Abstract:[Objective] This study is aimed to characterize fermentation and enzyme characteristics of an extremely thermophilic anaerobic lignocellulolytic bacterium Caldicellulosiruptor saccharolyticus F32. [Methods] Cell growth was monitored by cell counting. Acetate, lactate and residual reducing sugars were measured by using an ion chromatography system. H2 was detected by gas chromatography. DNS method and p-nitrophenyl method were used to measure the enzyme activities of the secreted proteins of C. saccharolyticus F32 and DSM 8903. [Results] In contrast to C. saccharolyticus DSM 8903, strain F32 grew better on cellulose (Avicel PH-101), even on unpretreated wheat straw. Compared to C. saccharolyticus DSM 8903, strain F32 produced more lactate as the end product, thereby decreasing the hydrogen yield when glucose was used as carbon source. The secretome of strain F32 showed higher endoglucanase and xylanase activities. [Conclusion] In comparison with C. saccharolyticus DSM 8903, C. saccharolyticus F32 could degrade lignocellulosic biomass more efficiently. There were significant difference in the products, cellulase and hemicellulase systems between C. saccharolyticus F32 and C. saccharolyticus DSM 8903.

Abstract:[Objective] White-rot fungus Trametes pubescens pellets without addition of nutrition treatment, a novel design, was used to lower the running cost as well as to enhance convenient availability for dye decolorization. [Methods] Liquid cultured pellets of T. pubescens were used to decolorize various dyes without addition of nutrition and then the removal process of the azo dye Congo Red with higher decolorization rate was analyzed. During the decolorization process, the extracellular and intracellular enzyme activities were monitored and the impact factors such as initial pH value, temperature, dye concentration and salinity were optimized. Moreover, metabolites of the dye Congo Red degraded by T. pubescens pellets without addition of nutrition were analyzed by gas chromatography-mass spectroscopy (GC-MS). Phytotoxicity experiment was carried out before and after dye decolorization to assess the toxic nature of the metabolites. [Results] The pellets could decolorize azo dye Congo Red. After a 7-day incubation period, the highest dye removal of 80.52% was observed under 150 r/min shaking speed at initial pH 2.0, temperature at 30 °C, dye concentration 80 mg/L and salinity 2.5% (W/V). The pellets performed good persistence in repetitive decolorization operations, as well as high potentials toward the degradation of dye Congo Red which could be attributed to the presence of biotransformation enzymes. Additionally, degraded metabolites were identified as naphthalene amine, biphenyl amine and naphthalene diazonium, as evidenced by GC-MS. Phytotoxicity experiment confirmed that the azo dye Congo Red degraded by T. pubescens pellets without addition of nutrition resulted in its detoxification. [Conclusion] These findings demonstrate that the T. pubescens pellets have potentials for the azo dye effluents treatment applications without addition of nutrition.

Abstract:[Objective] Analyze microbial diversity of Bacillus-like group isolated from soil samples in Excoecaria agallocha forest, Bamen Bay mangrove. [Methods] The low dilution soil suspensions with heat shock treatment and the high dilution soil suspensions without heat treatment were spread onto Petri dishes for isolating Bacillus-like group species selectively. Their genetic diversity and phylogeny were characterized by 16S rDNA PCR-RFLP and 16S rDNA sequence analysis. [Results] In the level of 100% similarity, UPGMA of 16S rDNA PCR-RFLP map showed that 155 isolates were grouped into 21 clusters, which presented abundant genetic diversity. Moreover, 16S rDNA sequence analysis of representative strains of 21 clusters proved that they were distributed in four genera, Bacillus, Halobacillus, Virgibacillus and Paenibacillus, in which Bacillus was the dominant one. Based on the comparison of 16S rRNA gene sequences, the high levels of 16S rRNA gene similarities of eight strains with the corresponding type strains ranged from 95.1% to 99.0%. [Conclusion] Cultivable Bacillus-like group species isolated from Bamen Bay mangrove soil revealed high genetic diversity and there existed some new species.

