What Is EM?
What is EM®?
Effective Microorganisms® (EM®) is a carefully balanced community of naturally occurring beneficial microorganisms. Developed by Professor Teruo Higa in 1982, EM® has been used in agriculture, animal husbandry, environmental restoration, and human health in more than 100 countries.
Three groups working as one
EM® is not a single-strain product. Its power comes from three distinct groups of microorganisms — lactic acid bacteria, yeast, and photosynthetic bacteria — working together in a stable, synergistic community. Each group plays a unique role, and together they activate native microorganisms already present in soil, water, and living systems.
© 2018 Gustavo Pinoargote. All rights reserved. Scanning electron micrograph.
Lactic acid bacteria
Ferment organic matter and produce lactic acid, which accelerates decomposition and enhances nutrient availability. They are the backbone of EM® fermentation.
Yeast
Synthesize vitamins, enzymes, and plant hormones from sugars and amino acids — supporting root development and overall vitality in agricultural and environmental applications.
Photosynthetic bacteria
Use sunlight and soil heat to synthesize amino acids, nucleic acids, and bioactive compounds from root secretions, organic matter, and gases. Found in ecosystems across the globe.
© 2018 Gustavo Pinoargote. All rights reserved. Scanning electron micrographs.
A microbiome approach — long before microbiomes were trending
EM® works by restoring a healthy balance of microorganisms in the environment it’s applied to. Rather than targeting a single problem with a single organism, EM® activates the full community of native microbes already in your soil, water, or system — amplifying their natural capacity to purify, regenerate, and sustain.
Modern microbiome science has confirmed what EM practitioners have known for decades: the diversity and balance of microbial communities is what drives healthy soil, clean water, and resilient ecosystems. EM Technology® was designed with that principle at its core.
More than microorganisms
The results observed with EM Technology® go beyond what any single strain — or even a blend of strains alone — can achieve. It is the interaction between the microbial groups, the metabolites they produce, and the native biological community they awaken that creates outcomes greater than the sum of any individual part.
Used in more than 100 countries
Where EM Technology® is applied
EM Technology® applications are supported by peer-reviewed research published in journals including Aquaculture Research, Journal of Environmental Radioactivity, and Journal of Probiotics & Health, among others.
The Origin: How Dr. Teruo Higa Discovered Effective Microorganisms®
The story of EM Technology® begins at the University of the Ryukyus in Okinawa, Japan, in the late 1970s. Dr. Teruo Higa was a professor of horticulture researching whether naturally occurring microorganisms could improve plant growth and reduce dependence on synthetic agricultural chemicals.
At the time, the dominant scientific view held that microorganisms were largely competitive — that different species of bacteria, fungi, and yeasts would fight each other for resources, making it impractical to combine them into a stable, beneficial community. The assumption was that you had to isolate a single strain and work with it alone.
Dr. Higa challenged that assumption. Through years of careful experimentation, he discovered something unexpected: when he combined specific groups of naturally occurring, beneficial microorganisms, they did not compete. Instead, they co-existed, supported each other, and produced a synergistic effect far greater than any single organism could achieve alone.
The accidental catalyst for this discovery is now well known in the EM® world. Dr. Higa had discarded a mixture of microorganisms onto a patch of grass near his laboratory — organisms he believed were no longer useful for his experiments. Days later, the grass in that area had grown noticeably stronger, greener, and more vibrant than the surrounding area. He traced the effect back to the discarded microbial mixture.
That observation launched the research that would become Effective Microorganisms® (EM®). In 1982, Dr. Higa published his foundational findings. In 1994, EM Research Organization, Inc. (EMRO Japan) was established to develop, standardize, and authorize the production of authentic EM® products worldwide. Today, EM Technology® is applied in over 120 countries across agriculture, environmental restoration, aquaculture, animal husbandry, and human wellness.
EM Technology® vs. Single-Strain Microbial Products
The market for microbial products has grown significantly in recent years, and it can be difficult to understand what sets EM Technology® apart from the dozens of other probiotic and inoculant products available. The difference is fundamental — it comes down to community vs. isolation.
Most commercial microbial products contain one or a small number of microbial strains, selected because they perform a specific function well in laboratory conditions. A product might contain only Bacillus subtilis, or only a mycorrhizal fungus, or only a nitrogen-fixing bacterium. These products can be effective within a narrow range of conditions, but they are inherently limited by their simplicity.
The real world — whether it is a field soil, a compost pile, a shrimp pond, or a human gut — is not a laboratory. Microbial environments are complex, dynamic, and constantly shifting. A single organism introduced into that complexity often fails to establish, because it is competing against thousands of native organisms already adapted to that environment.
EM Technology® addresses this through community ecology. The three groups of microorganisms in EM® — photosynthetic bacteria, lactic acid bacteria, and yeasts — have been co-fermented into a stable consortium that is adapted to surviving and thriving in complex environments. They support each other metabolically, which makes them far more resilient and effective than any single strain introduced alone.
- Photosynthetic bacteria produce organic compounds that feed the lactic acid bacteria and yeasts
- Yeasts produce bioactive compounds and enzymes that support plant growth and stimulate the photosynthetic bacteria
- Lactic acid bacteria produce lactic acid that suppresses pathogens and creates conditions where the whole community thrives
This is the principle that Dr. Higa identified in Okinawa more than 40 years ago, and it is what has been validated across hundreds of peer-reviewed studies and field trials on six continents since.
