Expression of NAMPT in Patients with Multiple Myeloma and Its Correlation with Clinical Manifestation / 中国实验血液学杂志

OBJECTIVE@#To analyze the expression level of nicotinamide phosphoribosyltransferase (NAMPT ) in bone marrow of multiple myeloma (MM) patients and its correlation with clinicopathological features, clinical efficacy and prognosis.@*METHODS@#RT-qPCR and Western blot were used to detect the expression of NAMPT mRNA and protein in bone marrow mononuclear cells from 85 newly diagnosed MM patients (including 17 relapsed MM patients) and 15 healthy donors, and explore the correlation of the expression of NAMPT gene with clinicopathological features and efficacy. Kaplan-Meier method was used to analyze the effects of NAMPT on progression-free survival (PFS) and overall survival (OS), and univariate and multivariate survival analysis were performed.@*RESULTS@#The median expression level of NAMPT mRNA in bone marrow of newly diagnosed and relapsed MM patients was significantly higher than that of healthy donors (P <0.001). The expression of NAMPT mRNA in relapsed MM patients was significantly higher than that in newly diagnosed MM patients (P <0.001), which was consistent with the expression of NAMPT protein. ISS staging, lactate dehydrogenase and C-reactive protein levels, p53 deletion and the proportion of myeloma cells were increased in high NAMPT expression group compared with low NAMPT expression group (P <0.001). Compared with complete remission group, NAMPT mRNA expression was significantly up-regulated in partial remission group, progression group and relapsed group (P <0.001). The median OS and PFS of patients in high NAMPT expression group was 27.3 and 14.9 months, respectively, which was significantly shorter than 39.1 and 27 months in low NAMPT expression group (P =0.048, P <0.001). Both univariate and multivariate analysis showed that NAMPT expression was correlated with PFS and OS.@*CONCLUSION@#The expression level of NAMPT in newly diagnosed and relapsed MM patients is significantly higher than that in normal controls, and its up-regulation is related to the adverse clinical characteristics, efficacy and prognosis of MM patients. NAMPT is an independent prognostic risk factor of MM.

Research Progress on Mechanism of Bortezomib Resistance in Multiple Myeloma / 中国实验血液学杂志

Multiple myeloma (MM) is a common plasma cell malignancy, accounting for the second largest hematological malignancy. Proteasome inhibitors represented by bortezomib (BTZ) have been the main treatment for patients with newly diagnosed and relapsed or refractory myeloma in nearly two decades. Although BTZ has improved the prognosis of MM patients, MM remains incurable in most patients, mainly because MM cells become resistant to BTZ. This review is to better understand the mechanism of MM resistance to BTZ and explore possible new therapeutic strategies.

Expression and Clinical Significance of NAMPT in Bone Marrow of Patients with Multiple Myeloma / 中国实验血液学杂志

OBJECTIVE@#To study the expression level of nicotinamide phosphoribosyltransferase (NAMPT) in multiple myeloma (MM), its relationship with clinical indicators, prognosis and potential role.@*METHODS@#Immunohistochemical staining was used to detect the expression of NAMPT in bone marrow biopsies of patients with newly diagnosed multiple myeloma (NDMM) and patients with iron deficiency anemia (IDA) hospitalized during the same period. According to the median expression level of NAMPT, NDMM patients were divided into high expression group and low expression group. The correlation between NAMPT expression level and clinical baseline data was analyzed, and survival analysis was performed to evaluate the relationship between NAMPT expression level and prognosis. The GSE24080 and GSE19784 datasets were used to analyze the effect of NAMPT on the prognosis. Gene set enrichment analysis (GSEA) explored the possible mechanism of NAMPT involved in MM cell function.@*RESULTS@#The mean staining intensity of NAMPT in bone marrow tissue of 31 NDMM patients was 0.007±0.002, and that of 10 IDA patients was 0.002±0.002 (P < 0.05). The median expression level of NAMPT was 0.0041 in NDMM patients, and the mean staining intensity of high expression group and low expression group was 0.007±0.005 and 0.002±0.001, respectively (P < 0.001). There were certain differences in lactate dehydrogenase (LDH), C-reactive protein (CRP) and ISS staging between high expression group and low expression group (P < 0.001), while no significant differences in other indicators. The overall response rate (ORR) of high expression group was significantly lower than that of low expression group (P < 0.001). The median survival time of patients in high expression group was significantly shorter than that in low expression group (P =0.024). The results of bioinformatics analysis showed that the event-free survival (EFS) rate and overall survival (OS) rate of low NAMPT group were both higher than high NAMPT group (P =0.037, P =0.009), and NAMPT was an independent prognostic factor for EFS and OS (P =0.006, P =0.020). GSEA suggested that NAMPT might affect MM cell function through mTORC1 signaling pathway.@*CONCLUSIONS@#The expression level of NAMPT in bone marrow of NDMM patients is significantly higher than that of IDA patients, and the high expression of NAMPT may be correlated with late ISS stage, and high level of LDH and CRP. Patients with high expression of NAMPT have worse response to bortezomib and survival time may be shorter. NAMPT may be involved in the occurrence and development of MM through mTORC1 signaling pathway.

