scholarly journals Effects of Plant Residue Extract and Cobalamin on Growth and Propionate Production of Propionicimonas paludicola Isolated from Plant Residue in Irrigated Rice Field Soil

2004 ◽  
Vol 19 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Hiroshi Akasaka ◽  
Katsuji Ueki ◽  
Atsuko Ueki
2011 ◽  
Vol 79 (2) ◽  
pp. 371-379 ◽  
Author(s):  
Jun Murase ◽  
Manami Shibata ◽  
Chol Gyu Lee ◽  
Takeshi Watanabe ◽  
Susumu Asakawa ◽  
...  

2009 ◽  
Vol 75 (14) ◽  
pp. 4879-4886 ◽  
Author(s):  
Junpeng Rui ◽  
Jingjing Peng ◽  
Yahai Lu

ABSTRACT The incorporation of rice residues into paddy fields strongly enhances methane production and emissions. Although the decomposition processes of plant residues in rice field soil has been documented, the structure and dynamics of the microbial communities involved are poorly understood. The purpose of the present study was to determine the dynamics of short-chain fatty acids and the structure of bacterial communities during residue decomposition in a rice field soil. The soil was anaerobically incubated with the incorporation of rice root or straw residues for 90 days at three temperatures (15, 30, and 45°C). The dynamics of fatty acid intermediates showed an initial cumulative phase followed by a rapid consumption phase and a low-concentration quasi-steady state. Correspondingly, the bacterial populations displayed distinct successions during residue decomposition. Temperature showed a strong effect on the dynamics of bacterial populations. Members of Clostridium (clusters I and III) were most dominant in the incubations, particularly in the early successions. Bacteroidetes and Chlorobi were abundant in the later successions at 15 and 30°C, while Acidobacteria were selected at 45°C. We suggest that the early successional groups are responsible for the decomposition of the easily degradable fraction of residues, while the late successional groups become more important in decomposing the less-degradable or resistant fraction of plant residues. The bacterial succession probably is related to resource availability during residue decomposition. The fast-growing organisms are favored at the beginning, while the slow-growing bacteria are better adapted in the later stages, when substrate availability is limiting.


2007 ◽  
Vol 57 (8) ◽  
pp. 1803-1809 ◽  
Author(s):  
Atsuko Ueki ◽  
Hiroshi Akasaka ◽  
Atsuya Satoh ◽  
Daisuke Suzuki ◽  
Katsuji Ueki

Two strictly anaerobic bacterial strains, KB7T and A42, were isolated from rice plant residue and living rice roots, respectively, from irrigated rice-field soil in Japan. These two strains were closely related to each other with 16S rRNA gene sequence similarity of 99.8 %. Both strains showed almost the same physiological properties. Cells were Gram-negative, non-motile, non-spore-forming rods. Growth was remarkably stimulated by the addition of haemin to the medium. The strains utilized various saccharides including xylan, xylose, pectin and carboxymethylcellulose and produced acetate and succinate with small amounts of formate and malate. The strains grew at 10–40 °C; optimum growth was observed at 30 °C and pH 5.7–6.7. Oxidase, catalase and nitrate-reducing activities were not detected. Aesculin was hydrolysed. The major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0, C15 : 0 and iso-C17 : 0 3-OH. Menaquinones MK-11 and MK-11(H2) were the major respiratory quinones and the genomic DNA G+C content was 39.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed both strains in the phylum Bacteroidetes. 16S rRNA gene sequence analysis showed that the most related species to both strains was Prevotella oulorum (92.8–92.9 % similarity). Prevotella veroralis and Prevotella melaninogenica were the next most closely related known species with sequence similarities of 91.9–92.4 %. Based on differences in the phylogenetic, ecological, physiological and chemotaxonomic characteristics between the two isolates and related species, it is proposed that strains KB7T and A42 represent a novel species, Prevotella paludivivens sp. nov. This is the first described Prevotella species derived from a natural habitat; all other Prevotella species are from mammalian sources. The type strain of Prevotella paludivivens is KB7T (=JCM 13650T=DSM 17968T).


2008 ◽  
Vol 74 (9) ◽  
pp. 2894-2901 ◽  
Author(s):  
Jingjing Peng ◽  
Zhe Lü ◽  
Junpeng Rui ◽  
Yahai Lu

ABSTRACT Incorporation of plant residues strongly enhances the methane production and emission from flooded rice fields. Temperature and residue type are important factors that regulate residue decomposition and CH4 production. However, the response of the methanogenic archaeal community to these factors in rice field soil is not well understood. In the present experiment, the structure of the archaeal community was determined during the decomposition of rice root and straw residues in anoxic rice field soil incubated at three temperatures (15°C, 30°C, and 45°C). More CH4 was produced in the straw treatment than root treatment. Increasing the temperature from 15°C to 45°C enhanced CH4 production. Terminal restriction fragment length polymorphism analyses in combination with cloning and sequencing of 16S rRNA genes showed that Methanosarcinaceae developed early in the incubations, whereas Methanosaetaceae became more abundant in the later stages. Methanosarcinaceae and Methanosaetaceae seemed to be better adapted at 15°C and 30°C, respectively, while the thermophilic Methanobacteriales and rice cluster I methanogens were significantly enhanced at 45°C. Straw residues promoted the growth of Methanosarcinaceae, whereas the root residues favored Methanosaetaceae. In conclusion, our study revealed a highly dynamic structure of the methanogenic archaeal community during plant residue decomposition. The in situ concentration of acetate (and possibly of H2) seems to be the key factor that regulates the shift of methanogenic community.


2017 ◽  
Vol 93 (5) ◽  
Author(s):  
Yuriko Takenouchi ◽  
Kazufumi Iwasaki ◽  
Jun Murase

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