Abstract:[Objective] Reteplase (rtPA, recombinant tissue plasminogen activator) is considered as the third generation of safe and effective thrombolytic agent. In order to explore the suitable system for secretory expression of rtPA, the rtPA gene was expressed in three different phenotypes of Pichia pastoris with pPIC9K as the vector. [Methods] The rtPA gene was obtained from plasmid pET28a-rtPA and inserted into the secretory expression vector pPIC9K. The recombinant plasmid pPIC9K-rtPA was digested with restriction endonuclease Sal I and then transformed into P. pastoris GS115, SMD1168 and KM71, respectively. The positive clones were screened on MD-G418 plates and verified by PCR. The expression of rtPA in the recombinant strains were induced with methanol, and analyzed by Western blot and fibrin agarose plate. [Results] The molecular weight of recombinant proteins was about 43 kD; both rtPA-GS115 and rtPA-KM71 had a specific band at 39 kD, and the former had a slight degradation band at 32 kD, while the latter did not; rtPA-SMD1168 showed no degradation. The specific fibrinolytic activity of rtPA-SMD1168 was 27% higher than that of rtPA-GS115, while the expression and activity of rtPA-KM71 displayed the lowest level among tested samples. [Conclusion] According to the expression of fibrinolytic activity, P. pastoris SMD1168 was proven to be the best expression system. On the premise of controlling the activity of protease and reducing the degradation of products, P. pastoris GS115 was selected as the preferred system for rtPA expression.

Abstract:[Objective] Recently, researchers reported that polystyrene?eating mealworms (Tenebrio molitor) can degrade plastic and the key point might be gut microbiotia, which may open a new way to solve the global plastic pollution problem. We try to explore the structure of microbial communities in the polystyrene-eating mealworms’ gut. [Methods] Mealworms were divided into 2 groups fed with polystyrene or paper for 90 days. After that, bacterial community structure of their gut microbiota were studied by high-throughput sequencing targeting V3?V4 regions of 16S rRNA gene. PICRUSt was used to predict the community function based on their 16S rRNA gene sequences. [Results] In total, 144 258 high-quality sequences and 174 OTUs were obtained, which were classified into 111 genera in 10 phyla. The three most dominant bacterial genera in polystyrene-eating mealworms’ gut were Alcaligenes, Brevundimona and Myroides, ranked by the relative abundance. The genes related to aromatic compounds degradation were significantly enriched in the polystyrene-eating group. [Conclusion] The result indicated the diversity of bacterial community in the gut of polystyrene-eating group, which may guide the isolation of the bacteria that can degrade polystyrene.

Abstract:[Objective] We studied the use of Hydrocotyle verticillata fermentation broth as carbon source for sulfate-reducing bacteria and to remove heavy metals from wastewater. [Methods] Anaerobic sludge was used as the seed of sulfate-reducing bacteria, and reactors were fed with Hydrocotyle verticillata fermentation broth and synthetic wastewater containing Pb2+, Cd2+, Cu2+, Ni2+ and sulfate. [Results] Sulfate-reducing bacteria could use the organic matter in the fermentation broth, and the sulfate reduction rates were 24.4%, 43.6% and 60.0% when the ratios of COD to SO42– were 1.2, 5.0 and 7.0, respectively. When the concentrations of Cd2+, Cu2+, Pb2+ and Ni2+ were 10 mg/L, the removal rates of these heavy metals were more than 90%, and the activity of sulfate-reducing bacteria was not inhibited. [Conclusion] Hydrocotyle verticillata fermentation broth can be used as carbon source of sulfate-reducing bacteria to treat wastewater containing heavy metals.

