Optimization of Cell Protectants, Adjuvant and Additives to Develop Liquid Formulation of Azospirillum
Loading...
![Thumbnail Image](assets/images/Item.jpg)
Date
2017-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Science, Dharwad
Abstract
An effort was made to optimize the additives, adjuvant and surfactant for the growth and shelf life of liquid formulations of Azospirillum ACD-15 at the Institute of Organic Farming, University of Agricultural Sciences, Dharwad during 2014-15.
Sodium malate broth was amended with additives such as polyethylene glycol at 0.5 and 1.0 per cent, trehalose at 5 and 10 mM and glycerol at 5 and 10 mM. Adjuvant like gum arabica at 0.15 and 0.30 per cent; surfactant like polysorbate - 20 at 125 and 250 ppm. A total of 32 combinations of formulations were developed and evaluated for their ability to support growth and higher populations of Azospirillum ACD-15 over a period of 72 h. Based on population dynamics only nine formulations with population more than 9.6 x 109 CFU ml-1 after 72 h were chosen for further incubation studies. These nine formulations were kept for shelf life study over a period of six months at both ambient and refrigerated conditions. Among them, formulation 2 under both conditions was found to be far superior to others in terms of the population of Azospirillum ACD-15 at all stages over 180 days of incubation. This formulation recorded the highest populations in terms of the most probable number estimation of Azospirillum ACD-15 under ambient condition (6.18 x 106 cells ml-1) and under refrigerated condition (1.07 x 106 cells ml-1). The population was also assessed by direct plate count technique with values of 1.58 x 109 cells ml-1 at ambient condition and 7.0 x 107cells ml-1 at refrigerated condition.
In the present study, the cost involved in the production of this efficient formulation 2 was 376 litre-1 and 58 per cent of this cost was on one amendment trehalose (additive) alone. The results from this study clearly indicated that the liquid formulation of Azospirillum ACD – 15 was better in terms of viable population and shelf life compared to lignite formulation.