Chemical composition analysis and value evaluation of stems and leaves of Astragalus membranaceus var. mongholicus / 中国中药杂志

This study aimed to provide data support for resource utilization of the stems and leaves of Astragalus membranaceus var. mongholicus(SLAM) by analyzing and evaluating the chemical constituents. The crude protein, crude fiber, and soluble saccharide of SLAM were analyzed by Kjeldahl method, filtration method, and UV-Vis spectrophotometry, respectively. The nucleosides, amino acids, flavonoids, and saponins of SLAM were analyzed by ultraperformance liquid chromatography-triple quadrupole mass spectrometry(UPLC-TQ-MS). Combined with principal component analysis(PCA), the quality difference of resource components of SLAM was comprehensively evaluated. The results showed that the average content of crude protein, crude fiber, total polysaccharide, and redu-cing sugar in SLAM was 5.11%, 30.33%, 11.03 mg·g~(-1), and 31.90 mg·g~(-1), respectively. Six nucleosides, 15 amino acids, 22 flavonoids, and one saponin were detected, with an average content of 1.49 mg·g~(-1), 6.00 mg·g~(-1), 1.86 mg·g~(-1), and 35.67 μg·g~(-1), respectively. The content of various types of chemical components in SLAM differed greatly in different harvesting periods and growing years. The results of PCA showed that the quality of SLAM produced in Ningxia was superior. The results can provide references for the utilization of SLAM.

Comparison of methods for determination of gross α and gross β radioactivity in soil / 中国辐射卫生

Objective To improve the determination of gross α and gross β radioactivity in soil, establish a fast and accurate method for soil radioactivity analysis, and provide a basis for establishing standard methods for analysis of gross α and gross β radioactivity in soil. Methods Using the method of soil nuclide extraction and the sample preparation method for low background α/β counter, an extraction-enrichment method was established to monitor the radioactivity of gross α and gross β in soil. Meanwhile, the radioactivity of gross α and gross β in the same soil samples was determined using the direct paving method. An optimal method of monitoring gross α and gross β radioactivity in soil was put forward by comparing the advantages and disadvantages of the two methods. Results With the direct paving method, the radioactivity of gross α and gross β in soil was 0.47 Bq/g and 0.85 Bq/g, respectively; and the minimum detection limit was 0.04 Bq/g and 0.02 Bq/g, respectively. With the extraction-enrichment method, the radioactivity of gross α and gross β in soil was 0.32 Bq/g and 0.29 Bq/g, and the minimum detection limit was 0.02 Bq/g and 0.01 Bq/g. Conclusion Comparison of the two detection methods showed that the direct paving method is more accurate and easier to operate, while the extraction-enrichment method is complex in operation and has relatively large system error but provides a lower minimum detection limit.

Innovation and exploration of diversified teaching patterns for Biochemical Reaction Engineering under the new engineering education background / 生物工程学报

Biochemical Reaction Engineering is a professional discipline with emphasis on both theory and practice. It is the core course in the curriculum provision for students majoring in bioengineering and plays an important role in the cultivation of professional talents. However, there are so much theory knowledge, such as formulas and deduction, that students showed poor efficiency in their study. Herein, to cater the objective command of innovative talents under new education background, and to improve the practical teaching efficiency and the students' enthusiasm as well as the practical innovation capability, the teaching team innovated and explored the teaching pattern, the teaching method as well as the teaching technologies. The teaching efficiency has been remarkably improved by introducing the virtual simulate technology, the micro-lecture, the case teaching pattern attempts and the scientific platform, which can be used as reference by other peers.

