This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services E-mail this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hatamoto, M. Articles by Harada, H. Search for Related Content PubMed PubMed Citation Articles by Hatamoto, M. Articles by Harada, H. Agricola Articles by Hatamoto, M. Articles by Harada, H.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, February 2007, p. 1332-1340, Vol. 73, No. 4
0099-2240/07/$08.00+0     doi:10.1128/AEM.02053-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Identification and Cultivation of Anaerobic, Syntrophic Long-Chain Fatty Acid-Degrading Microbes from Mesophilic and Thermophilic Methanogenic Sludges

Masashi Hatamoto,¹ Hiroyuki Imachi,^1,2* Akiyoshi Ohashi,¹ and Hideki Harada^1,3

Department of Environmental Systems Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan,¹ Subground Animalcule Retrieval (SUGAR) Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Kanagawa 237-0061, Japan,² Department of Civil Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan³

Received 31 August 2006/ Accepted 11 December 2006

We investigated long-chain fatty acid (LCFA)-degrading anaerobic microbes by enrichment, isolation, and RNA-based stable isotope probing (SIP). Primary enrichment cultures were made with each of four LCFA substrates (palmitate, stearate, oleate, or linoleate, as the sole energy source) at 55°C or 37°C with two sources of anaerobic granular sludge as the inoculum. After several transfers, we obtained seven stable enrichment cultures in which LCFAs were converted to methane. The bacterial populations in these cultures were then subjected to 16S rRNA gene-based cloning, in situ hybridization, and RNA-SIP. In five of seven enrichment cultures, the predominant bacteria were affiliated with the family Syntrophomonadaceae. The other two enrichment cultures contained different bacterial populations in which the majority of members belonged to the phylum Firmicutes and the class Deltaproteobacteria. After several attempts to isolate these dominant bacteria, strain MPA, belonging to the family Syntrophomonadaceae, and strain TOL, affiliated with the phylum Firmicutes, were successfully isolated. Strain MPA converts palmitate to acetate and methane in syntrophic association with Methanospirillum hungatei. Even though strain TOL assimilated [¹³C]palmitate in the original enrichment culture, strain TOL has not shown the ability to degrade LCFAs after isolation. These results suggest that microbes involved in the degradation of LCFAs under methanogenic conditions might not belong only to the family Syntrophomonadaceae, as most anaerobic LCFA-degrading microbes do, but may also be found in phylogenetically diverse bacterial groups.

---

* Corresponding author. Mailing address: Subground Animalcule Retrieval (SUGAR) Program, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science & Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan. Phone: 81-46-867-9709. Fax: 81-46-867-9715. E-mail: imachi{at}jamstec.go.jp.

Published ahead of print on 22 December 2006.

---

Applied and Environmental Microbiology, February 2007, p. 1332-1340, Vol. 73, No. 4
0099-2240/07/$08.00+0     doi:10.1128/AEM.02053-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Crim, K. C., Sanders, L. M., Hong, M. Y., Taddeo, S. S., Turner, N. D., Chapkin, R. S., Lupton, J. R. (2008). Upregulation of p21Waf1/Cip1 expression in vivo by butyrate administration can be chemoprotective or chemopromotive depending on the lipid component of the diet. Carcinogenesis 29: 1415-1420 [Abstract] [Full Text]  
• Hatamoto, M., Imachi, H., Yashiro, Y., Ohashi, A., Harada, H. (2008). Detection of Active Butyrate-Degrading Microorganisms in Methanogenic Sludges by RNA-Based Stable Isotope Probing. Appl. Environ. Microbiol. 74: 3610-3614 [Abstract] [Full Text]  
• Imachi, H., Sakai, S., Sekiguchi, Y., Hanada, S., Kamagata, Y., Ohashi, A., Harada, H. (2008). Methanolinea tarda gen. nov., sp. nov., a methane-producing archaeon isolated from a methanogenic digester sludge. Int. J. Syst. Evol. Microbiol. 58: 294-301 [Abstract] [Full Text]  
• Hatamoto, M., Imachi, H., Fukayo, S., Ohashi, A., Harada, H. (2007). Syntrophomonas palmitatica sp. nov., an anaerobic, syntrophic, long-chain fatty-acid-oxidizing bacterium isolated from methanogenic sludge. Int. J. Syst. Evol. Microbiol. 57: 2137-2142 [Abstract] [Full Text]  
• Imachi, H., Sakai, S., Ohashi, A., Harada, H., Hanada, S., Kamagata, Y., Sekiguchi, Y. (2007). Pelotomaculum propionicicum sp. nov., an anaerobic, mesophilic, obligately syntrophic, propionate-oxidizing bacterium. Int. J. Syst. Evol. Microbiol. 57: 1487-1492 [Abstract] [Full Text]  
• Hatamoto, M., Imachi, H., Yashiro, Y., Ohashi, A., Harada, H. (2007). Diversity of Anaerobic Microorganisms Involved in Long-Chain Fatty Acid Degradation in Methanogenic Sludges as Revealed by RNA-Based Stable Isotope Probing. Appl. Environ. Microbiol. 73: 4119-4127 [Abstract] [Full Text]  
• Sakai, S., Imachi, H., Sekiguchi, Y., Ohashi, A., Harada, H., Kamagata, Y. (2007). Isolation of Key Methanogens for Global Methane Emission from Rice Paddy Fields: a Novel Isolate Affiliated with the Clone Cluster Rice Cluster I. Appl. Environ. Microbiol. 73: 4326-4331 [Abstract] [Full Text]