Abstract:[Objective] The aims of the present study were to isolate and screen ammonifying bacteria, and to examin the conditions for their degradation of organic nitrogen. [Methods] Ammonifying bacteria were isolated from the micro-polluted raw water collected from the downstream water bodies of the Baiguishan Reservoir in Henan Province. The obtained nitrifying bacteria were studied for their capabilities to degrade organic nitrogen; The conditions for strain N24 to remove organic nitrogen were assessed by using single factor method. Strain N24 was identified by morphology, physiological and biochemical characteristics, and 16S rRNA gene-base phylogenetic alalyses. [Results] Four ammonifying bacterial strains were isolated from the collected water samples, The NH4+-N concentration reached 138.926 mg/L after 40 hours’ fermentation of strain N24. The optimal conditions for strain N24 to remove organic nitrogen were about 30?35 °C, initial pH 6.0, and medium volume 75 mL. Strain N24 was identified as Bacillus flexus (GenBank accession number: JX291240.1). Its 16S rRNA gene sequence had 99%?100% similarity with those of Bacillus sp. deposited in GenBank, and showed closest relatedness to Bacillus flexus IFO15717T (GenBank accession number: NR024691.1). [Conclusion] N24 is an efficient organic nitrogen-degrading Bacillus flexus; The present study enriched the microbial resources for organic nitrogen removal and provided a theoretical framework for the practical use of strain N24 in environmental engineering.

Abstract:[Objective] To discover the defense mechanisms of Acidithiobacillus caldus SM-1 responding to reactive oxygen species at the whole genome level. [Methods] The genomic DNA of At. caldus SM-1 was sequenced by the Roche 454 Genome Sequencer FLX instrument. Gene function was annotated by homology searching in the NCBI NR (non-redundant) and UniProt protein database. The KEGG database was used to reconstruct the metabolism pathways in the cell. Genes related to ROS defense mechanisms were identified through the comparative genomic analysis. [Results] Enzymatic and non-enzymatic antioxidant systems were both identified in the SM-1 genome. The former was used to eliminate the ROS and the latter was utilized to provide a reducing intracellular environment through maintaining the redox homeostasis in the cell. The robust DNA repair system was used to deal with DNA oxidative damage. In addition, whether the large number of transposable elements in the SM-1 genome might enhance the genome plasticity for adaptation to extreme bioleaching environments is still need further interpretation. [Conclusion] Genome sequence of SM-1 will help us to discover the ROS detoxification mechanisms of SM-1, and this will give us insights to construct the engineered stains with better bioleaching performance.

Abstract:[Objective] To obtain the fungal stain with high-yield laccase. [Methods] Strains producing laccase were screened out by the guaiacol method. Then the strain with the high-yield laccase screened was optimized by the orthogonal experiment design and identified using the morphological characters and the molecular systematics. [Results] Four strains could produce laccase in these 26 fungal strains, and the strain H52.1 was the best high-yield strain, and its optimal medium components and conditions were as follows, the optimal carbon source was soluble starch, nitrogen source was ammonium nitrate, pH value was 8 and metal ion was Ca2+. The result of identification showed that the strain H52.1 was Taifanglania major. [Conclusion] Taifanglania major has been worth doing further research and exploitation in the laccase development.

Abstract:[Objective] The PcoI/PcoR quorum-sensing (QS) system in Pseudomonas fluorescens 2P24, important for biofilm formation and plant root colonization, was influenced by multiple upstream regulatory elements. In this study, the effect of the gidA gene on QS system was studied by genetic analysis. [Methods] The transcriptional reporter of pcoI gene on plasmid p970km-pcoIp was used to monitor the pcoI expression in the wild type strain 2P24 and its gidA gene mutant. Agrobacterium tumefaciens NTL4 (pZLR4) was used as the reporter strain to detect QS signal molecule N-acyl-homoserine lactone (AHL) production. [Results] Mutation of the gidA gene in strain 2P24 did not influence its swimming capacity, but significantly decreased pcoI transcription and AHL production. Furthermore, the biofilm formation and the colonization on the wheat rhizosphere and tips in both the gnotobiotic and natural soil were remarkably reduced in the gidA gene mutant compared with the wild type and the complementary strain. Although the gidA mutation in strain 2P24 did not affect the bacterial growth in the rich medium (LB), it significantly affected the utilization of multiple carbon sources in the minimal medium, including glucose, sucrose, fructose, glycerol, galactose, arabinose, mannose, xylose and sorbitol. [Conclusion] These results suggest that GidA function as a globle regulatory element influenced the PcoI/PcoR QS system, biofilm formation, colonization ability and carbon source utilization in P. fluorescens 2P24.

