An operon consisting of a P-type ATPase gene and a transcriptional regulator gene responsible for cadmium resistances in Bacillus vietamensis 151-6 and Bacillus marisflavi 151-25

Abstract

Background: Cadmium (Cd) is a severely toxic heavy metal to most microorganisms. Many bacteria have developed Cd 2+ resistance. Results: In this study, we isolated two different Cd 2+ resistance Bacillus sp . strains, Bacillus vietamensis 151-6 and Bacillus marisflavi 151-25 , which could be grown in the presence of Cd 2+ at concentration up to 0.3 mM and 0.8 mM, respectively. According to the genomic sequencing, transcriptome analysis under cadmium stress, and other related experiments, a gene cluster in plasmid p25 was found to be a major contributor to Cd 2+ resistance in B. marisflavi 151-25. The cluster in p25 contained orf4802 and orf4803 which encodes an ATPase transporter and a transcriptional regulator protein, respectively. Although 151-6 has much lower Cd 2+ resistance than 151-25, they contained similar gene cluster, but in different locations. A gene cluster on the chromosome containing orf4111 , orf4112 and orf4113 , which encodes an ATPase transporter, a cadmium efflux system accessory protein and a cadmium resistance protein, respectively, was found to play a major role on the Cd 2+ resistance for B. vietamensis 151-6. Conclusions: This work described cadmium resistance mechanisms in newly isolated Bacillus vietamensis 151-6 and Bacillus marisflavi 151-25. Based on homologies to the cad system (CadA-CadC) in Staphylococcus aureus and analysis of transcriptome under Cd 2+ induction, we inferred that the mechanisms of cadmium resistance in B. marisflavi 151-25 was as same as the cad system in S. aureus . Although Bacillus vietamensis 151-6 also had the similar gene cluster to B. marisflavi 151-25 and S. aureus , its transcriptional regulatory mechanism of cadmium resistance was not same. This study explored the cadmium resistance mechanism for B. vietamensis 151-6 and B. marisflavi 151-25 and has expanded our understanding of the biological effects of cadmium.

Draft genome sequence of Pseudomonas sp. A46 isolated from mercury‐contaminated wastewater

“…As such, the four ZntA P-type transporting ATPases (PSDM-0653, PSDM-1071, PSDM-1166, and PSDM-4297) in particular may mediate resistance to Zn 2+ , Cd 2+ , and Pb 2+ [28], and heavy metals could be transported by the resistancenodulation-division (RND) family efflux transporters PSDM-0708 and PSDM-4729 [29,30]. CzcA (PSDM-3120, PSDM-0710, and PSDM-1540) and CzcB (PSDM-0709) heavy metal proteins are involved in the efflux of metal ions such as Cd 2+ [31,32]. The chromate transport protein ChrA (PSDM-0705 and PSDM-4465) is involved in the chromate efflux system and has been shown to enhance the chromate tolerance capacity [33,34].…”

Determinantes Genéticos Y Sus Mecanismos De Acción Implicados en La Resistencia Bacteriana a Metales Pesados: Una Revisión.

“…El sistema de resistencia al cadmio en las bacterias Gram positivas es el sistema cad, se ha identificado el conjunto de genes cadCA en S. aureus ATCC12600 aislado de un ambiente hospitalario, en Bacillus vietamensis 151-6 y Bacillus marisflavi 151-25 aisladas de un suelo contaminado con cadmio (64,65,66,67). Por otro lado, en el genoma de la cepa JMAK1 de Bacillaceae aislada de la estación Concordia de la Antártica, se ha evidenciado la presencia de los genes cadA, cadC y cadD (68).…”

“…Por otro lado, en el genoma de la cepa JMAK1 de Bacillaceae aislada de la estación Concordia de la Antártica, se ha evidenciado la presencia de los genes cadA, cadC y cadD (68). El gen cadC codifica para el represor CadC que se disocia del operador/promotor de cad tras la unión de Cd 2+ (65). CadC de la cepa ATCC12600 presenta dos sitios de unión al metal (64).…”

“…Un sistema de resistencia al Cd 2+ , Co 2+ y Zn 2+ en bacterias Gram negativas es el sistema (czc). P. putida SB32 y Pseudomonas monteilii SB35 contienen en sus plásmidos el sistema czc (65,75). En A. ferrooxidans ATCC 23270 y en Marinobacter adhaerens HP15 aislada de un entorno marino, se han encontrado los genes: czcA, czcB y czcC, además, se ha evidenciado que la bomba czcABC en la cepa HP15 es específica para zinc (72, 76, 77).…”