The Use of Shredded Asbestos in Methane Fermentations

Our plain-English summary of The Use of Shredded Asbestos in Methane Fermentations, by C.R. Breden, A.M. Buswell (Journal of Bacteriology, 1933).

The study

• Authors: C.R. Breden, A.M. Buswell
• Journal: Journal of Bacteriology
• Published: 1933;26(4):379-83
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

The use of shredded asbestos to form an artificial mechanical support for the bacteria in the mixed-culture methane fermentation of soluble substances has solved the problem of successful small inoculations. It has also completely displaced the use of sludge solids in the quantitative carbon balance studies in progress in this laboratory.

PubMed has no abstract for this study. This is the authors' abstract, copied from the article.

In plain English

This 1933 laboratory study from the State Water Survey in Urbana, Illinois, was about bacteria, not human health. The authors used asbestos (fiber type not named) to support methane-producing bacteria from sewage sludge digestion tank liquid. In a first test, a bottle inoculated with material caught on a thin asbestos mat produced 200 cc of gas in three days. Two bottles inoculated with settled solids produced 30 to 40 cc each. In a second test, four of eight bottles of filtered liquor received 5 grams of finely shredded asbestos. Each produced 150 to 200 cc of gas in three weeks; the others produced only a few bubbles. One trial using sand failed. Under the microscope, many fibers were covered with bacteria and showed no visible dissolving. Cultures in a sterile medium with acid-washed asbestos were carried through many transfers, each from a single loop of fiber-free liquid. The authors concluded that shredded asbestos had solved the problem of successful small inoculations in mixed-culture methane fermentation of soluble substances. They also stated that the fibers' exact role was by no means clear.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory bacteriology experiments: fermentation bottles and test tube cultures
• Who was studied: Mixed bacterial cultures from the overflow liquor of a sewage sludge digestion tank, studied at the State Water Survey, Urbana, Illinois (article received January 1933). The main experiment used eight fermentation bottles. No people were studied.
• Exposure: Finely shredded asbestos (fiber type not stated) added to cultures: 5 grams per 200 cc bottle in the main experiment, and 15 to 25 grams of acid-washed asbestos per liter in a sterile medium. Calcium acetate was the substrate.
• Main results:
  • In the first test, the bottle inoculated with an asbestos mat used to filter suspended material produced 200 cc of gas containing methane in three days. Each of the two bottles inoculated with settled solids produced 30 to 40 cc.
  • In the second test, each of the 4 bottles with asbestos produced 150 to 200 cc of gas containing methane in three weeks. The other 4 bottles, without asbestos, produced no more than a few bubbles.
  • One experiment using sand instead of asbestos failed.
  • Test tube cultures in the sterile asbestos medium were carried through many transfers. Each transfer used only one loop of fiber-free liquid from the previous culture as inoculum.
  • Under the microscope, many asbestos fibers were covered with bacteria.
  • The authors observed no dissolution of the asbestos fibers.
  • Control cultures of the same medium without asbestos, sealed against air, produced little or no gas. The authors took this to indicate that the asbestos was not acting by protecting the bacteria from oxygen.
• The authors' conclusion: The authors concluded that shredded asbestos, used as an artificial mechanical support for the bacteria, solved the problem of successful small inoculations in the mixed-culture methane fermentation of soluble substances. They added that it had replaced sludge solids in their laboratory's studies.
• Limitations the authors state:
  • The authors stated that the exact role of the asbestos (or cellulose) fibers in the fermentation was not clear.

Related studies

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• Elucidation of the Structure-Activity Relationship for Cu-Erionite in the Direct Conversion of Methane to Methanol: An Operando XAS Study — J. Zhu, V.L. Sushkevich, et al. (2025)
• Division for Planetary Sciences meeting: Martian methane: rocky birth, then gone with the wind? — G. Schilling (2005)

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