Research On Food Safety Of Pure Culture Of Eurotium Cristatum

Fuzhuan brick tea is an important dark tea and is the necessity of daily life for minority in North-western China. But the food safety of Eurotium cristatum is still demanded to conduct a further evaluation. In order to insure dietary safety of public and utilize resource completely, the food security of Eurotium cristatum from Fuzhuan brick tea is evaluated according to "procedures for toxicological assessment of food of P.R.C.". These methods include acute toxicity test by oral, micronucleus test of bone marrow polychromatic erythrocyte and sperm shape abnormality test,30 days feeding test and denaturing gradient gel electrophoresis (DGGE) analysis. The acute toxicity test shows mouse LD50 is above 10000 mg/(kg·bw), which suggests Eurotium cristatum is non-toxic according to acute toxicity grading. The fracture and spindle toxic effect of bone marrow cell chromosome in mouse which are fed Eurotium cristatum at high-dose up to 5000mg/(kg·bw). In other words, micronucleus test is negative. Sperm shape abnormality test is also negative within the dosage of experimental conditions. Mouse, fed Eurotium cristatum for 30 days, grows well. The color, diet, activity, food ingestion ratio, hematology (Hb,RBC,WBC,etc) and hematology biochemistry (TP,ALB,ALT,etc) index are all normal. No abnormal symptoms are observed after gross anatomy. Compared with negative control, the ratio of liver to body, the same ratios of kidney and spleen have no any little difference significantly. And there are no symptoms for kidney, stomach, liver, spleen and duodenum through histopathological examination. PCR-DGGE analysis for colon bacteria in mice tested show that the diversity all changed and the diversity of Lactobacillus and Clostridium cluster IV increased, but there is no obvious effect for bacteroides. This suggests that the low dose Eurotium cristatum suspension can be benefit for improving of colon bacteria.