Isolation, identification and characterization of phosphate solubilizing bacteria from rhizosphere soil of Aloe vera and Vigna unguiculata (original) (raw)
Related papers
SCREENING OF PHOSPHATE SOLUBILIZING BACTERIA FROM SOILS OF DHARAN, SUNSARI, NEPAL
Visnav, 2020
Phosphorus is one of the essential macronutrients for plant growth and reproduction. Plant absorbs phosphorus from soil solution as phosphate anions which are highly reactive and may be immobilized by precipitation with cations such as Ca 2+ , Mg 2+ , Fe 3+ and Al 3+ , present in the soil and thus it becomes insoluble and unavailable for plants. PSB can be used as biofertilizer since they increase phosphorus availability in the soil for growing plants. The main objective of this study was to isolate and identify PSB morphologically and biochemically from the agricultural soil sample. For this purpose, total 16 samples were collected. Isolation was performed on Pikovskaya's (PVK) media by spread plate technique. PSB were isolated from soil sample of Dharan, taken from agricultural field. The isolated organisms were identified according to colony morphology, gram staining reactions and various biochemical properties. The solubilization index (SI) and solubilization efficiency (SE) were calculated on the basis of the halozone and colony diameter. Only two PSB were isolated. Both were gram positive, spore forming rod shaped bacteria. According to colony characteristics, staining reactions and biochemical tests, the isolates were Bacillus megaterium and Streptomyces spp. Their phosphate solubilizing ability was analyzed qualitatively on PVK plate. Their solubilizing indexes (SI) were found to be 1.75 and 1.33 while solubilizing efficiency (SE) were calculated 75% and 33% respectively. Both PSB isolates were spore former, as the soils of Dharan generally contain comparatively low moisture (drought) in April to June.
IJACBS, 2020
Phosphorus is essential for the growth and productivity of plant which can absorb phosphate only in soluble form. The phosphate solubilizing bacteria (PSB) mobilize insoluble phosphate into soluble form through enzymatic and organic acid production. Thus, PSB can be used as biofertilizers and are able to improve the soil fertility. The phosphorous is most abundant in soil both in organic as well as inorganic form and is the major limiting factor for the growth of the plant. In the present study, 6 phosphate solubilizing bacteria were isolated from various agricultural fields and designated as NR1-NR6. NR-1, NR-2 and NR-5 were found to be strong phosphate Solubilizer, with halo zone diameters of 13, 12 and 12 mm respectively on Pikovskaya agar. All the isolates were further screened for plant growth promoting factor such as siderophore, HCN, ammonia and cell wall degradation enzyme production. All the isolates were found to be positive for siderophore production and their frequency ranged from 5mm -11 mm. NR-1, NR-3, NR-4 and NR-5 were positive for HCN production. NR-1, NR-2, NR-3 and NR-5 produced ammonia. While isolates NR-1, NR-2, NR-4 and NR-6 produced cellulase and protease which are cell wall degrading enzymes. All the isolates were also characterized in term of morphological and biochemical test and after comparison with the Bergy’s Manual of Systematic Bacteriology the isolates NR-1, NR-2, NR-3 and NR-5 tentatively assigned as Pseudomonas spp. while NR-4 and NR-6 assigned as Bacillus spp.
2018
Microorganisms present in soil play an important role in maintaining the ecological balance by active participation in Nitrogen, Phosphorous and Carbon cycle in nature. Phosphorous plays an important role in plant nutrition and have important biochemical role in respiration, cell division, photosynthesis, cell enlargement and several other processes in the living plant. It is one of the most important vital macronutrient requisite for the growth and development of plants. The present study was undertaken to investigate the occurrence of phosphate solubilizing bacteria (PSB) from tomato rhizosphere soil samples collected across Jaipur, Rajasthan. Twenty soil samples were collected randomly to isolate phosphate solubilizing bacteria (PSB) by using plate assay method on Pikovskaya’s agar medium (PVK). The microbial colonies showing clear halo zone formation around them were considered as phosphate solubilizing. The isolated PSB were characterized by biochemical different biochemical ...
