Starch hydrolysing Bacillus halodurans isolates from a Kenyan soda lake.
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Date
2004Author
Hashim, S.O
Delgado, O
Hatti-Kaul, R
Mulaa, F.J
Mattiasson, B
Type
ArticleLanguage
enMetadata
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Fourteen obligate alkaliphilic and halotolerant bacterial isolates, exhibiting extracellular amylase activity at 55 degrees C and pH 10, were isolated from hot springs around Lake Bogoria, Kenya. From 16S rDNA sequence analysis, nine isolates shared 100% identity with Bacillus halodurans strain DSM 497T, while the rest shared 99% identity with alkaliphilic Bacillus species A-59. PCR of the intergenic spacer region between 16S and 23S rRNA genes (ISR-PCR) divided the isolates into two groups, while tDNA-PCR divided them into three groups. Bacillus halodurans DSM 497T had a different ISR pattern from the isolates, while it had a tDNA-PCR profile similar to the group that shared 99% identity with alkaliphilic Bacillus species A-59. All isolates hydrolysed soluble starch as well as amylose, amylopectin and pullulan. The amylase activity (1.2-1.8 U ml(-1)) in the culture broths had an optimum temperature of 55-65 degrees C, was stimulated by 1 mm Ca2+, and was either partially (16-30%) or completely inhibited by 1 mM EDTA. Activity staining of the cell-free culture supernatant from the isolates revealed five alkaline active amylase bands.
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http://hinari-gw.who.int/whalecomwww.ncbi.nlm.nih.gov/whalecom0/pubmed/15269555http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/17502
Citation
Biotechnol Lett. 2004 May;26(10):823-8Collections
- Faculty of Health Sciences (FHS) [10378]