The extraction method and structure of exo-polysoccharide from schizophyllum commune by submerged cultivation were studied. Proteins were removed com p letely from the polysoccharide by the sevag method following the isoelectric poi nt precipitation method. The purified schizophyllan was proved to be homogeneou s with molecular weight 4?10 4D by sephadex G-200 column chromatography, PAGE and HPLC. Its monomer was determined by hydrolysis, PC, GC and its structure wa s analyzed by IR, enzymolysis, periodate oxidation, the results showed that schi zophyllan was only composed of glucose and it was the ?-glucan consisting of ?-(1-3) and ?-(1-6) glucosidic linkages.

This study was based on live yeast cell derivative (LYCD), which was produced by live yeast cell stressed with high temperature and H 2O 2. The results showed that pretreating of low dose(37℃and 0.2mmol/L H 2O 2) could increase the content of GSH and the activity of SOD and CAT. These pretreatment could induce the resistance to lethal concentration of H 2O 2. LYCD was produced by yeast treated with 37℃ and 0.2mmol/L H 2O 2. And it was found that the survival of yeast treated with lethal concentration of H 2O 2 obviously increased, while LYCD was added in yeast culture. It indicated that LYCD could have resistance to oxidative condition.

Mandibular symphysis fracture combined with anteromedial dislocated condyle fracture is commom in clinical,but mandibular symphysis fracture associated with superolateral dislocation of the mandibular condyle is rare,which is often misdiagnosed or completely over-looked.Malpractice can lead to ankylosis and other sequelae.This article reviews 10 patients with mandibular symphysis fracture associated with superolateral dislocation of the mandibular condyle,discusses the causative mechanism,diagnostic features and clinical management according to literature data.

Bacillus subtilis ZC-7 was obtained by implantation with N+ ions beam to B.subtilis AS1.398,and compared with the AS1.398 neutral protease,the enzyme activity of ZC-7 neutral protease was about 1 timeshigher in previous research.A neutral protease was purified from the culture of B.Subtilis ZC-7 by the procedures including amoninium sulfate precipitation,ultrafiltration,DEAE-Sepharose Fast Flow chromatography and Sephadex G-75 chromatography.By multi-step purification,the ZC-7 neutral protease was purified to 78.5 folds and its yield was 27.7%,at last,the specific activity of ZC-7 neutral protease was up to 4.1?105U/mg.Analysed by SDS-PAGE,the purified protease has shown a molecular mass of about 42kDa.The Km for casein hydrolysis was 3.67?10-3?g/ml and the Vmax was 12.21?g/min.The optimum pH and temperature forhydrolysis of casein were 7.0 and 55℃,respectively.This protease was stable up to 40℃ within the pH range of 6.5 and 8.0.EDTA,isopropanol and alcohol nearly inhibited its activity while some ions such as Ca2+,Mg2+,Fe3+ can improve its activity.In addition,it could resist 1 mol/L H2O2.

To improve 3-ketosteroid-△1-dehydrogenase(KSDH) activity and the transformation level for androst-4-ene-3,17-dione, 3-ketosteroid-△1-dehydrogenase gene(ksdD) from Arthrobacter simplex was cloned into plasmid pWB980 and expressed in B. subtilis WB600 under the control of promoter P43. The molecular weight of expressed enzyme was about 55kDa by SDS-PAGE analysis. The activitities assayed by spectrophotometrical method of intracellular and extracellular soluble enzyme were 110?0.5mU and 15?0.6mU per milligram of protein respectively. The transformation rate of androst-4-ene-3,17-dione by the B. subtilis recombinant cells was 45.3%. Compared with Arthrobacter simplex, the enzyme activity of KSDH expressed in B. subtilis was improved about 30 fold, and the transformation level of androst-4-ene-3,17-dione by the B. subtilis recombinant cells was improved about 10 fold. The recombinant B. subtilis cells used in biotransformation of steroids provided a new way for steroid medicines production.

To obtain high-yield avilamycin-producing strains,low energy N~+ ion implantation technology and screening of streptomycin-re- sistant mutants are used in the study on breeding mutation.The results show that,“saddle”region,which range is from 3?10~(15) to 5?10~(15) ions/cm~2,has got better induced mutation action.It also means that the strain's resistant mutation and yield mutation closely correlate to each other,and the method of streptomycin resistant screening is feasible.We have isolated a high-yield strain SVT-45 which the productivi- ty is 195% higher than the original strain's in the rotation-flask experiments.These results showed that the ion implantation was an effective method for microbe mutagensis.

The promoter and signal peptide sequence of sacB gene (sacR gene) has been amplified by PCR.An inducible expression and secretion vector pHP13SN has been constructed with this amplified sequence,which was ligated with the pro-peptide and mature peptide of neutral protease gene on the vector pHP13.Transforming Bacillus subtilis DB104 with the vector pHP13SN, and the recombinant strain DB104(pHP13SN) can be got.The neutral protease gene has been expressed by the inducement of sucrose and the regulation of sacR,and the production has been secreted with bioactivity.

To obtain a number of extracellular penicillinase,the gene(penp)encoding penicillinse of Bacillus cereus ATCC10987 was cloned into expression vector in Bacillus subtilis,transformed into Bacillus subtilis DB104 deficient in two proteases.When recombinant bacteria was cultured in LB medium for 24 hours,the result of SDS-PAGE showed that the molecular weight of the protein was 28kDa and the penicillinase activity reached 339U/ml.By screening seven different fermentation media,the result showed that 4# medium is favorable to producing penicillinase by the recombinant cells than the others,with the yield of the enzyme being 1580U/ml.When the recombinant cells was cultured in 7 liter fermentor for 24h,the penicillinase activity reached 1255.8U/ml.

To obtain a number of penicillinases and degrade penicillin in milk by using the penicillinases,the gene encoding penicillinase was amplified by PCR from Bacillus cereus ATCC10987,cloned into pET28a(+) ,transformed into E. coli BL21;analysis of SDS-PAGE and penicillinase activity of the recombinant protein were done under induction of IPTG and the result showed that the maximum penicillinase activity reached 480 U/mL;the purity of penicillinase purified by Ni2+ Purification System was more than 90%;the immobilized penicillinases were obtained by sodium periodate method and the residual quantity of penicillin in milk(containing 0.5 U penicillin G/mL) was less than 4 ppb after degraded by the immobilized penicillinase.

0. 05). Conclusion On the CTA exams with 64-slice spiral CT, good CTA image quality can be acquired with reduced contrast dose and saline flush, thereby we can afford reliable diagnostic information for the clinicians.