RESUMO
Present study deals with the isolation of rhizobacteria and selection of plant growth promoting bacteria from Crocus sativus (Saffron) rhizosphere during its flowering period (October-November). Bacterial load was compared between rhizosphere and bulk soil by counting CFU/gm of roots and soil respectively, and was found to be ~40 times more in rhizosphere. In total 100 bacterial isolates were selected randomly from rhizosphere and bulk soil (50 each) and screened for in-vitro and in vivo plant growth promoting properties. The randomly isolated bacteria were identified by microscopy, biochemical tests and sequence homology of V1-V3 region of 16S rRNA gene. Polyphasic identification categorized Saffron rhizobacteria and bulk soil bacteria into sixteen different bacterial species with Bacillus aryabhattai (WRF5-rhizosphere; WBF3, WBF4A and WBF4B-bulk soil) common to both rhizosphere as well as bulk soil. Pseudomonas sp. in rhizosphere and Bacillus and Brevibacterium sp. in the bulk soil were the predominant genera respectively. The isolated rhizobacteria were screened for plant growth promotion activity like phosphate solubilization, siderophore and indole acetic acid production. 50 % produced siderophore and 33 % were able to solubilize phosphate whereas all the rhizobacterial isolates produced indole acetic acid. The six potential PGPR showing in vitro activities were used in pot trial to check their efficacy in vivo. These bacteria consortia demonstrated in vivo PGP activity and can be used as PGPR in Saffron as biofertilizers.This is the first report on the isolation of rhizobacteria from the Saffron rhizosphere, screening for plant growth promoting bacteria and their effect on the growth of Saffron plant.
Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Crocus/crescimento & desenvolvimento , Crocus/microbiologia , Rizosfera , Bacillus/classificação , Bacillus/genética , Bacillus/isolamento & purificação , Bacillus/metabolismo , Bactérias/classificação , Bactérias/genética , Carga Bacteriana , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Brevibacterium/classificação , Brevibacterium/genética , Brevibacterium/isolamento & purificação , Brevibacterium/metabolismo , Ácidos Indolacéticos/metabolismo , Fosfatos/metabolismo , Filogenia , Raízes de Plantas/microbiologia , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RNA Ribossômico 16S/genética , Sideróforos/metabolismo , Microbiologia do SoloRESUMO
Lipases are placed only after proteases and carbohydrases in world enzyme market and share about 5% of enzyme market. They occur in plants, animals and microorganisms and are accordingly classified as plant, animal and microbial lipases. Wherever they exist, they function to catalyze hydrolysis of triglycerides to glycerol and fatty acid. Like carbohydrases and proteases, lipases of microbial origin enjoy greater industrial importance as they are more stable (compared to plant and animal lipases) and can be obtained in bulk at low cost. Majority of yeast lipases are extracelluar, monomericglycoproteins with molecular weight ranging between ~33 to ~65 kD. More than 50% reported lipases producing yeast, produce it in the forms of various isozymes. These lipase isozymes are in turn produced by various lipase encoding genes. Among many lipase producing yeasts Candida rugosa is most frequently used yeast as the source of lipase commercially. This review is aimed at compiling the information on properties of various yeast lipases and genes encoding them.