Feature

Revolve Around Microorganisms: Life, Earth, and Us

Index

  1. Breaking down and Rebuilding: Revisiting the Definition of Life

  2. Fukuoka’s Original Exploration of Life: The Shared Nature Among All Living Things

  3. Respect for Microorganisms: A Key to Earth’s Survival

  4. Recoverable Cycles of Our Planet: Call to Action in the Grand Scheme of History

  5. Living in the Future: Rethinking the Standard

When the term microorganisms comes to mind, what image does it conjure? Perhaps benefactors that decompose waste, or enigmatic entities ubiquitously intertwining with our existence? Our understanding of these microscopic beings is often shallow, despite living around and within us by the trillions, essential to our survival. The definition of a microorganism is deceptively simple: an organism too small to be seen by the naked eye. Yet, this simplicity belies the complexity and crucial roles these tiny organisms play in life’s grand tapestry and their intricate connection with us. In this edition, we aim to demystify microorganisms, exploring their pivotal contributions to life’s cycles and their symbiotic relationship with humanity.

Our journey led us to Mr. Shin-ichi Fukuoka, a distinguished biologist and the thematic project producer “Dynamic Equilibrium of Life,” a pavilion dedicated to unraveling the mysteries of life at Expo 2025 Osaka, Kansai. Fukuoka, celebrated for his insightful book “Seibutsu to Museibutsu no Aida (Between Living and Non-living Things),” sheds light on microorganisms, linking them to broader environmental dilemmas and the essence of life itself. His reflections provoke a deeper contemplation on the composition of our world and the role we, as humans, ought to play within it. By the end of this article, your perspective on microorganisms will change forever, leaving you to ponder their significance long after the lights go out.

Words: Shin-ichi Fukuoka

Breaking down and Rebuilding:
Revisiting the Definition of Life

Before delving into the realm of microorganisms, it's imperative to address a fundamental question: What is life?

Merely listing observable characteristics like cells, DNA, movement, metabolism, and respiration falls short of capturing life’s true essence. My initial foray into biology in the early 1980s, a period marked by the advent of biotechnology, was driven by a fascination with molecular biology—the study of life’s microscopic mechanisms within cells.

Photo of a light pink water balloon floating in water. The surface of the water sparkles with reflecting light, while ripples of shadow and light trace the bottom of the water.

I too was immersed in the trend of isolating individual microscopic molecules like DNA and proteins to analyze their mechanisms, essentially viewing life through a mechanical lens. The prevailing belief was that unlocking the secrets of life was as straightforward as deciphering the DNA blueprint, which comprises 20,000 different proteins, through initiatives like the Human Genome Project.

However, a profound realization emerged from our DNA studies: understanding all 20,000 proteins would not bring us any closer to comprehending life. This revelation prompted a shift in focus from separating life into individual components to exploring the interactions between these components. We began to see life not as a static entity but as a dynamic phenomenon. It became clear that life is not about the simple exchange of old for new through metabolism; rather, life is about actively dismantling itself and using the ensuing instability to re-establish order.

This concept, which I’ve termed “dynamic equilibrium,” is the cornerstone of my theory on life.

Photo of ground where dark soil and dry grass intermingle. The soil looks slightly damp, with a porous and soft texture. Although the dry grass dots the surface of the soil, it appears that the soil is encroaching on the dry grass.

Fukuoka’s Original Exploration of Life:
The Shared Nature Among All Living Things

As a child, I was what you might call an insect aficionado. With few human companions and a naturally introverted demeanor, I found solace not in the gaze of people but in the intricate details of the ground beneath me, exclaiming in silent wonder at the sight of a longhorn beetle. My days were filled with poring over insect encyclopedias and venturing outdoors in pursuit of these creatures. For a summer project, I meticulously documented the breeding patterns of butterflies, fascinated by each species’ unique preference for certain leaves. Swallowtail butterflies favored the leaves of mandarin and trifoliate oranges, while yellow swallowtails were drawn to parsley and carrot leaves. The Chinese windmill butterfly sought out the slender Dutchman’s pipe. Despite the uniform nutritional value across these plants, I was intrigued by their selective diets.