Abstract:[Objective] The anode modified with graphene-multi walled carbon nanotube composite materials was used to enhance the performance of microbial fuel cell (MFC). [Methods] The composite-material of resazurin (R/CC), resazurin+graphene (R+GNS/CC), resazurin+multi walled carbon nanotube (R+MWCNT/CC) and resazurin+graphene+multi walled carbon nanotube (R+GNS+MWCNT/CC) were dropped on the surface of carbon cloth electrode. [Results] The maximum MFC output voltages of R+GNS/CC (87 mV), R+MWCNT/CC (145 mV), R+GNS+MWCNT/CC (275 mV) were increased by 61.11%, 168.25% and 409.26% and the degradation rate of perchlorate were also increased by 59.1%, 89.7%, 147.3%, respectively. The results of electrochemical impedance (EIS) and Tafel for the four anode materials implied that the anode resistance of R+GNS/CC, R+MWCNT/CC, R+GNS+MWCNT/CC were decreased relative to that of R/CC, and electrode reaction rate were increased, but R+GNS+MWCNT/CC had smaller anode electrode activation resistance and faster reaction rate. At the same time, the extracellular polymeric substances analysis of microorganism on the four anode surface indicated that the amount of microorganism and polysaccharide increased and decreased respectively, R+GNS+MWCNT/CC anode is better for electron transfer. [Conclusion] The modified anode by graphene-multi walled carbon nanotubes composites material with resazurin decreased the resistance of MFC and enhanced the electron transfer rate.

Abstract:[Objective] To study the spatiotemporal dynamic of endophytic bacteria numbers in Acanthus illicifolius. [Methods] Annual dynamic of total endophytic bacteria and culturable endophytic bacteria in different organs of A. illicifolius were studied using fluorescence microscopy and plate counting method, respectively. [Results] The number of total endophytic bacteria in roots, stems and leaves was 12.25×107, 7.59×107 and 5.72×107 ind./g(FW) successively. And the number of culturable endophytic bacteria corresponds to 3.98×103, 3.70×103 and 2.18×103 cfu/g(FW). [Conclusion] There were numerous endophytic bacteria in A. illicifolius. The highest concentration of endophytic bacteria was in roots, followed by stems and leaves. Culturable endophytic bacteria accounted for only 0.000 2%?0.146 8% of total endophytic bacteria in A. illicifolius. The fluctuation of the number of total endophytic bacteria and culturable endophytic bacteria in A. illicifolius varied greatly with the change of seasons. The number of total endophytic bacteria in A. illicifolius was highest in summer (July). While the number of culturable endophytic bacteria in A. illicifolius was highest in spring (March).

Abstract:[Objective] The main aim of this study is to study the diversity of culturable bacteria in alpine lakes of different regions located in Southwest China, and to analyze their capabilities for producing proteases, cellulases and exopolysaccharides. [Methods] Four water samples in different alpine lakes located in Southwest China, including Horse Lake in Leibo (LB), Kanbon sub Lake in Sino-Burmese border (ZM), Lotus Lake in Shade (SD) and Qinghai Lake in Tengchong (TC), were collected to isolate the cultural bacteria based on the spread plate method. The genera of culturable bacteria were identified by analyzing the physiological and biochemical indexes and 16S rRNA gene sequences. The strains were further detected for production of proteases, cellulases and exopolysaccharides. [Results] A total of 41 strains were isolated from four lakes in southwestern China, of which 15 strains from LB, 13 strains ZM, 7 strains SD and 6 strains TC. According to phylogenetic analysis of 16S rRNA gene sequences, there were obvious differences in composition and abundance of culturable bacteria among four lakes. The dominant genus was Bacillus, and followed by Aeromonas and Pseudomonas in LB and ZM. All isolates were Bacillus in TC, whereas strains were highly specific in SD. Further research on enzyme activities and exopolysaccharides were detected in 41 cultural bacteria, of which 28 strains had protease activity, 6 strains had cellulase activity and 17 strains produced exopolysaccharides (EPS). In addition, 2 strains produced proteases, cellulases and exopolysaccharides simultaneously, 10 strains produced proteases and exopolysaccharides, 2 strains produced proteases and cellulases, and only 1 strain produced cellulases and exopolysaccharides. [Conclusion] The culturable bacteria in alpine lakes were capable of secreting various extracellular active substances, with potential for further development and research.

