Open AccessMethanogenesis affected by the co‐occurrence of iron( III ) oxides and humic substances
Author(s) -
Zhou Shungui,
Xu Jielong,
Yang Guiqin,
Zhuang Li
Publication year - 2014
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/1574-6941.12274
Subject(s) - methanogenesis , ferrihydrite , anoxic waters , environmental chemistry , hematite , microcosm , magnetite , lepidocrocite , goethite , chemistry , inorganic chemistry , biology , methane , mineralogy , organic chemistry , paleontology , adsorption
Iron oxides and humic substances (humics) have substantial effects on biochemical processes, such as methanogenesis, due to their redox reactivity and ubiquitous presence. This study aimed to investigate how methanogenesis is affected by the common occurrence of these compounds, which has not been considered to date. The experiment was conducted with anoxic paddy soil microcosms receiving a humics surrogate compound (anthraquinone‐2,6‐disulfonate, AQDS ) and three iron( III ) oxides (ferrihydrite, hematite, and magnetite) differing in crystallinity and conductivity. Ferrihydrite suppressed methanogenesis, whereas AQDS , hematite, and magnetite facilitated methanogenesis. CH 4 production in co‐occurring ferrihydrite + AQDS , hematite + AQDS , and magnetite + AQDS cultures was 4.1, 1.3, and 0.9 times greater than the corresponding cultures without AQDS , respectively. Syntrophic cooperation between G eobacter and M ethanosarcina occurred in the methanogenesis‐facilitated cultures. Experimental results suggested that the conductive characteristics of iron( III ) oxides was an important factor determining the methanogenic response to the co‐occurrence of iron( III ) oxides and humics in anaerobic paddy soil. This work indicated that the type of iron( III ) oxides may significantly affect carbon cycling under anoxic conditions in natural wetlands.