Abstract:[Objective] in order to screen and identify endophytic bacteria with nitrogen fixation and pathogen inhibition functions, 21 endophytic bacteria were isolated from Polygonum viviparum on the Eastern Qilian Mountains in the Qinghai-Tibetan Plateau, China. [Methods] Nitrogen fixation endophytic bacteria were identified by the 16S rRNA genes sequences analysis, physiological and biochemical characterization. [Results] The results show that 28.6% endophytic bacteria of Polygonum viviparum could fix nitrogen and 76.2% had strong antagonistic against plant pathogen, furthermore, 23.8% endophytic bacteria inhibited more than 5 plant pathogen. Strain Z19 had strong ability of nitrogen fixation and decomposing-cellulose. The cellulase activity was 0.31 U, and ratio of the diameter of lysis zone to colony diameter was up to 3.33. Furthermore, strain Z19 inhibited pathogenic fungi, such as Rhizoctonia solani, Sclerotinia sclerotiorum, Botrytis cinerea, Bipolaris sorokiniana and Alternaria solani. Through PCR amplification and sequencing, the sequence of nifH gene and 16S rRNA gene were obtained and they were registered in GenBank (accession numbers were EU693340 and EU236746, respectively). Strain Z19 is rod, Gram-positive, and produce spore. Based on the physiological and biochemical characteristics and 16S rRNA gene sequence analysis, Z19 was identified as Bacillus subtilis. [Conclusion] The study provides new insights for the exploration and utilization of promoting growth and antagonistic endophytic bacteria in alpine grassland.

Abstract:[Objective] To clarify the antibacterial activity of Lysobacter antibioticus strain 13-1 against rice bacterial blight. [Methods] Four antibiotic compounds were isolated from the fermentation extracts of the strain 13-1 by sephadex LH-20 column chromatography, reverse C-18 Silica gel and high performance liquid chromatography (HPLC). [Results] These purified compounds were identified as 6-Methoxy-1-phenazinol-10-oxide, Phenazine, 1-Phenazinecarboxylic acid and 1-Hydroxy-6-methoxyphenazine by nuclear magnetic resonance (NMR), ESI-Mass spectrum analysis. Four phenazine analogs strongly inhibited mμLtiple Xoo strains growth. The protective efficacy of strain 13-1 was above 60% in field plot compared to controls. [Conclusion] The antimicrobial substances of strain 13-1 was phenazine substances that have the inhibition potential against rice bacterial blight.

Abstract:[Objective] This study aimed to screen biocontrol bacillus strains with broad-spectrum and highly efficient antagonistic activity against plant pathogen fungi, and further to study the antagonist function. [Methods] Present study used eight kinds of plant pathogenic fungi as target bacteria to screen superior bacillus strains from 9 candidate strains, the method of flat confrontation, antagonistic activity determination of fermentation filtrate were used. [Results] Two bacillus strains B06 and B07 were found with the characteristics of broad-spectrum and highly efficient antagonistic activity. B06 was more effective in inhibiting 8 pathogenic fungi than other strains, with R2/R1 ranging from 0.4 to 1.8, and the inhibition rate of sterile fermentation filtrate from 66.7% to 87.5%. B07 took second place in inhibiting 8 pathogenic fungi than other strains, with R2/R1 ranging from 0.23 to 1.21, and the inhibition rate of sterile fermentation filtrate from 55.56% to 81.25%. Bacillus strains B06 and B07 were both identified as Bacillus amyloliqueaciens with the methods of 16S rDNA sequence analysis. [Conclusion] The result indicates that bacillus strain had the ability to inhibit kinds of plant pathogen fungi. Screening of bacillus strains with broad-spectrum and highly efficient antagonistic activity has a great development and application value in agricultural biological control.