Abstract:[Objective] We compared the effect of nutritional conditions and start-up method on the biofilm augmented purification performance of ammonia-polluted water and the microbial community structures. [Methods] The effect of ammonia removal was tested in three lab-scale reactors, including control reactor (Blank), biofilm reactor with the raw carrier (Raw) and biofilm reactor with the functional bacteria-immobilized carrier (PCC). The microbial community structures were assessed by terminal restriction fragment length polymorphism and the succession process of community was analyzed using the plot of nonmetric multidimensional scaling. [Results] When the C/N ratio was kept at 1:1 for 25 days, the ammonia removal efficiency was only 10%?20% for all the reactors, except for that the PCC showed a temporary high efficiency in the first 5 days. However, the ammonia removal efficiencies of both the Raw and PCC were higher than 95% when the C/N ratio was adjusted to 2:1. The NMDS results showed that the microbial structures of Raw and PCC had high similarity when the C/N was 2:1, and the dominant bacteria were composed of Gammaproteobacteria, Actinobacteria and Nitrospira. [Conclusion] The C/N ratio is not only a key factor impacting on the ammonia removal efficiencies of biofilm augmentation but also a driving force for the shifts of microbial community structures in the biofilm reactors.

Abstract:[Objective] In order to understand the microbial community structure and microbial diversity which was obtained at nine soil samples (primary, secondary saline alkali soil and farmland soil) in saline alkali soil from the area of Hexi Corridor. [Methods] Soil microbial total DNA was extracted. The microbial community structure and diversity were analyzed by using Illumina Miseq high-throughput sequencing system. [Results] Total of 325 089 partial 16S rRNA gene sequences were obtained from the samples. Redundancy analysis and heatmap analysis showed that the microbial community composition were quite different between primary and secondary saline alkali soil, and were different between primary saline alkali soil and farmland soil, but the composition of secondary saline alkali soil and farmland soil were similar. Soil pH effected on microbial community composition was the most significant. The diversity index and rarefaction curves analysis showed that in nine soil samples, the lowest microbial diversity was No. 1 sample from primary saline alkali soil and the highest microbial diversity was No. 6 sample from secondary saline alkali soil. Saline alkali soil mainly comprised nine phyla, among which Proteobacteria was the dominant population, followed by Actinobacteria, Bacteroidetes, Acidobacteria, Planctomycetes, Chloroflexi, Gemmatimonadetes, Firmicutes and Verrucomicrobia. Proteobacteria was the dominant population in primary saline alkali soil and farmland soil. Acidobacteria was the dominant population in secondary saline alkali soil. [Conclusion] Microbial diversity in the Hexi Corridor saline alkali soil was very rich, there were a large quantity of microbial groups, especially in the secondary saline alkali soil.

Abstract:[Objective] In order to alleviate the harm of cinnamic acid, an auto-toxic substance to the watermelon and other related crops, a bacterial strain with high efficacy of degradation of cinnamic acid was isolated from soils collected in watermelon field of Zhong-wei county, Ningxia. Its characteristics of cinnamic acid-degradation were evaluated. [Methods] A microbe which could effective use cinnamic acid was isolated. 16S rRNA gene sequence data was used to the strain identification. The degrading kinetics of cinnamic acid by strain R30 was determined by HPLC. A plant growth chamber test was performed to confirm the efficacy of R30 to resume the vitality of watermelon seedlings. [Results] A bacterial strain R30, which was isolated from watermelon continuous cropping soil, was identified as Exiguobacterium sp.. This strain could degrade 99% of cinnamic acid within 96 h at 30 °C, pH 7.0. Strain R30 was also found to degrade coumalic acid, ferulic acid, and benzoic acid efficiently as well as cinnamic acid. Plant growth chamber test indicated that strain R30 could efficiently alleviate the inhibition of cinnamic acid on watermelon seedlings. [Conclusion] The R30 strain possesses the ability of degrading a wide range of phenolic acids, thus has a potent applications in management of crop continuous cropping obstacles which caused by cinnamic acid, coumalic acid, ferulic acid, and benzoic acid.

