astaxanthin is an effective antioxidant and natural pigment which has wide application. Phaffia rhodozyma is a good source of astaxantin, but wild strain has limited use in industry because of low production level of astaxanthin. Several mutants of Phaffia rhodozyma were obtained by exerting mutagen N-methyl-N-nitro-N-nitrosoguanidine. The growth curve suggested that pigments were mainly produced in the middle and latter periods of log phase. The pigments were extracted from Phaffia rhodozyma and analysed by esterification, thin layer chromatography and absorption spectrometry. It was proved that astaxanthin, astaxanthin diester and β-carotene were the major components of the pigments produced by Phaffia rhodozyma. We also studied the pigments producing phase of Phaffia rhodozyma. and founded that astaxanthin was stable to light under butylatedhydroxytoluene coexistance.

Four cellulolytic strains, which can be used as feed additive, were studied under the conditions of various temperature, incubation time, and anaerobic process, and examined the changes of their cell protein content, cellulase and hemi-cellulase activity. The results show: 1) The maximum cellulolytic enzyme activities were observed incubation 20h; 2) Constant medium temperature 28℃ was adequate to the growth of the 4 strains ; 3) anaerobic condition, 39℃±2℃ and fermentation 12h, 24h, 36h, the tested strains can growth well in PDA plate, however, the cellulolytic enzyme activities and growth of the tested strains were influenced adversely when fermentation 48h. The experiment provide many important basis for the strains production, storage and utilization.

Four bacterial and 8 fungal isolates were incubated in media for 6 days. It was found that organic acid content in the media increased largely, but pH decreased sharply. Phosphorus content in the media enhanced dramatically as well. The fungal isolates showed stronger ability to dissolve phosphate rock than the bacterial ones. These isolates excreted not only quite distinct volume of organic acids but diverse organic acid chemicals. The fungi produced more kinds of organic acids than the bacteria. However, there was no significant relationship between the total quantity of organic acids and P content in the media.

Six atrazine-degrading strains, Pseudomonas spp. AD1, AD2, AD6, Agrobacterium sp. AD4, Xanthomonas AD5, and Erwinia sp. AD7, were isolated from industrial wastewater. These strains are able to grow on atrazine as sole nitrogen source. Strain AD1 is able to degrade atrazine of 0. 3g/L in minimal medium at a percentage of 99.9% in 72 hours. PCR products that are homologous to the atrazine chlorohydrolase gene atzA)from Pseudomonas sp. strain ADP were obtained by PCR method using total DNA of the strains AD1 ,AD4,AD5,AD6,and AD7 as templates.

The enzyme activity of α－Acetolactate Decaroboxylases (ALDC)from different microbes was studied, the results demonstrated that it was quite different among them. There were diversities of their enzyme reaction velocities. It was clear that the enzyme activity was affected by the pH of the enzyme reaction system, for example, the optimum pH of ALDC from Lactococcus lactis was 6.6, while for Aerobacter Aerogenes it was 5.8. Addition leucine,valine and isoleucine into enzyme reaction system obviously affected the enzyme activity of ALDC from different microbes.

We first find Xanthomonas campestris N. K-01 which don't produce xanthan at 28℃ cansynthesize and secrete the xanthan under low temperature (4℃). Little string is the most minute unit of the secreted under low temperature. Many little strings ecreted by bacterium cell extend to form a wider xanthan fiber. When depart from cell, xanthan fiber either twine to form double helix of bundle together. They are both advanced structures of the xanthan strings. Xanthan secreted under 4℃ has the same chemical composition and structure as that under 28℃, but lower moleculer weight and lower pyruvate content.

The experiment was carried out to inquire about the possibility of strain selection and improvement in Lentinus edodes through protoplast formation and mutagenesis by UV. Mycelial growth rate, yield, and period of fructification of 105 selected regenerants from UV-treated protoplasts have been measured and compared with their parents. Several selected regenerants achieved some better qualities such as higher yield and earlier fruiting. Several repeated cultivations of these regenerants reconfirmed their new capacities. The results indicated that protoplast formation and mutagenesis are the potential methods for strain selection and improvement in edible fungi.

Shan Qi soy has busting bags, bacteria sum overproof, continue acidification and other problems occasionally during the storage. It's probably caused by the Lactobacillus continue growth in the soy. We tried expounding the relationship between growth and producing acid when Lactobacillus growing in the thin fermented material.

From air bacteria capable of decomposing creatinine, three single independent strains K9510、K9511 and K9512 have been isolated. The highest creatinine amidohydrolase (EC 3.5.2.10; creatininase) producing strain K9510 was screened out. The strain K9510 was identified as Pseudomonas sp. The results of culture condition for creatininase formation by strain K9510 were obtained as follows: creatinine and creatine were found to be the effective inducers for enzyme formation; the solution of mixed metallic salts could stimulate cell growth and enzyme formation. The suitable medium for creatininase formation was consisted of 0.9% creatinine、 0. 15% yeast extract、 0. 09% malt extract、0.05% NH4C1 and some amount of the solution of mixed metallic salts at pH5. 5. When the bacterium was grown in 250mL conic flask containing 50mL of the medium mentioned above on the rotary shaker(250r/min) at 35℃ for 33 h, about 50 u creatininase was obtained.

The microbial counts, type, as well as relationship between microbial counts and the temperature of water in reticulating water system of heating pipeline in Taiyuan were studied, which the main biofouling harmful microbes included slimeforming heterotrophic bacteria, sulfate reducing bacteria, iron bacteria and fungi, respectively. The results showed that the harmful microbes in water system were lower than that of control guideline during heating period, whereas the microbes were higher than that of control guideline, which would result in biofouling of water tube during non-heating period.