Abstract:[Objective] To express a non-crystal protein GabR in Bacillus thuringiensis, the B. thuringiensis expression system directed by cry8E gene promoter was constructed and verified. [Methods] The gabR gene of B. thuringiensis was cloned into the high-level expression vector pHT315-8E21b initiated by cry8E gene promoter and the resulted vector was introduced into the acrystalliferous mutant HD73–, to obtain HD-8E-gabR. The SDS-PAGE and electrophoretic mobility shift analysis were performed for analysis of expression and function of GabR protein. [Results] SDS-PAGE analysis showed that GabR protein were successfully overexpressed in B. thuringiensis with the high-level expression vector pHT315-8E21b initiated by cry8E gene promoter, which was the first time to express a non-crystal protein in B. thuringiensis. The solubility of GabR protein in B. thuringiensis could be improved in the alkaline buffer. Electrophoretic mobility shift assay showed that GabR could bind with its regulated promoter PgabT. [Conclusion] This study proved that the B. thuringiensis expression system directed by cry8E gene promoter can be utilized to express a large number of non-crystal proteins.

Abstract:[Objective] Using the 16S rRNA, clpX and recA gene sequences to identify the phylogenetic relationship among closely related Enterococcus faecalis and Enterococcus faecium species. [Methods] Nine E. faecium and one E. durans strains originally isolated from traditional dairy products were characterized by PCR methods. The gene sequences, clpX and recA, were amplified and assessed for their suitability as phylogenetic markers. Phylogenetic trees were constructed with 16S rRNA and the aforementioned housekeeping genes obtained from this study and public gene databases. [Results] In the phylogenetic tree of clpX and recA genes, 10 tested strains and E. faecalis belonged to the same branch. The sequence similarity was 99.6% and 98.6% with E. faecalis, and 61.5% and 33.5% with the Faecium-group (E. durans and E. faecium), respectively. The differences of these two genes between the closely related strains of E. durans and E. hirae were 20.3% and 39.0%. Based on the phylogenetic tree of 16S rRNA, the tested strains and Faecium-group (E. lactis, E. faecium, E. durans and E. hirae) belonged to the same branch. These members shared a similarity of higher than 99.6%, while an average homology of 98.4% with E. faecalis. No obvious difference was observed between closely related strains. [Conclusion] Based on the analysis results of the housekeeping genes, clpX and recA, we propose that nine E. faecium and one E. durans, could be transferred to E. faecalis. Meanwhile, the clpX and recA genes are suitable for classification and identification of some closely related E. faecalis and E. faecium species.

Abstract:[Objective] To clone and express the truncated surface-associated subtilisin-like protease gene 05SSU0811 of Streptococcus suis serotype 2 (SS2) highly virulent strain 05ZYH33 and measure the activity of the recombinant protease; Construct the 05SSU0811 gene knockout mutant strain and analyze its contribution to pathogenicity. [Methods] The 05SSU0811 gene encoding SspA was amplified and cloned into the expression plasmid pET28a and then transformed into Escherichia coli BL21 to overproduce the protein. The recombinant protease was purified by chromatography procedures. Its activity was measured by using the chromogenic substrate Succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (pNa). The 05SSU0811 gene was replaced with spectinomycin resistance cassette through homologous recombination, then multiple-PCR and sequence analysis were adopted to identify the knockout strain ?05SSU0811. The virulence of SS2 wild type and ?05SSU0811 mutant strain were then evaluated by calculating the survival rate of the infected mice. [Results] The recombinant SspA was expressed and purified. Its activity was demonstrated by the subtilisin-like protease assay. The isogenic mutant ?05SSU0811 was successfully constructed and the virulence of the ?05SSU0811 mutant strain was attenuated remarkably compared to the wild type strain. [Conclusion] The truncated SspA encoded by 05SSU0811 gene in SS2 exhibits its activity in vitro. And it also contributes to the virulence of SS2.

