scholarly journals The culture medium volume and the inoculation method should be considered in semi-quantitative screening of calcium phosphate solubilization by bacteria

2020 ◽  
Vol 42 ◽  
pp. e44332
Author(s):  
Silvia Maria de Oliveira-Longatti ◽  
Leandro Marciano Marra ◽  
Teotonio Soares de Carvalho ◽  
Fatima Maria de Souza Moreira

Agar media with insoluble phosphates are used for semi-quantitative screening of phosphate-solubilizing bacteria based on the solubilization halo formed around the colonies. We show that the volume of the culture medium (15, 20, and 30 mL) and the inoculation method (toothpick vs microdrop) strongly influence the diameter of the solubilization halo, and this should be considered in advance selection of the isolates most efficient in this process.

2020 ◽  
Vol 1 (2) ◽  
pp. 37-51
Author(s):  
C. E. Oshoma ◽  
S. O. Nwodo ◽  
I. S. Obuekwe

The processing of cassava into value-added products is associated with discharge of effluents which contain substances that have adverse effect on the environment. Remediative activity of indigenous bacteria can be stimulated by supplementing effluents with phosphorus. Rock phosphate (RP) solubilization and enzymatic activities from bacteria on the cassava mill effluents (CME) contaminated soil was investigated. Soil mixed with varying concentrations of CME (0, 100, 200, 300, 400, 500 and 600 ml) and 10 g of RP were analyzed on days 0 and 16. Parameters analyzed were changes in pH, heterotrophic bacteria load, phosphate-solubilizing bacteria load, available phosphorus, acid phosphatase, cellulase and urease concentrations. The results showed that the medium containing 400 ml CME contaminated soil had the highest phosphate-solubilizing bacteria load (12.60 ± 2.08 x 106 cfu/ml), available phosphorus (126.00 ± 4.08 mg/kg), acid phosphatase (9.54 ± 0.51 mgN/g/min), cellulase (15.24 ± 0.81 mg/g/6h) and urease concentration (2.15±0.22 mg/g/2h). The control had the lowest phosphate-solubilizing bacteria load and enzymatic activity. Biostimulation of indigenous bacteria to enhance the degradation of cassava mill effluent-contaminated soil, using rock phosphate, showed promising results. This implies that rock phosphate solubilization by indigenous bacteria in CME-contaminated soils could be important for the remediation and reclamation of contaminated lands.


2019 ◽  
Vol 60 (5) ◽  
pp. 985-995
Author(s):  
Yusur Ramzi ◽  
Hutaf A. A. Alsalim

Sixteen soil samples were collected from wheat, barley and yellow corn rhizosphere in Abu-Ghraib, Aqraqof, Latifieh,Tarmiah, Jadriya and  of Agriculture in Baghdad university/ Baghdad city. The results found nine phosphate solubilizing bacteria (PSB) isolates (Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9), formed clear zones on National Botanical Research Institute's (NBRIP) agar. The solubility index (SI) of PSB isolates ranged from 2.00 to 3.66. Y4 have the highest SI (3.66) followed by Y3 and Y6 (3.33). Phosphate solubilization abilities varying from (20.10-39.00 μg.ml-1), Y4 was the highest (39.00 μg.ml-1) followed by Y3 (37.00μg.ml-1). The results of hydrolytic enzymes production showed that almost all nine isolates are able to produce protease and pectinase, while Y1 and Y2 showed negative results in cellulase production. Maximum ability for hydrogen cyanide (HCN) and indole acetic acid (IAA) production were showed byY3 and Y4 isolates. The isolate Y4 was found to be the most efficient isolate, so it was selected identified as Bacillus cereus using biochemical tests confirmed by VITEC 2 compact system. The results of High performance liquid chromatography (HPLC) revealed that Bacillus cereus produce oxalic acid (2.996), citric acid (9.117) and malic acid (3.734). Bacillus cereus (Y4) enhanced the growth of mung bean plants. A significant increase in branches number (12.33), plant length (83.0cm), fresh weight (27.25 g) and dry weight (1.427g) were obtained compared with control treatments. The main objective of this study is to isolate PSB and evaluate their roles in plant growth promotion. The results showed the high phosphate solubilization efficiency of PSB isolates and the identified isolates was found to be good enough for plant growth promoting.


