A Novel Low-Cost Method for Liquid Bacterial Biofertilizer Production

This study was conducted to develop a low-cost technology to produce liquid bacterial biofertilizer. Sterilized Rice Porridge (SRP) was tested as a growth medium for mass multiplication of bacteria using fourteen bacterial isolates. Survival and bioactivity of seven growth promoting rhizobacterial isolates were determined by using sterilized distilled water (SDW) at room temperature (30 ± 2 °C) (RT) as a low-cost and convenient method for storage of bacteria. The novel biofertilizer production technology consisted of SRP and beneficial bacterial isolates storing in SDW at RT (30 ± 2 °C). Preparation of biofertilizer was done by mixing SRP and bacterial isolates in SDW at RT. Then the mixture was sealed immediately and incubated at RT for 24 hours before application. All the fourteen bacterial isolates produced more than 1x108 CFU/mL colony count after 24-hour incubation period in SRP at RT confirming the suitability of SRP for mass multiplication of bacteria. Tested seven growth promoting rhizobacterial isolates survived in SDW at RT without losing their bioactivity with a sufficient viable cell count in SDW up to 18 months when stored in SDW at RT. It revealed the suitability SDW at RT for storage of bacteria A biofertilizer produced by this technology using N-fixing rhizobacterial isolate Priestia aryabhattai (OP950582) was evaluated under field condition using two popular rice varieties. (At 362 & Bw 367). N biofertilizer developed using Priestia aryabhattai reduced chemical N fertilizer application by 50% when applied as a seed treatment at a rate of 1 x 108 CFU/mL of P. aryabhattai. This technology can be used to produce liquid bacterial biofertilizer at a low cost.