Abstract:[Objective] We designed a new antibacterial peptide LK. The peptide was composed of Leu residues in the nonpolar face and Lys residues in the polar face based on the helical wheel projection. The activities of LK were tested. [Methods] The secondary structure of LK was studied by Circular Dichroism (CD) spectrometry. Minimal inhibitory concentrations (MICs) of LK against Gram-positive and Gram-negative bacteria were determined. The stability, hemolytic activity and cytotoxicity of LK were also determined. [Results] LK had strong antimicrobial activities against detected bacteria with MICs of 2?4 μmol/L. LK exhibited high pH stability and salt tolerance. The peptide showed very weak hemolysis against human red blood cells and cytotoxicity against vero cells at its MICs. [Conclusion] These results suggest that LK might have potential as an attractive potential alternative to pharmaceutical antibiotics.

Abstract:[Objective] To prepare the polyclone antibody of human parvovirus B19-VP1u and study the impact of anti-VP1u and N-terminal amino acids outside the VP1u conserved domain on the sPLA2. [Methods] In the present study, target genes were firstly cloned to the prokaryotic expression vectors to express and purify the full length and N terminal truncated VP1u-MBP fusion proteins by using prokaryotic expression system. Purified MBP-VP1u was used to make the polyclonal antibody in New Zealand rabbit. The sPLA2 activities of the purified proteins were measured using a PLA2 assay kit. [Results] Western blot and immunofluorescence experiments showed that the polyclonal antibody against VP1u was specific. The purified VP1u-MBP fusion protein exhibits sPLA2 enzyme activity which was inhibited by anti-VP1u antibody. Meanwhile, when first 12 amino acids were truncated, the sPLA2 enzyme activity decreased 53% compared to the full length VP1u protein, and the activity was completely abolished when 67 amino acids were truncated. [Conclusion] Our research firstly determined that amino acids outside the conserved domain of VP1u, especially for the first N terminal 12 amino acids and the region from 22 to 67 amino acids play important roles in maintaining its sPLA2 enzyme activity, suggesting that the truncation of N terminal sequences may affect protein conformation. The prepared polyclonal antibody may provide a basis for the further studies on viral replication life cycle of parvovirus B19.

Abstract:[Objective] To study the structure and application of penicillin-binding protein 3 (PBP3), the pbp3 gene of Streptococcus pneumoniae R6 was cloned and the recombinant protein of PBP3 was expressed in Escherichia coli with expression vector pGEX-6p-pbp3*. [Methods] The truncated pbp3 gene (15?413 aa) was cloned from S. pneumoniae R6 with PCR, and the pbp3* fragment digested by BamH Ⅰand Xho Ⅰwas inserted into pGEX-6p-1 to generate pGEX-6p-pbp3* expression plasmid. GST-PBP3* fusion protein was expressed in cytoplasm of E. coli BL21(DE3) and purified with Glutathione-Sepharose 4B column. The recombinant fusion protein, GST-PBP3, was firstly digested by PreScission Protease for cutting off the GST tag, and then pass through the Glutathione-Sepharose 4B column for getting the purified PBP3 protein. The PBP3 activity was identified by its binding activity to β-lactam antibiotics, such as cefquinome. [Results] The truncated pbp3 gene was verified by sequence analysis and the pGEX-6p-pbp3* expression plasmid was constructed successfully. Finally the soluble PBP3 protein with biologic activity was purified. [Conclusion] The active recombinant PBP3 was successfully obtained from prokaryotic expression system, and this laid a firm foundation for further study of the structure and application of PBP3.

Abstract:Production of melanin has been described in a variety of life forms ranging from bacteria to human. Though melanin is not essential to the growth of organisms, it can help to improve their competitive abilities through confering organisms diverse functions such as resistance to UV radiation and toxic free radicals elimination. Nowadays, research on enzymes essential for the formation of melanin has attracted more attentions because they can metabolize dozens of phenol compounds. It made these enzymes, like tyrosinase, a significant value in biotechnology application. This review summarizes the present knowledge of melanin categories, biosynthetic pathways and physiological functions.

Abstract:Current generation and contaminant degradation are two basic functions, as well as two most attractive advantages for microbial fuel cells (MFCs). It has been extensively documented that MFCs have more efficient contaminant-degrading capacities relative to traditional anaerobic biodigestion reactors. The mechanisms underlying the higher degrading capacity of MFCs are important for optimizing the performances of MFCs, as well as for the in-situ applications of MFCs. This paper reviewed the recent studies that comparatively assessed the degrading-capacities in MFCs and other anaerobic digestion reactors. Potential mechanisms of the higher degrading capacity in MFCs, including the microbial metabolic pathways, biofilm viability and redox-impacts of anode on the ambient environment, were analyzed and suggested for improving the performances of MFCs for contaminant degradation.