Analytical method for 14C in urine / 中华放射医学与防护杂志

Objective:To improve the analytical method of radionuclide 14C, and estimate the internal dose caused by 14C to human, in order to protect the health of workers and the public in workplaces involving potential 14C exposure. Methods:Urine samples were pretreated by wet oxidation. In the analysis, potassium persulfate was used as an oxidant to decompose urea into carbon dioxide, which was absorbed by 1 mol/L sodium hydroxide, and the absorption solution was converted into calcium carbonate precipitation. After calcium carbonate powder was prepared into sample source by suspension method, the low background liquid scintillation counter was applied to measure the radioactivity, which can be used for calculating the result.Results:The reaction time optimized by using carbamide as carrier was 1 h. For 80 ml urine, the amount of potassium persulfate used was 10 g. The method recovery rate reached about 100%. Four real urine samples were tested using the optimized method, and the result of activity concentration 14C was 0.32, 0.60, 0.86 and 0.74 Bq/L, respectively. Conclusions:The optimized method had good stability, high accuracy and stable experimental result, which could meet the needs of routine radiological detection. The establishment of a quantitative method for 14C in urine sample has improved the methodological system for 14C monitoring.

Dopamine D1 receptor in ventrolateral periaqueductal gray modulates propofol anesthesia in rats / 医学研究生学报

ObjectiveVentrolateral periaqueductal gray (vlPAG) locates in ascending reticular activating system, which plays a key role in the sleep-wake circle. However, the role of vlPAG in general anesthesia has not been identified. To investigate the effect of the dopamine receptor in vlPAG neurons on propofol anesthesia, we used real-time in vivo fiber photometry, microinjection and EEG.MethodsTo observe the alteration of neuronal activity in the vlPAG throughout propofol anesthesia, 10 Sprague-Dawley rats were used for calcium fiber photometry recording. 50 vlPAG bilateral microinjection models were established and assigned into five groups randomly, including D1R agonist group, D1R antagonist group, D2R agonist group, D2R antagonist group, and control group (n=10). Under propofol anesthesia, 1 μL of D1R agonist, D1R antagonist, D2R agonist, D2R antagonist, and isotonic saline were microinjected into the vlPAG of animals in the corresponding groups, respectively. The induction time, recovery time and the changes in electroencephalogram (EEG) before and after microinjection were recorded and analyzed.ResultsThe neuronal activity in the vlPAG was significantly inhibited during the induction period and markedly recovered during the recovery period from propofol anesthesia (P<0.05). Subsequently, the microinjection of D1R agonist into the vlPAG notably prolonged the induction time and reduced the emergence time of propofol anesthesia with a decrease of δ-band ratio. While the microinjection of D1R antagonist accelerated the induction time and prolonged the emergence time of propofol anesthesia with an increase of δ-band ratio and a decrease in β-band ratio in cortical EEG (P<0.05). The induction and recovery time of D2R agonist /antagonist group did not differ with those of control group. As well, EEG before and after microinjection in D2R agonist /antagonist group did not different.ConclusionThese results indicate that vlPAG modulates the process of propofol anesthesia via D1R.

Longitudinal pancreaticojejunostomy for paediatric chronic pancreatitis with dilated pancreatic ducts / 中华肝胆外科杂志

Objective To analyze the results of longitudinal pancreaticojejunostomy in treatment of paediatric chronic pancreatitis with dilated pancreatic ducts.Methods A retrospective study was carried out on 13 patients with paediatric chronic pancreatitis complicated with dilated pancreatic ducts treated with longitudinal pancreaticojejunostomy in Children's Hospital of Chongqing Medical University from December 2011 to January 2017.The perioperative morbidity and mortality rates,long-term treatment results and postoperative growth of these children were analyzed.Results The 13 patients all underwent successful surgery.In 11 patients,the serum and urine amylase levels returned to normal after 8 days of operation,and the abdominal pain disappeared completely.In 1 patient,the abdominal pain gradually disappeared in 1 year,and the serum and urine amylase levels gradually returned to normal.This patient gained weight well.In the remaining patient who had severe pancreatic atrophy,the patient took high-fat diets before and after surgery,and drank alcohol occasionally.The patient developed repeated attacks of abdominal pain with occasional increase in serum and urine amylase levels and had poor weight gain.There were no complications such as postoperative bleeding,pancreatic leakage and intestinal obstruction in this study.The body weight and growth rates of the whole group of patients before and 1 year after surgery were different.Conclusion Longitudinal pancreaticojejunostomy for paediatric chronic pancreatitis complicated with dilated pancreatic ducts was safe and effective in alleviating symptoms,improving quality of life,and resulted in normal growth of these children.

