Isolation and identification of Aeromonas caviae strain KS-1 as TBTC- and lead-resistant estuarine bacteria

Environ Monit Assess. 2013 Jun;185(6):5243-9. doi: 10.1007/s10661-012-2940-2. Epub 2012 Nov 8.

Abstract

Tributyltin chloride (TBTC)- and lead-resistant estuarine bacterium from Mandovi estuary, Goa, India was isolated and identified as Aeromonas caviae strain KS-1 based on biochemical characteristics and FAME analysis. It tolerates TBTC and lead up to 1.0 and 1.4 mM, respectively, in the minimal salt medium (MSM) supplemented with 0.4 % glucose. Scanning electron microscopy clearly revealed a unique morphological pattern in the form of long inter-connected chains of bacterial cells on exposure to 1 mM TBTC, whereas cells remained unaltered in presence of 1.4 mM Pb(NO₃)₂ but significant biosorption of lead (8 %) on the cell surface of this isolate was clearly revealed by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. SDS-PAGE analysis of whole-cell proteins of this lead-resistant isolate interestingly demonstrated three lead-induced proteins with molecular mass of 15.7, 16.9 and 32.4 kDa, respectively, when bacterial cells were grown under the stress of 1.4 mM Pb (NO₃)₂. This clearly demonstrated their possible involvement exclusively in lead resistance. A. caviae strain KS-1 also showed tolerance to several other heavy metals, viz. zinc, cadmium, copper and mercury. Therefore, we can employ this TBTC and lead-resistant bacterial isolate for lead bioremediation and also for biomonitoring TBTC from lead and TBTC contaminated environment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Aeromonas caviae / isolation & purification
  • Aeromonas caviae / physiology*
  • Biodegradation, Environmental
  • India
  • Lead / analysis
  • Lead / toxicity*
  • Trialkyltin Compounds / analysis
  • Trialkyltin Compounds / toxicity*
  • Water Pollutants, Chemical / analysis
  • Water Pollutants, Chemical / toxicity*

Substances

  • Trialkyltin Compounds
  • Water Pollutants, Chemical
  • Lead
  • tributyltin