Divers search for novel marine bacteria that could yield new kinds of antibiotics. Photo by Christian Jogler/Friedrich Schiller University of Jena
Nov. 18 (UPI) -- Scientists in Germany and the Netherlands have successfully cultivated dozens of new marine bacteria in the laboratory. Early analysis of the new strains -- published this week in the journal Nature Microbiology -- suggests the bacteria could yield new antibiotics.
Most current antibiotics are natural compounds produced by bacteria. As a result of overuse, many of these antibiotics are losing their effectiveness as more and more pathogens develop resistance.
To date, the search for antibiotic compounds has involved just 1 percent of the known bacteria species. Most bacteria species are too difficult to cultivate in the lab and have been ignored by scientists seeking new drugs.
But scientists are beginning to make progress in the search for new sources of antibiotic compounds.
While bacteria are abundant and extremely diverse, not all strains and species are particularly useful to scientists hunting for antibiotics. The kinds of bacteria that are most likely to produce antibiotic compounds are those engaged in intense microbiological battles over limited resources.
"Talented producers are primarily microorganisms with complex lifestyles, an unusual cell biology and large genomes," study co-author Christian Jogler, a microbiologist with the Friedrich Schiller University of Jena in Germany, said in a news release. "Such organisms produce antibiotic compounds and deploy them in the fight against other bacteria for nutrients and habitats."
For the study, Jogler and his colleagues deployed both human divers and deep-sea robots to search for Planctomycetes, a unique phylum of aquatic bacteria, at several marine locations in the Mediterranean, North, Baltic and Black seas, as well as the Atlantic, Pacific and Arctic oceans.
"We know that Planctomycetes live in communities with other microorganisms and compete with them for habitat and nutrients," Jogler said.
Their sampling efforts yielded cultures of 79 new Planctomycetes, comprising 31 new genera and 65 new species.
Back in the lab, scientists subjected the new cultures to sophisticated bioinformatic and microscopic analysis, which revealed each bacterium's potential to produce small molecules like antibiotic compounds.
The analysis methods also revealed each bacterium's level of cellular signal transduction, a proxy for the complexity of its microbial lifestyle.
"The results of these analyses show that the newly obtained Planctomycetes have extraordinarily complex lifestyles and have the potential to produce new antibiotics," said lead study author Sandra Wiegand, researcher at Radboud University in the Netherlands.
Perhaps most importantly, the new research suggests many bacteria species dismissed as non-cultivable can in fact be collected and cultured.
"Alongside unobserved aspects of cell signalling and small-molecule production, our findings demonstrate that exploration beyond the well-established model organisms has the potential to increase our knowledge of bacterial diversity," the researchers wrote in their paper.