Clinical epidemiological characteristics of neonatal respiratory failure: an analysis of 1,108 neonates / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the clinical epidemiological characteristics of neonatal respiratory failure in 1,108 neonates, and to provide a reference for improvement in clinical treatment and multicenter clinical studies.</p><p><b>METHODS</b>The clinical data of 1,108 neonates with respiratory failure were collected with questionnaires, and statistical analysis was performed for the epidemiological indices including primary diseases, clinical therapeutic methods, treatment outcome, and fatality.</p><p><b>RESULTS</b>In all the neonates with respiratory failure, the median gestational age was 37 weeks+1 day, the median birth weight was 2,600 g, the median age in days on admission to neonatal intensive care unit was 0.71 days (17 hours), and the boy/girl ratio was 3.1:1. The major primary diseases were respiratory distress syndrome (30.51%), pulmonary infection/sepsis (23.55%), and wet lung (13.18%). Of all the neonates, 48.64% received nasal continuous positive airway pressure (nCPAP), 12.81% received high-frequency oscillatory ventilation, 13.45% received pulmonary surfactant, and 8.66% received nitric oxide inhalation therapy. The fatality was 24.19%.</p><p><b>CONCLUSIONS</b>The major primary disease for neonatal respiratory failure is respiratory distress syndrome. Pulmonary surfactant, nCPAP, high-frequency oscillatory ventilation, and nitric oxide inhalation therapy are major therapeutic methods for neonatal respiratory failure, but neonatal respiratory failure still has a high fatality.</p>

Correlation and expression of PTEN, matrix metalloproteinase-9 and vascular endothelial growth factor-C in colorectal cancer / 中华内分泌外科杂志

Objective To investigate the correlation and expression of PTEN, matrix metalloproteinase-9 (MMP-9),and vascular endothelial growth factor-C(VEGF-C)in colorectal cancer.Methods The expression of PTEN, MMP-9 and VEGF-C in 102 cases of colorectal cancer tissues and 30 cases of normal colorectal tissues was detected using immunohistochemical SP method.Their correlations with cliniopathologic features were analyzed. Results The positive expression of PTEN in colorectal cancer was significantly lower than that in the controls (54.9%vs 100%, P<0.01).Both MMP-9 and VEGF-C were over expressed compared with the controls(83.3%vs 21.7%and 69.6%vs 16.7%respectively, P<0.01).The expression of PTEN was negatively correlated with that of MMP-9 and VEGF-C, and the expression of MMP-9 was positively correlated with that of VEGF-C ( P<0.05).The expressions of the three proteins in colorectal cancer tissues were not associated with age, gender, or tumor size.There were significant associations between the expression of these proteins and lymph node metastasis, distant metastasis, differentiation, and TNM staging(P<0.05).The 1, 3 and 5-year survival rates of the patients with positive PTEN were significantly higher than those of the patients with negative PTEN(P<0.05).The 1, 3 and 5-year survival rates of the patients with positive MMP-9 and VEGF-C were significantly lower than those of the patients with negative MMP-9 and VEGF-C( P<0.05) .Conclusions The decrease in the expression of PTEN and increase in MMP-9 and VEGF-C are closely correlated to the development of colorectal cancer.Their expressions may be favorable markers and useful prognostic indicators in the patients with colorectal cancer.

