This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Liu, Y. Articles by Mah, R. A. Search for Related Content PubMed PubMed Citation Articles by Liu, Y. Articles by Mah, R. A. Agricola Articles by Liu, Y. Articles by Mah, R. A.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1985 March; 49(3): 608-613
Copyright © 1985, American Society for Microbiology. All Rights Reserved.

Methanosarcina mazei LYC, a New Methanogenic Isolate Which Produces a Disaggregating Enzyme

Yitai Liu, David R. Boone, Robert Sleat and Robert A. Mah^*

Division of Environmental and Occupational Health, School of Public Health, University of California, Los Angeles, California 90024

ABSTRACT

A methanogenic coccoid organism, Methanosarcina mazei LYC, was isolated from alkaline sediment obtained from an oil exploration drilling site. The isolate resembled M. mazei S-6 by exhibiting different morphophases during its normal growth cycle. It differed from M. mazei S-6 by undergoint a spontaneous shift from large, irregular aggregates of cells to small, individual, irregular, coccoid units. In batch cultures at pH 7.0, M. mazei LYC grew as aggregates during the early growth stage. As the batch culture began exponential growth, the cell aggregates spontaneously dispersed: the culture liquid became turbid, and myriads of tiny (diameter, 1 to 3 µm) coccoid units were observed under phase-contrast microscopy. Disaggregation apparently was accomplished by the production of an enzyme which hydrolyzed the heteropolysaccharide component of the cell wall; the enzyme was active on other Methanosarcina strains as well. Although the enzyme was active when tested at pH 6.0, it apparently was not produced at that pH: when strain LYC was grown at pH 6.0, only cell aggregates were present throughout batch growth. Individual coccoid cells of M. mazei LYC were sensitive to sodium dodecyl sulfate, but the large aggregates of cells were not. Strain LYC rapidly used H₂-CO₂, in addition to methanol, and mono-, di-, and trimethylamine as methanogenic substrates; acetate was used very slowly. Its optimum growth temperature was 40°C, and its optimum pH was 7.2.

^* Corresponding author.

Present address: Institute of Microbiology, Academia Sinica, Beijing, China.