Determination of Biochemical and Physiological Aspects of a Biocontrol Agent Trichoderma harzianum Th azad

Potentiality of Trichoderma species as a bioagent has been greatly influenced by the physiological parameters like temperature, moisture, nutrients and pH. These factors greatly influence the growth, sporulation and also in determining the effectiveness of Trichoderma against phytopathogens. Among the different solid media, PDA shows excellent growth in average colony diameter (8.72cm) followed by Malt Extract (8.12cm) whereas liquid media such as PDB reveals the excellent average mycelium weight (190.9mg). The most favorable temperature for growth and sporulation of Trichoderma harzianum Th azad was found to be 30?C followed by 25?C. Similarly, most favorable pH 6.5-7.5 ranges was found in which total dry weight of mycelium also varies between 144.805-142.4 mg. Maximum pH was found at 7.0 (162.5mg). The xylanase activity of the fungus Trichoderma harzianum Th azad is profoundly influenced by environmental factors. Effect of different carbon sources such as, glucose, maltose, CMC, sucrose, corncob, wheat bran, oat spelt xylan and birchwood xylan, on xylanase expression was also studied at various time intervals. Highest xylanase activity (5.2 U/mL) was observed at 120 hours with 1 percent birchwood xylan as a carbon source. T. harzianum did not show xylanolytic activity without the presence of any carbon source. Expression of xylanase was induced maximally by xylan and repressed by glucose. The pH and temperature optima of the crude xylanase were 5.0 and 28ºC, respectively. Among the lignocellulosic materials tested as carbon source, birchwood xylan was far most effective for xylanase production. By analyzing xylanase activity on various substrates, we can conclude, that among the substrates tested, birchwood was found to be more effective for xylanase production and maximum xylanase activity was achieved on growth medium with the same.