Photo showing various size pools of water that have formed on a metal surface.

As an adult, this observation blossomed into a deeper understanding: butterflies diversify their diet to minimize competition for food, a strategy essential in a world where resources are finite. This behavior exemplifies dynamic equilibrium, not just at a cellular level but within entire ecosystems.

Photo of a green plant growing in abundance on a pale green background. Water droplets are found here and there on the leaves and flower buds.
Photo of densely grown plants whose changing autumn leaves are illuminated by red sunlight. The leaves are a mix of bright red and orange, and the ground is covered with fallen leaves.

Another profound lesson emerged from my study of butterflies—metamorphosis. A larva emerges from an egg and, over time, sheds its skin to form a chrysalis, entering a state of motionless transformation. As a young insect enthusiast, I once peered inside a chrysalis, expecting to find a larva in transformation. Instead, I discovered no larva at all, but rather a black liquid that had once been the larva, now reduced to sludge. The larva had been utterly dismantled in the process. Yet, from this apparent destruction, life renews itself, using the nutrients from the sludge to give rise to a butterfly. This process, if observed by someone unfamiliar with Earth’s biology, would seem miraculous—how could the larva and butterfly be the same organism?

This cycle of destruction followed by creation was my first personal encounter with the principle of dynamic equilibrium. It also marked the beginning of my lifelong awe and respect for the intricate and resilient processes of nature.

Respect for Microorganisms:
A Key to Earth’s Survival

As we delve into the realm of the unseen, it becomes clear that our world teems with countless invisible life forms: microorganisms. Antoni van Leeuwenhoek, a 17th-century Dutch scientist from the small town of Delft, was a pioneer who first glimpsed these mysterious organisms through a homemade microscope capable of 300x magnification, revealing the bustling life in what appeared to be transparent river water.

So, what roles do microorganisms play? Essentially, microorganisms are pivotal in driving the cycles of life.

Photo showing a long, thin, linear branch that has fallen in a circle pattern in the center of a patch of soil whose surface is dotted with pebbles. One end of the branch is green while the other is withered and dry.

This brings us to the concept of dynamic equilibrium, where life is a continuous flow of decomposition and synthesis. Who orchestrates the major cycles on Earth? It’s the carbon atom, currently vilified amidst global warming concerns. The aim for a decarbonized society is widely discussed, yet it’s crucial to remember that humans are carbon-based beings. The real issue is not carbon itself but the disruption of the global cycle. Microorganisms transform carbon into organic matter, which is subsequently broken down into simpler forms. Thus, we ought to appreciate the efforts of microorganisms, particularly those of plant origin, for their significant role in the carbon cycle.

Photo showing a mesh-like pattern formed by a distorted film adhered to a glass-like object. An irregularly shaped cloudy white pattern appears on a transparent background. The pattern is random, and subtle colors slip in and out of view due to the refracting light.

Moreover, microorganisms are instrumental in energy circulation. They harness sunlight, converting it into organic matter, and generously share it with other organisms. For instance, plants engage in photosynthesis beyond their own needs, offering their leaves, fruits, and roots to other life forms.

Admittedly, not all microorganisms are benign. Pathogens like cholera and dysentery bacteria pose significant threats. However, the vast majority of microorganisms are not only harmless but also beneficial to humans. The topic of intestinal bacteria has gained prominence recently. It's easy to assume they merely consume our food, but in reality, they detoxify harmful substances, transform nutrients into more accessible forms for us, and even serve as a protective barrier against external threats.

Photo of plants taken from a bird's-eye view. Dense, glossy green leaves grow, among which numerous white flowers blossom.
A close-up photo of an object with a green waveform pattern. The waveform stands out on the light green background at the top, and the waveform appears on the dark background at the bottom. These are in fact parts of train seats that were photographed.

