Intracellular sequestration of manganese and phosphorus in a metal-resistant fungus Cladosporium cladosporioides from deep-sea sediment.
A heavy metal resistant fungus was isolated from the sediment of Pacific Ocean, and identified to be Cladosporium cladosporioides. It grew normally in a medium containing 60 mM Mn(2+) and could endure 1,200 mM as the highest concentration tested. Quantification analysis confirmed a high accumulation of Mn which was 58 mg/g in dried biomass. Under transmission electron microscope, many intracellular crystals were observed in the cytoplasm of the hypha cells grown in a Mn-rich medium, and varied from a few nanometers to 200 nm in length. Energy dispersive X-ray (EDX) analysis showed that the crystals were composed of manganese and phosphorus in atomic ratio of 1.6:1 (Mn/P). Further, factors which might influence the resistance of this fungus were investigated. As a result, its high resistance to Mn(2+) was found dependent on the presence of Mg(2+), and could be further enhanced by phosphate. However, the effect of phosphate was not observed without the presence of Mg(2+). In addition, the resistance was also influenced by pH of the medium, which was lost above pH 8. This is the first report on a fungus which showed a hyper resistance to manganese by forming a large quantity of intracellular Mn/P crystals.
Shao
Zongze
Z
Key Lab of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration, Daxue Road 178#, 361005, Xiamen, Fujian, China. shaozz@163.com
Sun
Fengqin
F
D001483:Base Sequence; D002963:Cladosporium / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D017931:DNA Primers; D019015:Geologic Sediments; D008345:Manganese / Q000378:metabolism* / Q000494:pharmacology; D046529:Microscopy, Electron, Transmission; D010758:Phosphorus / Q000378:metabolism* / Q000494:pharmacology; D010802:Phylogeny
D017931:DNA Primers; D010758:Phosphorus; D008345:Manganese