Arbuscular mycorrhizal fungi (AMF) are increasingly recognized for their potential to solve the critical challenge agriculture is facing today – producing more with less, while reducing carbon footprint and biodiversity decline. By forming symbiotic relationships with plant roots, AMF provide a wide range of valuable services – improving nutrient mobilization and uptake, increasing resilience to drought stress, and sequestering carbon. They have been captivating the interest of researchers for decades, and with promising advances in biotechnology, the agricultural industry is hopping on the hype train.  

However, despite the hype and the projected growth, the availability of AMF products in the ag input market remains limited. Why? Understanding the limitations of current AMF manufacturing technologies provides the key hints on the cause. 

How Are AMF Produced? 

There are two basic approaches in producing fungal organisms – in vivo, which includes cultivating the fungi in the soil and mimicking natural conditions, and in vitro, which includes cultivation under controlled conditions in artificial solid or liquid substrates. However, what makes AMF special compared to most other fungi is that they are obligate symbionts, which means that they require the presence of the host plant to grow and thrive.  

This attribute of AMF creates significant challenges for large-scale manufacturing. A new meta-study from the University of Kansas¹ quantifies the scope of these challenges and the fitness of current manufacturing technologies to meet them.  The study included over 300 unique AMF inoculant observations and more than 100 commercially available products, and analyzed whether they deliver effects in the field. The results were staggering – 85% of lab-scale products delivered the desired effects, while the same performance was observed in only 16% of commercial-scale products.  

To understand the cause of this gap, let’s explore specific AMF manufacturing approaches and how they impact scalability. 

In-Vivo Production 

In-vivo production seeks to replicate natural conditions and usually involves greenhouse or, less commonly, open field production. The process is pretty simple – host plants are planted in the soil (in pots or open fields) and inoculated with the desired AMF strains. The main advantages of this approach are that the production technology is simple and that compatibility between the plant and the fungus is ensured.  

However, in-vivo production comes with inherent reproducibility challenges, as the quality and the stability of fungal spores vary between the batches due to variable environmental factors and plant health. The production process can also get very time-consuming, being dependent on the growth cycle of the host plant.  

Since it includes growing the fungus in association with plant roots in the soil, efficient downstream processing of the fungal biomass is difficult to achieve, as the risk of unwanted organisms and substrate residues being present in the end product is high. Additionally, scaling greenhouse or open field production requires large growing areas and increased manual labor, increasing production costs and risks.  

In-Vitro Production 

In-vitro production eliminates the variables related to environmental conditions, cultivating AMF in controlled environments. Depending on the substrate and technologies used in the process, there are several methods. 

Solid Substrate Systems 

Methods using solid substrates include cultivating AMF in sterilized soil rhizosphere or synthetic solid substrates (e.g., perlite, vermiculite, biochar, agar), without the presence of free-flowing water. The main advantages of these methods are relatively simple technologies and low resource consumption (water, energy). The most widely used solid substrate system is the root organ culture (ROC) – the golden standard in AMF production. It utilizes hairy plant roots grown in Petri dishes, which allows a higher level of control, reproducibility, and stable spore counts compared to in vivo approaches, resulting in more consistent product quality.

However, scaling up these methods while maintaining product quality is challenging. Simply increasing volumes requires significant investment in infrastructure and staff, as well as increased maintenance efforts. Certain methods, like ROC, also require specialized lab equipment and highly skilled personnel to operate it, further increasing production costs.²

Another disadvantage of solid substrate systems is the arduous process of separating the fungal biomass from the substrate. This process needs to be done in a way that doesn’t decrease the viability of fungal spores and minimizes substrate residues in the end product, which can get very challenging with certain substrates.  

As a result of all these factors, large-scale solid substrate systems often fail to deliver the products of either desired quality or competitive costs.  

Bioreactor Systems 

Bioreactor systems utilize different types of bioreactors (e.g., stirred tank, airlift) in which plant roots and AMF grow in a liquid substrate. Nutrient levels are easily fine-tuned and evenly distributed, being suspended in free-flowing water. More technologically advanced, bioreactor systems allow a high level of process control and scalability, utilizing automation that increases productivity, reliability, and product quality. Liquid substrate also allows streamlined harvesting and downstream processing, improving overall process efficiency and end product quality.  

The key disadvantage of industrial bioreactor systems is the high capital investments in specialized equipment and infrastructure, energy and water consumption, as well as in expert staff operating and optimizing the processes. While being able to deliver high-quality products at scale consistently, these systems are currently too expensive to deliver competitive products outside high-margin markets like pharma.  

Better Products Require Better Manufacturing Technologies 

To make their product more competitive in the market, commercial manufacturers often choose to decrease product cost at the expense of quality. This inevitably results in inconsistent field performance and perceived inefficiency of biologicals by farmers.  

The success in the agricultural market heavily depends on trust and reliability, which are only established with quality products that deliver on their promises. Quality, on the other hand, is established during manufacturing, using the right manufacturing technologies and analytical approaches that secure desired performance.   

The evidence so far shows that in vivo methods are not scalable to the level required for global agricultural application, while state-of-the-art in vitro methods offer scalability, but at uncompetitively high costs.  

Addressing these challenges requires innovative manufacturing technologies that enhance scalability, reduce costs, and ensure consistent product quality. Advancements in vitro methods, particularly in bioreactor technology, offer promising solutions. 

Evologic’s Approach – Quality at Scale and Viable Costs 

Evologic is set to overcome the key manufacturing challenges in the production of biologicals to deliver quality products to the market and unlock their potential to disrupt the agricultural industry. Utilizing its proprietary bioreactor and a new approach to fungal production, Evologic has developed a disruptive technology that overcomes scalability and quality issues inherent to state-of-the-art AMF manufacturing technologies.  

As proof of quality and technological competence, Evologic has produced 1000L of AMF product that meets stringent quality requirements and has achieved 7x greater spore concentration than state-of-the-art methods, all at lower costs.  

If you’re exploring innovative ways to develop or scale AMF products, we’d love to hear from you. Reach out at office@evologic-technologies.com to discuss how we can help bridge the gap between research and commercialization.

1. Koziol L., McKenna T.P., & Bever J.D. Meta-analysis reveals globally sourced commercial mycorrhizal inoculants fall short. New Phytologist. Nov 2024.  ↩︎
2. Ghorui M., Chowdhury S., & Burla S. Recent advances in the commercial formulation of arbuscular mycorrhizal inoculants. Frontiers in Industrial Microbiology. Apr 2025. ↩︎