R. Ranjini and T. Padmavathi
A preliminary study of phenol tolerance of Pleurotus florida under varying nitrogen levels used Mandel and Weber’s Modified Agar Glucose medium. Urea, Ammonium sulphate, Peptone: variable nitrogen components. Phenol concentrations: 200, 400, 800 mg/L; nitrogen variations: sufficient(N), deficient(N/2), deprived(N/10), excess(N×10). Tolerance studied by computation of total growth area: rate of fungal tip extension, every alternate day, for 22 days. In N, growth area higher for 200 and 400 mg/L phenol (32.48, 31.38 sq.cm) than 800 mg/L (12.55 sq.cm). In N/2, higher for 400 and 800 mg/L (14.92, 22.21 sq.cm) than 200 mg/L (0.29 sq.cm) In N/10 and N×10, high for 800 mg/L (32.07, 42.2 sq.cm) compared to 200 and 400 mg/L (12.97, 13.04 sq.cm; 11.71, 14.54 sq.cm). In N, rate of increase positive for entire growth cycle upto 400 mg/L. In 800 mg/L, stopped by day twelve. In N/2, growth stopped between day six and eight in 200 and 400 mg/L; upto day fourteen in 800 mg/L. Pattern repeated for 200 and 400 mg/L in N/10 and Nx10. In N/10 800 mg/L, growth positive throughout. In N×10 800 mg/L, stopped by day twelve. Growth pattern similar for 200 and 400 mg/L in all media, indicated by correlation of 0.871. In 800 mg/L, similar growth patterns between N/2 and N/10; N/2 and N×10; N/10 and N×10; indicated by correlation of 0.75, 0.8 and 0.99. Optimum nitrogen (N) offered better tolerance and growth for P.florida in 200 and 400 mg/L phenol, while N/2, N/10, Nx10 provided the same tolerance in 800 mg/L.
