Integrated micro-biochemical approach for phytoremediation of cadmium and zinc contaminated soils Dinesh Mani a , Chitranjan Kumar a,b,n , Niraj Kumar Patel a a Sheila Dhar Institute of Soil Science, Department of Chemistry, University of Allahabad, Allahabad-211002, India b The National Academy of Sciences, India, 5 Lajpatrai Road, Allahabad-211002, India article info Article history: Received 13 June 2014 Received in revised form 17 September 2014 Accepted 18 September 2014 Keywords: Helianthus annuus L Heavy metals Phytoremediation Oilcake manure Microbes abstract The integrated potential of oilcake manure (OM), elemental sulphur (S 0 ), Glomus fasciculatum and Pseudomonas putida by growing Helianthus annuus L for phytoremediation of cadmium and zinc contaminated soils was investigated under pot experiment. The integrated treatment (2.5 g kg À1 OM, 0.8 g kg À1 S 0 and co-inoculation with G. fasciculatum and P. putida promoted the dry biomass of the plant. The treatment was feasible for enhanced cadmium accumulation up to 6.56 and 5.25 mg kg À1 and zinc accumulation up to 45.46 and 32.56 mg kg À1 in root and shoot, respectively, which caused maximum remediation efficiency (0.73 percent and 0.25 percent) and bioaccumulation factor (2.39 and 0.83) for Cd and Zn, respectively showing feasible uptake (in mg kg À1 dry biomass) of Cd (5.55) and Zn (35.51) at the contaminated site. Thus, authors conclude to integrate oilcake manure, S 0 and microbial co-inoculation for enhanced clean-up of cadmium and zinc-contaminated soils. & 2014 Elsevier Inc. All rights reserved. 1. Introduction Heavy metals cause environmental pollution as a result of anthropogenic activities such as mining, smelting, electroplating, energy and fuel production, power transmission, sludge dumping, military operations and un-hygienic approach of rapidly growing population such as application of heavy metal containing fertili- zers (i.e. superphosphate) or pesticides in agricultural soil (Rahimi et al., 2013; Thawornchaisit and Polprasert, 2009). They cause risk for primary and secondary consumers and ultimately to humans. Due to high Cd 2 þ mobility in the soil–plant ecosystem it can easily enter into food chain ultimately become hazardous to human beings, animals, plants and the whole environment (Pinto et al., 2004). Soil pollution by heavy metals is a global environmental problem as it has affected about 235 million hectares of arable land worldwide (Bermudez et al., 2012). 1.1. Remediation of heavy metals Contaminated soils may be remediated by physical, chemical or biological techniques but the physical or chemical methods can be very costly and also destructive to the soil ecosystem. Phytoextraction or hyperaccumulation, one of the biological tech- niques, has been proposed as an eco-friendly in situ remediation technology for the contaminated soils (Tandy et al., 2006). How- ever, the technique has several advantages and disadvantages as well (Erakhrumen and Agbontalor, 2007; Ghosh and Singh, 2005). Low biomass production in hyperaccumulator plants and suscept- ibility of root to high metal concentration lead to extension of researches on the use of microorganisms in order to develop application of phytoextraction and to make this method more feasible and economical (Glick, 2003; Ansari and Malik, 2007). The adequate restoration of the environment requires cooperation, integration and assimilation of biotechnological approaches along with traditional and ethical wisdom to conserve our natural resources (Mani and Kumar, 2014). 1.2. Microbe assisted phytoremediation The use of rhizospheric microbes such as arbuscular mycor- rhizal fungi (AMF) in phyto/bioremediation of heavy metal con- taminated soils has attracted more attention recently. AMF provide direct links between soil and roots and consequently may have an essential contribution to plant growth by improving mineral nutrition and enhancing plant tolerance to stress (Gaur and Adholeya, 2004; Juwarkar and Singh, 2010; Banni and Faituri, 2013). Furthermore, AMF also affect metal uptake by plants from soil and translocation from root to shoot, however, mycorrhizal effects may depend on elements, plant and fungal species/ecotypes Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/ecoenv Ecotoxicology and Environmental Safety http://dx.doi.org/10.1016/j.ecoenv.2014.09.019 0147-6513/& 2014 Elsevier Inc. All rights reserved. n Corresponding author at: The National Academy of Sciences, India, 5 Lajpatrai Road, Allahabad-211002, India. E-mail addresses: dineshmanidsc@gmail.com (D. Mani), chitranjan.alld@gmail.com (C. Kumar), nirajkumarpatel0@gmail.com (N. Kumar Patel). Ecotoxicology and Environmental Safety 111 (2015) 86–95