TY - JOUR
T1 - Increase in sedimentary organic carbon with a change from hypoxic to oxic conditions
AU - Mahmood, Mukseet
AU - Taki, Shunsuke
AU - Satoshi, Nakai
AU - Gotoh, Takehiko
AU - Nishijima, Wataru
AU - Umehara, Akira
AU - Aoyagi, Tomo
AU - Sato, Yuya
AU - Hori, Tomoyuki
AU - Katayama, Yoko
AU - Hajdu-Rahkama, Reka
AU - Puhakka, Jaakko A.
PY - 2021/5/4
Y1 - 2021/5/4
N2 - In the Seto Inland Sea, Japan, chemical oxygen demand has increased over recent decades, while average dissolved oxygen concentrations in the bottom water have increased. In this study, we investigated responses of organic carbon (OC) in hypoxic sediment to changes of redox conditions using experimental columns containing sediment and overlying water. Surface sediment showed an increase in OC along with the change to an aerobic condition. Microbial community analysis showed a predominance of sulfur-oxidizing bacteria (SOB) such as Sulfurovum sp. in the sediment. This dominance could account for the increased OC. Additionally, the dissolved organic carbon (DOC) concentration in the overlying water increased. Further experiments using sandy sediment showed that biodegradation of Sulfurimonas denitrificans was associated with DOC release. These results show that a change in the sedimentary environment (increase in dissolved oxygen) increased the sedimentary OC and DOC of overlying water by stimulating certain autotrophic bacteria, especially the SOB.
AB - In the Seto Inland Sea, Japan, chemical oxygen demand has increased over recent decades, while average dissolved oxygen concentrations in the bottom water have increased. In this study, we investigated responses of organic carbon (OC) in hypoxic sediment to changes of redox conditions using experimental columns containing sediment and overlying water. Surface sediment showed an increase in OC along with the change to an aerobic condition. Microbial community analysis showed a predominance of sulfur-oxidizing bacteria (SOB) such as Sulfurovum sp. in the sediment. This dominance could account for the increased OC. Additionally, the dissolved organic carbon (DOC) concentration in the overlying water increased. Further experiments using sandy sediment showed that biodegradation of Sulfurimonas denitrificans was associated with DOC release. These results show that a change in the sedimentary environment (increase in dissolved oxygen) increased the sedimentary OC and DOC of overlying water by stimulating certain autotrophic bacteria, especially the SOB.
U2 - 10.1016/j.marpolbul.2021.112397
DO - 10.1016/j.marpolbul.2021.112397
M3 - Article
SN - 0025-326X
VL - 168
JO - Marine Pollution Bulletin
JF - Marine Pollution Bulletin
M1 - 112397
ER -