Abstract:[Background] The expression of fugal P450s in Escherichia coli system is often in low efficiency. The N-terminal domain (NTD) amino acid sequence modification has been emerged as a potential strategy to achieve high-level expression of these membrane-bound proteins. [Objective] The Au8002 gene in Aspergillus ustus 094102 is predicted to encode a fungal P450. It cannot be expressed successfully in its natural sequence. Three NTD modifications were carried to prove the efficiency of this strategy on the heterologous expression in E. coli system. [Methods] Three NTD-modified Au8002 protein were designed to facilitate the gene expression and 5-aminolevulinic acid (5-ALA), the substrate for biosynthesis of P450s, was added during the heterologous expression to increase the yield of protein. [Results] The identifying results by SDS-PAGE and western blot indicated that the NTD modifications used in this study could improve the fungal gene expression and the addition of 5-ALA improved the P450 protein yield in E. coli. When the NTD was truncated in full length, the NTD-modified Au8002 appeared to be partially soluble, and CO binding test also proved its solubility and proved that it was a P450 protein. [Conclusion] The NTD modification of Au8002 of strain 094102 can help to overcome the low efficiency of its heterologous expression in E. coli and the addition of 5-ALA can also help to increase its expression level. The observation made in this study may provide a useful guideline for improving the expression yield of fungal P450s in E. coli.

Abstract:[Background] Abundant microbial resources exist in the sea with various species and functions, playing important roles in driving substance circulation and energy flow. Screening and studying the diversity of marine strains capable of degrading hydrocarbons can be important for this purpose, especially in the South and East China Seas where this resource is still underexplored. [Objective] We screened culturable strains with hydrocarbon degradation ability, and studied their diversity and function to degrade hydrocarbons. [Methods] The sediment samples were collected from the South and East China Seas. Different hydrocarbons were used as the sole carbon source to isolate bacterial strains by serial dilution and plate streaking procedures. Then the growth of the isolated strains was investigated using corresponding hydrocarbon compounds as the sole source of carbon and energy. [Results] From the samples used, 63 strains with the ability to degrade hydrocarbon compounds were isolated, belonging to 3 phyla, 4 classes, 8 orders, and 10 genera. They are mainly Rhodococcus, Acinetobacter, Vibrio, Halomonas, Pseudomonas. The degrading strains from sediments in the East China Sea were mainly Acinetobacter, whereas those from the South China Sea were mainly Rhodococcus, exhibiting differences in major genera of degrading strains between the two areas. [Conclusion] Hydrocarbon-degrading strains from the South and East China Seas have the potential bioremediation of petroleum-polluted marine environments.

Abstract:[Background] In the process of composting, different denitrification microorganisms interact with each other to produce a large amount of gaseous nitrogen, which not only leads to nitrogen loss, but also reduces the compost efficiency. However, the current knowledge about the changes in the structure of denitrifying bacterial community, especially the correlation between the community structure and physicochemical factors is still lacking. [Objective] We studied the denitrifying bacteria in compost to reveal the dynamic changes of denitrifying bacterial communities and to provide scientific data of the mechanism of compost nitrogen cycle. [Methods] We designed a static aerobic high-temperature composting process to treat dairy manure and rice stalk. High throughput sequencing technique was used to unravel the dynamic changes of nirK type denitrifying bacteria community. Spearman was used to analyze the correlation between the dominant denitrifying bacteria and physicochemical indexes. [Results] The compost was matured as shown by physicochemical and biological indexes. The community structure of nirK type denitrifying bacteria was significantly different. The analysis of phylum classification level showed that the main denitrifying bacteria were Proteobacteria and unclassified denitrifying bacteria. The order classification level shows that the dominant genera mainly belong to Rhizobiales, Rhodobacterales and Burkholderiales. Among them, Rhizobiales species were the most, but the relative abundance of Burkholderiales was the highest. Spearman correlation analysis shows that Unclassified_k_norank_d_Bacteria and Unclassified_o_Rhizobiales were significantly negatively correlated with the pH, TOC (total organic carbon), C/N, water content (P<0.05). There was significantly positive correlation with TKN (total kjeldahl nitrogen) and NO3?-N (P<0.05), the other dominant genera were significantly positively correlated with the pH, TOC, C/N and water content (P<0.05), and significantly negatively correlated with the TKN and NO3?-N (P<0.05). It was found that only the Unclassified_o_Burkholderiales, Unclassified_p_Proteobacteria, Pusillimonas and Paracoccus were significantly related to NH4+-N (P<0.05). [Conclusion] The static aerobic high-temperature composting technology used in this paper can shorten the composting cycle. At different stages of composting, the community structure of nirK type denitrifying bacteria was significantly different, and the change of the community structure was significantly affected by the physicochemical indexes. This study will be useful to reveal the nitrogen conversion law in compost and provide a theoretical basis for improving the composting process.