1983 ◽  
Vol 63 (4) ◽  
pp. 671-678 ◽  
Author(s):  
R. M. N. KUCEY

Seventeen sites throughout southern Alberta were sampled in the spring of 1981. Total and NaHCO3-extractable phosphorus and soil texture were determined for each soil sampled. Phosphate-solubilizing and total bacterial and fungal populations were determined by serial dilution and plate counting. Available P constituted an average of 1% of the total P present in the soils. Phosphate-solubilizing bacteria and fungi made up 0.5 and 0.1%, respectively, of the total bacterial and fungal populations. A highly significant correlation was found between the numbers of total and phosphate-solubilizing fungi and the levels of total P in the soil. As a group, the fungi were superior to bacteria in solubilizing both freshly precipitated calcium phosphate and Idaho rock phosphate. Fungi also retained this ability over many subculturing transfers. A high percentage of the bacterial isolates lost their solubilizing ability when subcultured. A significant correlation was found between an organism’s ability to solubilize freshly precipitated calcium phosphate in agar plates and Idaho rock phosphate in solution culture. Key words: Fungi imperfecti, Penicillium sp., phosphate-solubilizing microorganisms


2010 ◽  
Vol 12 (3,4) ◽  
pp. 231 ◽  
Author(s):  
M. Ogut ◽  
F. Er ◽  
N. Kandemir

<p>Phosphate solubilizing bacteria can be used as soil or seed inoculum to increase soil phosphorus (P) availability for agricultural purposes. There is also a possibility of using these microorganisms to biotechnologically dissolve phosphate ores for the production of phosphorus fertilizers. Twenty-one soil samples were collected along a highway in Turkey to isolate phosphate solubilizing bacteria. A total of 20 phosphate solubilizers were isolated from the rhizosphere of wheat and maize grown in the pots, which contained the collected soil samples. The isolates were distributed among the genera, <em>Acinetobacter</em> (7), <em>Pseudomonas</em> (7), <em>Enterobacter</em> (2), <em>Enterococcus</em> (1), <em>Escherichia</em> (1), <em>Photorhabdus</em> (1), and <em>Bacillus</em> (1) as determined by the 16S rDNA gene sequence analysis. Since the <em>Acinetobacter</em> species were most effective in Pikovskaya’s agar, which contained tricalcium phosphate for the sole P-source, they were further experimented for the phosphate solubilization in batch cultures. The mean phosphorus dissolved in 5 day incubation ranged between 167 and 1022 ppm P. The initial pH of 7.8  dropped below 4.7 in six isolates with a gluconic acid production in the concentrations ranging between 27.5 and 37.5 mM. <em>Acinetobacter</em> isolates have some potential as an inoculum both for soil and biotechnological P-solubilization.</p>


2020 ◽  
Vol 11 ◽  
Author(s):  
Luciana F. Brito ◽  
Marina Gil López ◽  
Lucas Straube ◽  
Luciane M. P. Passaglia ◽  
Volker F. Wendisch

