University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Doctoral Thesis:
Teresa Susanne Berninger
(2017):
Development of Formulations for Plant Beneficial Bacterial Inoculants.
Doctoral Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 105.
UB BOKU
obvsg
FullText
- Abstract:
- Plants live in close association with microorganisms, some of which have beneficial effects on the plant and may thus be applied in the field as a sustainable alternative to agrochemicals. In many cases, however, their susceptibility to environmental factors and short shelf life are limiting their practical use. To address this issue, the development of protective formulations is crucial. For formulation of the model organism Paraburkholderia phytofirmans PsJN, alginate beads were produced by a range of lab-scale methods. The throughput and compatibility of the respective methods with different matrix compositions as well as the morphology of resulting beads, the controlled release of bacteria and suitability for seed coating were described. Alternatively, granules and powders carrying the inoculant based on a matrix of zeolite, a film forming agent and protectants were developed and characterized. 20 chemically diverse protectants were checked regarding their ability to maintain a high viability of PsJN after lyophilization or air drying. Furthermore, secretion of exopolysaccharides was triggered in PsJN and tested as a protectant during desiccation. The bacterial viability was monitored over a period of up to seven months of storage at different temperatures. We demonstrated that the selection of appropriate protectants and their combination with suitable drying methods is highly important and dramatically increases the survival rate of PsJN by up to 100,000-fold. A high shelf life of more than three months at room temperature was achieved applying skimmed milk powder or PsJN’s exopolysaccharide as protectants. Small sized alginate beads (< 100 µm) proved suitable for seed coating, whereas zeolite granules may be a feasible means to deliver the inoculant in-furrow. These observations contribute to identifying suitable formulations, not only for PsJN but also for other promising, plant beneficial bacteria.
- Betreuer:
- 1. Berater: Zechmeister-Boltenstern Sophie