Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions.
Project description:Bacterial aromatic degradation may cause oxidative stress. The long-chain flavodoxin FldX1 of Paraburkholderia xenovorans LB400 counteracts reactive oxygen species (ROS). The aim of this study was to evaluate the protective role of FldX1 in P. xenovorans LB400 during the degradation of 4-hydroxyphenylacetate (4-HPA) and 3-hydroxyphenylacetate (3-HPA). Functionality of FldX1 was assessed by P. xenovorans p2-fldX1 that overexpresses FldX1. The effects of FldX1 on P. xenovorans were studied measuring growth on hydroxyphenylacetates, degradation of 4-HPA and 3-HPA, and ROS formation. The effects of hydroxyphenylacetates on the proteome (LC–MS/MS) and gene expression (qRT-PCR) were quantified. Bioaugmentation with strain p2-fldX1 of 4-HPA-polluted soil was assessed, measuring aromatic degradation (HPLC), 4-HPA-degrading bacteria, and plasmid stability.
2024-03-27 | PXD047097 | Pride
Project description:Microbial community in soil receiving bioaugmentation
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions. We were interested to study the global reactions of bacteria with biodegradative properties under near-environmental as compared to laboratory culture conditions. We compared here the genome-wide responses of RW1 between regular laboratory batch growth on the aromatic substrates DBF and salicylate with growth in sandy soil with or without the same aromatic compounds. We analysed the cellular reactions immediately after introduction into the sand, during exponential growth and at stationary phase, all in carefully controlled and replicated experimental conditions.
Project description:The efficacy of inoculation of single pure bacterial cultures into complex microbiomes, for example, in order to achieve increased pollutant degradation rates in contaminated material (i.e., bioaugmentation), has been frustrated by insufficient knowledge on the behaviour of the inoculated bacteria under the specific abiotic and biotic boundary conditions. Here we present a comprehensive analysis of global gene expression of the bacterium Sphingomonas wittichii RW1 in contaminated sand, compared to regular suspended batch growth in liquid culture. RW1 is a well-known bacterium capable of mineralizing polycyclic aromatic hydrocarbons such as dioxins, dibenzofurans and other chlorinated congeners. We tested the reactions of the cells both during the immediate transition phase from liquid culture to sand with or without dibenzofuran, as well during growth and stationary phase in sand. Cells during transition resemble going through stationary phase, showing evidence of stress responses and nutrient scavenging, and even of major adjustments in their primary metabolism if they were not pre-cultured on the same contaminant as found in the soil. Cells growing and surviving in soil show very different signatures as in liquid or in liquid culture exposed to chemicals inducing drought stress, and we obtain evidence for numerous soil-specific expressed genes. We conclude that studies focusing on inoculation efficacy should test behavior under conditions as closely as possible mimicking the intended microbiome conditions We were interested to study the global reactions of bacteria with biodegradative properties under near-environmental as compared to laboratory culture conditions. we compared here the genome-wide responses of RW1 between regular laboratory batch growth on the aromatic substrates DBF and salicylate with growth in sandy soil with or without the same aromatic compounds. We analysed the cellular reactions immediately after introduction into the sand, during lag phase, all in carefully controlled and replicated experimental conditions.