Abstract:Resveratrol, a plant-derived polyphenolic compound, has significant physiological activities, including scavenging free radicals, antioxidant and extending lifespan. It has a pleasing market for health products, cosmetics and medicines. At present, resveratrol is mainly extracted from plant, which is limited by the low concentration and extraction efficiency. The rapid development of synthetic biology gives a new approach to produce resveratrol using microogrganisms. Resveratrol has been biosynthesized through introducing exogenous genes into microorganisms. Moreover, the recombinant strains are optimized in encoding sequences and combination of genes with suitable fermentation process control. This paper outlines the research achievement on resveratrol production in engineered microorganisms.

Abstract:Recombinant adeno-associated virus (rAAV) vector, one of the most promising vectors, has been widely used in clinical trials for gene therapy. However, the contradiction between the effectiveness of gene delivery and the immunogenicity of viral capsid protein restricts the development of gene drugs designed based on this vector. Thus, improving the transduction efficiency is one of the most important research fields for rAAV vector. Recent results showed that radiations, such as UV light and γ-ray, can significantly improve the gene expression efficiency of rAAV vector in various types of cells and tissues. These effects vary across the radiation types and doses, the cell types and statuses, the time and infection index of vectors. It is proposed that DNA damage responses (especially for double strand break repair) induced by radiations might contribute to improve transgene expression of rAAV vector. A better understanding of the relationship between radiations and rAAV gene expression will facilitate the combination use of these two strategies in disease therapy. This review discussed the mechanism of UV and γ-ray radiation to improve the expression efficiency of rAAV, the influencing factors as well as the application and progress of it in the field of gene therapy.

Abstract:The study of cellular networks is one of the hot research topics in systems biology. Combining computational network models with experiment techniques, researchers can analyze complex biological systems from a systemic perspective, and provide new hypothesis and guidance for biological discovery. In the last ten years, many methods for the reconstruction and analysis of genome-scale metabolic networks, gene regulatory networks and signal transduction networks have been developed. The integration of these different types of biological networks is becoming a new research hotspot recently. The study of integrated network raises many new challenges. In this paper, we reviewed the methods for the reconstruction and analysis of integrated networks, with a particular focus on the integrative models of metabolic and transcriptional regulatory networks as most researches are on this type of integrated networks. We first gave a brief introduction of the different cellular networks, and then discussed the reconstruction methods and the application of integrated networks. In the end, the problems and future development directions were also discussed．

Abstract:In recent years, fungal infections caused by Candida albicans are increasing, and the development of novel antifungal drugs becomes a hotspot. On basis of antifungal mechanism, the induction of fungus apoptosis has become a new trend for the search of antifungal agents. In this paper, we review comprehensively the drug-induced apoptosis in C. albicans.

Abstract:To build medical microbiology experiment teaching system taken the specialty education objective as the main line, the quality education and capacity as the core. According to the township health service and professional characteristics, the medical microbiology experiment teaching system has been reformed, based on experimental process management, optimized the teaching contents in terms of job competency requirements, reformed the teaching methods to improve comprehensive ability, with the application of a multi-faced, multi-angle, multi-level evaluation.

Abstract:[Objective] We identified predominant strains causing membrane biofouling in membrane bioreactors (MBR). [Methods] 454 high-throughput pyrosequencing was applied to analyze the genes of bacteria originated from the sludge mixed liquor (S1) and membrane foulant (S2). Chao richness index and Shannon diversity index of two samples were calculated and the sequencing results were analyzed by phylogenetic analysis. [Results] In total 9 353 and 7 504 effective reads were obtained from S1 and S2, respectively, indicating that the microbial richness and diversity of S2 were higher than those of S1. By performing the phylogenetic spectra, we found that the microbial community structure of S2 was changed during the membrane surface colonization, and in S2, the abundance of β-Proteobacteria was significantly reduced while α-Proteobacteria、γ-Proteobacteria and Phycisphaerae were enriched. [Conclusion] 454 high-throughput pyrosequencing revealed that Xanthomonadaceae, Thermoanaerobacter, Phycisphaera and 2 strains of uncultured bacteria (Candidate_division_TM7 and Candidate_division_OD1) were predominant taxons involved in membrane fouling. These strains included those with high surface viscosity and hydrophobicity (e.g., γ-Proteobacteria) which were prone to adhesion onto the membrane surfaces, and the proficient species (e.g., Candidate_division_OD1) that facilitated the interspecies hydrogen transfer.

