The effect of different organic, inorganic nitrogen sources and trace elements on growth and ligninolytic enzymes production by Grammothele fuligo has been investigated. Amongst all the nitrogen compounds used, the most favourable for growth was ammonium oxalate. It showed maximum Lignin Peroxidase activity (80.6 IU/mL) with ammonium chloride. The optimum Manganese Peroxidase activity (4.13 IU/mL) was observed with ammonium acetate. DL-alanine served as the best organic nitrogen source for the growth. The highest MnP (36.7 IU/mL) and laccase (3921.5 IU/mL) activities were revealed in medium supplemented by DL-tryptophan. However, their positive effects on enzyme accumulation were due to a higher biomass production. The higher concentrations of trace elements were found to be fungistatic for its growth viz. B, Co, Cu, Fe (400 ppm) and Co (100 ppm). It exhibited maximum LiP activity (456.9 IU/mL) with 10−3 ppm Fe and MnP activity (3.30 IU/mL) with 10−6 ppm B and 10−3 ppm Ca. The maximum laccase activity (653.5 IU/mL) was observed with 10−6 ppm Cu. This is the first report on nitrogen sources and trace elements effect on ligninolytic enzymes production of Grammothele. The results will facilitate research to understand the nature of the fungus and to increase its enzymes production under controlled conditions.
The author acknowledges the Department of Science and Technology, Government of India, for the financial support in the form of fellowship under PURSE grant during the course of the study and also thankful to the Chairperson, Department of Botany, Panjab University, Chandigarh, for providing the facilities used during part of the experiments in this study.