The diversity, plant growth promoting and anti-microbial activities of endophytic actinomycetes isolated from Emblica officinalis Gaertn.

A total of 36 endophytic actinomycetes were isolated from roots, stems and leaves of Emblica officinalis Gaertn (Gooseberry) and identified as Streptomyces sp. (17), Micromonospora sp. (17) and Microbispora sp. (2). The distribution of endophytic actinomycetes in roots was (50%), stem (25%) and leaves (25%). Twenty five (69.4%) isolates were observed to produce indole-3-acetic acid ranging between 1.93±0.3 to 125.7±0.6 ?g/ml and sixteen isolates (44.4%) were able to solubilize phosphate in the range of 0.014±0.005 to 0.45±0.004 mg/ml. Streptomyces griseofuscus AL5 was producing maximum amount of IAA and Streptomyces cinereus AR3 solubilized maximum amount of phosphate. Thirteen isolates were producing catechol type of siderophores and fifteen were producing hydroxamate type of siderophores. The catechol siderophores production ranged from 6.2±0.3 to 55.6±0.4 µg/ml while hydroxamate siderophore were in the of range 8.0±0.2 to 91.3±0.5µg/ml. Streptomyces griseofuscus AL5 produced maximum catechol type siderophore (55.6±0.4 ?g/ml) and maximum hydroxamate- type of siderophore production was also observed in Streptomyces griseorubroviolaceus AR3 (88.6±0.7 ?g/ml). Fifteen isolates were active against one or the other phytopathogenic fungi. Streptomyces cinereus AR16 was displaying maximum antagonistic activity against five plant pathogenic fungi (Fusarium oxysporum, Rhizoctonia solani, Aspergillus niger, Alternaria brassicicola and Phytophthora dresclea). Twenty nine isolates were displaying the antibacterial activity against pathogenic bacteria (Aeromonas hydrophila, Yersinia enterocolitica, Staphylococcus aureus and Klebsiella sp.).