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Polyphasic characterisation of enrichment cultures from four hypersaline Inner Mongolian Lakes Shangmatala, Ejinnor, Bagaejinnor, and Erliannor.

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posted on 2009-07-09, 11:25 authored by Andrew Wallace
Enrichment media were formulated using analysis of the chemistry of the salt lakes Shangmatala, Ejinnor, Bagaejinnor, and Erliannor in Inner Mongolia. These enrichments contained yeast extract with either glycerol, betaine or starch as carbon sources. Samples of salt, brine and mud from the lakes were used as inoculants and enrichments were incubated at 37◦C for 18 days. A total of twenty different bacterial isolates were selected. All isolates were genotypically characterised by their 16S rDNA sequences, thirteen were phenotypically characterised. Despite the unusual carbon sources in the enrichment media analyses revealed that the majority of the isolates were related to organisms previously isolated from similar hypersaline sites. A large number have gene sequence identity to not validly published bacteria. Most isolates were Gram positive bacilli and cocci although there were a small number of Gram negative halomonads. Phenotypically the isolates were different. The majority of isolates could grow over a range of pH and salt concentrations. Isolates from the same lake appear to show similar ability to grow on different culture media. Three isolates significantly degraded starch. All isolates were susceptible to chloramphenicol and to ampicillin. Most isolates have an ribosomal RNA gene sequence identity above 99% to data base entries (lowest identities observed were isolate En1 98% to Bacillus sp. SL5-2 and isolate EJBB2 97% to Bacteroidetes bacterium KMM). It is therefore unlikely that many of the isolates represent new species.

History

Supervisor(s)

Grant, William

Date of award

2008-11-12

Awarding institution

University of Leicester

Qualification level

  • Masters

Qualification name

  • Mphil

Language

en

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