Investigation on anti-hepatitis B virus active components and mechanism of Salvia miltiorrhiza based on network pharmacology / 药学学报

We predicted the anti-hepatitis B virus (HBV) active components and mechanism of Salvia miltiorrhiza based on network pharmacology. The active components of S. miltiorrhiza were obtained through TCMSP, PubChem database and literature research. The potential targets of the active components and HBV infection were predicted by SwissTargetPrediction and GeneCards databases, respectively. The protein-protein interaction (PPI) network was constructed by String database. Cytoscape software was adopted to construct a visual network of active component-disease target and perform topological analysis. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using DAVID platform. The molecular docking of key components and core targets was carried out by AutoDock Vina software. We screened out a total of 38 active components and 178 disease-component overlapping targets. Enrichment analyses obtained 405 related GO items and 68 signaling pathways, such as T/B cell receptor signaling pathways, PI3K/AKT signaling pathway, and mTOR signaling pathway. According to the results of molecular docking, most characteristic components of S. miltiorrhiza (miltionone Ⅱ, miltirone, protocatechuic acid, lithospermic acid, protocatechualdehyde) showed good affinity with the key targets (PIK3CA, APP, STAT3,AKT1 and mTOR). Furthermore, the anti-HBV activity of lithospermic acid, the representative active component of S. miltiorrhiza, and its regulation on PI3K/AKT and mTOR signaling pathways were investigated in an HBV replicating mouse model. Animal welfare and experimental procedures follow the regulations of the Animal Ethics and Welfare Committee of Hubei University. The results showed that lithospermic acid significantly inhibited HBV DNA replication, reduced serum HBsAg and HBeAg levels, and decreased the phosphorylation protein expression levels of AKT and mTOR in liver, indicating that lithospermic acid might exert the anti-HBV activity by regulating PI3K/AKT and mTOR signaling pathways.

Early Diagnosis of One Multiple Myeloma Patient with Cold Agglutinin Syndrome as the Initial Presentation / 中国实验血液学杂志

OBJECTIVE@#To analyze one case of multiple myeloma (MM) initially presenting cold agglutinin syndrome (CAS), so as to improve clinical understanding and screening of this disease.@*METHODS@#The clinical data, laboratory examination, bone marrow result, diagnosis and treatment of the patient were analyzed and summarized to provide ideas and clinical experience for the early diagnosis and treatment of CAS secondary to MM.@*RESULTS@#The clinical manifestations of asthenia, hemolysis, jaundice and scattered livedo reticularis were caused by CAS secondary to MM, which was different from the general Raynaud's phenomenon. IgMκ type MM was definitely diagnosed according to the morphological features of bone marrow cells and immunofixation electrophoresis. After 3 courses of chemotherapy with BAD regimen and enhanced thermal support, anemia was corrected, M protein was decreased and the cold agglutinin phenomenon was significantly reduced. The evaluation of efficacy reached very good partial response.@*CONCLUSION@#There are very few MM patients with CAS as the initial presentation, so it is easy to misdiagnose. Early diagnosis and individual therapy are particularly important, which requires clinicians to observe and gain experience further.

Advances of Sirolimus in the Treatment of Patients with Autoimmune Cytopenia---Review / 中国实验血液学杂志

Autoimmune cytopenia is a general term for all hemocytopenia diseases caused by humoral or cellular immunity abnormalities, and its common immune mechanism determines the importance of immunosuppressive therapy. Sirolimus, as an immunosuppressant against of mTOR, induces immune tolerance by adjusting Treg cells, which has application prospect in the treatment of refractory autoimmune cytopenia. This article reviews the mechanism, application, and possible adverse reactions of sirolimus in the treatment of idiopathic autoimmune cytopenia.

