• Ms. Vaishali Mane
• Dr. Deepak Thakare
• Dr. Shubhada Nayak

Abstract: This work aimed to evaluate stress tolerance of nine Rhizobium isolates obtained from Sesbania bispinosa root samples collected from Navi Mumbai coastal region with reference to heavy metals, fungicide, antibiotics and bile salts. Effects of 100µg – 500µg concentrations of 13 heavy metal salts (Ag2SO4, KI, Co3(PO4)2, MnCl2,(NH4)2MoO4, LiCl, ZnSO4, CuSO4, FeSO4, K2Cr2O7, CdCl2, HgCl2, Pb(CH3COO)2) on the growth of 9 isolates of Rhizobium.The results clearly show different levels of intrinsic tolerance of Rhizobium strains to the applied concentrations of heavy metals in terms of growth. All the strains displayed the lowest intrinsic tolerance when growing on 100µg of ZnSO4, CuSO4, K2Cr2O7, CdCl2 & HgCl2while most strains were found to show the highest intrinsic tolerance of 500µg of Co3 (PO4)2, MnCl2,(NH4)2MoO4, LiCl, KI and Pb(CH3COO)2.The effect of the fungicide on the isolates of Rhizobium was variable, depending on the concentration of fungicide Bavistine and the isolate. All of the Rhizobium isolates showed resistance to the 10µg whereas 55% of isolates showed tolerance upto 30 µg/disc fungicide. One isolate could tolerate 40 µg/disc fungicide. Effect of different concentrations of 32 antibiotics on growth of Sesbania Rhizobium spp was studied. Nearly 90% isolates showed highest intrinsic resistance to Augmentine, Bacitracin, Cefuroxime, Cephotoxime, Ceptrixime, Erythromycin, Furozolidone, Gentamycin, Kanamycin, Lincomycin, Neomycin,Optochin, Penicillin G & Trimethoprim and around 55% isolates exhibited intrinsic resistance to some antibiotics like Chloromphenicol, Ciprofloxacin, Methicillin, Pipericillin, & Ofloxacine. Highest intrinsic tolerance to surfactant i.e. 10% sodium taurocholate used in this study was shown by 3 isolates. Highest tolerance to anionic detergent (sodium lauryl sulphate) upto 6% was exhibited by isolate IS-02. In future these stress tolerant Rhizobium spp. isolates can be successfully employed for biotechnological applications in terms of bioremediation and biomineralization.

Keywords: Rhizobium, Sesbania bispinosa, Heavy metals, Fungicides, Antibiotics, surfactant, sodium taurocholate, stress tolerance

"STUDIES ON STRESS TOLERANCE OF RHIZOBIUM ISOLATED FROM SESBANIA WITH REFERENCE TO HEAVY METALS, FUNGICIDE, ANTIBIOTICS, BILE SALTS AND ANIONIC DETERGENTS.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 4, page no.931-940, April-2019, Available :http://www.jetir.org/papers/JETIR1904G45.pdf

"STUDIES ON STRESS TOLERANCE OF RHIZOBIUM ISOLATED FROM SESBANIA WITH REFERENCE TO HEAVY METALS, FUNGICIDE, ANTIBIOTICS, BILE SALTS AND ANIONIC DETERGENTS.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 4, page no. pp931-940, April-2019, Available at : http://www.jetir.org/papers/JETIR1904G45.pdf