Isolation, Characterization, and Growth Promotion of Phosphate-Solubilizing Bacteria Associated with Nicotiana Tabacum (Tobacco)

Abstract

Phosphate-solubilizing bacteria (PSB) increase phosphate bioavailability, thereby reducing the application frequency of chemical fertilizers in the production of Nicotiana tabacum (tobacco). In this study, PSB were isolated from tobacco plants for the fi rst time. These PSB were screened in vitro for their ability to solubilize inorganic P (Pi) when grown in association with tobacco plants. Thirty-six PSB with the ability to solubilize P i were isolated and screened for their indolyl-3-acetic acid and siderophore-producing capabilities. In addition, all 36 PSB strains had a partial fragment of their 16S rRNA gene sequenced. The analysis revealed high sequence identity to 16S rDNA sequences from Bacillus, Arthrobacter, Providencia, Enterobacter, Proteus, Psychrobacter, Serratia, Rhodococcus, Pseudomonas, Ochrobactrum, and Acinetobacter. Of the 36 PSB strains analyzed, three (Psychrobacter alimentarius HB15, Enterobacter ludwigii HB21, and Ochrobactrum haematophilum HB36) were selected for a controlled plant inoculation experiment. Inoculation of tobacco plants with these bacterial strains signifi cantly increased plant dry weight. Additionally, inoculation increased P, K, and N uptake by tobacco seedlings as well as soil P availability. The increases observed with inoculation were even more pronounced when tricalcium phosphate (TCP) was added to the soil. The phosphate-solubilizing activity of these three strains was correlated with the release of gluconic, tartaric, acetic, and citric organic acids. Overall, co-inoculation of PSB and TCP appears to represent a promising option for increasing the yield of tobacco plants. The adoption of this technique could provide a pathway to reducing fertilizer input in agricultural settings.

Multi-Omics Reveal the Efficient Phosphate-Solubilizing Mechanism of Bacteria on Rocky Soil

“…These results indicated that in the greenhouse and field environments, the PSB could improve the barren rocky soil fertility and promote sweetpotato growth. In adition, some PSB also showed a good growth-promoting effect on a variety of crops, such as O. haematophilum could promote the growth of corn and tobacco ( Pereira and Castro, 2014 ; Gao et al, 2016 ). It would be an interesting and valuable work to study the effect of these screened PSB, especially the FP12, on other crops in future.…”

Potential of phosphate solubilizing fungi isolated from peat soils as inoculant biofertilizer

“…Control was determined as medium without fungi inoculation. The pH of medium was measured to determine the effect of phosphate dissolution by fungi on the pH of medium (Gao et al 2016).…”

Complete Genome Sequence of Ochrobactrum haematophilum FI11154, Isolated from Kunu-Zaki, a Nigerian Millet-Based Fermented Food

“…Here, we report the first complete genome sequence of Ochrobactrum haematophilum , a Gram-negative, nonmotile, rod-shaped, oxidase-positive bacterium from the Alphaproteobacteria class. This species was first isolated from human blood ( 1 ) but is frequently associated with plants ( 2 ) and the rhizosphere ( 3 , 4 ). O. haematophilum has been reported to promote plant growth through the solubilization of phosphates and the production of siderophores ( 3 , 4 ) and to produce fungicidal substances ( 4 ).…”

“…Among them are the gene cluster efeUOB, putatively encoding an elemental ferrous iron transporter ( 11 ), the fepC , fepG, fepD , and fepB genes, putatively encoding a ferric enterobactin transport system, a gene cluster putatively encoding the vitamin B 12 transport system BtuCDF ( 12 ), and several genes putatively encoding TonB-dependent transporters, which bind and transport ferric chelates, as well as vitamin B 12 , nickel complexes, and carbohydrates ( 13 ). The capacity of this microorganism to chelate iron can promote plant growth ( 3 , 4 ); however, it could be detrimental to the nutritional value of the fermented foods from which it was isolated. The presence of two genes encoding putative exopolyphosphatases could be related to the phosphate solubilization activity described for this species ( 2 , 4 ).…”