Clinical characteristics of invasive pulmonary aspergillosis in non-neutropenic patients / 医学研究生学报

Objective In recent years, the incidence of invasive pulmonary aspergillosis (IPA) in non-neutropenic patients has been increasing. Most previous studies have focused on the diagnosis and treatment of IPA in severely immunocompromised patients. The purpose of this study was to investigate the clinical characteristics of IPA in non-neutropenic patients. Methods We enrolled 183 IPA patients (including 46 proven IPA cases and 137probable IPA cases) admitted to our hospital from 2008 to 2018, after excluding possible IPA cases and neutropenic cases. The clinical and laboratory data were collected and analyzed. Results In this study, 164 (89.6%) patients had underlying diseases and risk factors, among which chronic obstructive pulmonary disease and prolonged steroid treatment were the most common. Cough (79.8%), dyspnea (71.0%), sputum (68.9%)and fever (61.2%) were the common symptoms. Chest CT findings were mainly consolidation (45.9%), nodule (32.8%), ground-glass opacity (29.0%) and cavity (26.8%). The halo sign (8.2%) and air crescent sign (7.1%) were relatively rare. The mean numbers of leucocyte and neutrophils were 14.6×109/L and 10.2×109/L, respectively. Positive rates of sputum culture and bronchoalveolar lavage fluid culture were 32.5% and 35.1%, respectively. Positive rates of galactomannan (GM) antigen test in serum and bronchoalveolar lavage fluid samples were 55.2% and 77.1%, respectively. Transthoracic needle biopsy and transbronchial lung biopsy were associated with positive rates of 45.3% and 20.6%, respectively. Conclusion The clinical and imaging features of IPA in non-neutropenic patients are atypical. Compared with sputum culture and GM antigen test in serum, alveolar lavage fluid GM test has higher sensitivity which can assist in definitive diagnosis.

Application of Multi-Test II prick device in the skin prick test for allergens in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the applicability of Multi-Test II prick device in the skin prick test (SPT) for allergens in children.</p><p><b>METHODS</b>A total of 87 children with allergic diseases who attended the hospital between March and September, 2017 were enrolled as subjects. The SPT for six inhaled allergens and serum specific IgE (sIgE) measurement were performed for all children. SPT was performed with a single-headed device on the left forearm and Multi-Test II prick device on the right forearm. ELISA was used to measure the serum level of sIgE. Visual Analog Scale (VAS) was used to assess the degree of pain during SPT. The three methods were compared in terms of the detection rates of six allergens, and the sensitivity and specificity of Multi-Test II prick device were analyzed.</p><p><b>RESULTS</b>There were no significant differences in the detection rates of six allergens among the Multi-Test II method, the single-headed method, and ELISA (P>0.05). Compared with the single-headed method, the Multi-Test II method had a sensitivity of 72.7% and a specificity of 78.2%. Compared with ELISA, the Multi-Test II method had a sensitivity of 73.4% and a specificity of 77.5%. The Multi-Test II method had a significantly lower degree of pain than the single-headed method (P<0.05).</p><p><b>CONCLUSIONS</b>The Multi-Test II method has high sensitivity and specificity and is easily accepted by children, but the test results should be combined with children's medical history and serum level of sIgE when necessary.</p>

Lithagogue effects of Pyrrosia lingua from Guizhou province on experimental renal calculus in rats / 中国中药杂志

To screen the active fractions with lithagogue effects of Pyrrosia lingua from Guizhou province and preliminarily investigate its mechanism. The rats were fed with 1% ethylene glycol and 2% ammonium chloride to establish the nephrolithiasis models, which were used to evaluate thelithagogue effects of different polar fractions of P. lingua from Guizhou province. The level of urinary calcium and oxalic acid in urine, renal calcium, oxalic acid, superoxide dismutase (SOD), catalase(CAT) and malondialdehyde (MDA) in renal tissues,as well as crystalline deposit and lithogenesis in renal tissues and the levels of creatinine(Cr) and blood urea nitrogen (BUN) in the serum were detected. The effective compounds were inferred from the analysis of active fractions extract based on LC-MS technology. Petroleum ether fraction and dichloromethane fraction of P. lingua from Guizhou province can reduce renal oxalic acid and renal calcium concentration, increase urinary oxalic acid and urine calcium, with significant inhibitory effect on the formation of renal calculus in rats, significantly increase SOD and CAT activities in renal tissues, and significantly reduce MDA levels. LC-MS analysis showed that the caffeine, citric acid and tartaric acid among the compounds from petroleum ether fraction and dichloromethane fraction had lithagogue effects. Both the petroleum ether fraction and dichloromethane fraction of P. lingua from Guizhou province showed good effect on prevention and treatment of calculus in middle dose groups, and the mechanism may be associated with antioxidation, reducing calcium oxalate crystal deposition, and promoting calcium oxalatecrystal release, in addition, caffeine, citric acid and tartaric acid had lithagogue effects.

