Physical, chemical, and biological properties of the soils used in this study.

<p># Total soil organic carbon (OC); total soil nitrogen (TN); the ratio of OC to TN (C/N); exchangeable potassium (K); dissolved organic carbon (DOC); total dissolved nitrogen (TDN); the ratio of fulvic acid to organic carbon (FA); the ratio of humic acid to organic carbon (HA); total phospholipid fatty acids (PLFA-T); fungus phospholipid fatty acids (PLFA-F); actinomyces phospholipid fatty acids (PLFA-A); bacteria phospholipid fatty acids (PLFA-B); Gram-negative bacteria phospholipid fatty acids (PLFA-G^-); Gram-positive bacteria phospholipid fatty acids (PLFA-G⁻); the ratio of PLFA-G⁻ to PLFA−G⁺ (G⁻/G⁺);</p

Survival of <i>E. coli</i> O157:H7 in the tested soils.

<p>Solid line: neutral soils; dashed line: acidic soils.</p

Stepwise multiple-linear regression analysis of soil properties and the survival time (<i>t_d</i>) of <i>E. coli</i> O157:H7 in the test soils.

<p># Survival time to reach detection limit (<i>t_d</i>), the ratio of Gram-negative bacteria phospholipid fatty acids (PLFAs) to Gram-positive bacteria PLFAs (G⁻/G⁺); exchangeable potassium (K); total soil organic carbon (OC); correlation is significant at the 0.001 probability level(***).</p

Principal component analysis (PCA) of the survival parameters (<i>δ</i>, <i>p</i> and <i>t_d</i>).

<p><i>δ</i>, <i>p</i> and <i>t_d</i> are the same as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0081178#pone-0081178-t002" target="_blank">Table 2</a>. A-S: acidic soils; N-S: neutral and slight alkaline soils.</p

Statistical measures and fitted parameter values of the Weibull model describing the survival of <i>E</i>. <i>coli</i> O157:H7 in soils.

<p># Survival time to reach detection limit (<i>t_d</i>); time needed for first decimal reduction in <i>E</i>. <i>coli</i> O157:H7 population (<i>δ</i>); shape parameter (<i>p</i>).</p>*<p>Significant differences (p < 0.05) indicated by different letters.</p

Bacterial strains and plasmids.

<p>Rif^r, rifampicin resistance; Km^r, kanamycin resistance; Cm^r, chloramphenicol; Ap^r, ampicillin resistance.</p

Growth curves of wild type strain (•) and its derivative mutants strains, Δ<i>stx</i>₁ (◊), Δ<i>eae</i> (▴), Δ<i>stx</i>₂ (□), and Δ<i>stx</i>_1–2 (○).

<p>The data represent the average of triplicate measurements.</p

Survival of the wild type (•) and its mutant derivatives, Δ<i>stx</i>₁ (◊), Δ<i>eae</i> (▴), Δ<i>stx</i>₂ (□), and Δ<i>stx</i>_1–2 (○), in loamy sand (3A), sandy loam (3B), and silty clay (3C).

<p>The data represent the average of triplicate experiments.</p

Double Weibull Model parameters of wild type strain and its mutant derivatives in loamy sand (4A), sandy loam (4B), and silty clay (4C).

<p>Double Weibull Model parameters of wild type strain and its mutant derivatives in loamy sand (4A), sandy loam (4B), and silty clay (4C).</p

Effects of clay content (%), soil organic carbon (OC, %), total nitrogen (T-N, %), water extractable organic carbon (WEOC, mg/kg) <i>Td</i>.

<p>Gray, white, and black columns represent loamy sand, sandy loam, and silty clay, respectively.</p