DESIGNING LOW COST SSF STRATEGY FOR MASS PRODUCTION OF BIOINOCULANT TRICHODERMA HARZIANUM KSNM WITHLONGER SHELF LIFE

摘要

Solid substrate fermentation based mass production strategy has been explored as an option for economic and environmentally safe method for multiplication of agriculturally important biocontrol fungus Trichoderma harzianum KSNM (T103). The study elaborates designing optimal SSF technique incorporating low cost substrate combinations that could produce maximum biomass and also retain viability of T103 for very long period. Fifteen different substrate combinations were made from wheat straw, wheat branand wheat grain (WS:WB:WG V/V). Based on their physical attributes such as, pore space, water holding capacity, particle density and available moisture content, substrate combination number 12 (SC12) was chosen to carry out SSF. Optimization experimentsinvolved testing of two different wetting media (WS1 and WS2) with different salt combinations. Wetting solution WS1 showing better biomass production (>35%T) and less pH change (<1 pH unitt) in the substrate post incubation was further optimized. WS1 was further tested at normal, double, half and quarter (X, 2X, X/2 and X/4) strengths. Both X and X/2 resulted in consistent biomass yield till week 4. However X/2 showed better growth promotion (50% with X viz. 59% with X/2) and was thus selected for SSF. Post SSF, substrate utilization studies revealed increased nutrients release till fourth week of incubation beyond which a decline in nutrient release was observed (Total N: 4-2.4%, P: 20-11 ppm and K: 0.5-0.3 ppm). Periodic growth evaluation studies with optimized SSF grown fungal inoculum have shown sustained viability and consistent spore production ability till 56 weeks maintaining an average of 1.69><108 spore count. This is a first of its kind study reporting a shelf life of 14 months when maintained at room temperature with no compromise in inoculum potential.