Turkish Journal of Biology
Low phosphate solubility is one of the most important factors limiting the plant growth in Indian soils. Many microorganisms can enhance phosphate solubility, but little is known about the magnitude of their phosphorussolubilizing ability. Th e native populations of phosphate-solubilizing bacteria and fungi were studied in diff erent rhizospheric soil samples obtained from betel vine plants (Piper betel L.) in order to compare the results. Th e present study focuses on the phosphate-solubilizing capacity of bacteria and fungi in rhizospheric soil samples obtained from betel vine plants, revealing the dominance of Aspergillus species (26.1 mm) as major phosphate solubilizers, along with Bacillus subtilis (46.6 mm) among the bacteria that utilize tricalcium phosphate, potassium dihydrogen phosphate, and rock phosphate as phosphate sources. Th e other phosphorus-solubilizing microorganisms were Bacillus species, Streptomyces, Aspergillus fumigatus, Nocardia, actinomycetes, and certain yeasts. Th e presence of high numbers of phosphate-solubilizing bacterium Bacillus subtilis (3 × 10 6 cfu g-1) and fungus Aspergillus niger (3 × 10 5 cfu g-1) in the rhizospheric zones of Piper betel plants explains how the plants obtain their nutrient requirements. Th e identity of Aspergillus species and Bacillus with the maximum zone was confi rmed using molecular sequencing with 16s rDNA. Th e sequence data were aligned and analyzed to identify the bacteria along with their closest neighbors.
2021
Phosphorus is a second key plant nutrient and the ‘kingpin’ in Indian agriculture, occupies an exclusive position both in conventional as well as in alternative agriculture. However, the phosphate solubilizing bacteria (PSB) converts the insoluble phosphate into biologically available form through the production of organic acids. Hence, the present study explored the presence of PSB from the Karavalasu agricultural field, Sivagiri, Erode District. The percentages of bacterial solubilization were 14.40 % to 60.70 % in non rhizospheric and rhizospheric crops adhering to root soils respectively.Out of 14 morphologically distinct isolates of PSB, two isolates (PSB8 and PSB11) displayed high P solubilization efficiency on solid medium amended with tricalcium phosphate Ca3(PO4)2 as the insoluble source (0.2 %). They were further characterized andcontinued with identification used by Picovskaya’s selective medium. The selective medium was incubated for 48 hours at a temperature of 37°C. The characterization was done for two strains by looking at the colony morphology and biochemical properties. The isolates showed the optimum pH for growth of the organism was pH 7 and the optimum temperature was 37 °C. Two strains exhibited significant release of P at the concentrations of 1.96 and 2.26 mg/l by PSB – 8 and PSB – 11 respectively on 10th day of incubation in broth medium amended with Ca3(PO4)2. The strains released acids as evident by decline in pH of the broth medium. They also secreted IAA with the maximum of 17.06 mg/l by PSB - 8 with Ca3(PO4)2 as a source of P. The potential strains for P solubilization were identified using 16S rRNA as Bacillus megaterium and Pseudomonas aeruginosa for further application as bioinoculants to agricultural fields. Finally we afford some indication that the use of Phosphate solubilising microorganisms will support sustainable agriculture and conclude that this knowledge is ready for commercial utilization in various regions worldwide. Keywords: Rhizospheric soil, phosphate solubilizing bacteria, indole-3 acetic acid, bioinoculants
International Letters of Natural Sciences, 2014
A considerable number of bacterial species are able to exert a beneficial effect upon plant growth. Mostly they are associated with the plant rhizosphere, so they are called as rhizobacteria. Phosphorus is an essential element for plant development and growth making up about 0.2 % of plant dry weight. Several scientists have reported the ability of different bacterial species to solubilize insoluble inorganic phosphate compounds, such as tricalcium phosphate, dicalcium phosphate, hydroxyapatite, and rock phosphate. Detection and estimation of the phosphate solublization ability of microorganisms have been possible using plate screening methods. Phosphate solubilizers produce clearing zones around the microbial colonies in growth media. In the present investigation a total number of fifteen phosphate solubilizing bacterial colonies isolated from different paddy soils in Cuddalore district of Tamilnadu, India. The isolated PSB were identified and characterized for effective use in the...