Screening of Locally Isolated Aspergillus species for Their Cellulolytic Potential and Their Optimization on Vigna mungo in Solid State Fermentation

Aims: To evaluate cellulolytic potential of locally isolated Aspergillus species and emphasis the importance of screening on qualitative bases. Also, to enhance cellulase production by optimizing the process parameters of the solid state fermentation of Vigna mungo with the isolated Aspergillus species.

Place and Duration of Study: Institute of Biological Sciences, Department of Botany, University of Gujrat, Gujrat, Pakistan, from February, 2012 to November, 2012.

Methodology: Aspergillus species were isolated from different deteriorated plant materials and maintained on potato dextrose agar. The purified isolated species were qualitatively screened on caboxymethylcellulose agar plates. The cellulolytic ability was further tested by culturing Aspergillus species on V. mungo in solid state fermentation. Various nutritional and cultivation parameters were optimized for the production of cellulases by Aspergillus species on V. mungo.

Results: Most of the isolated Aspergillus species showed potential for cellulase production. However, A. terreus gave qualitatively, the highest cellulase activity by fermenting V. mungo of 0.566 IU/g while A. niger gave quantitatively, the highest cellulase activity of 0.435 IU/g. Cellulase production by A. terreus reached at its maximum with 0.1% of urea as nitrogen source and 80% of initial moisture level at 35°C after 144 hours of fermentation.

Conclusion: A. terreus was identified as highest cellulase producer among the isolated Aspergillus species. The cellulolytic ability of Aspergillus specie greatly depends upon the nutritional and cultivation parameters of fermentation.