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Stimulation of porphyrin production by application of an external magnetic field to a photosynthetic bacterium, Rhodobacter sphaeroides.

Journal of bioscience and bioengineering · 2003 · Mixed · Low evidence

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MixedLow evidencePaper 3750

Applying an external magnetic field (0.13–0.3 T) slightly suppressed growth and increased extracellular porphyrin production at both N and S poles, with the largest increase at the N pole (up to ~5.3× control; maximum 35.8 mg/L at 0.3 T). ALAD concentration i…

Study snapshot

PublicationJournal of bioscience and bioengineering · 2003
Study typeanimal
Reported directionMixed
Evidence ratingLow

Abstract

The effects of an external magnetic field on the production of porphyrin were investigated using Rhodobacter sphaeroides IF012203 under anaerobic-light conditions. Upon application of a 0.13-0.3-T magnetic field, the growth was slightly suppressed and porphyrin extracellular production was activated at both the N and S poles, particularly at the N pole up to about 5.3 times that in the control experiment (6.7 mg/1) (without magnetic filed application). The maximum production was 35.8 mg/1 at the N pole with a magnetic field of 0.3 T. At the same time, the 5-aminolevulinic acid dehydratase (ALAD) concentration was enhanced in the cells at the N and S poles, but particularly at the the N pole. This suggested the possibility that the magnetic field might activate ALAD gene expression in R. sphaeroides IF012203 and result in enhanced porphyrin production.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal
Effect directionmixed
PopulationRhodobacter sphaeroides IF012203 (photosynthetic bacterium) under anaerobic-light conditions
Sample sizeNot supplied
ExposureELF
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Applying an external magnetic field (0.13–0.3 T) slightly suppressed growth and increased extracellular porphyrin production at both N and S poles, with the largest increase at the N pole (up to ~5.3× control; maximum 35.8 mg/L at 0.3 T). ALAD concentration in cells was enhanced at both poles, particularly at the N pole.

Outcomes measured

  • Porphyrin extracellular production
  • Bacterial growth
  • 5-aminolevulinic acid dehydratase (ALAD) concentration

Limitations

  • No sample size or replication details provided in the abstract
  • Exposure duration and magnetic field characteristics beyond flux density (e.g., static vs time-varying) not specified
  • Mechanistic inference (ALAD gene expression activation) is suggested but not directly demonstrated in the abstract
View raw extracted JSON
{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": "other",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Rhodobacter sphaeroides IF012203 (photosynthetic bacterium) under anaerobic-light conditions",
  "sample_size": null,
  "outcomes": [
    "Porphyrin extracellular production",
    "Bacterial growth",
    "5-aminolevulinic acid dehydratase (ALAD) concentration"
  ],
  "main_findings": "Applying an external magnetic field (0.13–0.3 T) slightly suppressed growth and increased extracellular porphyrin production at both N and S poles, with the largest increase at the N pole (up to ~5.3× control; maximum 35.8 mg/L at 0.3 T). ALAD concentration in cells was enhanced at both poles, particularly at the N pole.",
  "effect_direction": "mixed",
  "limitations": [
    "No sample size or replication details provided in the abstract",
    "Exposure duration and magnetic field characteristics beyond flux density (e.g., static vs time-varying) not specified",
    "Mechanistic inference (ALAD gene expression activation) is suggested but not directly demonstrated in the abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "magnetic field",
    "porphyrin",
    "Rhodobacter sphaeroides",
    "ALAD",
    "5-aminolevulinic acid dehydratase",
    "anaerobic-light conditions",
    "static magnetic field",
    "0.3 T"
  ],
  "suggested_hubs": []
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 16233427

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