Characterization of ACC Deaminase producing B. cepacia, C. feurendii and S. marcescens for Plant Growth Promoting activity

Abstract

Finding solutions to global issues like food security entails greater use of chemicals fertilizers, pesticides, fungicides etc. posing serious risks of soil salinity, heavy metal bioaccumulation. PGPR produce enzyme ACC deaminase which degrades (ACC) 1-aminocyclopropane-1-carobylic acid the immediate precursor of the plant growth hormone ethylene, into α-ketobutyrate and ammonia, thus lowering the level of ethylene in a developing or stressed plant. In the present study, three rhizobacterial strains were isolated from rhizospheric soil of mustard plant in Allahabad region. On the basis of morphological, biochemical, molecular characterization, these isolates were identified as Burkholderia cepacia, Citrobacter feurendii I and Serratia marcescens. The 16S rRNA gene sequences of B. cepacia, and S. marcescens, C. feurendii were submitted to NCBI GenBank under accession numbers LC169488, LC169489, LC169490, respectively, followed by their phylogenetic analysis predicting significant sequence homology with related sequences of NCBI Gene bank. After isolation ACC Deaminase enzyme was partially purified and molecular weight was determined 35-42 kDa. Screeningthe rhizobacterial isolates for plant growth promoting traits (ACC deaminase activity assay; Ninhydrin assay; Phosphate solubilization assay; Production of Siderophore, IAA, Gibberellic Acid, HCN, Ammonia) revealed thatS. marcescens, C. feurendii and B. cepacia are capable of producing ACC deaminase and solubilizing phosphate along with exhibiting various other plant promoting traits.