title: Isolation, characterization and beneficial effects of rice associated plant growth promoting bacteria from Zanzibar soils.
abstract: This study was undertaken to isolate and characterize plant growth promoting bacteria (PGPB) occurring in four soils of Zanzibar, Tanzania as well as to evaluate their potential use as biofertilizers for rice. A total of 12 PGPB strains were isolated from rice and studied for growth characteristics, carbon/nitrogen source utilization patterns using QTS-24 kits, phosphate solubilization, indole acetic acid (IAA) production, antibiotic resistance patterns and growth at different pH, temperature and salt concentrations. All the isolates were motile and gram negative except Z3-4. Acetylene reduction activity was detected in all isolates ranging from 5.9-76.4 nmole C2H2 reduced/h x mg protein while 9 isolates produced IAA ranged from 20-90.8 mg/l. Most of the isolates showed resistance against different environmental stresses like 10-40 degrees C temperature, 0.2-1 M salt concentration and 4-8.5 pH range. Only one isolate Z2-7 formed clear zones on Pikovskaia's medium showing its ability to solubilize phosphates. Z3-2 was used to develop fluorescent antibodies to check the cross reactivity of the isolates. Inoculation of these bacterial isolates resulted in higher plant biomass, root area, and total N and P contents on Tanzanian rice variety BKN PRAT3036B under controlled conditions. Bacillus sp. Z3-4 and Azospirillum sp. Z3-1 are effective strains and, after further testing under field conditions, can be used for inoculum production of rice in Tanzania. The plant growth promoting effects of these PGPRs suggest that these can be exploited to improve crop productivity of rice in Tanzania.
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, P.O. Box 577, Jhang Road, Faisalabad 3800-Pakistan.
authors.forename: Sumera
authors.initials: S
authors.lastname: Yasmin
authors.forename: M Abdul
authors.initials: MA
authors.lastname: Rahman Bakar
authors.forename: Kausar A
authors.initials: KA
authors.lastname: Malik
authors.forename: Fauzia Y
authors.initials: FY
authors.lastname: Hafeez
mesh_terms: D000114:Acetylene / Q000378:metabolism; D000222:Adaptation, Physiological; D016949:Azospirillum / Q000145:classification / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D001407:Bacillus / Q000145:classification / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D001419:Bacteria / Q000145:classification / Q000166:cytology / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D018533:Biomass; D002244:Carbon / Q000378:metabolism; D004351:Drug Resistance; D006863:Hydrogen-Ion Concentration; D007210:Indoleacetic Acids / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology*; D010710:Phosphates / Q000378:metabolism; D012988:Soil Microbiology; D013636:Tanzania; D013696:Temperature
chemical_list: D007210:Indoleacetic Acids; D010710:Phosphates; C030737:indoleacetic acid; D002244:Carbon; D009584:Nitrogen; D000114:Acetylene