Distribution characteristics of serum specific IgE for inhaled allergens in children with different airway allergic diseases / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the distribution characteristics of serum specific IgE (sIgE) for inhaled allergens in children with different airway allergic diseases.</p><p><b>METHODS</b>Fluorescent enzyme-linked immunosorbent assay on the UniCAP250 system was performed to measure serum sIgE for 9 common inhaled allergens in 256 children aged 3-14 years with different airway allergic diseases. According to the clinical diagnosis, these children were divided into rhinitis group (37 children with allergic rhinitis), asthma group (82 children with bronchial asthma), and rhinitis-asthma group (137 children with allergic rhinitis complicated by bronchial asthma). The three groups were compared in terms of the detection rates of 9 inhaled allergens, sensitization level, and number of allergens.</p><p><b>RESULTS</b>The detection rate of serum sIgE for inhaled allergens was 57.3% (47/82) in the asthma group, 86.5% (32/37) in the rhinitis group, and 82.5% (113/137) in the rhinitis-asthma group (P<0.05). The most common allergen in the asthma, rhinitis, and the rhinitis-asthma groups was mould fungi (32.9%, 54.1%, and 48.9% respectively), followed by dust mites (30.5%, 45.9%, and 46.0% respectively), pollen (26.8%, 35.1%, and 32.8% respectively), pets (12.2%, 27.0%, and 18.2% respectively), and cockroach (9.8%, 5.4%, and 5.8% respectively). The rhinitis group and the rhinitis-asthma group had a significantly higher detection rate of mould fungi (mx2) than the asthma group (P<0.0166). There were no significant differences in the sensitization level of 9 allergens and number of allergens between the three groups.</p><p><b>CONCLUSIONS</b>In children with either bronchial asthma, allergic rhinitis, or bronchial asthma complicated by allergic rhinitis, the three most common inhaled allergens are mould fungi, dust mites, and pollens. Compared with bronchial asthma, allergic rhinitis may be more closely associated with sensitization by mould fungi. The three common airway allergic diseases have similar distribution characteristics of inhaled allergens.</p>

Apoptosis of the adriamycin-resistant leukemia cell line induced by the recombinant mutant human TNF-related apoptosis-inducing ligand combined with arsenic trioxide / 中国实验血液学杂志

This study was aimed to investigate the effect of recombinant mutant human TNF-related apoptosis-inducing ligand (rmhTRAIL) combined with As(2)O(3) on inducing apoptosis of adriamycin-resistant leukemia cell line K562/A02 (mdr-1(+)). The morphologic changes of cells treated with rmhTRAIL were observed by inverted microscope, taking adriamycin-sensitive cell line K562 (mdr-1(-)) as control; the inhibitory rate of cell proliferation after being treated with rmhTRAIL, As(2)O(3) alone or combined was assayed by MTT method; the apoptosis peaks of K562/AO2 and K562 were quantitatively detected by flow cytometry with PI staining after being treated with rmhTRAIL, As(2)O(3) alone or in combination. The results indicated that the inhibition effect of rmhTRAIL and As(2)O(3) in combination on K562/AO2 and K562 cells was higher than that of riTRAIL and As(2)O(3) alone (p < 0.01), rmhTRAIL combined with As(2)O(3) had synergistic effect in killing K562/AO2 and K562 cells by king's formula. The apoptosis rates of K562/AO2 and K562 cells were 34.93 +/- 0.10% and 10.53 +/- 0.16% (p < 0.01), as well as 5.95 +/- 0.07%, and 3.50 +/- 0.01% (p < 0.05), 50.95 +/- 0.91% and 20.75 +/- 0.95% (p < 0.05) respectively when their cells were treated by rmhTRAIL and As(2)O(3) alone. The apoptosis rate in K562/AO2 group was higher than that in K562 group. It is concluded that rmhTRAIL can induce K562/A02 and K562 cell apoptosis; rmhTRAIL combined As(2)O(3) had synergistic effects; the efficacy of on rmhTRAIL or As(2)O(3) inducing K562/AO2 cell apoptosis is higher than that on their parental cell line K562.

