enzyme immunoassay and immunoblotting have been confirmed. Thus, the presence of specific antibodies in several serum samples registered as false negative has been established. The intertypical reactivity of two serotypes of the virus, HIV-1 and HIV-2, has been studied. Cross reactivity of antibodies with respect to the HIV gene gag, but not with respect to viral glycoproteids, has been established. Ideas on the expediency and prospects of using RIP for the serological control of HIV infection are presented.     

Regulation of growth,nutritive, phytochemical and antioxidant potential of cultivated <Emphasis Type="Italic">Drimiopsis maculata</Emphasis> in response to biostimulant (vermicompost leachate,VCL) application

The effect of vermicompost leachate (VCL, low-cost biostimulant) on the growth, elemental (macro and micro-nutrients) and phytochemical content as well as the antioxidant potential of Drimiopsis maculata was evaluated. Three dilutions (1:5; 1:10 and 1:20) of VCL were tested and the cultivation lasted for 3 months. In addition to the recorded growth parameters, dried and ground plant materials (leaves and bulbs) were evaluated for nutrients, phenolic acids and antioxidant capacity. Vermicompost leachate application enhanced the growth of D. maculata, particularly, the leaves (VCL 1:10) and bulbs (VCL 1:20) which were significantly bigger than the controls. Apart from the concentration of phosphorus which was significantly lower in the leaves of VCL (1:20)-treated plants, the quantity of all four macro-nutrients analysed were similar with and without VCL. Similar observations were also demonstrated in the majority of quantified micro-nutrients in D. maculata. Relative to the control, VCL-treated plants had higher concentrations of the 10 phenolic acids quantified in the leaves. However, the majority of the quantified phenolic acids were not significantly enhanced in bulbs. Antioxidant activity of D. maculata extracts was generally higher in leaves than in the bulbs. The leaf extract from VCL (1:10 and 1:20)-treated plants exhibited lower oxygen radical absorbance capacity (ORAC) when compared to the control. However, bulbs from VCL (1:5) treatment had significantly higher ORAC than the control. From a conservational perspective, the current findings provided insight on viable approaches useful for mitigating challenges associated with over-harvesting of highly utilized but slow-growing plant species.