{"id":64860,"date":"2019-07-16T07:38:29","date_gmt":"2019-07-16T05:38:29","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=64860"},"modified":"2019-07-12T14:58:17","modified_gmt":"2019-07-12T12:58:17","slug":"bacterium-turns-waste-into-food","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/bacterium-turns-waste-into-food\/","title":{"rendered":"Bacterium turns waste into food"},"content":{"rendered":"
\"original\"
Live image of Kentrophoros sp. from Elba, Italy. This ciliate, a single giant (>1 millimeter) eukaryotic cell carries several million bacterial symbionts everywhere it goes, and harvests them for food. Half the biomass visible in this image is bacterial. \u00a9 MPI f. Marine Microbiology\/ Brandon Seah<\/figcaption><\/figure>\n

Kentron, a bacterial symbiont of ciliates, turns cellular waste products into biomass. It is the first known sulfur-oxidizing symbiont to be entirely heterotrophic. Researchers from the Max Planck Institute for Marine Microbiology now report about this unexpected bacterium.<\/strong><\/p>\n

Plants use light energy from the sun for photosynthesis to turn carbon dioxide (CO2<\/sub>) into biomass. Animals can\u2019t do that. Therefore, some of them have teamed up with bacteria that carry out a process called chemosynthesis. It works almost like photosynthesis, only that it uses chemical energy instead of light energy. Many animals rely on chemosynthetic bacteria to supply them with food. The symbionts turn CO2<\/sub> into biomass and are subsequently digested by their host. Kentron, a bacterium nourishing the ciliate Kentrophoros, was thought to be \u2018just another\u2019 chemosynthetic symbiont. However, recent results indicate that it is not.<\/p>\n

An international team led by scientists from the Max Planck Institute for Marine Microbiology sequenced the genome of Kentron, the sulfur-oxidizing symbiont of the ciliates. \u201cContrary to our expectations, we couldn\u2019t find any of the known genes for the fixation of CO2<\/sub>,\u201d reports first author Brandon Seah.<\/p>\n

Upcycling garbage<\/h3>\n
\"original\"
Sampling for Kentrophoros in Elba, Italy and Niv\u00e5, Denmark. \u00a9 MPI for Marine Microbiology\/ Brandon Seah (left), Silke Wetzel (right)<\/figcaption><\/figure>\n

Without being able to fix CO2<\/sub>, what does Kentron grow on? \u201cFrom their genes, it seems that Kentron uses small organic compounds and turns those into biomass,\u201d Nicole Dubilier, director at the Max Planck Institute for Marine Microbiology and senior author of the study, explains. These include compounds such as acetate or propionate, which are typical \u2018low value\u2019 cellular waste products. \u201cIn this sense, Kentron is upcycling the garbage. It most probably recycles waste products from the environment and from their hosts into \u2018higher value\u2019 biomass to feed their hosts.\u201d<\/p>\n

Kentrophoros is a thin, ribbon-like ciliate that lives in sandy marine sediments, where it can easily squeeze and move between sand particles. It almost entirely relies on its symbionts for nutrition and has even given up its own mouth. Seah, who now works at the Max Planck Institute for Developmental Biology in T\u00fcbingen, and his colleagues collected specimens at sites in the Mediterranean, Caribbean and Baltic Seas. However, Kentrophoros does not grow and reproduce in the lab.<\/p>\n

Underpinning genetic analyses with isotope fingerprinting<\/h3>\n
\"original\"
The same species of Kentrophoros stained with a fluorescent dye that stains its DNA green. The three bright spots in the middle are the three cell nuclei of the eukaryotic host. \u00a9 MPI for Marine Microbiology\/ Brandon Sea<\/figcaption><\/figure>\n

So how could the researchers investigate Kentron\u2019s food preferences? \u201cOur collaborators in Calgary and North Carolina have developed a way to estimate the stable isotope fingerprint of proteins from the tiny samples that we have,\u201d Seah explains. This fingerprint tells a lot about the source of carbon an organism uses. The Kentron bacteria have a fingerprint that is completely unlike any other chemosynthetic symbiont\u2019s fingerprint from similar habitats. \u201cThis clearly shows that Kentron is getting its carbon differently than other symbionts.\u201d<\/p>\n

This research provides a counterexample to textbook descriptions. These usually say that the symbiotic bacteria make most of their biomass from either CO2<\/sub> or methane. In contrast, Kentron does not appear to have this ability to make biomass from scratch. \u201cUptake of organic substrates from the environment and recycling waste from their hosts might play a bigger role in these symbioses than previously thought,\u201d senior author Harald Gruber-Vodicka from the Max Planck Institute for Marine Microbiology concludes. \u201cThis has implications in ecological models of carbon cycling in the environment, and we are excited to look further into the details and pros and cons of either strategy.\u201d<\/p>\n

 <\/p>\n

Contacts<\/h3>\n

Prof. Dr. Nicole Dubilier
\nMax-Planck-Institute for Marine Microbiology, Bremen
\nTel.: +49 421 2028-932
\nE-Mail: ndubilie@mpi-bremen.de<\/a><\/p>\n

Dr. Fanni Aspetsberger
\nMax-Planck-Institut f\u00fcr marine Mikrobiologie, Bremen
\nTel.: +49 421 2028-947
\nE-Mail: faspetsb@mpi-bremen.de<\/a><\/p>\n

 <\/p>\n

 <\/p>\n

\nOriginal Publication<\/h3>\n

Brandon K. B. Seah, Chakkiath Paul Anthony, Bruno Huettel, Jan Zarzycki, Lennart Schada von Borzyskowski, Tobias J. Erb, Angela Kouris, Manuel Kleiner, Manuel Liebeke, Nicole Dubilier, Harald R. Gruber-Vodicka
\n‘Sulfur-oxidizing symbionts without canonical genes for autotrophic CO2 fixation’
\nmBio. DOI: 10.1128\/mBio.01112-19<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Kentron, a bacterial symbiont of ciliates, turns cellular waste products into biomass. It is the first known sulfur-oxidizing symbiont to be entirely heterotrophic. Researchers from the Max Planck Institute for Marine Microbiology now report about this unexpected bacterium. Plants use light energy from the sun for photosynthesis to turn carbon dioxide (CO2) into biomass. Animals […]<\/p>\n","protected":false},"author":59,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","nova_meta_subtitle":"","footnotes":""},"categories":[5572],"tags":[13383,5842],"supplier":[621,10112,1757],"class_list":["post-64860","post","type-post","status-publish","format-standard","hentry","category-bio-based","tag-bacteria","tag-biomass","supplier-max-planck-gesellschaft","supplier-max-planck-institut-fuer-entwicklungsbiologie","supplier-max-planck-institut-fuer-marine-mikrobiologie"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/64860","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/59"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=64860"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/64860\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=64860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=64860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=64860"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=64860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}