Abstract
A mutant strain of Cellulomonas sp. CS1-17 was compared with Cellulomonas gelida 2480 as the cellulolytic component of a mixed culture which was responsible for the breakdown of wheat straw to support asymbiotic nitrogen fixation by Azospirillum brasilense Sp7 (ATCC 29145). Cellulomonas sp. strain CSI-17 was more efficient than was C. gelida in cellulose breakdown at lower oxygen concentrations and, in mixed culture with A. brasilense, it supported higher nitrogenase activity (C2H2 reduction) and nitrogen fixation with straw as the carbon source. Based on gravimetric determinations of straw breakdown and total N determinations, the efficiency of nitrogen fixation was 72 and 63 mg of N per g of straw utilized for the mixtures containing Cellulomonas sp. and C. gelida, respectively. Both Cellulomonas spp. and Azospirillum spp. exhibited a wide range of pH tolerance. When introduced into sterilized soil, the Cellulomonas sp.-Azospirillum brasilense association was more effective in nitrogen fixation at a pH of 7.0 than at the native soil pH (5.6). This was also true of the indigenous diazotrophic microflora of this soil. The potential implications of this work to the field situation are discussed.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Halsall D. M., Gibson A. H. Cellulose Decomposition and Associated Nitrogen Fixation by Mixed Cultures of Cellulomonas gelida and Azospirillum Species or Bacillus macerans. Appl Environ Microbiol. 1985 Oct;50(4):1021–1026. doi: 10.1128/aem.50.4.1021-1026.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lynch J. M. Phytotoxicity of acetic acid produced in the anaerobic decomposition of wheat straw. J Appl Bacteriol. 1977 Feb;42(1):81–87. doi: 10.1111/j.1365-2672.1977.tb00672.x. [DOI] [PubMed] [Google Scholar]