Researchers identify bacteria and viruses ejected from the ocean
Certain types of bacteria and viruses are readily ejected into the atmosphere when waves break while others less likely to be transported into the air
Certain types of bacteria and viruses are readily ejected into the atmosphere when waves break while other taxa are less likely to be transported by sea spray into the air, researchers reported May 22.
An interdisciplinary team of scientists from Scripps Institution of Oceanography, the University of California San Diego, and the J. Craig Venter Institute (JCVI) reached this conclusion after replicating a phytoplankton bloom in a unique ocean-atmosphere wave facility developed by scientists in the National Science Foundation-funded Center for Aerosol Impacts on Chemistry of the Environment (CAICE) on the Scripps campus. They found that bacteria and viruses coated by waxy substances or lipids appear in greater quantity and are enriched in sea spray aerosols. According to researchers, the results suggest that the water-repellent properties of the surfaces of these microbes are what make them more likely to be cast out of the ocean as waves break at the sea surface.
The team in the National Science Foundation-funded study included chemists, oceanographers, microbiologists, geneticists, and pediatric medicine specialists who are attempting to understand how far potentially infectious bacteria and viruses can travel and if those that pose the greatest risks to public health are among those most likely to escape the ocean. In previous studies, individual members of the team have characterized sea spray aerosols, which form when waves break and bubbles burst at the ocean surface.
"Some of the bacteria we detected have been found on skin as well as in your gut, so they could be affecting your health--at this point, no one really knows the health effects of breathing in ocean microbes," said Kim Prather, who has a joint appointment at UC San Diego's Scripps Institution of Oceanography and the Department of Chemistry and Biochemistry. "We are trying to understand sources of environmental microbes using the unique ocean-atmosphere facilities we have developed here at Scripps. By breaking waves in fresh seawater in an isolated wave channel, UC San Diego is the only place in the world that can directly measure the microbes transferred from the ocean to the atmosphere."
Prather's research group has previously shown how microbes have a nearly worldwide reach, able to travel tens of thousands of kilometers on the wind, sometimes re-entering the ocean and re-emerging from it along the journey. As they do, their chemical attributes, their ability to infect, and their effects on cloud formation and precipitation can evolve.
"In CAICE, we realized that many of the chemical components found in the aerosols are derived from living microorganisms in the ocean, so one of our first goals was to find out which ones are present in the water and then understand which of them are able to hitch a ride on the aerosol particles," said Michael Burkart, a researcher at the Department of Chemistry and Biochemistry at UC San Diego.
The study tapped into techniques developed in the Earth Microbiome Project, which was founded by co-author Rob Knight and others in 2010 to sample as many microbial communities as possible to understand the ecology of microbes and their interactions with humans.
"In the Earth Microbiome Project a key challenge is to model microbes across the planet," said Knight, a UC San Diego professor of pediatrics and computer science and engineering with the UC San Diego Center for Microbiome Innovation. "The ocean spray results provide a completely new and unexpected mechanism for dispersal that we will have to take into account for a full understanding of Earth's microbial biosphere."
The researchers conducted the experiment by establishing blooms of phytoplankton over a 34-day period. They did this inside an ocean-atmosphere facility housed at the Hydraulics Laboratory at Scripps Oceanography. After several days, the replicated ocean, which scientists call a mesocosm, began emitting into the air bacterial taxa such as Actinobacteria and Corynebacteria. Viruses contained in the aerosols that became airborne were few relative to bacteria, but the strains that were detected in the air such as Herpesvirales had a similar kind of water repelling surface that enables them to be transferred from the ocean to the atmosphere.
The potential human health effects of the ocean microbes most often found in the sea spray aerosols will now begin to be studied by the team at UC San Diego. There is little known about the health effects-- good or bad--of breathing ocean air enriched in microbes and other biological material. The researchers reported the presence of strains not often found in seawater such as Legionella and an avian strain of E. coli, which they said could be evidence of contamination in certain coastal waters. Knowledge of which pathogens occurring in pollution runoff become aerosolized could help improve the understanding of human exposure pathways for those living near the coast.
"No one expected that it might be an evolved strategy for particular bacteria and viruses to get themselves into the ocean spray," Knight said. "Our next challenge is to figure out why they're doing it, and when it's good or bad for our health, or even for the planet's climate."
The study, "Taxon-specific aerosolization of bacteria and viruses in an experimental ocean atmosphere mesocosm," which appeared May 22 in the journal Nature Communications, was supported by CAICE, which is led by Prather and designated in 2013 as an NSF Center for Chemical Innovation.
