Isolation of Peanut (Arachis hypogaea L.) Nodulating Rhizobia and Assessment of Their Phosphate Solubilizing Activity
Mba Edou Simon Jeremie,
Ngo Nkot Laurette,
Youagang Gougueu Harris Stephane,
Semboung Lang Firmin,
Nyaka Ngobissa Aurelie Irene Claire,
Timb Sara Augustine Laurence,
Asseng Charles Carnot
Issue:
Volume 9, Issue 1, March 2023
Pages:
1-8
Received:
13 March 2023
Accepted:
1 April 2023
Published:
27 April 2023
Abstract: Phosphate-solubilizing bacteria can enhance the dissolution of insoluble phosphorus in the soil, promoting the availability of soluble phosphorus. Thus, their application can reduce the use of chemical fertilizers and ease sustainable agriculture. The study aimed at isolating and assessing the phosphate solubilizing activity of peanut rhizobia isolated from root nodules of peanut in three Cameroonian soils (Douala, Bafoussam and Ebolowa). Rhizobia were trapped by seeding peanut in plastic pots containing different soils. 45 days later, at the flowering time, root nodules were harvested. From these nodules, rhizobia were isolated, purified on Yeast Extract Mannitol Agar (YEMA) medium and authenticated by inoculating them on sterile sand containing peanut plants and watered with a nutrient solution without nitrogen. The phosphate solubilizing activity of the rhizobia isolates was then assessed in Modified Mineral Salt Medium (MMSM) containing bromocresol green and where the soluble phosphate was replaced by insoluble inorganic phosphates from Cameroon, Algeria, Senegal and tricalcium phosphate in both solid and broth media. The results were analysed statistically by one-way ANOVA using SPSS. A collection of twenty-five isolates was constituted among which 04 from Douala, 12 from Bafoussam and 09 from Ebolowa. All isolates were distinct morphologically. There was significant solubilization of inorganic phosphate in both solid and broth media (p<0.05). Isolated bacteria were characterized as being phosphate solubilizers with values ranging from 1.75 (AhBf1 on Algeria rock phosphate) to 18.9 mg/L (AhDa3 on Algeria rock phosphate). The Algeria rock phosphate was the most solubilized by peanut nodulating bacteria, followed by the tricalcium phosphate, the Senegal rock phosphate and the Cameroon rock phosphate. The solubilizing activity of inorganic phosphates in the broth medium was associated with a global decrease in the pH of the culture medium. The peanut nodulating rhizobia isolates that show the best solubilizing capacity could alleviate the problem of phosphorus availability in agricultural soils.
Abstract: Phosphate-solubilizing bacteria can enhance the dissolution of insoluble phosphorus in the soil, promoting the availability of soluble phosphorus. Thus, their application can reduce the use of chemical fertilizers and ease sustainable agriculture. The study aimed at isolating and assessing the phosphate solubilizing activity of peanut rhizobia isol...
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Production, Optimization and Characterization of Amylase Using Solid State Fermentation Method
Emmanuel Olabode Ayinde,
Timothy Olubisi Adejumo,
Olusegun Richard Adeoyo
Issue:
Volume 9, Issue 1, March 2023
Pages:
9-17
Received:
1 April 2023
Accepted:
21 April 2023
Published:
17 May 2023
Abstract: Amylases are enzymes produced by a wide range of organisms. The applications of these biomolecules cut across different industries such as detergent, brewing and food industries. Aspergillus flavus has been well documented as one the microbes capable of degrading starch-based agricultural waste materials. This study aimed at optimizing and characterizing amylase produced using agro-waste (potato peels) as a sole carbon source. A. flavus was obtained from the Department of Microbiology laboratory, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria. The fungus was preserved on PDA and stored at 4°C throughout the study period. This was followed by characterization and purification. Preliminary screening result showed that A. flavus had a clear zone of 13.33 mm (diameter of hydrolytic zone) and amylase activity of 545 U/ml. Stability assay revealed that the enzyme was stable at 50°C and 60°C by retaining 91% and 84% residual activities respectively after 4 h of pre-incubation period, while residual activities of 80% and 90% were observed at pH 6.0 and 8.0 respectively. Protein band analysis showed that the amylase from A. flavus had molecular weight of 35 kDa. These results indicated that the amylase produced from A. flavus had good catalytic properties and compared well with those from other known fungi. This study therefore recommends industrial production of amylase from A. flavus using potato peels as a substrate.
Abstract: Amylases are enzymes produced by a wide range of organisms. The applications of these biomolecules cut across different industries such as detergent, brewing and food industries. Aspergillus flavus has been well documented as one the microbes capable of degrading starch-based agricultural waste materials. This study aimed at optimizing and characte...
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