Abstract:[Objective] In order to understand the distribution and genomic characteristics of complex class 1 integron in aquaculture environment. [Methods] 108 strains of drug-resitstiant bacteria were isolated from aquaculture farms in Fujian province to check the carrying status of the upstream and downstream conserved and variable regions of the complex class 1 integron by PCR and sequencing. [Results] The results showed that 86 strains (79.6%) carried class 1 integrons and 47 strains (43.5%) carried ISCR1 elements. However, only 26 strains (24.1%) have both of the elements, of which 16 strains (14.8%) were successfully amplified upstream and downstream variable regions, involving 9 species, 8 genera. Furthermore, splicing and analysis of upstream and downstream sequences indicated that these 16 strains carried two types of complex class 1 integrons: (1) intI1-aac(6′)-Ib-cr-arr-3-dfrA27-aadA16-qacE△1-sul1-ISCR1-sdr-qnrB6-qacE△1-sul1(15 strains); intI1-aac(6′)-Ib-cr-arr-3-dfrA27-aadA16-qacE△1-sul1-ISCR1-sapA-like-qnrB2-qacE△1(truncated)-sul1 (only Klebsiella pneumoniae C12 strain), which is a noval structure of complex class 1 integron. [Conclusion] The complex class 1 integron is not infrequent in aquaculture environment and exists in various bacteria, yet its gene structure lacks diversity.

Abstract:[Objective] The objective of this study is to isolate a bacterium strain from industrial oil wastewater with benzene, toluene and styrene as the sole carbon source, then to analyze the degradation characteristics of the strain and to study the effect of substrate interaction on the degradation. [Methods] The strain was identified with physiological-biochemical and 16S rRNA gene sequence analysis; HS-GC was used to determine benzene series concentration; the degradation characteristics of the strain was analyzed by the hydrophobicity, emulsifying ability, oil displacement and transmission electron microscopy. [Results] The strain was identified as Pseudomonas putida, named SW-3. The maximum degradation rates of benzene, toluene and styrene were 0.072, 0.035 and 0.019 g/(L·h), and the total degradation rate of benzene mixture was 79.99% under the optimum degradation conditions. The interactions between substrates indicated that the degradation of toluene and styrene was stimulated by benzene, while the degradation of toluene was inhibited in the presence of styrene. The analysis about characteristics of adsorption, uptake and degradation of SW-3 suggested that SW-3 could transport the benzene by the energy-dissipating vesicle transport with the aid of the secreted surfactants. [Conclusion] Strain SW-3 has the ability to produce surfactants and degrade benzene compounds, and the interaction between substrates can significantly affect the degradation of different substrates.

Abstract:[Objective] Assessment the diversity of lactic acid bacteria in the breast milk of healthy women. [Methods] The diversity of lactic acid bacteria was analyzed by using pure culture, repetitive genomic fingerprinting (Rep-PCR) analysis patterns and 16S rRNA gene sequence analysis. [Results] A total of 193 strains of lactic acid bacteria were obtained from eleven breast milk samples. The phylogenetic analysis showed that these strains belonged to four phylogenetic groups, they were Lactobacillus, Streptococcus, Lactococcus and Enterococcus respectively. The dominant genus was Enterococcus, which is up to 46%. [Conclusion] The abundant diversity of lactic acid bacteria in the human breast milk of Kashi area in Xinjiang provided rich resources for exploiting probiotic lactic acid bacteria products.

Abstract:[Objective] To analyze and compare the microbial community composition and structure of four nitrobacteria enrichments i.e A: enrichment using ammonium as nitrogen source in freshwater, B: enrichment using nitrite as nitrogen source in freshwater, C: enrichment using ammonium as nitrogen source in freshwater at low temperature and D: enrichment using nitrite as nitrogen source in seawater. [Methods] The DNA of microbes in four samples were extracted, then high-throughput sequencing technology was used to analyze bacterial communities, abundance and diversity. [Results] The results showed that the microbial community was dominated by phylum Proteobacteria. β-Proteobacteria and γ-Proteobacteria were the dominant bacteria of sample A, B and C, while γ-Proteobacteria, δ-Proteobacteria and Bacilli were the dominant bacteria of sample D. The dominant genera were different in four nitrobacteria enrichments, the dominant species of sample A was Nitrosomonas (24.56%), the dominant species of sample B was Streptomyces lushanensis (7.15%), the dominant species of sample C were Bacteriovorax stolpii (19.36%) and Nocardioides daecheongensis (19.35%), while the dominant species of sample D were Acidovorax anthurii (13.6%) and Caulobacter segnis (11.5%). 7 groups of nitrobacteria were detected in 4 samples, the majority genus of sample A, B and D was Nitrosomonas, accounting for 24.56%, 4.94% and 0.63% relative abundance, respectively; Nitrospirillum (0.69%) and Nitrospira (0.69%) were the dominant bacteria of sample C. Apart from that, there were beneficial bacteria and pathogens detected in samples, such as Alcanivorax, Bradyrhizobium, Vibrio and Burkholderia etc. [Conclusion] Bacterial diversity, the group of nitrifying bacteria which played a main role in nitrification and other microbial groups related to environmental cycling or special physiological characteristics laid a foundation for its practical application.

