3 research outputs found
Museum genomics provide insight into the extinction of a specialist North American warbler species
Museum genomics provide an opportunity to investigate population demographics of extinct species, especially valuable when research prior to extinction was minimal. The Bachman’s warbler (Vermivora bachmanii) is hypothesized to have gone extinct due to loss of its specialized habitat. However, little is known about other potential contributing factors such as natural rarity or changes to connectivity following habitat fragmentation. We examined mitochondrial DNA (mtDNA) and genome-wide SNPs using specimens collected from breeding and migration sites across the range of the Bachman’s warbler. We found no signals of strong population structuring across the breeding range of Bachman’s warblers in both mtDNA and genome-wide SNPs. Thus, long-term population isolation did not appear to be a significant contributor to the extinction of the Bachman’s warbler. Instead, our findings support the theory that Bachman’s warblers underwent a rapid decline likely driven by habitat destruction, which may have been exacerbated by the natural rarity, habitat specificity and low genetic diversity of the species
Isolation of Lactic Acid Bacteria with High Biological Activity from Local Fermented Dairy Products
The thirty-two strains of lactic acid bacteria were isolated from the Mongolian traditional fermented
dairy products, among them 25 strains show antimicrobial activity against test microorganisms including
Escherichia coli
,
Staphylococcus aureus
,
Enterococcus faecalis
,
Pseudom
о
nas
aeruginosa
. Protease
sensitivity assay demonstrated that the antimicrobial substances produced by isolates
А
23,
Т
2 are
bacteriocins as their antibacterial activities were eliminated completely after treatment with protease.
Identi
fi
cation of bacteria is being carried out. Among the isolates 22 strains show protease enzyme
producing activity. The selected strains isolated from mare’s fermented milk (airag or kumis) and
yoghurt (tarag) show the speci
fi
c protease activity from 7.9
μ
g/ml to 11.9
μ
g/ml. The strain T2, isolated
from yoghurt exhibited the highest proteolytic activity