Metagenomic analyses conducted by JCVI leverage methods and funding from the Global Ocean Sampling project, a long running metagenomic survey of marine environments that was funded by the Beyster Family Fund of the San Diego Foundation and the Life Technologies Foundation.
Members of the research team include lead author Jennifer Michaud, Michael Burkart, Luke Thompson, Zhenjiang Zech Xu, Christopher Lee, Kevin Pham, Charlotte Beall, Francesca Malfatti, and Farooq Azam of UC San Diego; and Christopher Dupont, Drishti Kaul, Josh Espinoza, and R. Alexander Richter of the J. Craig Venter Institute in La Jolla, Calif.
Robert Monroe, 858-534-3624, firstname.lastname@example.org
Watafiti wamegundua aina fulani za bakteria na virusi vinavyotupwa kutoka baharini: aina fulani za bakteria na virusi hutupwa kwa urahisi angani wakati mawimbi yanapovunjika, wakati zingine hazipatikani hewani. Timu ya wanasayansi kutoka Taasisi ya Scripps ya Oceanography, Chuo Kikuu cha California, San Diego, na Taasisi ya J. Craig Venter (JCVI) walifikia hitimisho hili baada ya kuiga maua ya phytoplankton katika kituo cha pekee cha mawimbi ya bahari-anga iliyoundwa na wanasayansi katika Kituo cha Aerosol Impacts juu ya Kemia ya Mazingira (CAICE) kilichofadhiliwa na Shirika la Sayansi la Kitaifa. Utafiti huo ulionyesha kwamba bakteria na virusi vilivyofunikwa kwa vipande vya mafuta au mafuta ya mti wa wax, huonekana kwa wingi zaidi na huongezeka katika aerosol za maji ya bahari. Watafiti wanasema matokeo ya utafiti huo yanaonyesha kuwa uwezo wa wadudu hao wa kutuliza maji ndio unaowafanya waweze kutolewa baharini wakati mawimbi yanapovunja bahari. Timu ya utafiti huo, uliofadhiliwa na Shirika la Sayansi la Taifa, ilijumuisha wanakemia, wataalamu wa bahari, wataalamu wa microbiolojia, wataalamu wa chembe za urithi na wataalamu wa dawa za watoto ambao wanajaribu kuelewa ni kwa umbali gani bakteria na virusi vinavyoweza kuambukiza vinaweza kusafiri na ikiwa wale wanaowakabili hatari kubwa zaidi kwa afya ya umma ni miongoni mwa wale ambao wana uwezekano mkubwa wa kutoroka baharini. Katika utafiti wa awali, washiriki wa timu hiyo walifafanua aina ya aerosol zinazotokana na maji ya baharini, ambazo hutokea wakati mawimbi yanapovunjika na mlipuko wa Bubbles kwenye uso wa bahari. "Bakteria hizi zimepatikana kwenye ngozi na matumbo, kwa hivyo zinaweza kuathiri afya yako, kwa wakati huu hakuna mtu anayejua athari za afya za kupumua vimelea vya bahari, ""alisema Kim Prather, ambaye ana uteuzi wa pamoja katika Taasisi ya Scripps ya Oceanography ya UC San Diego na Idara ya Kemia na Biochemistry." "Tunajaribu kuelewa vyanzo vya vijidudu vya mazingira kwa kutumia vifaa vya kipekee vya bahari na anga ambavyo tumeendeleza hapa Scripps. Kwa kuvunja mawimbi katika maji safi ya bahari katika mfereji wa mawimbi, UC San Diego ni mahali pekee ulimwenguni ambapo inaweza kupima moja kwa moja vimelea vilivyopitishwa kutoka baharini hadi angahewa. Watafiti wa Prather wameonyesha jinsi vimelea vinavyoweza kusafiri maelfu ya kilomita kwa upepo, wakati mwingine kuingia baharini na kutokea tena. Kadiri wanavyofanya hivyo, sifa zao za kemikali, uwezo wao wa kuambukiza, na athari zao juu ya kuundwa kwa mawingu na mvua zaweza kubadilika. "Katika CAICE, tuligundua kwamba sehemu nyingi za kemikali zilizopatikana katika aerosol zinatokana na viumbe hai katika bahari, kwa hivyo moja ya malengo yetu ya kwanza ilikuwa kujua ni zipi