Abstract:[Objective] Substrates in the environment can be transported into the cell by oligopeptide transporters (OPTs), and then contribute to various biological processes. OPTs proteins are involved in metal transports and distributions in plants, which can promote the plants to use and adapt various metals. However, if OPTs from fungi participates in this process is still unknown. To explore if OPTs play a role in the adaptation process of Ganoderma lucidum to metals. [Methods] Mycelium growth and biomass of G. lucidum (No. 1 Rongbao) were tested in the presence of different concentrations of Cu2+, Se4+ and Fe2+. The specific or differential expression profiles of OPTs were analyzed by real-time quantitative PCR (RT-PCR) from the samples cultured for 15 d and 30 d. [Results] Growth and biomass were inhibited under all metal concentrations of Cu2+, Fe2+ and Se4+. The results of RT-PCR showed that, except three genes (OPT7, OPT8 and OPT9), whose transcripts were not detected, the other 10 OPT genes have differential expression profiles. At the early culture stage (15 d), the relative expression levels of 6 OPT genes (OPT1, OPT3-6 and OPT10) were up-regulated under Cu2+ stress, but the expression levels of all OPTs gene were down-regulated under Fe2+ and Se4+ treatments. At the later culture stage (30 d), the relative expression levels of all OPTs gene were down-regulated under Se4+ stress, but the expression levels were significantly up-regulated under Cu2+ and Fe2+ treatments. [Conclusion] These results indicate that these metals can affect the growth and biomass of G. lucidum, while the oligopeptide transporter genes responded to metal stress at transcriptional levels, suggesting that OPT genes may function in the metal adaption processes in G. lucidum.

Abstract:[Objective] To study the application parameters of thermo-stabilizer in the manufacture of swine paratyphoid vaccine, and provide reference for the preparation of thermo-stable bacterial live vaccine. [Methods] The thermo-stabilizer was mixed with same amount of bacteria culture, Salmonella enterica serovar Choleraesuis strain C500. The mixture was lyophilized using freeze-drying curves 1, 2 and 3, and the matched freeze-drying curved was then determined by sampling the survival ratio post lyophilization. Based on the optimal freeze-drying curve, the effect of various factors on the vaccine quality post lyophilization was further investigated. The studied factors included the culture age (C500 culture fermented for 12, 15, 18 and 21 h), the culture concentration (3×1010, 5×1010 and 7×1010 CFU/mL), interaction time for thermo-stabilizer and C500 culture (0, 24 and 48 h), storage time of fresh prepared thermo-stabilizer (0, 10, 20, 30 and 40 d) and the sub-package volume (2, 3 and 4 mL). [Results] The lyophilized product by freezing-drying curve 1 had the properties of surface crystallization and bottom shrinkage. The lyophilized product by freezing-drying curve 3 had a small amount of crystallization and the lower concave on the surface. The lyophilized product by freeze-drying curve 2 had the best properties, highest survival ratio and best aging resistance. The C500 strain cultured at 37 °C for 18 h was optimal for lyophilization with a highest survival ratio of 78%?81%. The optimal culture concentration was 3×1010?5×1010 CFU/mL. The optimal incubation time for the C500 culture and thermo-stabilizer was 24 h at 2?8 °C, with the survival ratio of 85.3%?90.5%. After stored at 2?8 oC for 40 days, the thermo-stabilizer has the same effect with fresh prepared one. The survival ratio after lyophilization was almost the same for the sub-package of 3 mL or 4 mL compared with 2 mL, but the survival ratio was 3?7 percentage points higher than sub-packing with 2 mL after stored at 37 °C for 7 days. [Conclusion] The optimal parameters for the thermo-stabilizer in manufacture of swine paratyphoid live vaccine were the following: freeze-drying curve 2, culture time of 18 h, culture concentration of 3×1010?5×1010 CFU/mL, thermo-stabilizer used within 40 days if storage at 2?8 °C from fresh preparation, incubation time of 24 h for the C500 culture and thermo-stabilizer, sub-package volume of 3?4 mL.

