ENVIRONMENTAL BIOTECHNOLOGY The impacts of different long-term fertilization regimes on the bioavailability of arsenic in soil: integrating chemical approach with Escherichia coli arsRp::luc-based biosensor Qi-Hui Hou & An-Zhou Ma & Di Lv & Zhi-Hui Bai & Xu-Liang Zhuang & Guo-Qiang Zhuang Received: 3 December 2013 /Revised: 12 February 2014 /Accepted: 2 March 2014 /Published online: 1 April 2014 # Springer-Verlag Berlin Heidelberg 2014 Abstract An Escherichia coli arsRp::luc-based biosensor was constructed to measure the bioavailability of arsenic (As) in soil. In previous induction experiments, it produced a linear response (R 2 =0.96, P <0.01) to As from 0.05 to 5 μmol/L after a 2-h incubation. Then, both chemical sequential extraction, Community Bureau of Reference recommended sequential extraction procedures (BCR-SEPs) and E. coli biosensor, were employed to assess the impact of different long-term fertiliza- tion regimes containing N, NP, NPK, M (manure), and NPK+ M treatments on the bioavailability of arsenic (As) in soil. Per the BCR-SEPs analysis, the application of M and M+NPK led to a significant (P <0.01) increase of exchangeable As (2–7 times and 2–5 times, respectively) and reducible As (1.5–2.5 times and 1.5–2.3 times, respectively) compared with the no fertilization treated soil (CK). In addition, direct contact assay of E. coli biosensor with soil particles also supported that bioavailable As in manure-fertilized (M and M+NPK) soil was significantly higher (P <0.01) than that in CK soil (7 and 9 times, respectively). Organic carbon may be the major factor governing the increase of bioavailable As. More significantly, E. coli biosensor-determined As was only 18.46–85.17 % of exchangeable As and 20.68–90.1 % of reducible As based on BCR-SEPs. In conclusion, NKP fertilization was recommend- ed as a more suitable regime in As-polluted soil especially with high As concentration, and this E. coli arsRp::luc-based biosensor was a more realistic approach in assessing the bio- availability of As in soil since it would not overrate the risk of As to the environment. Keywords Long-term fertilization . Arsenic (As) pollution . Bioavailability . Sequential extraction . Microbial biosensor Introduction Arsenic (As) is an odorless and nearly tasteless but toxic natural element. It is classified as one of the most toxic and prioritized pollutants by the WHO and EPA. The permissible level of As in potable water is 10 μg/L for most European countries and the USA (Nordstrom 2002). Inorganic As is a serious human carcinogen, and its accumulation in the body may contribute to the cancer risk of the bladder, liver, kidney, and skin, even at low concentrations (Naujokas et al. 2013). Generally, As contamination originates from its release from the Earth’ s crust due to a variety of geochemical conditions or microbiological activity (De Brouwere et al. 2004; Dowdle et al. 1996; Nickson et al. 1998). In addition, increasing application of agricultural chemicals, such as fertilizers, or- ganic manure, and pesticides, could also increase the risk of As pollution to farmland and humans (Chirenje et al. 2003; Li et al. 2010; Li and Chen 2005). To comprehensively imitate the bioavailable metal fraction in soil, kinds of chemical sequential extraction procedures (SEPs) based on a series of selective reagents were widely introduced to clarify the relationship of metal and geochemi- cal phases (Huang and Kretzschmar 2010; Larios et al. 2013; Wenzel et al. 2001). There are different definitions of metal fraction based on different extraction methods, for example, according to a proposal of the European Community Bureau of Reference (BCR), the -acid extractable, -reducible, and - oxidizable metal was defined as the SEPs fraction (Rauret Qi-Hui Hou and An-Zhou Ma contributed equally to this study. Q.<H. Hou : A.<Z. Ma : Z.<H. Bai : X.<L. Zhuang : G.<Q. Zhuang (*) Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Beijing 100085, China e-mail: houqihui190@163.com D. Lv Insitute of Microbiology, Chinese Academy of Sciences, Beichen West Road 1, Beijing 100101, China Appl Microbiol Biotechnol (2014) 98:6137–6146 DOI 10.1007/s00253-014-5656-0