STANDARDISATION OF MICROENCAPSULATED Trichoderma asperellum FOR PROLONGED SHELF LIFE AND EFFECTIVE DELIVERY SYSTEM

A study was conducted to develop a novel formulation of Trichoderma asperellum, with sodium alginate, a biodegradable polymer as the encapsulating carrier material. The concentration of sodium alginate was standardized to 0.75 and 1.5 per cent for formation of spherical beads. Based on the shape of bead, 8 - 12 cm was selected as optimum height of air column between the orifice of separating funnel and level of CaCl2 bath. Calcium chloride at 2.5, 3.0 and 3.5 % was adopted to prepare beads by employing ionotropic gelation and cross linking technique. Beads were dried for 48 h at room temperature and stored in air tight containers. Maximum per cent bead yield was noticed in T19 (trehalose, PVP, CMC, tween 80, sodium alginate 1.5%, CaCl2 2.5%) and maximum of 26.91 beads were formed in T9. Shelf life evaluation was carried out for six months, where T21 (trehalose, PVP, CMC, tween 80, sodium alginate 1.5%, CaCl2 3.5%) was superior to other treatments. Degree of contamination was estimated where T1 - T6 and T19 - T30 remained free of contamination even after six months of preparation. Per cent of potentially infective beads were estimated where cent per cent germination was recorded at 72 h after incubation. Moisture content of beads was assessed where beads retained its intact shape at 48 h. Gradual increase in weight of beads at pH 7.4 confirmed the swelling behaviour while reduction in weight at pH 1.0 revealed its shrinking nature. Time of gelation was standardized as 60 min.