Counter Effect of Trichoderma harzianum Rifai. Against Cr (VI)

Abstract

Industrial and sewage water ejection in river and streams on daily basis and wide use of heavy metal is contaminating our surroundings. Among all the valences, Cr (VI) is regarded as a hazardous ion, which contaminates groundwater and can be transferred through the food chain In-vitro study was carried out in laboratory in which impact of Cr (VI) on Trichoderma harzianum was studied. For those two experiments i.e., solid medium assay and liquid broth assay were conducted. In solid medium assay, the radial growth, morphological alterations (appearance of colony, changes in the morphologies of spores and hyphae) in T. harzianum and inhibition zone under the stress of Cr (VI) at different doses i.e., 0, 1000, 2000, 3000, 4000 and 5000 ppm were studied. The results showed that radial growth was insignificantly reduced at highest dose (5000 ppm) i.e., 3.3% as compared to control. Moreover, no inhibition zone formed, and the mycelial pattern of tested fungi was crossing the disc zones. However, at 5000 ppm of Cr (VI), about 0.2 mm of concentric zone was observed. While no phialides were observed at higher doses of Cr (VI). Furthermore, in liquid broth experiment, mycelial growth, and biochemical attributes [Total protein content (TPC), Peroxidase (POX) and Catalase (CAT) activities] were studied after 7 days of incubation. The results revealed that the fresh and dry weight of T. harzianum was increased up to -200% comparison to control. The level of TPC, POX AND CAT increased by -10 % to -94% with the increasing concentration of Cr (VI) i.e., 1000 to 5000 ppm. Thus, the findings showed that T. harzianum could be used as bioremidier against Cr (VI). Further in- situ studies need to be taken to eradicate the presence of heavy metals in the environment by using fungus for bioremediation purpose in future.