Abstract:[Objective] To identify some specimens of Gibellula spp. collected in China, the DELTA expert system and its function extension were performed. [Methods] The DELTA expert system was built based on 30 characters of the genus Gibellula, and then, the key, natural descriptions, distance matrix, phenetic tree and interactive automatic identification were performed. [Results] All the specimens were identified as three species as follows, respectively: Gibellula clavulifera var. clavulifera, G. leiopus and G. pulchra. [Conclusion] Based on the DELTA expert system, a database of phenotype characters and its function extension could provide a valuable information platform for the taxonomic and phylogenetic study of the genus Gibellula in the future.

Abstract:[Objective] 3,5-Dinitrosalicylic acid (DNS) assay, a rapid detection method of naringin conversion rate established and used to analyze the dynamic process of naringin conversion into naringenin catalyzed by naringinase. [Methods] Naringinase was obtained from Aspergillus aculeatus JMUdb058 under solid-state fermentation. The 3,5-dinitrosalicylic acid (DNS) method was used to determine the yields of reducing sugars to calculate the conversion rate of naringin via a certain way. Then the conditions of naringin enzymolysis were optimized by traditional “one-variable-at-a-time” strategy. [Results] Good linear relationships were showed among the yields of reducing sugars and hydrolysis of naringin as well as the yields of naringenin in the process of naringin enzymolysis. Therefore, the DNS method that was used to determine the yields of reducing sugars can be applied to analyze the process of naringin bioconversion into naringenin by naringinase. The optimum operating conditions obtained from the “one-variable-at-a-time” design were temperature of 50 °C, pH value of 5.0, enzyme dosage of 8 U/mL, and substrate concentration of 0.2 g/100 mL. Under the optimal condition, the conversion rate of naringin reached 85% after 150 min. Then Km=413.44 mg/L and Vmax=0.022 g/(min·L) were got by the double reciprocal plot of Lineweaver-Burk. [Conclusion] The DNS assay can be used to analyze the process of naringin bioconversion into naringenin by naringinase, which provided a new convenient and simple method for study on naringin enzymolysis into naringenin.

Abstract:

Abstract:[Objective] For establishing taxonomic relationships among Bartonella species, gas chromatography (GC) was utilized to investigate their cellular fatty acids (CFAs) compositions with particular attention on the different growth conditions in the qualitative and quantitative changes of CFAs. [Methods] The whole cellular fatty acid methyl esters (FAMEs), from the different base media and the media at different percent of sheep blood, subculture and temperature of incubation, were obtained by saponification, methylation or extraction and then analyzed using the Sherlock Microbial Identification System. The dendrograms of ten strains of Bartonella species, isolated from different hosts (cats, dogs, rats, voles and human), and nine Bartonella strains of cats from different areas, were generated based on the CFAs data matrix using SPSS 16.0 software package. [Results] There were 20 CFAs in Bartonella strains tested. Among them, seven CFAs were common components and detected in all tested type strains of Bartonella species, which include C18:1ω7c, C18:0 and C16:0 and account for more than 80% of the total CFAs. The rest were minor with their presence and relative contents of being affected significantly by differences of culture media and conditions. The dendrogram of the isolates from cats with different type strains was approximately consistent with the hierarchical structure of molecular phylogenetic systematics. [Conclusion] The CFAs profiles are obtained by carefully regulating and standardizing the growth conditions and these profiles are successfully used to identify B. henselae wild isolates. Although these CFAs profiles are very useful in terms of Bartonella taxonomy, they must be viewed with caution until our knowledge of the quantitative and qualitative distributions of fatty acids over a wide variety of taxa and the growth conditions.

Abstract: