By Albert B. Olayemi
The microbial taxa are the most abundant, widespread and largest evolving forms. Their most striking feature is that they are ubiquitous: they are everywhere.
This success is supported by their huge diversity. It is observed in a recent review that the earth is home to a staggering one trillion species which include mainly viruses, bacteria and fungi.
The total number of microbial cells as earth hovers around a nonillion, a number that outstrips imagination and the estimated number of stars in the universe!
The human body (and animals) is not spared. It is now known that we are actually more of microbe than human, for only 43 percent of cells in our body are human while the rest are microbes (our microbiome).
Also, important to note in a significant dimension is, that whereas the entire human genome (full set of genetic instructions) is made up of 20,000 genes, the genes of our microbiome is between two and twenty million. The stark interpretation is that, more than half of the human body is not human.
Two other attributes of microbes that account for their success at colonization of the earth include their generation time (mean doubling time), which is on the average of 20 to 30 minutes.
Another is the capacity to mutate and thereby, correspondingly changing its genome and code of instructions. This is a serious trait that portends danger for man in certain instances.
Naturally, different kinds of relationships have evolved between man and the microbes over time. The human body (as a host) may merely provide shelter and nutrients to the microbes (as commensals) without causing any havoc, or the microbes and the host may mutually benefit from the relationship, as in the case of mutualism.
The relationship that man has so long battled with is that in which the microbe, grows, multiplies and affects the tissues or their function (s) and lead to a disease/infection.
This has remained a major challenge to man, as we are being reminded today by COVID-19 virus and its devastation.
In spite of this negative relationship, man’s attention has justifiably been diverted to the exploration, manipulation and exploitation of the positive potentials of microbes that live outside the human body.
In this direction, scientists have successfully been able to drive the global economy by harnessing these potentials, especially in the microbial bio-conversion of natural substances into the production of commercially viable and useful end or by-products.
Virtually all pharmaceutical, chemical, medical, food and beverage industries are sustained by microbial actions. There are many other areas of human endeavours in which microbes play major roles, including the restoration of our environment that is in constant danger of degradation.
In the area of medicine, the discovery of penicillin by Fleming proved to be a magic that substantially mitigated human losses during the world wars.
Accidents that would have led to massive deaths were reduced to amputation at the worst. In the vital area of man’s foremost occupation, they play very important roles – positive and negative.
Microbes assist fertilizing/enriching the soil and play active ecological roles that sustain and improve food crop yields.
On the negative side, I shudder to imagine the damage or ruination microbes can do. They are responsible for numerous diseases and pathological condition of plants – economic and otherwise.
Microbes have the potential of crippling agriculture through devastating reduction in yields and spoilage of products/by products, even at the level of storage.
Imagine a similar scenario of COVID-19 virus happening on our farms. Again, we thank the scientists for the advancement made in the developments of herbicides, pesticides, etcetera for controlling microbes on the field.
These and many other human achievements in ‘taming’ or controlling microbes had made man shift from viewing microbes as enemies to respecting them as our unseen allies on earth.
Just as microbes colonise every part of human body so they do of animals – domesticated and those in the wild. The former may enjoy some protection from humans for economic purposes or as pets, while the latter are left to their fate.
And so, they remain a sure source/reservoir of pathogens that can threaten human survival or existence. This threat is constantly being played out in animal husbandry, particularly in poultry farming.
The fear of microbes is the beginning of success in the important areas of economy that we hope will ensure food security. One can go on!
How else can the microbes prove to us that they own the earth with the ruthlessness of the rabid COVID-19 virus, that closed down the world.
Before now some of us know that the toxins of some microbes are so potent and lethal that their employment in warfare can be by some dangerous and devastating than any other weapons.
The competitive build-up and accumulation of weapons of massive destruction by the East and West are rendered useless and unnecessary in the face of COVID-19 virus. Without a single shot, the world is brought down on its knees. No thanks to our allies.
One fact keeps raising an alarm that the world is not safe from microbes in spite of its long co-existence and human success at controlling them. And that is the fact that 99.9% of microbes on earth are yet to be discovered. Their potentials whether positive or negative are therefore unknown, as allies or enemies.
Hence there is the need to show more interest in the diversity of microbial species on earth. Knowing the number of species and wider knowledge of them on earth has the potential implications for the improvement of quality of life.
There is also the prospect that the yet-to-be harnessed bio-diversity might spur the development of alternative fuels, new crops to feed our ever-growing population and medicines to fight emerging infectious diseases.
Actually, there should be an intrinsic curiosity now about the natural world and our place in it. We can then appraise and decide to admire, protect, transform or exploit. We surely require greater knowledge of the species that inhabit the earth with us.
Unfortunately, in the academic world, little or no importance/low rating is accorded any scientific research that stops at merely isolating and identifying microbial species in an environment, including even those considered novel.
Highly rated works are those that re-affirm, confirm, agree with published works in the West; and those that emphasize significance, especially on economy. From our experience now, I suggest that such works (probing into neglected environments/niches) should be promoted.
Their findings should be taken up for further investigation to enrich knowledge of the new isolates by specialized institution like NCDC. The latter should not remain as it is confirming existing cases or knowledge about established diseases.
Regrettably man has been behaving as if he owns the world and other occupants are there for manipulation, exploitation and management. Events are now suggesting a better attitude.
We need to know more of the other occupants, understand them and learn to co-exist with them, more so, as they are invisible. God did not create them for no purpose. Indeed, ecology informs us that every life form anywhere has a role.
Microbes can make the world a better place, Not only us. We should do less to endanger ecological balance in most environments as we currently do. Finally, let us learn to manage the microbes more strategically as they wait to return us effectively to the earth: dust to dust.
- Prof Olayemi writes from University of Ilorin.