Scientists find bacteria living in microwave ovens Premium

Scientists have found certain microbes living in microwave ovens, offering insights into biological processes, industrial applications, and potential extraterrestrial life.

Microorganisms have mastered the art of surviving on the earth. They are found practically in all niches where life can possibly thrive. Over millions of years of evolution, they have developed mechanisms to adapt to diverse habitats. They are very flexible and able to colonise extreme environments, even those off limits to more complex life-forms.

Scientists have isolated microbes from volcanic vents, permafrost, acid mines, deep-sea hydrothermal vents, and dark lakes buried kilometres under polar ice caps. Microbes have also been found thriving on the exteriors of spacecraft and around nuclear waste storage sites. Microbes that live in extreme natural conditions are called extremophiles. Many researchers believe that life began on the earth in an extreme environmental niche, in the form of an extremophile, before spreading and adapting to more temperate ecosystems.

Microbes adapt to extreme environments by incorporating unique biological and biochemical processes. More complex life-forms like humans have evolved to have one set of proteins with which they navigate life. Extremophile microbes on the other hand have multiple sets of proteins, each customised for life in a specific environmental niche. They ‘activate’ each set depending on the conditions around them and what they need to survive: say, one set for the super-high temperature during a volcanic eruption, one for the debilitating lack of water during a prolonged drought, and one for the gruesome acidity of a volcanic crater lake.

Our knowledge of microbes, especially in the earth’s various environmental niches, is still in its infancy. Many global initiatives are currently trying to map, organise, and understand this diversity. One is the ambitious ‘Earth Microbiome Project’. It was founded in 2010 to sequence 200,000 genetic samples and assemble 500,000 microbial genomes. Another is the ‘Earth Biogenome Project’ — to sequence the genomes of all of the planet’s eukaryotic organisms to create one of the largest and most comprehensive maps of organisms on the earth in a decade.

A further advantage to understanding how extremophiles adapt lies in a number of biological and industrial applications. For example, in the 1960s, U.S. researchers isolated a new species of bacteria from a hot spring at Yellowstone National Park and named it Thermus aquaticus. This microbe is able to produce a heat-resistant enzyme called Taq DNA polymerase. This enzyme is an important and valuable workhorse of molecular biology because of its application in the polymerase chain reaction (PCR). Readers will recall this is a technique to identify the presence of certain DNA in a biological sample, popularised during the COVID-19 pandemic.

Since the discovery of Taq, researchers have found a number of other polymerases from a variety of extremophile microbes, and have reengineered them for various applications in molecular biology with remarkable success.

Our rapidly expanding ability to ‘read’ the genomes of organisms — thanks in turn to the increasing throughput of sequencing machines and their dropping costs and and our ability to synthesise DNA nucleotides in the lab — has spawned a new era in utilising biological processes at scale to solve human problems. Unravelling the biological rules governing extremophiles could thus enable researchers to engineer organisms to have new abilities, like helping poultry resist an infectious disease or creating synthetic biological systems that can augment the immune system.