title: Development of alginate-based aggregate inoculants of Methylobacterium sp. and Azospirillum brasilense tested under in vitro conditions to promote plant growth.
abstract: OBJECTIVE
  To develop co-aggregated bacterial inoculant comprising of Methylobacterium oryzae CBMB20/Methylobacterium suomiense CBMB120 strains with Azospirillum brasilense (CW903) strain and testing their efficiency as inoculants for plant growth promotion (PGP).
  
  
  RESULTS
  Biofilm formation and co-aggregation efficiency was studied between A. brasilense CW903 and methylobacterial strains M. oryzae CBMB20 and M. suomiense CBMB120. Survival and release of these co-aggregated bacterial strains entrapped in alginate beads were assessed. PGP attributes of the co-aggregated bacterial inoculant were tested in tomato plants under water-stressed conditions. Results suggest that the biofilm formation efficiency of the CBMB20 and CBMB120 strains increased by 15 and 34%, respectively, when co-cultivated with CW903. Co-aggregation with CW903 enhanced the survivability of CBMB20 strain in alginate beads. Water stress index score showed least stress index in plants inoculated with CW903 and CBMB20 strains maintained as a co-aggregated inoculant.
  
  
  CONCLUSIONS
  This study reports the development of co-aggregated cell inoculants containing M. oryzae CBMB20 and A. brasilense CW903 strains conferred better shelf life and stress abatement in inoculated tomato plants.
  
  
  CONCLUSIONS
  These findings could be extended to other PGP bacterial species to develop multigeneric bioinoculants with multiple benefits for various crops.
authors.affiliation: Department of Agricultural Chemistry, Chungbuk National University, Cheongju, Korea.|Department of Microbiology, School of Life Sciences, Vels University, Chennai, India.
authors.forename: M M
authors.initials: MM
authors.lastname: Joe
authors.affiliation: Department of Microbiology, Indira Gandhi College of Arts and Science, Kathirkamam, Pondicherry, India.
authors.forename: V S
authors.initials: VS
authors.lastname: Saravanan
authors.affiliation: Department of Biological Sciences, Inha University, Incheon, Korea.
authors.forename: M R
authors.initials: MR
authors.lastname: Islam
authors.affiliation: Department of Agricultural Chemistry, Chungbuk National University, Cheongju, Korea.
authors.forename: T
authors.initials: T
authors.lastname: Sa
mesh_terms: D000464:Alginates / Q000737:chemistry*; D015806:Azospirillum brasilense / Q000201:enzymology / Q000502:physiology* / Q000648:ultrastructure; D018441:Biofilms / Q000254:growth & development*; D003681:Dehydration / Q000517:prevention & control; D055864:Droughts; D005030:Ethylenes / Q000378:metabolism; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006868:Hydrolysis; D015227:Lipid Peroxidation; D018551:Solanum lycopersicum / Q000254:growth & development* / Q000382:microbiology; D008315:Malondialdehyde / Q000378:metabolism; D020580:Methylobacterium / Q000201:enzymology / Q000502:physiology* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D009195:Peroxidase / Q000378:metabolism; D012987:Soil / Q000737:chemistry
chemical_list: D000464:Alginates; D005030:Ethylenes; D006603:Hexuronic Acids; D012987:Soil; D008315:Malondialdehyde; D020723:Glucuronic Acid; C036216:ethylene; D009195:Peroxidase
keywords: ACC deaminase; Azospirillum brasilense; Methylobacterium oryzae; Plant growth-promoting bacteria; biofilm; co-aggregation; water stress