Aldehyde dehydrogenase expression in Metaphire posthuma as a bioindicator to monitor heavy metal pollution in soil.

Raju Panday,Padam Shekhar Bhatt,Tribikram Bhattarai,Kumudini Shakya,Lakshmaiah Sreerama

doi:10.1186/s13104-016-2297-7

Abstract

BackgroundSoil contamination and associated pollution plays a detrimental role in soil flora and fauna. Soil is processed and remodeled by subterranean earthworms, accordingly are referred to as soil chemical engineers. These worms, besides processing carbon and nitrogen, serve as minors for processing metals. In heavy metal contaminated soils, they accumulate heavy metals, which in turn cause altered gene expression, including aldehyde dehydrogenase (ALDH) enzymes. This study explores the possibility of ALDH expression in earthworms as a novel biomarker for the heavy metal contamination of soil.ResultsEarthworms cultured in contaminated soils accumulated significantly higher levels of Pb and Cd. Similarly, significantly higher levels of ALDH enzyme activities were observed in earthworms cultured in soils contaminated with Pb and Cd. The ALDH activity was found to be highest in worms cultured in 5 ppm heavy metal contaminated soils. Although, ALDH activities decreased as the heavy metal concentration in soil increased, they were significantly higher when compared to control worms cultured in uncontaminated soils. The accumulation of heavy metal in earthworms measured after 28 days decreased as the heavy metal concentration in soil increased.ConclusionsLevels of ALDH expression correlated with total Pb and Cd concentration in the earthworm tissue. This study showed that the ALDH activity in earthworms could potentially be used as a biomarker to show heavy metal pollution in soil.

Highlights

Soil contamination and associated pollution plays a detrimental role in soil flora and fauna
Specific aldehyde dehydrogenase (ALDH) activity increased with time in all treatments
Specific ALDH activity in first week samples for worms grown on 20 ppm treatment of Pb (117.2 mIU/mg protein) was not statistically significant (Duncan: P value = 0.612) than that of the control (119.52 mIU/mg protein)

Summary

Introduction

Soil contamination and associated pollution plays a detrimental role in soil flora and fauna. Soil is processed and remodeled by subterranean earthworms, are referred to as soil chemical engineers These worms, besides processing carbon and nitrogen, serve as minors for processing metals. Soil is processed and remodeled by subterranean earthworms, they are referred to as soil chemical engineers These worms, besides processing carbon and nitrogen, serve as minors for processing metals, including heavy metals in contaminated soils [1, 2]. Earthworms have been shown to accumulate relatively high concentrations of heavy metals by either active or passive uptake mechanisms [1, 2]. Heavy metals such as lead (Pb) and cadmium (Cd) induce oxidative. It is already known that exposure to sub-lethal concentrations of cadmium leads to over expression of a Cd- specific ALDH protein in Enchytraeus buchholzi [12] as well as cultured human tumor cells [13]

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Conclusion