Natronococcus amylolyticus sp. nov., a haloalkaliphilic archaeon

Area of Science:

• Microbiology
• Archaea research
• Biochemistry

Background:

• Haloalkaliphilic archaea inhabit extreme environments like soda lakes.
• Natronococcus occultus is the only previously described species in the genus Natronococcus.
• Strain Ah-36T was isolated from Lake Magadi, Kenya, and produces alpha-amylase.

Purpose of the Study:

• To characterize Natronococcus sp. strain Ah-36T.
• To determine its taxonomic position within the Natronococcus genus.
• To propose a new species designation for strain Ah-36T.

Main Methods:

• Isolation and cultivation of haloalkaliphilic archaea.
• Analysis of polar lipid composition.
• 16S rRNA gene sequencing for phylogenetic analysis.
• DNA-DNA hybridization for homology studies.

Main Results:

• Strain Ah-36T exhibited unique polar lipid profiles, lacking phosphatidylglycero-(cyclo-) phosphate.
• 16S rRNA gene sequence analysis showed 96.4% similarity to Natronococcus occultus.
• DNA homology studies revealed low DNA-DNA relatedness between strain Ah-36T and N. occultus.
• Strain Ah-36T was identified as a distinct species based on genotypic and phenotypic data.

Conclusions:

• Natronococcus sp. strain Ah-36T represents a new species, Natronococcus amylolyticus.
• This finding expands the known diversity of the Natronococcus genus.
• Natronococcus amylolyticus is an alpha-amylase-producing haloalkaliphilic archaeon from a Kenyan soda lake.