By now, we have all heard of the visible filth, including microplastics, floating in and lying at the bottom of our ocean and seas, including the nearly closed Mediterranean. But there’s more to be concerned about: potentially harmful bacteria and viruses that are invisible to the human eye and can spread diseases and launch pandemics among sea creatures as well as animals and humans on the seashore. Those tiny organisms, found everywhere on the Earth’s surface, are also important in influencing various processes including soil health, pollutant decomposition, agricultural growth, and carbon sequestration. Bacteria constitute about 70% of marine biomass and play a very significant role in biogeochemical processes.

Although they impact carbon, nitrogen and sulfur cycles, little is known about their distribution and role in the environment. While scientists have identified the microbes, they have been in the dark about how they travel so far. The research focuses, among other things, on the mutual influence (bio-exchanges) of the oceans and the atmosphere on the transportation of bacteria over the oceans. Researchers at the Technion-Israel Institute of Technology in Haifa and the Weizmann Institute of Science in Rehovot have been investigating a lesser-known aspect related to those microorganisms: their distribution mechanisms, survival, and activity in the atmosphere.

Understanding disease transmission Their studies have dramatic implications for understanding the transmission of diseases and pandemics, as well as for devising strategies to slow their dissemination. In a new article published in the Multidisciplinary Journal of Microbial Ecology under the title “Impact of airborne algicidal bacteria on marine phytoplankton blooms,” Dr. Naama Lang-Yona, formerly from Weizmann and now at the Technion’s Faculty of Civil and Environmental Engineering in Haifa, along with Weizmann scientists Dr. J. Michel Flores, Prof. Ilan Koren, and Prof. Assaf Vardi, describe active bacteria found above the oceans. One of these types of bacteria, Roseovarius nubinhibens, is capable of killing algae.

The research found that this bacterium is released into the atmosphere with the aerosol rising from ocean water during the blooming of Emiliania huxleyi algae. While in the air, it managed to survive, preserving its ability to infect algae. These capabilities allow such disease-causing bacteria to expand their infection range and impact algal blooms spreading over thousands of square kilometers in the ocean.

Lang-Yona has published articles focusing on genomic mapping of airborne microbial populations (bioaerosols), which migrate thousands of kilometers above oceans; the dissemination of antibiotic-resistant genes through the air, combined with the impact of climate change and air pollution on respiratory allergens (aero-allergens); the airborne transport of endotoxins; the characterization of different microorganisms in the environment such as allergenic cyanobacteria; the spread of airborne plant pathogens; and more.

She and her team are currently conducting research on the distribution of bacteria via dust storms reaching Israel all the way from the Sahara and Arabian deserts, with the aim of understanding the survival mechanisms and distinctive traits of these pathogens. In addition, they are examining the idea that along with the bacteria carried and dispersed in the air, antibiotic resistance may also disperse and propagate across continents.