It was discovered in this experiment that 3 days after inoculation of the ascitic fluid from P_(388) leukemic mice, the positive percentages of AcP and ?-Gase of the lymphocytes within the TNC of the recipients were increased significantly, while the positive percentage of ANAE was decreased. All the positive percentages of the three enzymes of the thymocytes within the thymus were increased significantly, but no abnormal structural changes were seen in the thymus. No histological and cytochemical changes were found in the lymph nodes and the spleen. Nine days after inoculation, the leukemia cell infiltration, hemorrhage and cell degeneration occurred in all the thymus, lymph nodes and spleen of the mouse. The normal structures of the organs were destroyed. The positive percentages of the cytochemical reactions of the three enzymes in the lymphocytes were all increased significantly. At this stage, TNC was very difficult to be isolated from the thymus. The results indicate that thymus and TNC may have a close relationship with the development of this type of leukemia.

We used four strains (Y1, Y2, M1 and M2) to screen out the high lipid production strains. We first adopted cell morphology and cytochemical methods (Sudan III dyeing technique) to observe intracellular characteristics. Observation results indicated that M2 strain had the potential lipid accumulation capacity. To prove this, lipid content of these strains was determined by soxhlet extraction. One strain (M2) was found to produce lipids up to 53.09%. In order to increase the production of oleaginous microorganism, the effects of hydrolysate concentration, nitrogen source, pH, fermentation temperature and time on cell growth and lipid accumulation were studied. The optimal fermentation conditions were obtained as follows: corn starch byproduct hydrolysate concentration at 10(o) Bx as carbon source; NaNO3 as nitrogen source at 0.2%; initial pH of 6.0; temperature at 28 degrees C, cultivated for 6 d. Under these conditions, M2 strain accumulated lipids up to 75.21% on a cellular biomass basis with biomass yield of 30.40 g/L, and the corresponding lipid production reached 22.86 g/L. GC analysis demonstrated that the fatty acid composition of the lipid was similar to that of vegetable oil, which mainly contained 16-and 18-carbon fatty acids. Thus, microbial lipid is a promising material for biodiesel production, and its unsaturated fatty acid content reached around 68%. These unsaturated fatty acids show great potential applications in food, medicine and cosmetics industries.
Biomass ; Culture Media ; Fatty Acids ; analysis ; biosynthesis ; Fermentation ; Hydrogen-Ion Concentration ; Industrial Microbiology ; Starch ; metabolism ; Temperature ; Yeasts ; growth & development ; metabolism

Biomass carbohydrates assimilation and lipid accumulation by Mortierella isabellina M2 strain were investigated. Corn fiber hydrolysate was specially studied. The results showed M. isabellina M2 strain achieved growth and lipid accumulation while glucose, xylose, mannose and arabinose were introduced as single carbon source, respectively. When M. isabellina M2 strain was cultivated on corn fiber hydrolysate with 6% sugars concentration, the biomass reached 18.2 g/L, the lipid content of dry mycelia was 45.7%, and the lipid yield achieved 8.3 g/L. It provided a promising perspective for microbial oils production with biomass hydrolysates.
Biomass ; Carbohydrate Metabolism ; Carbon ; metabolism ; Fermentation ; Industrial Microbiology ; methods ; Lipids ; biosynthesis ; Mortierella ; metabolism ; Zea mays ; metabolism