Role of NLRP3 inflammasomes in lung injury induced by gut hypoxic stress and its mechanism / 解放军医学杂志

Hypoxic stress of the gut may induce impairment of gut barrier function, ensuing translocation of gut-derived factors which can damage the function of remote organs, especially the development of acute lung injury (ALI). High altitude pulmonary edema (HAPE) is a non-cardiogenic pulmonary injury caused by hypoxia, while inflammation involved in the pathogenesis of HAPE has been gradually recognized. It has been also recognized that the cleavage and maturation of proinflammatory cytokines mediated by NLRP3 inflammasome play a crucial role in the pathogenesis of lung injury. Further investigation on the role of NLRP3 inflammasome in lung injury induced by gut hypoxic stress is of an important clinical significance for further improvement in the treatment of hypoxic inflammatory diseases.

Relationship between peri-menopausal women blood lipid level and the gallstone disease / 中国综合临床

Objective To investigate the relationship between peri-menopausal women blood lipid level and the gallstone disease in order to provide theoretical basis for the prevention of gallbladder stone.Methods Seventy-two patients with gallbladder calculus from Department of Hepatobiliary Surgery Jinshan District Central Hospital of Shanghai and 52 healthy women coming for physical examination as the control group.Participants were divided into five age groups (20-29,30-39,40-49,50-59 and 60-69 years old) and two age stages (young period (30-40 years old) and peri-menopausal period (45-55 years old)),total cholesterol (TC),triglyceride (TG),high density lipoprotein (HDL-C),low-density lipoproteins (LDL-C) and Body Mass Index (BMI) were determined and compared between the stone group and the control group at different age stages.Results In comparison of the menopausal transition period,the stone group had significantly lower blood TC,HDL-C and LDL-C levels than the control group (TC:(4.58 ± 0.27) mmol/L vs.(5.15 ± 0.26) mmol/L,t=3.112,P ＜0.01 ;HDL-C:(1.17 ±0.11) mmol/L vs.(1.40 ±0.08) mmol/L,t =3.351,P ＜0.01 ;LDL-C:(2.71 ± 0.30) mmol/L vs.(3.15 ± 0.26) mmol/L,t =2.437,P ＜ 0.05).For the young period,there were no significant difference on blood lipid level and BMI was observed between the stone group and the control group (P ＞ 0.05).The fat HDL-C level in blood was significantly lower in the stone group in the menopausal transition period than in the young period ((1.17 ± 0.11) mmol/L vs.(1.33 ± 0.07) mmol/L,t =2.455,P ＜ 0.05).The control group had significantly higher peri-menopausal TC,TG,LDL-C levels in blood and BMI than those in the control group young period (P ＜ 0.05) ; And HDL-C level,no significant difference (TC:(5.15 ± 0.26)mmol/L vs.(4.47 ± 0.34) mmol/L,t =3.175,P ＜ 0.01 ; TG:(1.88 ± 0.39) mmol/L vs.(1.10 ± 0.24)mmol/L,t=3.066,P＜0.01;LDL-C:(3.15 ±0.26) mmol/L vs.(2.71 ±0.31) mmol/L,t =2.261,P＜0.05;BMI:(24.75±0.99) kg/m2vs.(21.73±1.11) kg/m2,t=4.217,P＜0.01).Conclnsion For perimenopausal (45-55 years old) females,decline of serum TC,HDL-C and LDL-C levels may be related to the formation of cholesterol stone.Lower HDL-C level is closely associated with formation of cholesterol stone,indicating that it may be one of the measures to prevent gallbladder stone by adjusting blood fat in perimenopausal women.

