title: Role of cosubstrate and bioaccessibility played in the enhanced anaerobic biodegradation of organochlorine pesticides (OCPs) in a paddy soil by nitrate and methyl-β-cyclodextrin amendments.
abstract: The present study was conducted to investigate the anaerobic biodegradation potential of biostimulation by nitrate (KNO3) and methyl-β-cyclodextrin (MCD) addition on an aged organochlorine pesticide (OCP)-contaminated paddy soil. After 180 days of incubation, total OCP biodegradation was highest in soil receiving the addition of nitrate and MCD simultaneously and then followed by nitrate addition, MCD addition, and control. The highest biodegradation of chlordanes, hexachlorocyclohexanes, endosulfans, and total OCPs was 74.3, 63.5, 51.2, and 65.1%, respectively. Meanwhile, MCD addition significantly increased OCP bioaccessibility (p < 0.05) evaluated by Tenax TA extraction and a three-compartment model method. Moreover, the addition of nitrate and MCD also obtained the highest values of soil microbial activities, including soil microbial biomass carbon and nitrogen, ATP production, denitrifying bacteria count, and nitrate reductase activity. Such similar trend between OCP biodegradation and soil-denitrifying activities suggests a close relationship between OCP biodegradation and N cycling and the indirect/direct involvement of soil microorganisms, especially denitrifying microorganisms in the anaerobic biodegradation of OCPs.
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, People's Republic of China, yemao@issas.ac.cn.
authors.forename: Mao
authors.initials: M
authors.lastname: Ye
authors.forename: Mingming
authors.initials: M
authors.lastname: Sun
authors.forename: Ni
authors.initials: N
authors.lastname: Ni
authors.forename: Yinwen
authors.initials: Y
authors.lastname: Chen
authors.forename: Zongtang
authors.initials: Z
authors.lastname: Liu
authors.forename: Chengang
authors.initials: C
authors.lastname: Gu
authors.forename: Yongrong
authors.initials: Y
authors.lastname: Bian
authors.forename: Feng
authors.initials: F
authors.lastname: Hu
authors.forename: Huixin
authors.initials: H
authors.lastname: Li
authors.forename: Fredrick Orori
authors.initials: FO
authors.lastname: Kengara
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
mesh_terms: D000693:Anaerobiosis; D000704:Analysis of Variance; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D002244:Carbon / Q000032:analysis; D002681:China; D006843:Hydrocarbons, Chlorinated / Q000032:analysis* / Q000378:metabolism; D009566:Nitrates / Q000494:pharmacology; D009584:Nitrogen / Q000032:analysis; D010575:Pesticides / Q000032:analysis* / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000494:pharmacology
chemical_list: D006843:Hydrocarbons, Chlorinated; D009566:Nitrates; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D002244:Carbon; D009584:Nitrogen