Bacillus polymyxa stimulates increased Rhizobium etli populations and nodulation when co-resident in the rhizosphere of Phaseolus vulgaris |
| |
| Authors: | Daniel J. Petersen Murali Srinivasan Chris P. Chanway |
| |
| Affiliation: | School of Biomolecular and Biomedical Sciences, Faculty of Science and Technology, Griffith University, Nathan, Brisbane, Qld. 4111, Australia; Department of Biochemistry, University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia; Sugar Research Institute, Nebo Road, Mackay, QLD 4741, Australia |
| |
| Abstract: | Abstract A Gram-negative sporulating thermophilic anaerobe, designated AB11Ad, was isolated from the heated waters of the Great Artesian Basin of Australia. It grew on a variety of carbohydrates including glucose, starch, and dextran and produced a thermostable and thermoactive extracellular endo-dextranase. The enzyme was produced more actively under pH controlled continuous culture conditions than under batch conditions. Ammonium sulfate precipitated crude dextranase exhibited a temperature optimum of 70 °C and a pH optimum between 5 and 6. The half life was ~ 6.5 h at 75 °C and 2 h at 80 °C at pH 5.0 and in the absence of added dextran. 16S rRNA sequence analysis indicated that isolate AB1 lAd was a member of the genus Thermoanaerobacter . |
| |
| Keywords: | Thermophilic bacteria Great Artesian Basin of Australia Thermal aquifer Thermoanaerobacter Thermostable dextranase |
|
|