Gene cloning, expression and characterization of a novel phytase from Hafnia alvei / 生物工程学报

A gene appA encoding a novel phytase was firstly cloned from Hafnia alvei by PCR and sequenced. The gene was consisted of 1335 bp, encoding 444 amino acids. The calculated molecular weight of the mature APPA was about 45.2 kD. The gene appA was expressed in E. coli BL21 (DE3). Recombinant APPA was purified and its enzymatic properties were determined. The optimum pH for the enzyme was 4.5 and the optimum temperature was 60 degrees C. The pH stability of r-APPA is good, the relative phytase activity was above 80% after treated in buffers of pH 2.0-10.0. The specific activity of r-APPA is 356.7 U/mg, and the Km value was 0.49 mmol/L and Vmax of 238 U/mg. The enzyme showed resistance to pepsin and trypsin treatment.

Mutation research on Q23L and Q23LG272E in phytase derivated from Aspergillus fumigatus / 生物工程学报

Aspergillus fumigatus wild-type phytase has many favorable properties, such as a good thermorstability and a broad pH optimum. However, the specific activity of the enzyme is relative low. A. fumigatus Q23L phytase resulted in a remarkable increase in specific activity around pH4.5 - 7.0, but the pH stability of Q23L was lower than A. fumigatus wild-type phytase. To increase the pH stability of Q23L, the mutant Q23LG272E was constructed by site-directed mutagenesis with PCR. The gene of A. fumigatus wild-type phytase and the mutant genes encoding the Q23LG272E and the Q23L were correctly expressed in Pichia pastoris GS115. Enzymes were purified and their enzymatic properties were determined. The results revealed that the specific activity of the Q23L improved remarkably, which increased from 51 u/mg of the wild type to 109 u/mg at pH5.5. Meanwhile, the pH stability of Q23L, decreased evidently, especially from pH3.0 to pH4.0.The pH stability of Q23LG272E in pH3.0 - 4.5 and pH6.5 - 7.0 has been improved compared with Q23L. The specific activity of Q23LG272E basically maintained at the level of Q23L. Analysis of 3-D structure and sequence similarity were used to reveal the presumable factors influencing the enzymatic properties of Q23LG272E, and discussion for the relationship between structure and function of phytase was given.

Improving phytase expression by increasing the gene copy number of appA-m in Pichia pastoris / 生物工程学报

In order to improve the fermentation potency of phytase in recombinant host and decrease the production cost, the pichia expression vector pGAPZalpha-A was modified by introduction of an AOX1 promoter from vector pPIC9 and the resulted vector pAOXZalpha is an methanol induced vector. After that, a phytase gene appA-m was cloned into pAOXZalpha to construct the recombinant vector pAOXZalpha-appA-m. The recombinant Pichia pastoris 74#, which already contains one copy of appA-m and its fermentation potency exceeded 7.5 x 10(6) IU/mL, was used as the host strain for the transformation of pAOXZalpha-appA-m. The Pichia pastoris transformants were gained by electroporation. PCR results indicated that the appA-m expression box has integrated into the genome of Pichia pastoris and the original construction of phytase gene has not changed. SDS-PAGE analysis revealed that phytase was overexpressed and secreted into the medium supernatant. Recombinants with high expression level were screened and used for fermentation. In 5L fermentor, the expression level of phytase protein achieved 4 mg/mL and the phytase activity (fermentation potency) exceeded 1.2 x 10(7) IU/mL, which was about 1.6-fold compared with that of the host strain 74#. Moreover, the improved recombinant Pichia pastoris is excellent at expression stability and heredity stability.

Improvement of the thermostability of xylanase by N-terminus replacement / 生物工程学报

The hybrid xylanase TB was constructed by the substitution of the N-terminus segment of the Streptomyces olivaceoviridis xylanase XYNB with corresponding region of Thermomonosporafusca xylanase TfxA. The hybrid gene tb, encoding the TB, was correctly expressed in Escherichia coli BL21 and Pichia pastoris GS115. TB was purified and its enzymatic properties were determined. The results revealed that the optimal temperature and optimal pH of TB were at 70 degrees C and 6.0, which have been obviously improved compared with those of XYNB. The thermostability of TB were all about six-fold of XYNB's after incubating the properly diluted enzyme solutions at 80 degrees C and 90 degrees C for 3min, respectively. The pH stability of TB was 5 to approximately 9, which was narrower than that of XYNB. Still, TB remains a high specific activity as XYNB does. Analysis of a homology modeling and sequence similarity were used to reveal the factors influencing the enzymatic properties of TB and the discussion for the relationship between structure and function of xylanase was given.