zipo katika maji na kisha kuelewa ni zipi zinaweza kuendesha chembechembe za aerosol, ""alisema Michael Burkhart, mtafiti katika Idara ya Kemia na Biochemistry katika UC San Diego." Utafiti huo ulitumia mbinu zilizotengenezwa katika Mradi wa Microbiome ya Dunia, ulioanzishwa na mwandishi mwenza Rob Knight na wengine mnamo 2010 kuchukua sampuli za jamii nyingi za vimelea ili kuelewa ikolojia ya vimelea na mwingiliano wao na wanadamu. "Kama sehemu ya mradi wa Earth Microbiome, changamoto kuu ni kuunda mifano ya vimelea duniani kote, ""alisema Knight, profesa wa pediatrics na sayansi ya kompyuta na uhandisi wa UC San Diego Center for Microbiome Innovation." "Mafunzo ya kunyunyizia bahari hutoa utaratibu mpya kabisa na usiotazamiwa wa kutawanyika ambao tutalazimika kuzingatia kwa uelewa kamili wa biosphere ya microbial ya Dunia. """ Watafiti walifanya majaribio hayo kwa kuanzisha maua ya phytoplankton kwa kipindi cha siku 34. Walifanya hivyo ndani ya kituo cha bahari na angahewa kilichokuwa katika Maabara ya Hydraulics katika Scripps Oceanography. Baada ya siku kadhaa, bahari hiyo iliyofanyizwa upya, ambayo wanasayansi wanaiita mesocosm, ilianza kutokeza bakteria kama vile Actinobacteria na Corynebacteria. Virusi vilivyomo katika aerosol zilizopelekwa hewani vilikuwa vichache ikilinganishwa na bakteria, lakini aina zilizogunduliwa hewani kama vile herpesviruses zilikuwa na aina sawa ya uso wa kuzuia maji ambayo inawawezesha kuhamishwa kutoka baharini hadi angahewa. Uwezekano wa athari za afya ya binadamu za vimelea vya bahari vinavyopatikana katika aerosols ya kunyunyizia bahari sasa utaanza kuchunguzwa na timu ya UC San Diego. Ni mambo machache yanayojulikana kuhusu athari za kiafya - nzuri au mbaya - za kupumua hewa ya bahari iliyotajwa kwa vimelea na vitu vingine vya kibiolojia. Watafiti hao wameripoti kuwa kuna aina za bakteria ambazo hazipatikani mara nyingi katika maji ya bahari kama vile Legionella na aina ya ndege ya E. coli, ambazo wanasema zinaweza kuwa ushahidi wa uchafuzi katika maji fulani ya pwani. Ujuzi wa vimelea vinavyotokea katika maji ya uchafuzi wa mazingira vinavyoweza kuwa aerosol inaweza kusaidia kuboresha uelewa wa njia za mfiduo wa binadamu kwa wale wanaoishi karibu na pwani. "Hakuna mtu aliyetarajia kwamba inaweza kuwa mkakati uliobadilika kwa bakteria na virusi maalum kujiingiza katika kunyunyizia baharini, "Knight alisema. "Tatizo letu la pili ni kujua ni kwa nini wanafanya hivyo, na ni lini ni nzuri au mbaya kwa afya yetu, au hata kwa hali ya hewa ya sayari.""" "Utafiti wa ""Taxon-Specific Aerosolization of Bacteria and Viruses in an Experimental Ocean Atmosphere Mesocosm"" uliochapishwa Mei 22 katika jarida la Nature Communications, uliungwa mkono na CAICE, inayoongozwa na Prather na iliyochaguliwa mnamo 2013 kama Kituo cha Kiufundi cha Kimakemia cha NSF." JCVI inatoa msaada wa kifedha kutoka kwa mradi wa Global Ocean Sampling, utafiti wa muda mrefu wa metagenomic wa mazingira ya baharini, uliofadhiliwa na Beyster Family Fund ya San Diego Foundation na Life Technologies Foundation. "Wanafunzi wa chuo kikuu cha UCLA, Jennifer Michaud, Michael Burkhart, Luke Thompson, Zheng Zhiyuan, Christopher Lee, Kevin Pham, Charlotte Beale, Francesca Malfatti, na Farooq Azam, pamoja na Christopher Dupont, Josh Espinosa, na Richard Alexander, wa Taasisi ya J. Craig Venter huko La Jolla, California, walijumuisha ""Kristo"" katika jina lake la kwanza."