Extremophiles

, Volume 5, Issue 2, pp 135–144

Starch-hydrolyzing bacteria from Ethiopian soda lakes

  • Rita F. Martins
  • Wagied Davids
  • Waleed Al-Soud
  • Fredrik Levander
  • Peter Rådström
  • Rajni Hatti-Kaul
Original paper

DOI: 10.1007/s007920100183

Cite this article as:
Martins, R.F., Davids, W., Al-Soud, W. et al. Extremophiles (2001) 5: 135. doi:10.1007/s007920100183

Abstract.

Alkaliphilic bacteria were isolated from soil and water samples obtained from Ethiopian soda lakes in the Rift Valley area – Lake Shala, Lake Abijata, and Lake Arenguadi. Starch-hydrolyzing isolates were selected on the basis of their activity on starch agar plate assay. Sixteen isolates were chosen, characterized, and subjected to 16S rRNA gene sequence analysis. All the isolates were gram positive and catalase- and β-galactosidase positive. All isolates except one were motile endospore-forming rods and were found to be closely related to the Bacillus cluster, being grouped with Bacillus pseudofirmus, Bacillus cohnii, Bacillus vedderi, and Bacillus agaradhaerens. The one exception had nonmotile coccoid cells and was closely related to Nesterenkonia halobia. The majority of the isolates showed optimal growth at 37°C and tolerated salinity up to 10% (w/v) NaCl. Both extracellular and cell-bound amylase activity was detected among the isolates. The amylase activity of two isolates, related to B. vedderi and B. cohnii, was stimulated by ethylenediaminetetraacetic acid (EDTA) and inhibited in the presence of calcium ions. Pullulanase activity was expressed by isolates grouped with B. vedderi and also most of the isolates clustered with B. cohnii; cyclodextrin glycosyltransferase was expressed by most of the B. agaradhaerens-related strains. Minor levels of α-glucosidase activity were detected in all the strains.

Alkaliphiles Soda lake Starch hydrolysis 16S rRNA gene Bacillus species Nesterenkonia halobia 

Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  • Rita F. Martins
    • 1
  • Wagied Davids
    • 1
  • Waleed Al-Soud
    • 2
  • Fredrik Levander
    • 2
  • Peter Rådström
    • 2
  • Rajni Hatti-Kaul
    • 1
  1. 1.Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden
  2. 2.Department of Applied Microbiology, Center for Chemistry and Chemical Engineering, Lund University, Lund, Sweden
  3. 3.Present address: Department of Biochemistry, Stockholm Bioinformatics Center, Stockholm University, Stockholm, Sweden
  4. 4.Present address: Department of Bacteriology, Lund University, Lund, Sweden