Due to the importance of phosphorus (P) in agriculture, crop inoculation with phosphate-solubilizing bacteria is a relevant subject of study. Paenibacillus sonchi genomovar Riograndensis SBR5 is a promising candidate for crop inoculation, as it can fix nitrogen and excrete ammonium at a remarkably high rate. However, its trait of phosphate solubilization (PS) has not yet been studied in detail. Here, differential gene expression and functional analyses were performed to characterize PS in this bacterium. SBR5 was cultivated with two distinct P sources: NaH2PO4 as soluble phosphate source (SPi) and hydroxyapatite as insoluble phosphate source (IPi). Total RNA of SBR5 cultivated in those two conditions was isolated and sequenced, and bacterial growth and product formation were monitored. In the IPi medium, the expression of 68 genes was upregulated, whereas 100 genes were downregulated. Among those, genes involved in carbon metabolism, including those coding for subunits of 2-oxoglutarate dehydrogenase, were identified. Quantitation of organic acids showed that the production of tricarboxylic acid cycle-derived organic acids was reduced in IPi condition, whereas acetate and gluconate were overproduced. Increased concentrations of proline, trehalose, and glycine betaine revealed active osmoprotection during growth in IPi. The cultivation with hydroxyapatite also caused the reduction in the motility of SBR5 cells as a response to Pi depletion at the beginning of its growth. SBR5 was able to solubilize hydroxyapatite, which suggests that this organism is a promising phosphate-solubilizing bacterium. Our findings are the initial step in the elucidation of the PS process in P. sonchi SBR5 and will be a valuable groundwork for further studies of this organism as a plant growth-promoting rhizobacterium.


2018 ◽  
Vol 52 (3) ◽  
pp. 305-308 ◽  
Author(s):  
Manoharan Melvin Joe ◽  
Shalini Deivaraj ◽  
Abitha Benson ◽  
Allen John Henry ◽  
G. Narendrakumar

2018 ◽  
Vol 10 (4) ◽  
pp. 1204-1209
Author(s):  
Mahendra Singh

The objective of the present study was to isolate and characterize most efficient phosphate solubilizing bacteria (PSB) from rice rhizosphere. The study was carried out during the Kharif season’2018 at Department of Soil Science and Agricultural Chemistry, Bihar Agricultural University, Sabour, Bhagalpur, Bihar. The availability of phosphorous to plants for uptake and utilization is limited in soil due to fixation in the form of Fe-P, Al-P and Ca-P. The use of phosphate solubilizing bacteria can prove to be helpful measure to supply phosphorous to the crops to increase the productivity. In the present investigation, a total of 10 isolates were obtained from rice rhizosphere soil samples. All ten isolated isolates were shown phosphorus solubilization. Out of ten isolates BAU3 was found to be most potent phosphate solubilizers showing clear halo zone around its colony. The isolate BAU3 showed 20.00 mm phosphate solubilizing halo zone around its colony. The solubilization index (SI) of the isolate BAU3 was also calculated at the end of the incubation period and observed phosphate solubilization index (SI) of 3.22.  The isolate BAU3 showed maximum insoluble phosphate solubilization of 450.24 ?g ml-1 and isolates BAU3 was selected for subsequent studies. The bacterial isolates BAU3 was gram negative, non-spore forming rods shaped. On the basis of the 16SrDNA sequencing, isolate BAU3 was identified as Enterobacter cloacae strain BAU3 (Genebank Accession No.   MK033472). The isolated strain of bacterial has potential to solubilize insoluble phosphorus and it can be utilized for preparation of microbial inoculants or biofertilizers.


2020 ◽  
Vol 4 (1) ◽  
pp. 22
Author(s):  
Oksana Oksana ◽  
Mokhamad Irfan ◽  
Annisa Ramadhani Fianiray ◽  
Syukria Ikhsan Zam

<p class="Abstract">Phosphate-solubilizing bacterial can fulfill the low available of soluble P on Ultisol. This research aimed to study on the quantity of the population bacteria and identify phosphate-solubilizing bacteria on Ultisol from Rumbai District, Pekanbaru. The research method used was descriptive method. Soil sample was collected from teak plantations of PT. Air Jernih, Sub district of Rumbai Pesisir, Pekanbaru and identification of phosphate-solubilizing bacteria was conducted in Laboratory of Pathology, Entomology and Microbiology, Faculty of Agriculture and Animal Husbandry, Universitas Sultan Syarif Kasim State Islamic, Riau from May-September 2017. The observed parameters were bacterial cell numbers, phosphate solubilization index, microscopic and biochemical characteristics. Four isolates were obtained with cell numbers ranging from 4.2 x 10<sup>5</sup> – 7.1 x 10<sup>5</sup> CFU/g of soil. All isolates showed the ability to dissolve phosphate with phosphate solubilization index ranging from 1.16 – 1.57. The four isolates were identified as <em>Klebsiella </em>(IBJ1 and IBJ2), and <em>Acinetobacter </em>(IBJ3 and IBJ4).</p>


