scholarly journals Bioprospecting of microbial isolates from biodynamic preparations for PGPR and biocontrol properties

2021 ◽  
Vol 42 (3) ◽  
pp. 644-651
Author(s):  
S. Vaish ◽  
◽  
N. Garg ◽  
I.Z. Ahmad ◽  
◽  
...  

Aim: To study the role of microorganisms behind their bioenhancing, biocontrol properties, their enzymatic potential, and characterization of high performing microbial isolates on molecular basis. Methodology: Dominant culturable microbes including bacteria and fungi were isolated from biodynamic preparations and screened on the basis of plant-growth promoting (PGP) activities viz., ammonia production, phosphate solubilization, siderophore production, hydrogen cyanide production, seed germination efficacy and biocontrol properties. The dominant and effective microorganisms were screened for enzymes activities viz., pectinase, cellulase and amylase. The selected bacterial and fungal isolates, exhibiting higher enzyme activities, were subjected to molecular characterization. Results: Out of 68 bacterial and 25 fungal isolates from 8 biodynamic preparations (BD 500 - BD 507), 15 bacterial isolates exhibited high plant growth promoting activities while 10 bacterial isolates exhibited biocontrol activity against pathogens. Bacillus licheniformis isolated from BD 504, expressed high pectinase (2.595 U ml-1 min-1), cellulase (0.308 U ml-1 min-1) and amylase (0.418 U ml-1 min-1) activities. Fungal isolates with high enzymatic activities, were isolated from BD 500, 503 and 506, respectively. Interpretation: Microorganism isolates from biodynamic preparations possessed strong plant growth promoting, biocontrol and enzymatic properties, which might be responsible for the efficacy of organic preparations under field conditions.

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Singh ◽  
Vinod Kumar ◽  
Sanjeev Agrawal

Bacterial inoculants are known to possess plant growth promoting abilities and have potential as liquid biofertilizer application. Four phytase producing bacterial isolates (phytase activity in the range of 0.076–0.174 U/mL), identified asAdvenellaspecies (PB-05, PB-06, and PB-10) andCellulosimicrobiumsp. PB-09, were analyzed for their plant growth promoting activities like siderophore production, IAA production, HCN production, ammonia production, phosphate solubilization, and antifungal activity. All isolates were positive for the above characteristics except for HCN production. The solubilization index for phosphorus on Pikovskaya agar plates was in the range of 2–4. Significant amount of IAA (7.19 to 35.03 μg/mL) production and solubilized phosphate (189.53 to 746.84 μg/mL) was noticed by these isolates at different time intervals. Besides that, a greenhouse study was also conducted with Indian mustard to evaluate the potential of these isolates to promote plant growth. Effect of seed bacterization on various plant growth parameters and P uptake by plant were used as indicators. The plant growth promoting ability of bacterial isolates in pot experiments was correlated to IAA production, phosphate solubilization, and otherin vitrotests. On the basis of present findings, isolate PB-06 was most promising in plant growth promotion with multiple growth promoting characteristics.


2009 ◽  
Vol 329 (1-2) ◽  
pp. 421-431 ◽  
Author(s):  
Tania Taurian ◽  
María Soledad Anzuay ◽  
Jorge Guillermo Angelini ◽  
María Laura Tonelli ◽  
Liliana Ludueña ◽  
...  

OENO One ◽  
2021 ◽  
Vol 55 (4) ◽  
pp. 145-157
Author(s):  
Mónica Oyuela Aguilar ◽  
Florencia Álvarez ◽  
Daniela Medeot ◽  
Edgardo Jofré ◽  
Liliana Semorile ◽  
...  