Successful liver transplantation for infant with biliary astresia by using liver graft from infant donor after cardiac death / 中华器官移植杂志

Objective To summarize the clinical experience of successful liver transplantation from infant donation after cardiac death (DCD) for infant with biliary astresia (BA).Methods The donor was a 16-months-old girl with a body weight of 10 kg,who died of irreversible anoxic cerebral damage after sudden asphyxiation.The recipient was a 24-months-old girl with a body weight of 12 kg,who suffered from icteric concurrent late biliary cirrhosis after the Porta-jejunum anastomosis because of congenital BA.The DCD liver was classically orthotopically transplanted into the infants recipient.The warm ischemia time was 7 min,the cold ischemia time was 360 min,and the graft volume to the standard liver volume (GV/SLV) was 1.02.After operation,the vital signs and transplanted liver function of the recipient were monitored,and the recipient was given treatments of anti-infection,anticoagulation,and improving the microcirculation.The recipient was treated with the triple immunosuppression protocol of tacrolimus,mycophenolate and prednisone to prevent rejection.Results The operating time of the recipient was 480 min,the non-liver stage was 65 min,and the blood loss was 230 mL.The endotracheal intubation was removed from the recipient at 12 h,and the recipient started to eat at 48 h aftcr operation.The recipient had a hepatic artery thrombus on the 3rd and 15th day after operation,and the hepatic artery had re-blood-supply after the hepatic artery catheterization and continuous perfusion with urokinase.The recipient was discharged on the 42nd day,and the recipient was in satisfactory condition to present.Conclusion The infant DCD liver is a better graft for infant liver transplantation for BA.The surgical complications can be reduced with matched volume of donor-recipient liver; and it can guarantee a successful operation with perfect operative technique and careful perioperative management.

Clinical analysis of repeated operations in 265 patients with biliary diseases / 中华消化外科杂志

Objective To investigate the causes of repeated operations in patients with biliary diseases.Methods The clinical data of 265 patients who received repeated operations at the Jinshan Branch of Shanghai Sixth People's Hospital from January 2005 to June 2011 were retrospectively analyzed.The causes of repeated operations were analyzed. The first reoperation aimed at removing the calculi completely,repairing the injured biliary ducts and managing malignant tumors. The primary surgical procesures of the first reoperation included choledochotomy + T tube drainage,choledochotomy + Roux-en-Y choledochojejunostomy,endoscopic retrograde cholangiopancreatography + endoscopic sphincterotomy,choledochotomy + hepatectomy + T tube drainage or Rouxen-Y choledochojejunostomy,choledochotomy + biliary-endo-drainage,end-to-end anastomosis of bile duct + T tube drainage,radical or palliative resection of tumor,endoscopic biliary stent drainage or exploratory laparotomy.The second and multiple reoperations aimed at reconstructing the passage for biliary drainage. All data were analyzed using the chi-square test.Results A total of 69.8％ (120/172) of patients who had recurrent or retained calculi received first reoperation,which was significantly higher than 31.2％ ( 29/93 ) of those who received second or multiple reoperations (x2 =36.51,P ＜ 0.05 ).A total of 58.1％ (54/93) of patients who had benign stenosis of bilioenteric anastomosis received multiple reoperations,which was significantly higher than 4.1％ (7/172) than those who received first reoperation (x2 ＝ 99.32,P ＜ 0.05 ).Of the 265 patients,46 had complications.The incidence of complications of patients who receive first reoperation was 10.5％ ( 18/172),which was significantly lower than 30.1％ (28/93) of patients who received second or multiple reoperations ( x2 =13.61,P ＜ 0.05 ).Six patients died of hemorrhagic shock or multiple organ syndrome dysfunction postoperatively.The mortality rates for patients who received first reoperation and second or multiple reoperations were 1.7％(3/172) and 3.2％ (3/93),respectively,with no significant difference ( x2 ＝ 0.59,P ＞ 0.05 ).Conclusions The causes for reoperation of biliary disease are muhifactorial.Full assessment of the status of biliary diseases and ample preperation preoperatively,careful operation and precise and rational selection of operative procedures are keys to decrease the reoperative rates and perioperative complications.

