Enrichment And Distribution Of Germanium In Ganoderma Lucidum

Ganoderma lucidum is one of most frequently used fungi in Chinese medicine and nutrition. Apart from its rich contents of polysaccharide, amino acids, Ganoderic acid, sterol, orgariogermanium is believed to be an effective component of the plant. In this work we have developed an effective and reliable method for accurate determination of germanium contents ; We have also investigated the possibility of enriching germanium by cultivating Ganoderma lucidum in germanium dioxide. A method for the determination of trace germanium in Ganoderma lucidum by graphite furnace atomic absorption spectroscopy was developed. After detailed selection, the best digesting method was found, which is as follows. Wet digest at 120C with HNO3-H202 ; The digest time, 26 hours; The addition of H202 not only can make the samples digest completely, but also can eliminate the residual HNO3 absolutely. The recovery rate of the digest method is found to be 97.5% ?98.7%.The ashing temperature is up to 1400 and the matrix effects can be eliminated by using palladium nitrate and strontium nitrate as matrix modifier. The detection limit is 0.154 g/L. The recovery rate of the instrument is 95.1% 100.3%, and the relative standard deviation is 3.80%. The enrichment and distribution of germanium in Ganoderma lucidum had been studied by adding different amount of germanium dioxide into culture media during cultivation. The results showed that the absorption of germanium in Ganoderrma lucidum is transmissive. The enrichment of gmium inevry growing period and every part of Ganoderma lucidum when it grows in culture media which contains different amount of germanium dioxide can be explained by Logistic equation. The growth of mycelium isinhibited when the Ge content in culture media exceeds lOOmgIL, and the inhibition effect increased with the increase of the germanium concentration. Simila case is also found in fruiting body when the G?content in culture media exceeds 200mgIL. Ge- enriched Ganoderma lucidum can be successfully obtained by adding lOOmgIL Ge (mycelium) and 1 OO00mg/L Ge (fruiting body) into culture media during cultivation. Among different growing periods of Ganoderma lucidum, the mycelium, followed by the spores, the fruiting body and the primordium, has the highest content of germanium. And among several parts of Ganoderma lucidum, the stem, followed by the pleat and the cap, has the highest content of germanium. The primordium and the cap have the lowest content of germanium and both of them are in the active cell division period which is significant for the formation of the primordiutn and the pleat.