The trillions of microorganisms in our digestive system play a crucial support role. The composition of these microbial communities varies with the climate of one’s environment. For instance, Japanese individuals, who consume a considerable amount of seaweed, host numerous bacteria capable of breaking down seaweed. Recent findings also indicate that the metabolic activities of intestinal bacteria impact not just physical health but our psychological state as well, highlighting a direct link to mental health concerns.

Recoverable Cycles of Our Planet:
Call to Action in the Grand Scheme of History

In the vast tapestry of Earth’s history, cycles of change have always been recoverable. Life on Earth, with its 3.8 billion-year history, has seen dramatic environmental shifts. Oxygen once ranged from 20% to 30% in the atmosphere. Ice ages enveloped the planet in frozen expanses. Dust from asteroid impacts shrouded the world, blocking sunlight. In this darkened era, photosynthesis ceased, leading to the demise of plants, herbivores, and eventually, the mighty dinosaurs. Yet, from this brink, a new age dawned as resilient creatures like rats ushered in the era of mammals. Earth’s dynamic equilibrium persisted, adapting through turmoil.

Photo of a white wall and countless thin branches. The branches are broken at various points and attached to the wall, making it look as if they were drawn directly on the white wall. There is a small white ventilation opening in the wall. A manicured green hedge grows from the ground in front of the wall.

Today’s environmental crises, however, are not natural phenomena. They are the consequences of human actions, where we have assumed dominion over the Earth’s resources. Acting selfishly instead of nurturing the cycle, we have disrupted the balance.

Human societies often prioritize selfish order within their communities, unwittingly unleashing entropy—disorder—manifested in mounting garbage and carbon dioxide emissions. While Earth can absorb some level of entropy, we have surpassed its limits. What we face today is less an energy crisis and more an entropy crisis.

Close-up photo of what looks like frosted glass. The top half features a faint blue-white gradation, and this gradually turns into to a dark gray in the bottom half. There is a thin vertical line in the center, and it seems to be a piece of abstract art.

Living in the Future:
Rethinking the Standard

To truly live in harmony with our planet’s ecosystems including microorganisms, we must reconsider our consumption behaviors regarding food, clothing, and shelter through the lens of entropy. Humans have disrupted the natural cycle by accumulating wealth unnecessarily. This accumulation not only puts strain on the environment but also goes against the natural order observed in other organisms. While other beings secure what they need and pass on the surplus, humans uniquely hoard wealth. This accumulation of wealth is not just about numbers; it directly impacts the global environment. Humans have exploited natural resources like oil and coal, claiming land that belongs to no one. To coexist sustainably, we must transcend individual desires and champion altruism as a political and social movement.

Photo of a fallen branch among dry, brown grass. The fallen branch is supported by the trunk of a thin plant, causing one end to lift up in the air. The broken section is white and features tens of tree rings. Part of the broken section droops downward.
Photo of white clouds floating in a clear blue sky. The clouds extend vertically, narrow at the bottom and gradually grow wider further up the photo, diffusing as they widen.

The Japan Pavilion at Expo 2025 Osaka, Kansai, holds immense potential to spread these crucial messages. In Japan, the concept of “yaoyorozu no kami” emphasizes that divinity resides in all places and things. This sentiment aligns with the opening lines of Hojoki (A Hermit's Hut as Metaphor), stating, “The flow of the river never ceases, and the water never stays the same. Bubbles float on the surface of pools, bursting, reforming, never lingering.” This simple expression embodies the concept of dynamic equilibrium. We must reevaluate life through the lens of nature’s constant flow, avoiding dichotomies and seeking moderate solutions within this ebb and flow. This is a unique attribute of humanity.

Photo showing sunlight shining through the branches of lush green trees.

Humans, with their intelligence, have constructed civilizations, cities, institutions, and economies. In this journey, we’ve recognized the value of individual life, including basic human rights. Nature, on the other hand, operates on the premise of species survival above all. While our intelligence has led to the structuring of the world, we must acknowledge when it has overreached. We find ourselves at a pivotal moment where we must seek harmony with all life forms, including microorganisms.

Photo: Go Itami

Photo of Shin-ichi Fukuoka
Biologist and Writer

Shin-ichi Fukuoka

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