University of Granada (UGR) is working on production and formulation of microbial inoculants

The EXCALIBUR Team of the UGR is working actively on production and formulation of microbial inoculants with plant growth promoting and biocontrol functions.

Together with other partners, different lines of studies have been carried out such as:

• Selection of compatible microorganisms, phytostimulants, and carriers.
• Optimization of the fermentation processes for higher yields of biomass and spores.
• Formulation of the resulting products.
• Application of the formulated in soil-plant systems.

Each one of these lines of studies contains a wide number of tasks with challenging results suggesting new ideas and opportunities.

• During the most recent research activities, the UGR team developed an efficient method for continuous production of fungal biomass and spores. It appeared that this method enhanced the yields of the microbial biomass and spores and makes easier their separation and the formulation step of a potential commercial biofertilizers/biocontrol agents.

• Additional work on optimization of the whole fermentation process included optimization of the medium characteristics. The UGR team successfully tested a new medium based on natural components, which shortened the microbial growth time increasing the total microbial production.

• We have also shown that the different mode of fermentation process affects the characteristics of the microbial development. Similarly, under different conditions of the fermentation process, the microorganisms responded differently to stress factors. It was shown that under conditions of solid-state and immobilized state, the model microorganisms demonstrated higher resistance to abiotic stress. The most probable reason is that microorganisms living in both fermentation systems are close to their natural state – immobilized in/on soil particles and plant tissues.

Based on the above achievements, the UGR team formulated doble inoculants – two compatible microorganisms in one carrier complemented with additional phytostimulating natural compound. This product (see Fig 1), tested at controlled conditions demonstrated both plant growth and biocontrol activities (see Fig.2).

Further work is needed to follow, at least partly, different potential developments in order to respond to the existing challenges related to the principles of the sustainability, circular economy, climate changes, and human health.