Diagnosis and treatment of acute pancreatitis: an analysis of 217 patients / 中华肝胆外科杂志

Objective To study the etiological factors,clinical characteristics and diagnosis of acute pancreatitis (AP).Methods The clinical data of 217 patients with AP treated from January 2005to December 2010 in our hospital were studied retrospectively.Results The majority of patients were male (60.4％).The average age was 52.5 years.Cholelithiasiss,hyperlipidemia and trauma were the most frequent etiologic causes of AP.There were 164 patients with mild (75.6％) and 53 patients with severe (24.4％) AP.151 patients underwent surgical or endoscopical treatment (69.6 ％) while 66 patients underwent non-operative treatment (30.4 ％).14 of 53 patients with severe AP died.Conclusions AP should be treated according to the cause and the type.The key to reduce complications and increase cure rate is to find the cause of AP and then treat the underlying disease.

Controlling the morphology of filamentous fungi for optimization of fermentation process / 生物工程学报

Filamentous fungi have been extensively used in industrial fermentation processes. One of the most interesting topics of filamentous fungi is their bothersome morphology, which closely correlates with the productivity and broth rheology. Aiming at the optimization of the microbial process, works mainly focused on the relationships between morphology, productivity and environment in the last decades. Based on those works, we tried to interpret the mechanism of filamentous fungi growth from physiological aspects, and reviewed the mathematical models describing the hyphal growth, differentiation during the formation of target products. Above all, efficient and effective morphology controlling strategies were addressed from the engineering view.

Treatment of jejunum perforation after living-related liver transplantation for infants with biliary atresia a report of 4 cases / 中华器官移植杂志

Objective To investigate the cause of jejunum perforation after infantile livingrelated liver transplantation (ILRLT) and summarize the experience of treatment. Methods The clinical data of 28 infants with biliary atresia who underwent ILRLT were analyzed and 4 of 28 infantile recipients (14. 3%) developed jejunum perforation after ILDLT. Results Four patients had 7 episodes of jejunum perforation after transplantation among 28 infantile recipients who underwent ILRLT because of biliary atresia. The median time between transplantation and perforation was 11 days.Perforation occurred at the point of silk in jejunum stoma (n = 3) and the Roux-en-Y limb (n = 1 ).None had a history of prior operation including Kasai in 4 patients. Clinical manifestation included fever, increased heart rate, abdominal distention, leukocytosis, and no free air on abdominal roentgenograrns. A simple repair was performed in three infants with silk: two developed recurrent perforation (67%) and underwent a re-exploration,and another had a third perforation and underwent a third repair because of re-perforation. Another child underwent a simple repair with prolene, and there was no recurrence. None died from the perforation in our study. Conclusion The occurrence and location of jejunum perforation after ILDLT suggests that the cause of the perforation is related to the jejunal anastomosis with silk, and the jejunum perforation may be avoided in the jejunal anastomosis with prolene. Early diagnosis and exploration may ensure better survival.

The building of chip-based capillary electrophoresis platform and application / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the point mutations by chip-based capillary electrophoresis and to provide a rapid and sensitive technique detection for beta-thalassemia.</p><p><b>METHODS</b>Multiplex primer-extension reaction was used to amplify the common loci of the samples for beta-thalassemia. The reaction products were detected by the chip-based capillary electrophoresis and the genotypes of the samples were discrened.</p><p><b>RESULTS</b>A system was constructed to detect the point mutations of beta-thalassemia by chip-based capillary electrophoresis, and the technology was ralidated by the patients' samples and the results coincided with those of detection kit.</p><p><b>CONCLUSION</b>Beta-thalassemia can be detected by chip-based capillary electrophoresis rapidly with a small amount of samples. It would be a new detection method of the genetic disorders.</p>