Abstract:[Objective] To systematically compare the physical, chemical and biological properties of the swine paratyphoid thermo-stable live vaccine (TS vaccine) and the traditional swine paratyphoid live vaccine (traditional vaccine), and provide references for evaluation of live vaccine prepared with thermo-tolerant stabilizer. [Methods] Three batches of TS vaccine and traditional vaccine were prepared. The vaccine physical properties, pureness, viable bacterial counts, safety, residual moisture, vacuity and storage period were measured according to the standard methods in Veterinary Pharmacopoeia of the People’s Republic of China. The survival ratio of the vaccines after lyophilization and the thermo-stabilities after storage at 37 °C for 7 days was compared. One batch of TS vaccine and traditional vaccine were selected for further protective efficacy study. Twenty-five piglets were randomly divided into five groups. With the exception of the non-vaccinated control, the other four groups were immunized orally (p.o.) or intramuscularly (i.m.) with 1 dose of TS or traditional vaccine. After thirty days, all piglets were challenged intravenously with 1 minimum lethal dose (MLD) of virulent Salmonella enterica serovar Choleraesuis. The protective efficacy of two vaccines were observed for 30 days post challenge. [Results] The physical properties, pureness, viable bacterial counts, safety, residual moisture and vacuity of two vaccines met the requirements of Veterinary Pharmacopoeia of the People’s Republic of China. The bacterial survival ratio after lyophilization of the TS vaccine was 88.2%, 83.1%, 86.4%, respectively, compared to the 52.3%, 56.2%, 61.4% for the traditional vaccine, respectively. After stored at 37 °C for 7 days, the survival ratio of the TS vaccine was 83.6%, 82.9%, 88.8%, respectively, compared to the 58.5%, 60.2%, 54.7% of the traditional vaccine, respectively. After stored at 37 °C for 7 days, the TS vaccine showed good properties, while the traditional vaccine had surface concave of 1/4?1/2. The storage period at 4 °C of the TS vaccine lasted 24 months, compared to the only 9 months for the traditional vaccine. The protective efficacy of the TS vaccine was 100% for oral or intramuscular immunization route. For the traditional vaccine, the protective efficacy was 100% for oral route and 80% for intramuscular route. [Conclusion] The TS vaccine had higher survival ratio after lyophilization and better thermo-stability. The TS vaccine could be stored at 4 °C for long-term and had good protective efficacy.

Abstract:[Objective] To screen and isolate endophytic fungal strains producing Huperzine A (HupA) from wild Huperzia serrata. [Methods] HupA producing endophytes were identified through thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC), and the identification of the fungus with relatively a high HupA productivity was performance based its morphological characteristics and nuclear rDNA-ITS sequences. [Results] One HupA producing endophyte (NSH-5) was identified as Fusarium verticillioides according to its morphological characteristics and an analysis based on nuclear rDNA-ITS sequences. The amount of HupA produced by NSH-5 was quantified to be 11.76 mg/100 mL on liquid culture basis by HPLC, which with hereditary stability after 20 generations. [Conclusion] Strain NSH-5 could produce HupA. Isolation of such a fungus may provide a promising alternative approach to producing HupA.

