Knowledge about microbes has proven to be useful for gaining a better understanding of the environment. As an example, phytoplankton – a photosynthetic marine microorganism – was discovered to be a source of half the Earth’s supply of oxygen, thereby providing insight to our relationship with the ocean.
However, researchers currently have an understanding about only a tiny fraction out of millions of existing microbial species. The problem is, most marine microbes cannot be cultivated with the same conditions used for laboratory bacteria. A recent study published in an edition of the Proceedings of the National Academy of Sciences, explains why this is so.
According to a recent study published in an edition of the Proceedings of the National Academy of Sciences, free-living marine microbes have simpler genetic makeup than laboratory cultures, which helps them survive under nutrient-poor conditions unlike their laboratory counterparts that thrive under nutrient-dense conditions. The specific conditions that their genomes have adapted to are difficult to simulate, thus making their cultivation difficult.
To obtain the results, researchers of the study collected samples of surface ocean bacterioplankton in different parts of the world. From the samples, they sequenced draft genomes of 56 single amplified genomes (Genome amplification increases the amount of limited DNA samples), which were then compared with the genomes of existing microbial cultures. The team was able to gain insight to the geographic distribution and genomic features of some of the microbes: They found that genome simplification in response to nutrient-poor conditions is a common feature among microbial populations. Also, temperature and latitude affect the where certain bacterial groups are likely to settle.
Another interesting thing to note is that the researchers have managed to obtain answers without cultivating microbial samples. This is made possible by their use of a relatively new technique in genomics known as single-cell sequencing, thus demonstrating the role of biotechnology in enabling new discoveries.