Bio-fertilizer Insights


What is the significance of local fertilizer production and the results of the DEEP PURPLE project in Europe?

There is a substantial reliance on imported inorganic fertilizers, as revealed by statistics provided by Fertilizer Europe. In 2021, Europe imported significant amounts of nitrogen, phosphorous, and potash, accounting for 32%, 65%, and 88% of their consumption, respectively. This highlights the heavy dependence of European agriculture on imported inorganic fertilizers. Secondly, the fertilizer manufacturing industry in Europe boasts a turnover of 9.8 billion euros and provides approximately 75,000 jobs. This sector contributes significantly to the region’s economy and employment opportunities. Europe’s organic market is experiencing impressive growth, with over 13 million hectares of organic farmland and 37 billion euros in retail sales. In 2021, the organic market size corresponded to 8.5 million tons of organic-derived nitrogen, 4.5 million tons of organic-derived phosphorus and 10.1 million tons organic-derived potash.

Additionally, to comply with upcoming regulatory rules aimed at preventing soil and water pollution, organic farming is expected to increase the use of coated fertilizers, representing 20% of total consumption over the next three years. This shift will contribute to reducing reliance on rock materials.

As DEEP PURPLE project proves its effectiveness in valorizing wastewater, it confirms a sustainable fertilizer production. Utilizing the vast annual generation of municipal wastewater in Europe (40,000 million m3 in 2013), it is possible to produce 15 million tons of slow-release fertilizer, recovering 450,000 tons of PO43- annually. This sustainable approach would alleviate the current need for importing rock materials.

Has the DEEP PURPLE project tested the effectiveness of its slow-releasing fertilizer?

The metabolic capabilities of Purple Phototrophic bacteria (PPB) can be directed towards C-based biorefinery for bioplastics or N-P-K-based biorefinery for organic fertilizers. DEEP PURPLE aims to demonstrate the applications of PPB fertilizers and explore potential future developments. Here are some results from tests conducted on plants using PPB fertilizers.

Why should organic fertilizers be used? What are the advantages of producing them?

Organic fertilizers offer numerous benefits. They improve soil health, organic fertilizers enrich the soil with nutrients, fostering beneficial microbial activity, enhancing soil structure and water retention capacity, and ultimately promoting overall soil health. Secondly, organic fertilizers are derived from renewable sources such as animal manure, compost, and plant-based materials. By reducing reliance on synthetic fertilizers, their use supports sustainable agricultural practices.

Unlike conventional fertilizers, organic fertilizers are free from harmful chemicals and synthetic compounds. This reduces the risk of soil and water contamination, leading to a minimized environmental impact in agriculture. Organic fertilizers also release nutrients gradually, which provides a sustained supply to plants. Moreover, the organic matter present in these fertilizers improves soil fertility, leading to increased crop yield and improved plant quality.

What complexities come in to play when treating wastewater with The Purple Phototrophic bacteria (PPB) into high-added value products like organic fertilizers?

The agronomic efficiency of organic fertilizers depends on both its chemical make-up and the capacity of microbes to convert the organic material into a form that plants can utilize. To ensure a constant quality of our fertilizers, we need to make sure that the raw materials we used, such as PPB biomass, fulfill the requirements in terms of stability and homogeneity. Using raw materials that adhere to strict stability and homogeneity requirements is crucial for guaranteeing the organic fertilizers’ high quality. In this instance, it is said that PPB biomass can be used as a raw material. Designing and running a wastewater treatment plant (WWTP) under ideal PPB growth conditions is necessary to maximize the recovery of elements from waste and guarantee that the PPB biomass is of high quality.

The PPB process, for instance, can be altered by variables including temperature, light intensity, and wastewater makeup. In order to maximize the circumstances for the PPB to thrive and produce the intended results, the treatment plant must be designed and run in a certain way.

Designing and running a wastewater treatment plant (WWTP) under ideal PPB growth conditions is required to maximize the recovery of components from waste and guarantee that the PPB biomass is of high quality. The mineral and carbon content of the generated PPB biomass can be significantly influenced by the make-up of the waste stream entering the WWTP.

To maintain the security of the produced fertilizer, it is crucial to effectively sterilize the PPB biomass. This entails treating the biomass to get rid of any potentially hazardous microbes.

How does the DEEP PURPLE project aim to address the increasing demand for organic fertilizers and diversify the market by utilizing PPB biomass as a renewable source?

In the DEEP PURPLE project, our goal is to utilize PPB biomass, a renewable material, as a source of carbon and minerals to produce organic fertilizers. This innovative approach allows us to tap into valuable resources and diversify the market with new organic options. Organic fertilizers are commonly used to improve soil properties, such as fertility, stability, aeration, and microbiological activity, ensuring optimal crop development. They are compatible with organic farming and typically consist of plant compost and/or animal manure.

The strength of organic fertilizers lies in their ability to not only provide essential elements for plant growth but also improve soil properties compared to chemical fertilizers. They have a lower risk of nutrient leaching due to their slow-release nature. However, the limitations of organic fertilizers include their relatively low nutrient enrichment or imbalances between elements due to the raw materials used. As a result, organic fertilization cannot completely replace the use of chemical fertilizers but provides complementary effects on crop growth.

The market for biofertilizers has remained relatively stable in the past decade but is expected to grow due to the expansion of organic farming. While Europe is currently the main consumer of organic fertilizers, there is also increasing interest from Asian countries. Therefore, finding new renewable sources of organic matter is essential to meet the rising demand.

In our project, we leverage the hyper-accumulative PPB bacteria, which can assimilate and accumulate organics and nutrients from liquid waste streams. PPB biomass is valuable due to its low C/N ratio and enrichment in phosphorus (P). We combine this raw material with other organic substances to enhance the properties of the organic fertilizer. Our preliminary experiments have demonstrated the positive effects of PPB biomass alone and the PPB-based organic fertilizer on crop growth in controlled conditions. Initial field trials have also shown positive effects compared to unfertilized wheat plots and confirmed the absence of any toxicity. Further characterization of the fertilizer is underway to evaluate its impact on soil and plants in both controlled conditions and field settings.



Industry-Facts-and-Figures-2022, Facts & Figures. (2022). Fertilizers Europe. Retrieved July 6, 2023, from

The EU’s organic food market: Facts and rules (infographic) | News | European Parliament. (2018, October 4).