Biodegration of groundnut shells to fermentable sugars using fungal isolates

This work was aimed at evaluating the potential of some fungal isolates in degradation of groundnut shell.Fungal strains were screened for their ability to produce cellulase. Effect of substrate concentration (5 - 20g), nitrogen sources (yeast extract, NaNO₃, peptone, soya-bean meal and NH₄H₂PO₄) and pH (3- 9) on the degradation of groundnut shells by fungal isolates were evaluated. The isolates were identified tentatively as Aspergillus sp.1-3 and Trichoderma sp. Increase in substrate concentration resulted in increase in glucose yield, Aspergillus sp 1, gave the highest glucose yield of 51.9 g/l with 20g substrate concentration followed by Aspergillus sp 3 glucose yield of 43.3g/l and Aspergillus sp 2, 15g substrate concentration gave glucose yield of 42.2g/l. With the use of different nitrogen source Aspergillus sp. 3 gave the highest glucose yield of 15.7g/l with NaNO₃  while Aspergillus sp 1, Trichoderma sp  and  Aspergillus sp 2 had their best source of nitrogen as soya bean meal with yields 7.5g/l, 9.8g/, and  8.6g/l respectively. pH 5 was optimal for the degradation of groundnut shells. Degradation of groundnut shells was carried out using four fungal strains in synergy a glucose yield of 58.7g/l was obtained at pH 5, 15g substrate concentration and Peptone was best nitrogen source. Degree of cellulose degradation was evaluated, 65%degradation was observed using co culture followed by Aspergillus sp 1 59%, Aspergillus sp 3 54.5%. Aspergillus sp 2 with 52.9% and Trichoderma sp 48.8%. This study revealed that use of co-culture improved biodegradation, hence higher yield of fermentable sugars.