Magnetotactic advantage in stable sediment by long-term observations of magnetotactic bacteria in Earth's field, zero field and alternating field

PAPER manual 2022 Animal study Effect: mixed Evidence: Low

Read original paper → DOI: 10.1371/journal.pone.0263593 Evidence Lab

Abstract

Magnetotactic advantage in stable sediment by long-term observations of magnetotactic bacteria in Earth's field, zero field and alternating field Xuegang Mao, Ramon Egli, Xiuming Liu, Lijuan Zhao. Magnetotactic advantage in stable sediment by long-term observations of magnetotactic bacteria in Earth's field, zero field and alternating field. PLoS One. 2022 Feb 24;17(2):e0263593. doi: 10.1371/journal.pone.0263593. Abstract Magnetotactic bacteria (MTB) rely on magnetotaxis to effectively reach their preferred living habitats, whereas experimental investigation of magnetotactic advantage in stable sediment is currently lacking. We studied two wild type MTB (cocci and rod-shaped M. bavaricum) in sedimentary environment under exposure to geomagnetic field in the laboratory, zero field and an alternating field whose polarity was switched every 24 hours. The mean concentration of M. bavaricum dropped by ~50% during 6 months in zero field, with no clear temporal trend suggesting an extinction. Cell numbers recovered to initial values within ~1.5 months after the Earth's field was reset. Cocci displayed a larger temporal variability with no evident population changes in zero field. The alternating field experiment produced a moderate decrease of M. bavaricum concentrations and nearby extinction of cocci, confirming the active role of magnetotaxis in sediment and might point to a different magnetotactic mechanism for M. bavaricum which possibly benefited them to survive field reversals in geological periods. Our findings provide a first quantification of magnetotaxis advantage in sedimentary environment.== Open access paper: journals.plos.org

AI evidence extraction

At a glance

Study type

Animal study

Effect direction

mixed

Population

Magnetotactic bacteria (wild type cocci and rod-shaped M. bavaricum) in sedimentary environment (laboratory)

Sample size

—

Exposure

ELF laboratory magnetic field manipulation · 6 months (zero field); alternating field with polarity switched every 24 hours (duration not stated)

Evidence strength

Low

Confidence: 74% · Peer-reviewed: yes

Main findings

In zero field, mean concentration of M. bavaricum dropped by ~50% over 6 months and recovered to initial values within ~1.5 months after Earth's field was reset; cocci showed larger temporal variability with no evident population changes in zero field. Under an alternating field with polarity switched every 24 hours, M. bavaricum showed a moderate decrease while cocci approached extinction.

Outcomes measured

Bacterial concentration/cell numbers over time
Population persistence/extinction indicators under different magnetic field conditions

Limitations

Sample size not reported in abstract
Magnetic field strength/amplitude not reported in abstract
Duration of the alternating-field condition not specified in abstract
Laboratory sedimentary environment; generalizability to natural settings not established in abstract

View raw extracted JSON

{
    "study_type": "animal",
    "exposure": {
        "band": "ELF",
        "source": "laboratory magnetic field manipulation",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "6 months (zero field); alternating field with polarity switched every 24 hours (duration not stated)"
    },
    "population": "Magnetotactic bacteria (wild type cocci and rod-shaped M. bavaricum) in sedimentary environment (laboratory)",
    "sample_size": null,
    "outcomes": [
        "Bacterial concentration/cell numbers over time",
        "Population persistence/extinction indicators under different magnetic field conditions"
    ],
    "main_findings": "In zero field, mean concentration of M. bavaricum dropped by ~50% over 6 months and recovered to initial values within ~1.5 months after Earth's field was reset; cocci showed larger temporal variability with no evident population changes in zero field. Under an alternating field with polarity switched every 24 hours, M. bavaricum showed a moderate decrease while cocci approached extinction.",
    "effect_direction": "mixed",
    "limitations": [
        "Sample size not reported in abstract",
        "Magnetic field strength/amplitude not reported in abstract",
        "Duration of the alternating-field condition not specified in abstract",
        "Laboratory sedimentary environment; generalizability to natural settings not established in abstract"
    ],
    "evidence_strength": "low",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "magnetotactic bacteria",
        "magnetotaxis",
        "geomagnetic field",
        "zero field",
        "alternating magnetic field",
        "sediment",
        "field reversals"
    ],
    "suggested_hubs": []
}

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AI-extracted fields are generated from the abstract/metadata and may be incomplete or incorrect. This content is for informational purposes only and is not medical advice.

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