Grace N Ijoma
Institute for the Development of Energy for African Sustainability
Title: Comparative evaluation of enzyme production efficiency of monocultures and paired interactions of fungi on different agricultural substrates
Biography
Biography: Grace N Ijoma
Abstract
There is a renewed interest in finding sustainable energy sources with particular focus on agricultural waste residues. The justification for this perspective is that this eliminates the need to cultivate already scarce land mass and has the added advantage of utilizing agricultural residues that otherwise would have presented problems of waste management. However, the use of agricultural waste residue is significantly hindered by the difficulty in degradation of lignocellulose components of its structure. Ligninolytic fungi have the ability to degrade these agricultural waste residues but enzymes employed in the degradation process are produced in limited quantities and more often during the secondary metabolism by these organisms. Methodology & Theoretical Orientation: The objective of this study was to investigate a strategy that could improve the production of these enzymes and likely accelerate the organisms into secondary phase enzyme production mode. Dual culture combinations of 10 fungi that had previously demonstrated the ability to produce ligninolytic enzymes were cultivated on PDA to ascertain their interspecific interaction and also on three agricultural residues, corn cob, sugarcane bagasse and wheat straw. Spectrophotometric analysis of the enzyme activities of laccase (Lacc), manganese peroxidase (MnP) and lignin peroxidase (LiP) demonstrated that observed antagonistic invasions yielded an increased enzyme activity in dual cultures on all the substrates. Findings: The highest ligninolytic enzyme production was observed in invasion/replacement interactions that involved Trichoderma sp. KN10 with average mean value in MnP production was approximately 1.46 U/ml compared to all monocultures of 0.055 U/ml. Similarly, Lacc mean value was 0.10 U/ml compared to monocultures value of 0.05 U/ml. This study demonstrated and proved that antagonistic invasion by some fungi in co-culture, although dependent on substrate affinity, can increase production of one or more of the three enzymes laccase, lignin peroxidase and manganese peroxidase.