Expression of acidophilic alpha-amylase from Alicyclobacillus acidocaldarius / 生物工程学报

The alpha-amylase (EC 3.2.1.1) from the Gram-positive Alicyclobacillus acidocaldarius was one kind of thermoacidophilic enzyme, with optimal temperature and pH of 75 degrees C and 3, respectively. The nucleotide sequence of the gene amy was cloned by PCR. The gene amy was 3901bp long, comprising one open reading frame encoding a polypeptide of 1301 amino acids. The calculated molecular weight of the alpha-amylase AMY was about 140kD. The gene amy was expressed in E. coli BL21 (DE3) and Pichia pastoris respectively, and both of the cloned proteins had bioactivity. The activity of amylase expressed in P. pastoris was further testified by amylase activity staining. The alpha-amylase expressed in P. pastoris had been purified and characterized. The apparent molecular weight of that was about 160kD according to SDS-PAGE. The optimum of pH for the enzyme was pH 3.2 as the native enzyme was; but the optimum of temperature was 65 degrees C and a little lower than that of the native enzyme. Above 50% of relative activity remained after incubation for 30 minutes in 70 degrees C. So the enzyme expressed by P. pastoris was also thermoacidophilic. Moreover some sequence was cloned by PCR, which ranged from + 1174 bp to + 3288 bp in the gene amy, encoding 705 amino acids with the calculated molecular weight of 79kD. The truncated gene amy' was expressed in E. coli BL21 (DE3) induced by 1 mmol/L IPTG, and the expressed enzyme also retained alpha-amylase activity.

Hydrophobic interaction between beta-sheet B1 and B2 in xylanase XYNB influencing the enzyme thermostability / 生物工程学报

A homology modeling of xylanase XYNB from Streptomyces olivaceoviridis A1 was made by Swiss-Model. The hydrophobic Interaction between beta-sheet B1 and B2 in the tertiary structure model of XYNB was compared with other thermophilic xylanase. A T11Y mutation was introduced in XYNB by site-dirrected mutagenesis to improve the thermostability of the enzyme. The XYNB and mutant xylanase (XYNB') expressed in Pichia pastoris were purified and their enzymatic properties were determined. The result revealed that the thermostability of XYNB' was obviously higher than that of XYNB. The optimal temperature of XYNB' for its activity was 60 degrees C, similar to XYNB. But, compare to XYNB, the optimal pH value, the Km value and the specific activity of XYNB' had also been changed. The research results suggested that the aromatic interaction between beta-sheet B1 and B2 in xylanase should increase enzyme thermostability. The mutant xylanase XYNB' is a good material for further research in the relationship between structure and function of xylanase.

Expression of xylanase gene xynA from Streptomyces olivaceoviridis A1 in Escherichia coli and Pichia pastoris / 生物工程学报

The gene xynA encoding xylanase was cloned from Streptomyces olivaceoviridis A1. The xynA with and without origin signal peptide sequence were fused behind pel B signal peptide in the plasmid pET-22b(+) respectively, then transfered into the host E. coli. The xylanase expressed in E. coli had normal bioactivity. Further, the xynA without origin signal peptide sequence was cloned into the plasmid pPIC9 under the control of AOX1 promoter and introduced into the host Pichia pastoris by electroporation. The results of SDS-PAGE and activity assay of the xylanase expressed by recombinant P. pastoris showed that the xynA had been overexpressed and secreted, and the xylanase expressed had normal bioactivity. The expression level of xylanase in recombinant P. pastoris exceeded 0.2mg/mL in shake culture.

Cloning and Alignment of the Partial Mannanase Gene of Bacillus spp / 微生物学通报

By functional plates,16 strains which can produce?-mannana-se were isolated frnm 28 Bacillus spp.Using a pair of degenerated primers,the conserved fragments of?-mannanase gene from the selected strains were amplified by PCR.The obtained nucleotide fragments were sequenced and compared with the homologous?-mannanase genes in GenBank and a phylogenetic tree was generated.Comparing to the genes coding?-mannanase published,the cloned nucleotide fragments show the highest sequence identity between 62% and 98%.The genes coding fnr?-mannanase of Bacillus circulus have low identity while the?-mannanase genes of Bacillus subtilis and other Bacillus spp. have high identity.