Abstract:[Objective] This study is aimed to explore the effects of zinc deficiency and the corresponding adaptive growth of Streptococcus pneumoniae D39. [Methods] We extracted whole proteins from S. pneumoniae D39 cultured with or without zinc, performed two-dimensional electrophoresis (2-DE) combined with immobilized metal affinity chromatography (IMAC) and mass spectra (MS) to identify differentially expressed proteins. [Results] The 2-DE maps of whole cell proteins showed that 32 proteins were down-regulated and 35 up-regulated. These Zn2+ regulated proteins are mainly involved in carbohydrate metabolism, nucleotide metabolism, oxidation, proteins translation, synthesis and folding. The 2-DE maps of Zn2+-binding proteins by using Zn-IMAC separation exhibited 7 differentially expressed proteins, 1 down-regulated and 6 up-regulated. These Zn2+-binding proteins participate in the bacterial response to stress stimuli, proteins folding and amino acid metabolism. [Conclusion] To survive and infect the host, S. pneumoniae regulate many metabolic pathways mainly including carbohydrate metabolism and nucleotide metabolism under zinc deficiency. This study provides a theoretical basis for revealing the adaptive growth mechanism of bacteria in host environment with limited metal ions.

Abstract:The specific interaction between antigen and antibody is determined by the specific complementary recognition between antigenic determinant and epitope motif on the surfaces of antibody and antigen, respectively. B cell epitope mapping involves both the fine location of B cell epitopes (location of the specific motifs on an antigen recognized and bound by antibodies) and the depiction of the distribution of all or nearly all epitopes of an antigen on its primary or secondary structure. Mapping of B cell epitopes constitutes a primary basis for the development of epitope-based vaccines and therapeutic epitope specific antibodies and the establishment of immunological diagnostic methods. So far, a number of experimental methods have been developed to map the B cell epitopes recognized by antibodies or to depict the map of epitopes on an antigen. B cell epitope mapping methods based on X-ray crystallography of antigen-mAb (monoclonal antibody) complex and screening of the mutant libraries of an antigenic protein or its fragments can reveal the key residues of antigen specifically bound by mAb at amino acid or even atom level. Other epitope mapping methods, such as peptide library screening technology using ELISA, are seldom used to identify the minimum epitope motifs because only the antigenic fragments can be obtained by these methods. On the other hand, the improved biosynthetic peptide method is usually used for the minimal motif identification and fine mapping of B cell epitopes. It is quite common that more than one methods were employed to fine map B cell epitopes due to the respective limitations of each method. This review discusses and compares different experimental methods commonly used in B cell epitope mapping and aims to assist researchers to design the most suitable protocol to map their B cell epitopes. The applications of B cell epitope mapping in animal disease prevention and control are also reviewed.

Abstract:Biological control of plant diseases is an effective way to reduce chemical pesticides and environmental pollution. Trichoderma spp. are important biocontrol fungi that play a key role in controlling plant disease. Some studies indicate that Trichoderma are widely used to Botrytis cinerea control. At present, screening, application and biocontrol mechanism of Trichoderma against B. cinerea are widely studied. Interaction between Trichoderma and B. cinerea can activate multiple antagonistic mechanisms of Trichoderma. One of the biocontrol mechanism of Trichoderma is direct mechanism, including the hyperparasitism, antibiotic and competition. The other, indirect mechanism, is the induced system resistance of plant by Trichoderma. We reviewed the mechanism of Trichoderma against B. cinerea including the interaction model, signal transduction pathway and the induce defense response of plants, for an efficiency application of Trichoderma as biocontrol agents.

Abstract:In recent years, great attentions have been paid to marine actinomycetes for their ability to synthesize new metabolites. Some of the synthesized metabolites with new lead structures have demonstrated great potential to be developed as new drugs. This situation has also prompted the development of marine actinomycetes research in China. This review mainly discusses the latest advances regarding Marinactinospora thermotolerans research in terms of the taxonomy, the discovery of novel metabolites, their biosynthesis mechanisms, and the species genome analytical results, etc. M. thermotolerans is considered to be a good model of marine actinobacteria for mining resource research in future.

Abstract:Mutation breeding is a new breeding technique, with the help of mutagens, and creates new traits that could not be obtained by conventional hybrid technique. The spontaneous mutation rate was only 0.1%, but the mutation rate of mutation breeding was 3%, and was 100 times higher than spontaneous mutation. The mutation technique has been used widely in breeding of edible and medicinal fungi. In this paper, we introduces the principle, method, application and prospect of mutation breeding in edible and medicinal fungi, and provide theoretical basis and reference for mutation breeding of edible and medicinal fungi.