2015 ◽  
Vol 20 (3) ◽  
pp. 121-131
Author(s):  
Luz Marina LIZARAZO FORERO ◽  
Elsa Giovanna ÁVILA MARTÍNEZ ◽  
Francisco CORTÉS PÉREZ

<p>El objetivo de esta investigación fue aislar y caracterizar bacterias solubilizadoras de fosfatos (BSF) asociadas a la rizosfera de <em>Baccharis macrantha </em>y <em>Viburnum triphyllum,</em> y evaluar su capacidad para solubilizar fosfatos en condiciones <em>in vitro</em>. Además se determinó el efecto de la inoculaciónde las cepas de BSF más eficientes sobre el crecimiento de <em>B. macrantha</em>. Las muestras de suelo rizosférico de <em>B. macrantha </em>y <em>V. triphyllum </em>fueron colectadas en los meses de mayo-período de lluvia y septiembre-período seco del 2012. Para la cuantificación de bacterias heterótrofas cultivables y BSF se empleó el método de recuento en placa en los medios Agar Tripticasa de Soya y Pikovskaya (PVK) respectivamente. La capacidad de solubilización de fosfatos de las cepas aisladas se estimó a partir del diámetro de los halos formados alrededor de las colonias en el medio de cultivo PVK después de 7 días de incubación a 28 °C. Los ensayos de inoculación en <em>B. macrantha </em>se realizaron con las BSF más eficientes<em>. </em>La inoculación de las BSF <em>B. firmus y P. fluorescens</em> de forma individual y como inoculante combinado mostro un efecto benéfico, incrementando significativamente el porcentaje de germinación de semillas, la altura de la plántula, la longitud de la raíz y el peso seco de <em>B. macrantha</em>. La inoculación de BSF podría ser considerada una estrategia para mejorar el crecimiento y establecimiento de <em>B. macrantha</em> en pastizales abandonados.</p><p><strong>Growth Promotion of <em>Baccharis macrantha </em>(Asteraceae) by Phosphate Solubilizing Rhizosphere Bacteria</strong>     </p><p>The objectives of this research was to isolate and characterize phosphate solubilizing bacteria (BSF) associated to the rhizosphere of <em>Baccharis macrantha</em> and <em>Viburnum triphyllum</em>, and to assess their ability to solubilize phosphate under conditions in vitro. Furthermore to determine the effect of inoculation of the strains BSF more efficient on the growth of <em>B. macrantha</em>. Rhizosphere soil samples of <em>B. macrantha</em> and <em>V. triphyllum </em>were collected in the months of May-rainy season and September-period dry the 2012. Trypticase Soya Agar and Pikovskaya (PVK) were used for quantification of culturable heterotrophic bacteria and BSF, respectively. The phosphate solubilizing capacity of the isolated strains was estimated from the diameter of the halo around the colonies formed in the culture medium PVK after 7 days incubation at 28 °C. Inoculation assays were performed with more efficient BSF in <em>B. macrantha. </em>Inoculation of BSF <em>Bacillus firmus</em> and <em>Pseudomona fluorescens </em>individually and as inoculant combined showed a beneficial effect, significantly increasing the percentage of seed germination, seedling height, root length and dry weight of <em>B . macrantha</em>. Inoculation the BSF could be considered a strategy to improve the growth and development of <em>B. macrantha</em> in abandoned pastures</p>


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