Effects of transforming growth factor-beta1 gene therapy on bone rarefaction around endosseous implant / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of transforming growth factor-beta1 (TGF-beta1) gene therapy on bone defect and bone rarefaction around endosseous implant.</p><p><b>METHODS</b>The primary cultured bone marrow derived stroma cells (BMSCs) was transfected by plasmid pCDNA3.1(+) -TGF-beta1, and was adhered with polylactic-co-glycolic acid (PLGA) for constructing TGF-beta1 gene-modified artificial bone. The model of rats with placed titanium implants in the proximal metaphyses of the tibiae after ovariectomy was made. The TGF-beta1 gene-modified artificial bone (experimental group), BMSCs-PLGA compound artificial bone (control group) and nothing (blank control group) were placed in the bone defect around implant. The tibiae were examined by decalcified sections with immunohistochemical method and histological analysis methods at intervals of 4 and 8 weeks after implant surgery in order to detect the expression of TGF-beta1 in new bone adjacent to the implant and the healing of the bone defect around the implant.</p><p><b>RESULTS</b>The expression level of TGF-beta1 of experimental group was higher than that of control group and blank control group at the 4th week. The histological analysis indicated that the gene-modified artificial bone had stronger osetogenic potential than others.</p><p><b>CONCLUSION</b>TGF-beta1 gene-modified artificial bone promotes the repair of the bone defect around titanium implants in osteoporotic rats.</p>

Research on process of polyurethane coating for self-expandable stent in medical use / 中国介入心脏病学杂志

Objective To improve the biocompatibility of the metallic stent used for interventional treatment. Methods Inner coatings, outer coatings and micro-porous coatings were made using the solution-injection method, and salt crystallite with demanded size was added in order to develop micro-porous coatings. Results The optical concentrations of polyurethane solution and of salt crystallite (for micro-porous coatings) were obtained, and the corresponding processes were developed. Conclusion The poly-coated stent retains its elasticity, and it become very convenient to develop stents carrying drugs. Its effects on animals ard under test.

Optimization of Fermentation Medium for Honggumycin Using Response Surface Methodology / 微生物学通报

Under the shaking-flask culture, fermentation medium of honggumycin produced by Streptomyces 702 were studied.The experiment was used response surface methodology to optimize the shaking-flask fermentation medium.Firstly, we applied full factorial design to screen important factors soybean meal and industrial peptone which affected hongmycin produced by Streptomyces 702.Furthermore, we designed experiment to obtain the steepest ascent path and optimal level by the central composite design.The optimum medium consisted of (g/L): maize starch 20, maize meal 20, glucose 20, soybean meal 23, industrial peptone 9, KNO_ 3 2.5, (NH_ 4 )_ 2 SO_ 4 2.5 KH_ 2 PO_ 4 0.3, NaCl 3, CaCO_ 3 6, bean oil 5mL/L.Under the optimal medium, the yield of honggumycin was up to 1500 g/mL, which was increased by 308% than the original medium.

Study on the Biochemical Mechanism of Degrading Keratins by Streptomyces fradiae / 微生物学通报

The biochemical mechanism of degrading keratins by S.fradiae var S-221 was primarily studied.The compounds (Na_ 2 SO_ 4 , Na_ 2 SO_ 3 and sulfdryl acohol), which respecitively enhance specific activity of keratinase, activate keratinase intensively and mainly act on the disulfide bonds reductase in the keratinase, Na_ 2 SO_ 3 activates intensively both disulfide bonds reductase and polypeptide hydrolytase at 0.01 mol/L, whereas Na_ 2 S_ 2 O_ 3 , which acts on the disulfide bonds reductase, inhibits keratinase.On the condition that substrate, keratins exists, S.fradiae var S-221 is induced to produce exo-keratinase, which is a multiproteinase, containing disulfide bonds reductase, which is a key enzyme degrading keratins, then, with polypeptidic, hydrolytase, graduately hydrolyzates denatured keratins into polypeptides, oligopeptides and free amino acids, so that keratins have been decomposed completely.Sulfur in the keratins was transferred into sulfhydryl compounds, H_ 2 S and sulfates in the course of keratinolysine.