Abstract:In recent years, the discovery of heterotrophic nitrification-aerobic denitrification bacteria has broken the traditional theory. It is not only able to simultaneously remove nitrogen and organics, but also some bacteria can achieve simultaneous nitrification and denitrification (SND), so it has gained widespread attention. Our review focuses on the influence factors of heterotrophic nitrification-aerobic denitrification bacteria, the optimal nitrogen removal effect of some bacteria, the difference between traditional nitrification-denitrification bacteria and heterotrophic nitrification-aerobic denitrification bacteria and the nitrogen metabolic pathways of some bacteria. In addition, it shows the research progress in the aspects of NO2?-N control and compound bacteria. Finally, the present situation of its application in bioaugmentation and challenges facing it are brought forward.

Abstract:Environmental estrogens, the major components in the new kinds of environment pollutants, threaten the health of human and animals by its effect on the functions of endocrine system. Microbial degradation is considered as the efficient method in the removal of estrogenic chemicals and the remediation of polluted environment. This paper discusses the well-studied estrogen-degrading microorganisms, compares their degradation products and pathways, then summarizes the proposed microbial degradation mechanisms of estrogens, and finally forecasts the potential research interests in the biodegradation of environmental estrogen.

Abstract:Microbiota is widely distributed in natural habitats and considered as “Dark Matter” because its distribution and function cannot be revealed by traditional culture-dependent methods. With the rapid development of next-generation sequencing technologies and high resolution mass spectrometric techniques, we can rapidly analyze the composition and dynamic changes of microbiome without culturing, which marks the beginning of new era of studying “Dark Matter”, thus changing the status of microbiology research. As an important part of the biogeochemical cycle, saprophytic habitats have been widely concerned because of their ability to degrade organic wastes efficiently. However, the complex materials and environments hindered comprehensive studies on saprophytic habitats. With the advent of integrated meta-omic technologies, these problems could be addressed by analyzing diversity and dynamic succession of microbiota in saprophytic habitats. Therefore, based on the analysis of integrated meta-omic data and optimization of environmental parameters, we can learn about the dynamic changes and functions of microbiome, and then establish the green biotechnologies for efficient degradation of complex materials, which would promote the process of harmlessness and resource utilization of agricultural wastes.

Abstract:In order to enhance the ability of food microbiology professionals and to cultivate the competitive talents needed in the development of the industry, the teaching model innovation research of food microbiology examination course is carried out under the core theory of CDIO (Conceive-Design-Implement-Operate) education idea. Combined with the actual needs of the industry and the objectives of higher education personnel training, the concept of food microbiological examination of teaching ideas, teaching methods of innovation, the introduction of scientific research projects, practical process of teaching reform, and evaluation system for the assessment model innovation are discussed. Practice has proved that food microbiology teaching reform and assessment model innovation has received a good educational effect, and the reformed training is in line with the level of social development of professional knowledge and comprehensive ability of the quality of dual professional talents. So the research is as to provide effective professional reform concept for peers, and provide reference for the training of higher education engineering and technical personnel and professional teaching reform.

Abstract:[Objective] To study and optimize loop-mediated isothermal amplification method for rapid detection of Shigella that can cause infectious diarrhea in conventional food consumption. [Methods] High conservative and specific target gene sequence of Shigella gene was aligned and obtained from NCBI (National Center for Biotechnology Information) database. Three pairs of corresponding LAMP primers were designed, synthesized and used to establish the LAMP-based visualized detection method. The detection result of practical samples by using LAMP-based detection method was compared with those obtained by conventional methods for statistical analysis. [Results] All 5 strains of Shigella standard strain samples were detected positive and 11 strains of non-Shigella standard samples were detected negative, which showed no cross reaction. The minimum test limit is 16 CFU per test or 3.2×102 CFU/mL, and by comparison, the sensitivity of LAMP detection was 10 times higher than PCR detection. All 161 sets of samples were detected by LAMP, and the results showed high consistency with conventional detection method. [Conclusion] The LAMP-based detection method is featured with advantages in convenience, rapidity and high reliability, which makes it applicable to meet the requirements of rapid detection for Shigella in different types of food samples.