Potential of cadmium resistant Burkholderia contaminans strain ZCC in promoting growth of soy beans in the presence of cadmium.

Bioremediation of Cd contaminated environments can be assisted by plant-growth-promoting bacteria (PGPB) enabling plant growth in these sites. Here a gram-negative Burkholderia contaminans ZCC was isolated from mining soil at a copper-gold mine. When exposed to Cd(II), ZCC displayed high Cd resistance and the minimal inhibitory concentration was 7 mM in LB medium. Complete genome analysis uncovered B. contaminans ZCC contained 3 chromosomes and 2 plasmids. One of these plasmids was shown to contain a multitude of heavy metal resistance determinants including genes encoding a putative Cd-translocating PIB-type ATPase and an RND-type related to the Czc-system. These additional heavy metal resistance determinants are likely responsible for the increased resistance to Cd(II) and other heavy metals in comparison to other strains of B. contaminans. B. contaminans ZCC also displayed PGPB traits such as 1-aminocyclopropane-1-carboxylate deaminase activity, siderophore production, organic and inorganic phosphate solubilization and indole acetic acid production. Moreover, the properties and Cd(II) binding characteristics of extracellular polymeric substances was investigated. ZCC was able to induce extracellular polymeric substances production in response to Cd and was shown to be chemically coordinated to Cd(II). It could promote the growth of soybean in the presence of elevated concentrations of Cd(II). This work will help to better understand processes important in bioremediation of Cd-contaminated environment.

Rapid purification of lung cancer cells in pleural effusion through spiral microfluidic channels for diagnosis improvement.

Lung cancer is one of the leading causes of death worldwide. Fifteen percent of lung cancer patients will present with malignant pleural effusion initially, and up to 50% will have malignant pleural effusion throughout the course of the disease. In this study, we developed a spiral microfluidic device that can rapidly isolate cancer cells and improve their purity through fluid dynamics. This label-free, high-throughput device continuously isolates cancer cells and other unrelated molecules from pleural effusion. Most of the background cells that affect interpretation are flushed to outlets 1 to 3, and cancer cells are hydrodynamically concentrated to outlet 4, with 90% of lung cancer cells flowing to this outlet. After processing, the purity of cancer cells identified in pleural effusion by CD45 and epithelial cell adhesion molecule (EpCAM) antibodies in flow cytometry will be increased by 6 to 24 times. The microfluidic device presented here has the advantages of rapid processing and low cost, which are conducive to rapid and accurate clinical diagnosis.