Bacterial community during ethanol production
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA508648 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR8285890_1.fastq.gz | Fastqsanger.gz | |||
| SRR8285890_2.fastq.gz | Fastqsanger.gz | |||
| SRR8285900_1.fastq.gz | Fastqsanger.gz | |||
| SRR8285900_2.fastq.gz | Fastqsanger.gz | |||
| SRR8285891_1.fastq.gz | Fastqsanger.gz |
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Project description:In microbial production of non-catabolic products, a loss of production capacity upon long-term cultivation (for example, chemostat), a phenomenon called strain degeneration, is nearly always observed. In this study, a systems biology approach (monitoring changes from gene to produced flux) was used to study degeneration of penicillin production by Penicillium chrysogenum in ethanol-limited chemostat fermentations where the biomass specific penicillin production rate decreased 10-fold within 30 generations. Results showed that the copy number of penicillin gene clusters and expression levels of central metabolism showed little decrease. With respect to penicillin production, major changes were observed: a strong downregulation of the cysteine pathway in agreement with its nearly 10-fold flux reduction. Also, levels of ACVS and IPNS, two penicillin pathway enzymes, and the penicillin transport capacity decreased many fold. This indicates that degeneration is caused by changed regulation of post-translational modifications or an increased protein degradation rate of these proteins. Continued subcultivation of a degenerated culture resulted in partial recovery of the biomass specific penicillin production rate, however, it was still 5-fold lower than the peak biomass specific penicillin production rate. Prolonged chemostat cultivations up to 500 hours (30 generations) with ethanol as the sole limiting carbon source were performed because degeneration is found to be more pronounced with ethanol as a limiting sole carbon source compared to glucose. Measurements included genome level (number of penicillin gene clusters), genome-wide transcriptome, protein levels of penicillin pathway enzymes, number of peroxisomes (microbodies where part of the penicillin pathway occurs), metabolome (of central metabolism, nucleotides, penicillin pathway intermediates including intracellular PAA and PenG) and fluxome.
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Project description:In microbial production of non-catabolic products, a loss of production capacity upon long-term cultivation (for example, chemostat), a phenomenon called strain degeneration, is nearly always observed. In this study, a systems biology approach (monitoring changes from gene to produced flux) was used to study degeneration of penicillin production by Penicillium chrysogenum in ethanol-limited chemostat fermentations where the biomass specific penicillin production rate decreased 10-fold within 30 generations. Results showed that the copy number of penicillin gene clusters and expression levels of central metabolism showed little decrease. With respect to penicillin production, major changes were observed: a strong downregulation of the cysteine pathway in agreement with its nearly 10-fold flux reduction. Also, levels of ACVS and IPNS, two penicillin pathway enzymes, and the penicillin transport capacity decreased many fold. This indicates that degeneration is caused by changed regulation of post-translational modifications or an increased protein degradation rate of these proteins. Continued subcultivation of a degenerated culture resulted in partial recovery of the biomass specific penicillin production rate, however, it was still 5-fold lower than the peak biomass specific penicillin production rate.
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