The rhizosphere-associated microbiome has diverse functions that support plant growth and health, varying among plant species, vegetation growth stages and environmental habitats. This microbiome includes a group of bacteria denominated plant growth-promoting rhizobacteria (PGPR) which can colonize plant roots. Certain PGPR isolates improve the ability of plants to adapt to a stressful environment. In this study, we collected and characterised the rhizosphere-associated bacteria, or epiphytic rhizobacteria, from Malbec and Cabernet-Sauvignon vineyards from the main wine-producing provinces of Argentina to analyse their potential use as biologic fertilisers and/or as pathogen-control agents. A total of 170 bacterial isolates were obtained, distributed into eleven different genera and classified into three phyla, Proteobacteria, Actinobacteria and Firmicutes. The in vitro analysis for plant-growth-promoting (PGP) activities demonstrated that a significant number of bacterial isolates had one or more of these traits. The Pseudomonas was the genus with the highest number of isolates and PGP activities, followed by the Arthrobacter, Serratia, Bacillus andPantoea. We observed that bacterial isolates identified as Bacillus exhibited a remarkable production of hydrolytic enzymes related to biocontrol activities. Biocontrol trials from the Bacillus collection revealed that at least five isolates were able to inhibit the fungal growth of Botrytis cinerea and Alternaria alternata. The results obtained suggest the biological potential of each isolate and the relevance of proceeding to greenhouse and field assays to obtain long-term environmentally compatible bio-products for vineyard management.


Author(s):  
Cun Yu ◽  
Ying Yao

Endophytic fungi were isolated from Phoebe bournei and their diversity and antimicrobial and plant growth-promoting activities were investigated. Of the 389 isolated endophytic fungi, 88.90% belonged to phylum Ascomycota and 11.10% to phylum Basidiomycota. The isolates were grouped into four taxonomic classes, 11 orders, 30 genera, and 45 species based on internal transcribed spacer sequencing and morphologic analysis. The host showed a strong affinity for the genera Diaporthe and Phyllosticta. The diversity of the fungi was highest in autumn, followed by spring and summer, and was lowest in winter. The fungi exhibited notable tissue specificity in P. bournei, and the species richness and diversity were highest in the root across all seasons. Five isolates showed antimicrobial activity against eight plant pathogens, and reduced the incidence of leaf spot disease in P. bournei. Additionally, 9 biocontrol isolates showed plant growth-promoting activity, with five significantly promoting P. bournei seedling growth. This is the first report on the endophytic fungi of P. bournei and their potential applicability to plant disease control and growth promotion.


2019 ◽  
Vol 11 (2) ◽  
pp. 346-351
Author(s):  
Deepika Chhabra ◽  
Poonam Sharma

Bacteria that colonize plant tissues other than rhizobia and are beneficial for plant growth referred to non rhizobial plant growth-promoting endophytic bacteria (PGPEB). This study was designed to assay the biocontrol activity of plant growth promoting endophytic bacterial isolates those found positive for P. solubilization, ACC deaminase, Indole acetic acid and Gibberelic acid production. These bacterial isolates were obtained from chickpea (Cicer arietinum L.) tissues (roots and nodules).  In a previous study a total of 263 non rhizobial endophytic bacterial isolates were isolated. Out of 263 isolates, 64.5% and 34.5% were Gram positive and negative, respectively. Further for biochemical characterization, catalase, oxidase, citrate utilization, nitrate reduction, methyl red and Voges Proskauer’s tests, were performed. On the basis of P solubilization, ACC deaminase, Indole acetic acid and Gibberelic acid production 75 potential isolates were selected and screened for their biocontrol activity viz. (production of cell wall degrading enzymes, production of HCN and fluorescent pigment). Out of 75 isolates, only 29 isolates produced cellulase, 64 isolates were able to produce protease and 28 were positive for both cellulose and protease. Of 75 endophytic isolates 12 isolates (7 from root tissue and 5 from nodules tissue, respectively) were positive for HCN production and 16 isolates were found to be fluorescent pigment producer under µv ligh. As chemical fertilizers and pesticides have detrimental effects on the environment. So these bacterial endophytic isolates will be used not only as a biofertilizer because of their plant growth promotional activities but also used as an alternative of synthetic chemicals for control of several plant diseases.


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