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Food selectivity of anaerobic protists and direct evidence for methane production using carbon from prey bacteria by endosymbiotic methanogen
- Source :
- ISME J
- Publication Year :
- 2020
- Publisher :
- Springer Science and Business Media LLC, 2020.
-
Abstract
- Anaerobic protists are major predators of prokaryotes in anaerobic ecosystems. However, little is known about the predation behavior of anaerobic protists because almost none have been cultured. In particular, these characteristics of anaerobic protists in the phyla Metamonada and Cercozoa have not been reported previously. In this study, we isolated three anaerobic protists, Cyclidium sp., Trichomitus sp., and Paracercomonas sp., from anaerobic granular sludge in an up-flow anaerobic sludge blanket reactor used to treat domestic sewage. Ingestion and digestion of food bacteria by anaerobic protists with or without endosymbiotic methanogens were demonstrated using tracer experiments with green fluorescent protein and a stable carbon isotope. These tracer experiments also demonstrated that Cyclidium sp. supplied CO(2) and hydrogen to endosymbiotic methanogens. While Cyclidium sp. and Trichomitus sp. ingested both Gram-negative and -positive bacteria, Paracercomonas sp. could only take up Gram-negative bacteria. Archaeal cells such as Methanobacterium beijingense and Methanospirillum hungatei did not support the growth of these protists. Metabolite patterns of all three protists differed and were influenced by food bacterial species. These reported growth rates, ingestion rates, food selectivity, and metabolite patterns provide important insights into the ecological roles of these protists in anaerobic ecosystems.
- Subjects :
- Sewage
Microbiology
Article
03 medical and health sciences
Bioreactors
Microbial ecology
parasitic diseases
Botany
Bioreactor
Anaerobiosis
Ecosystem
Ecology, Evolution, Behavior and Systematics
030304 developmental biology
0303 health sciences
Bacteria
biology
030306 microbiology
business.industry
fungi
biology.organism_classification
Methanogen
Carbon
business
Digestion
Methane
Anaerobic exercise
Cercozoa
Subjects
Details
- ISSN :
- 17517370 and 17517362
- Volume :
- 14
- Database :
- OpenAIRE
- Journal :
- The ISME Journal
- Accession number :
- edsair.doi.dedup.....bda120de5fc0a6a8650cd9c351670504