SCREENING FOR CITRIC ACID PRODUCING FUNGI FROM THE SOIL ENVIRONMENT OF JOS NORTH, PLATEAU STATE, NIGERIA

Résumé

The investigation was aimed at screening for citric acid producing fungi from the soil environment of Jos North Local Government Area using standard mycological methods. Serial dilution method was employed using Potato Dextrose Agar as culture medium for fungi isolation. Total Fungal Counts at the different locations were determined and expressed as CFU/ml. Farin Gada had the highest fungi count of 2.9 x 103 while Angwan Rogo had the least fungi count of 7.3 x 102. The frequency of occurrence for each species of fungus was also determined using standard mycological method. Aspergillus niger and Fusarium oxysporum had the highest frequency of occurrence of 80% while Saccharomyces cerevisiae had the lowest frequency of occurrence of 10%. Fungal isolates were identified using standard methods based on their cultural and morphological features. A total of ten (10) fungi species were isolated and identified (Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium glaucum, Penicillium rugulosum, Penicillium chrysogenum, Fusarium oxysporum, Rhizopus stolonifer, Rhodotorula rubra and Saccharomyces cerevisiae). Six species were found to
produce citric acid at varying concentrations (Aspergillus niger, 3.2g/L; Aspergillus flavus, 2.3g/L; Penicillium glaucum, 2.0g/L; Penicillium chrysogenum, 1.9g/L; Penicillium rugulosum, 1.7g/L; and Saccharomyces cerevisiae, 0.7g/L). This investigation demonstrated that there are citric acid producing fungal strains in the soil environment of Jos North Local Government Area of Plateau State, Nigeria, which can be harnessed locally for industrial production