Long‐term ferrocyanide application via deicing salts promotes the establishment of Actinomycetales assimilating ferrocyanide‐derived carbon in soil

Abstract

SummaryCyanides are highly toxic and produced by various microorganisms as defence strategy or to increase their competitiveness. As degradation is the most efficient way of detoxification, some microbes developed the capability to use cyanides as carbon and nitrogen source. However, it is not clear if this potential also helps to lower cyanide concentrations in roadside soils where deicing salt application leads to significant inputs of ferrocyanide. The question remains if biodegradation in soils can occur without previous photolysis. By conducting a microcosm experiment using soils with/without pre‐exposition to road salts spiked with 13C‐labelled ferrocyanide, we were able to confirm biodegradation and in parallel to identify bacteria using ferrocyanide as C source via DNA stable isotope probing (DNA‐SIP), TRFLP fingerprinting and pyrosequencing. Bacteria assimilating 13C were highly similar in the pre‐exposed soils, belonging mostly to Actinomycetales (Kineosporia, Mycobacterium, Micromonosporaceae). In the soil without pre‐exposition, bacteria belonging to Acidobacteria (Gp3, Gp4, Gp6), Gemmatimonadetes (Gemmatimonas) and Gammaproteobacteria (Thermomonas, Xanthomonadaceae) used ferrocyanide as C source but not the present Actinomycetales. This indicated that (i) various bacteria are able to assimilate ferrocyanide‐derived C and (ii) long‐term exposition to ferrocyanide applied with deicing salts leads to Actinomycetales outcompeting other microorganisms for the use of ferrocyanide as C source.

Pro-Inflammatory versus Immunomodulatory Effects of Silver Nanoparticles in the Lung: The Critical Role of Dose, Size and Surface Modification

“…After measuring the fragment size and concentration with a DNA 7500 Chip on a Bioanalyzer 2100 device (Agilent, Santa Clara, CA, USA), indexing PCR was performed as follows: 98 °C for 30 s, followed by eight cycles of 98 °C for 10 s, 55 °C for 30 s, 72 °C for 30 s, and final extension at 72 °C for 5 min. Each 25 μL PCR reaction contained 1× NebNext High Fidelity Mastermix (New England Biolabs), indexing primer 1 (N7xx) and indexing primer 2 (S5xx) and 10 ng of template DNA [ 46 , 47 ]. All samples were purified using AMPure beads XP (Beckman Coulter, Brea, CA, USA).…”

“…Raw sequences were processed with MOTHUR v.1.39.3 [ 48 ] as described previously in [ 46 , 47 ]. Briefly, contiguous sequences were formed by removing barcodes and primers.…”

“…Results were considered significant as * p < 0.05, ** p < 0.01, *** p < 0.001. Lung microbiome data were analyzed in R v3.4.0 ( ) using multivariate analysis of variance (Adonis function) based on Yue Clayton dissimilarity and Euclidean distances of Hellinger transformed data as described previously in [ 46 , 47 ]. Replicate similarity ( n = 5) was checked by clustering all OTUs according to a dissimilarity matrix based on the Yue Clayton coefficient, resulting in the unweighted pair group method (UPGMA) dendrogram.…”

Effect of the post treatments for biowaste‐based digestates on water solubility of nutrients and iron‐cyanide (Fe‐CN) complex mobility

“…Moreover, in Europe there are plenty of abandoned manufactured gas plant sites from the nineteenth to early twentieth century posing a hazard to soils and groundwater. According to Gschwendtner et al (), annually 75–425 Mg cyanide is spread to the road soil environment in Germany, due to the fact that about 100 mg Fe (CN) 6 is contained in 1 kg road salt. The potential risk to human health depends on the tendency of Fe‐CN complexes to release toxic free cyanide, which is influenced by the kinetic stability of the complexes and by the presence of light (Kjeldsen, ; Sut, Boldt‐Burisch, & Raab, ).…”