Exploring the bioremediation potential of nonpathogenic Pb-resistant strain Klebsiella pneumoniae in Oreochromis niloticus

Abstract

Lead (Pb) has been released into the environment due to increased urbanization in recent years, causing severe environmental impacts on soil and water. Therefore, the goal of the present study is to investigate the bio-remedial potential of the Pb-resistant strain Klebsiella pneumoniae PbS3A2 against Pb induced toxicity in Oreochromis niloticus. For this purpose, O. niloticus body weight (14.5 ± 0.19) and body length (9.8 ± 0.08) fishes were taken and divided into three groups (Control (To), lead (T1), and Lead +K. pneumoniae (T2) groups). The lead group was subjected to Pb (1 mg L−1), and bacterial groups were exposed to Pb + K. pneumoniae (1.5 × 108 CFU/ml) for four weeks. The outcomes revealed that waterborne Pb had lethal effect on Fish growth performance, body composition, hemato-biochemical parameters, enzymes activity, histopathological alteration, along with elevated Pb accumulation in various tissues (gills, liver & muscles). Conversely, bioremediated with K. pneumoniae effectively mitigated the toxic potential of Pb and improved fish longevity. Notably, K. pneumoniae (1.5 × 108 CFU/ml) significantly (p ≤ 0.05) boosted growth, body composition, reversed blood parameters, restored enzymes function in the liver and gut, reversed the histopathological alteration as well as ameliorates the Pb accumulation in tissues. Thus, the findings of the current study showed that K. pneumoniae is effective for the bioremediation of Pb from industrial effluent and preventing Pb induced toxicity in aquaculture.