A 40-Year Research Record
EM Technology® is not a new idea or an unproven concept. It has been the subject of rigorous scientific research since the early 1980s, conducted by universities, government agricultural agencies, environmental engineering firms, and independent researchers worldwide.
Key areas of documented research include:
- Soil health and crop yields — improvements documented in rice, vegetables, fruit crops, and row crops across multiple countries and climates
- Nitrogen reduction — commercial-scale field trials have documented reductions of up to 50% in synthetic nitrogen inputs while maintaining or improving yields
- Pathogen suppression — documented suppression of soilborne and waterborne pathogens without chemical intervention
- Wastewater treatment — measurable reductions in biological oxygen demand (BOD), hydrogen sulfide, and ammonia emissions in treatment systems
- Aquaculture — improved survival rates, feed conversion efficiency, and water quality in shrimp and fish production
- Composting — accelerated decomposition rates and significant odor reduction in both small-scale and commercial operations
- Animal husbandry — improved gut health, feed efficiency, and reduced odor in poultry, swine, and livestock operations
- Human wellness — probiotic and microbiome research supporting the use of EM-fermented products for digestive health
Research has been published in peer-reviewed journals including Aquaculture Research, Journal of Environmental Radioactivity, Journal of Probiotics & Health, and numerous agricultural science publications. EMRO USA is committed to making this research accessible — visit our EM Technology® Research Library for studies, field trial reports, and technical documentation.
EMRO USA: The Authorized Manufacturer in the United States
EMRO USA, Inc. is the sole authorized manufacturer of EM Technology® products in the United States and Canada. We operate under a direct licensing and quality agreement with EM Research Organization, Inc. (EMRO Japan) — the organization founded by Dr. Teruo Higa to develop, standardize, and protect the integrity of EM Technology® worldwide.
What this means in practice:
- Every product we manufacture meets the same formulation and quality standards established by EMRO Japan
- Our EM•1® Microbial Inoculant is produced using authentic starter cultures maintained in alignment with EMRO Japan's specifications
- We are not a reseller, a distributor, or a third-party reformulation — we are the manufacturer
- EM•1® is OMRI Listed® for use in certified organic production
- When you buy from EMRO USA, you are buying directly from the source — no intermediaries, no uncertainty about what is in the bottle
EMRO USA is based in Tucson, Arizona. We manufacture and ship authentic EM® products across the United States and Canada. For bulk orders, distributor inquiries, or commercial applications, contact us at orders@emrousa.com or call 520-492-2010.
Frequently Asked Questions About EM Technology®
Is EM Technology® safe for humans, animals, and the environment?
Yes. EM Technology® is composed entirely of naturally occurring microorganisms found in healthy soils, fermented foods, and natural water systems. The organisms in EM® are not genetically modified, not pathogenic, and not toxic to humans, animals, plants, or the environment. EM•1® is OMRI Listed® for use in certified organic production.
What is the difference between EM•1® and a regular probiotic or microbial inoculant?
Most probiotics and inoculants contain one to a dozen strains of bacteria selected for a single function. EM•1® contains a stable, co-fermented consortium of three groups of microorganisms — photosynthetic bacteria, lactic acid bacteria, and yeasts — that work synergistically. The photosynthetic bacteria in EM•1® are rarely found in conventional products and are central to what makes EM Technology® uniquely effective across agricultural and environmental applications.
Can EM Technology® reduce fertilizer use?
This is one of the most well-documented benefits of EM Technology® in agriculture. By improving soil biology and nutrient cycling, EM•1® enables plants to access nutrients more efficiently. Commercial-scale field trials have documented reductions of up to 50% in synthetic nitrogen inputs while maintaining or improving yields. Results vary depending on soil conditions, crop type, and application protocols.
What is the difference between EM•1® and ProEM•1®?
EM•1® is formulated for agricultural, environmental, and general applications — soil, compost, water, livestock, and more. ProEM•1® is our human-grade fermented probiotic, formulated specifically for consumption. Both are rooted in the same EM Technology® science, but ProEM•1® is produced to food-grade standards for digestive and wellness support.
How do I get started with EM Technology®?
The best starting point is EM•1® Microbial Inoculant. Whether you are a home gardener, a commercial farmer, a livestock producer, or working on an environmental project, EM•1® is the foundation from which all EM Technology® applications begin. Visit our Applications page for protocols specific to your use case, or contact us directly for guidance.
What is Activated EM® (AEM) and how is it made?
Activated EM® (AEM) is produced by fermenting EM•1® with molasses and water over 5–7 days. This process multiplies the microbial population and extends the volume of product available for large-scale applications such as field agriculture or wastewater treatment. AEM retains the full spectrum of Effective Microorganisms® and is a cost-effective way to scale EM Technology® for commercial use.
Where can I find research on EM Technology®?
EMRO USA maintains a growing library of peer-reviewed studies, field trial reports, and technical documentation. Visit our EM Technology® Research Library to explore the science behind our products.
Commercial growers: learn how EM Technology® can reduce your nitrogen costs by up to 50% with the EM Nitro™ Protocol.
Not sure if the EM® product you are looking at is the real thing? Read our guide: How to Identify Authentic EM Technology®.
EM®, Effective Microorganisms®, EM Technology®, EM•1®, and ProEM•1® are trademarks of EM Research Organization, Inc. (Japan), used under license by EMRO USA, Inc.