Use of cadA-Specific Primers and DNA Probes as Tools to Select Cadmium Biosorbents with Potential in Remediation Strategies

Biosorption, using cadmium-resistant bacterial isolates, is often regarded as a relatively inexpensive and efficient way of cleaning up wastes, sediments, or soils polluted with cadmium. Therefore, many efforts have been devoted to the isolation of cadmium-resistant isolates for the efficient management of cadmium remediation processes. However, isolation, identification and in situ screening of efficient cadmium-resistant isolates are primary challenges. To overcome these challanges, in this study, cadA, cadmium resistance coding gene, specific primers and DNA probes were used to identify and screen cadmium-resistant bacteria in the cadmium-polluted river waters through polymerase chain reaction (PCR) and fluorescein in situ hybridization (FISH). PCR amplification of the cadA amplicon coupled with 16S rRNA sequencing revealed various gram-positive and -negative bacterial isolates harboring cadA. Accordingly, a cadA-mediated DNA probe was prepared and used for in situ screening of cadmium-resistant isolates from water samples collected from cadmium-polluted river waters. The FISH analyses of cadA probe showed highly specific and efficient hybridization with cadA harboring isolates. The use of primers and DNA probes specific for cadA gene seems to be very helpful tools for the selection and screening of cadmium biosorbents with potential to be used in the remediation of cadmium-polluted sites.


Diversity of the Aromatic-Ring-Hydroxylating Dioxygenases in the Monoaromatic Hydrocarbon Degraders Held by a Common Ancestor
Yavas, Alper; İçgen, Bülent (Springer Science and Business Media LLC, 2018-09-01)
Aromatic ring hydroxylating dioxygenases (ARHDs), harboured by a variety of bacteria, catalyze the initial reaction in the degradation of a wide range of toxic environmental contaminants like aromatic and polycyclic aromatic hydrocarbons (PAHs). Regardless of the source, bacteria harbouring RHDs play major role in the removal of these toxic contaminants. The diversity of ARHDs in contaminated sites is supposed to be huge. However, most of the ARHD diversity studies are based on the PAH degraders and the ARH...
Biofilms attached to Myriophyllum spicatum play a dominant role in nitrogen removal in constructed wetland mesocosms with submersed macrophytes: Evidence from N-15 tracking, nitrogen budgets and metagenomics analyses
Mu, Xiaoying; Lv, Xiaoyang; Liu, Wei; Qiu, Changhao; Ma, Yu; Zhang, Songhe; Jeppesen, Erik (Elsevier BV, 2020-11-01)
The mechanisms behind nitrogen removal by the submersed macrophyte-biofilm complex in wetlands remain to be fully elucidated. This study investigated the role of Myriophyllum spicatum and the biofilm on their leaves in nitrogen removal in mesocosm experiments. N-15 tracking showed that 61.9% and 30% of the N-15, respectively, was removed from the system and assimilated by the macrophyte-biofilm complex after loading with 5.4 mg L-1 N-15 labelled NH4+ for 17 days. Nitrogen budget results showed that about 0....
Characterization of SDS-degrading Delftia acidovorans and in situ monitoring of its temporal succession in SDS-contaminated surface waters
YILMAZ, Fadime; İçgen, Bülent (Springer Science and Business Media LLC, 2014-06-01)
Incomplete removal of sodium dodecyl sulfate (SDS) in wastewater treatment plants may result in SDS residues escaping and finding their way into receiving water bodies like rivers, lakes, and sea. Introduction of effective microorganisms into the aerobic treatment facilities can reduce unpleasant by-products and SDS residues. Selecting effective microorganisms for SDS treatment is a big challenge. Current study reports the isolation, identification, and in situ monitoring of an effective SDS-degrading isola...
Exposure to a microplastic mixture is altering the life traits and is causing deformities in the non-biting midge Chironomus riparius Meigen (1804)
Stankovic, Jelena; Milosevic, Djuradj; Savic-Zdrakovic, Dimitrija; Yalçın, Gülce; Yildiz, Dilvin; Beklioğlu, Meryem; Jovanovic, Boris (Elsevier BV, 2020-07-01)
The effect of microplastics (MP) exposure on the chironomid species Chironomus riparius Meigen, 1804 was investigated using the OECD sediment and water toxicity test. Chironomid larvae were exposed to an environmentally relevant low microplastics concentration (LC), a high microplastics concentration (HC) and a control (C). The LC was 0.007 g m(-2) on the water surface + 2 g m(-3) in the water column + 8 g m(-2) in the sediment, and the HC was 10 X higher than this for each exposure. The size of the majorit...
Water column nutrient concentrations are related to excretion by benthic invertebrates in Lake Taihu, China
Peng, Kai; Qin, Boqiang; Cai, Yongjiu; Gong, Zhijun; Jeppesen, Erik (Elsevier BV, 2020-06-01)
Internal release of nutrients is an important contributor to the nutrient dynamics in shallow eutrophic lakes. Zoobenthic organisms may contribute to this release by excreting nutrients to the overlaying water. Based on experiments and using results from previous experimental studies as well as field monitoring density data from 2007 to 2017, we calculated the annual and seasonal nutrient excretions of the two most common macroinvertebrates (Corbicula fluminea and Limnodrilus hoffmeisteri) in Lake Taihu, Ch...
Citation Formats
B. İçgen, “Use of cadA-Specific Primers and DNA Probes as Tools to Select Cadmium Biosorbents with Potential in Remediation Strategies,” BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, pp. 685–693, 2016, Accessed: 00, 2020. [Online]. Available: