Project description:A three-stage continuous fermentative system was developed to simulate and control physicochemical factors of the gut biology. Inoculation was of each reactor was performed from a human fecal sample which was initially amplified with a batch procedure. Samples from the initial feces, the batch and from the bioreactors media were collected to extract bacterial DNA. 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray.
Project description:A three-stage continuous fermentative system was developed to simulate and control physicochemical factors of the gut biology. Inoculation was of each reactor was performed from a human fecal sample which was initially amplified with a batch procedure. Samples from the initial feces, the batch and from the bioreactors media were collected to extract bacterial DNA. 16S PCR amplification was performed to assess the microbial diversity at the family level using the HuGChip. Amplified DNA was purified and labelled with either Cy3 or Cy5 dye and hybridized on the microarray. A 5 chip study was realized, each corresponding to hybridization with 250ng of labelled 16S rRNA gene amplicons from either the initial stool, the batch inoculum or fermentative medium different compartments of the simulated colon (Proximal, Transversal and Distal). Each probe (4441) was synthetized in three replicates.
Project description:This study investigates the role of carbon-to-phosphorus (C/P) ratios in shaping microbial community dynamics and polyhydroxyalkanoates (PHA) production in sequencing batch reactors (SBR) fed with volatile fatty acids. Three conditions, characterized by fixed organic loading rates but varying C/P ratios (Run 1 = 170 Cmol Pmol-1; Run 2 = 235 Cmol Pmol-1; Run 3 = 400 Cmol Pmol-1;), were tested to explore their impact on PHA accumulation, biomass growth, and reactor stability. Results indicate that the moderate phosphorus limitation of Run 2 achieves the best overall performance, with a PHA volumetric productivity of 2.02 g PHA L⁻¹ d⁻¹ and process stability. Under these conditions, PHA-accumulating bacteria, primarily Sphaerotilus and Leadbetterella, dominated the microbial community, with a notable contribution from eukaryotic organisms, particularly Rhogostoma, Vorticella and Tokophrya, which appeared to regulate bacterial populations through selective predation. Conversely, higher C/P ratio increased the storage yield but lowered the productivity (1.55 gPHA L-1 h-1), compromising sludge settleability and reactor stability, indicating impaired microbial functionality. Transmission electron microscopy further confirmed the presence of intracellular PHA granules and polyphosphate reserves, reinforcing the connection between nutrient limitation and adaptive microbial strategies. Overall, these findings highlight the critical role of the C/P ratio in shaping the performance of mixed microbial cultures, demonstrating that a well-balanced nutrient supply can enhance PHA production while maintaining microbial community stability. The results contribute to optimizing the selection process for mixed microbial cultures, offering valuable insights into the impact of carbon-to-nutrient ratios in the feeding strategy.
Project description:This study investigates the role of carbon-to-phosphorus (C/P) ratios in shaping microbial community dynamics and polyhydroxyalkanoates (PHA) production in sequencing batch reactors (SBR) fed with volatile fatty acids. Three conditions, characterized by fixed organic loading rates but varying C/P ratios (Run 1 = 170 Cmol Pmol-1; Run 2 = 235 Cmol Pmol-1; Run 3 = 400 Cmol Pmol-1;), were tested to explore their impact on PHA accumulation, biomass growth, and reactor stability. Results indicate that the moderate phosphorus limitation of Run 2 achieves the best overall performance, with a PHA volumetric productivity of 2.02 g PHA L⁻¹ d⁻¹ and process stability. Under these conditions, PHA-accumulating bacteria, primarily Sphaerotilus and Leadbetterella, dominated the microbial community, with a notable contribution from eukaryotic organisms, particularly Rhogostoma, Vorticella and Tokophrya, which appeared to regulate bacterial populations through selective predation. Conversely, higher C/P ratio increased the storage yield but lowered the productivity (1.55 gPHA L-1 h-1), compromising sludge settleability and reactor stability, indicating impaired microbial functionality. Transmission electron microscopy further confirmed the presence of intracellular PHA granules and polyphosphate reserves, reinforcing the connection between nutrient limitation and adaptive microbial strategies. Overall, these findings highlight the critical role of the C/P ratio in shaping the performance of mixed microbial cultures, demonstrating that a well-balanced nutrient supply can enhance PHA production while maintaining microbial community stability. The results contribute to optimizing the selection process for mixed microbial cultures, offering valuable insights into the impact of carbon-to-nutrient ratios in the feeding strategy.
Project description:This study investigates the role of carbon-to-phosphorus (C/P) ratios in shaping microbial community dynamics and polyhydroxyalkanoates (PHA) production in sequencing batch reactors (SBR) fed with volatile fatty acids. Three conditions, characterized by fixed organic loading rates but varying C/P ratios (Run 1 = 170 Cmol Pmol-1; Run 2 = 235 Cmol Pmol-1; Run 3 = 400 Cmol Pmol-1;), were tested to explore their impact on PHA accumulation, biomass growth, and reactor stability. Results indicate that the moderate phosphorus limitation of Run 2 achieves the best overall performance, with a PHA volumetric productivity of 2.02 g PHA L⁻¹ d⁻¹ and process stability. Under these conditions, PHA-accumulating bacteria, primarily Sphaerotilus and Leadbetterella, dominated the microbial community, with a notable contribution from eukaryotic organisms, particularly Rhogostoma, Vorticella and Tokophrya, which appeared to regulate bacterial populations through selective predation. Conversely, higher C/P ratio increased the storage yield but lowered the productivity (1.55 gPHA L-1 h-1), compromising sludge settleability and reactor stability, indicating impaired microbial functionality. Transmission electron microscopy further confirmed the presence of intracellular PHA granules and polyphosphate reserves, reinforcing the connection between nutrient limitation and adaptive microbial strategies. Overall, these findings highlight the critical role of the C/P ratio in shaping the performance of mixed microbial cultures, demonstrating that a well-balanced nutrient supply can enhance PHA production while maintaining microbial community stability. The results contribute to optimizing the selection process for mixed microbial cultures, offering valuable insights into the impact of carbon-to-nutrient ratios in the feeding strategy.
2025-07-14 | GSE302519 | GEO
Project description:bacteria microbial diversity in anammox reactor
| PRJNA1011489 | ENA
Project description:Microbial diversity of an anammox reactor
| PRJNA526345 | ENA
Project description:microbial diversity in Sewage treatment reactor
Project description:In large-scale production processes, metabolic control is typically achieved by limited supply of essential nutrients like ammonia. With increasing bioreactor dimensions, microbial producers such as Escherichia coli are exposed to changing substrate availabilities due to limited mixing. In turn, cells sense and respond to these dynamic conditions leading to frequent activation of their regulatory programs which result in production yield losses. This study is focused on transcriptional changes due to fluctuating ammonia supply, while sampling a continuously running two-compartment bioreactor system comprising a stirred tank reactor (STR) and a plug flow reactor (PFR). A previously created mutant E.coli SR was used to limit the reaction to environmntal influences via knock-out of stringent response. E. coli WT revealed highly diverging short-term transcriptional responses in ammonia fluctuation compared E. coli SR.