"Trade-off" in Antarctic bacteria: limnetic psychrotrophs concede multiple enzyme expressions for multiple metal resistance.
The present study examines the metal and antibiotic resistant bacteria in ice and water from lakes east and west of the Indian base camp (Maitri) in Antarctica. The isolates from western and eastern lakes showed distinct geographical differences in properties like metal resistance and enzyme expression. This may be attributed to high organic loading in the lakes on the west of Maitri. However, there was no marked geopraphical distinction in antibiotic resistance between the lakes. Bacteria from the lakes on the eastern side showed resistance to three or more metals including mercury while, those from the western were resistant to only 1-2 metals excluding mercury. Multiple enzyme expression was more pronounced in the lakes on the western side. On the eastern side multiple metal resistance was encountered in bacterial isolates associated with fewer enzyme expressions suggesting a "trade-off". Thus these Antarctic isolates from the east trade their ability to express multiple enzymes for developing resistance to multiple metals including mercury.
De Souza
Maria-Judith
MJ
Microbiology Laboratory, National Institute of Oceanography, Dona Paula, Goa, 403 004, India. mjudith@darya.nio.org
Loka Bharathi
P A
PA
Nair
Shanta
S
Chandramohan
D
D
D000864:Antarctic Regions; D001419:Bacteria / Q000201:enzymology / Q000378:metabolism*; D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial; D004352:Drug Resistance, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D005843:Geography; D006863:Hydrogen-Ion Concentration; D008628:Mercury / Q000032:analysis* / Q000494:pharmacology*; D008670:Metals / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D014867:Water / Q000737:chemistry; D014871:Water Microbiology
D008670:Metals; D014867:Water; D008628:Mercury