Abstract:[Background] Light and oxygen are important limited factors for cell growth and the inorganic nitrogen removal of anoxygenic phototrophic bacteria (APB). Marichromatium gracile YL28, a member of purple sulfur bacteria in APB, can grow with nitrite as the sole nitrogen source and efficiently remove inorganic nitrogen. [Objective] This work aims to explore the relationship between light and/or oxygen and the removal efficiency of inorganic nitrogen by YL28, and acquire the optimal condition of light and oxygen for biological nitrogen removal processes. [Methods] A simulated seawater system with high concentration of co-exist inorganic nitrogen was used to investigate the effect of sample loading quantity (SLQ, it represents dissolved oxygen level) on the inorganic nitrogen removal efficiency by YL28 under the light or dark conditions. The three major factors of SLQ, light intensity and photoperiod were optimized by the response surface analysis. [Results] Under the light condition, the highest removal efficiency of inorganic nitrogen and cell growth were achieved at 80% of SLQ. When SLQ was in the range of 10% to 100%, the range of biomass value (OD660) was from 0.938 to 2.719 and the removal rate of ammonia, nitrite and nitrate reached 71.44%?89.09%, 99.22%?99.83% and 91.60%?97.33% when exposed to 7.16, 5.67, 4.83 mmol/L of ammonia, nitrite, nitrate, respectively. Under the dark condition, when SLQ was in the range of 20% to 100%, the removal rate of ammonia, nitrite and nitrate reached 48.07%?64.27%, 73.51%?86.42% and 42.57%?46.34%, respectively, however, the biomass (OD660, 0.615?0.903) decreased significantly. The response surface analysis showed that the cell growth and ammonia removal efficiency were increased by 21.28% and 14.11% under the 80.0% of SLQ (dissolved oxygen (DO) is approximately 0.32 mg/L), 2 800 lx of light intensity and 24L:0D of photoperiod condition. In practical application, more than 95% of cell activity was achieved under 72% to 89% of SLQ (DO is in the range of 0.26 to 0.63 mg/L), 2 240?3 460 lx of light intensity and 21L:3D?24L:0D of photoperiod conditions. [Conclusion] The 80% of SLQ is of benefit to YL28’s phototrophic growth and the inorganic nitrogen removal efficiency; YL28 remains the good nitrogen removal activity under anaerobically and/or aerobically in the dark. This study provides useful information for the removal of inorganic nitride by APB in bioreactor.

Abstract:[Background] The indigenous microbial community in the porous medium of the reservoir is the basis for the indigenous microorganism enhanced oil recovery. Because of the difficulty and high cost of the sampling technique from porous media in the reservoir, the spatial distribution of indigenous microbes from the injected into the output of porous media after the indigenous microorganism flooding has not been clarified. [Objective] simulation of indigenous microbial enhanced oil recovery process was done via long core dynamic continuous displacement experiment. The spatial distribution of the indigenous microbial communities from injection to output end was revealed by analysis the internal microbial community structure adsorbed on the oil sand of different spatial loci after implementation. [Methods] The microbial community structure adsorbed on the oil sand of different space sites of core was analyzed by the high-throughput sequencing and fluorescent quantitative PCR. [Results] from injection to output end, the difference in the ecological environment of porous media and microbiological interaction lead to the spatial difference of the microbial community. There has been a clear law of aerobic to anaerobic succession. Aerobic microbes are mainly distributed in the front of the core, such as Pseudomonas, which can drive the crude oil in the front of the core by producing the biological surfactants. Facultative and anaerobic microorganisms such as Geobacillus and Anaerobaculum are mainly in the middle of the core, while anaerobic bacteria and methanogens are mainly at the end of core. Anaerobic bacteria produce H2, CO2 and small molecular acids through the anaerobic metabolism of organic nutrition, which provides a metabolic substrate for the methanogens at the end of the core. [Conclusion] aerobic and anaerobic succession spatial distribution of indigenous microorganisms in the porous media was clarified for the first time, and the understanding of the indigenous microorganisms in the reservoir was further deepened.

Abstract:[Background] Endophytes are widely distributed in nature, and have great potential for further exploration and application. [Objective] To isolate and identify endophytic bacteria of Curcuma wenyujin and evaluate their antimicrobial activity. [Methods] Endophytic bacteria from rhizomeof C. wenyujin were separated using routine tissue-separation method and identified by 16S rRNA gene sequences analysis. Their antimicrobial activity against Colletotrichum gloeosporioides was tested by confront-culture method. Strain B-11. C. gloeosporioides was identified through morphological, physiological, biochemical characteristics and 16S rRNA gene sequences analysis. Its influence on the hyphae of 6 pathogenic fungi, belonging to different families, was detected. Its antimicrobial components were determined by 4 specific culture mediums and MALDI-TOF-MS. The control efficacy against C. gloeosporioides on Dendrobium officinale was analyzed by inoculation of leaves in vitro. [Results] Twenty-five strains of endophytic bacteria, belonging to 12 families, were isolated and Bacillus spp. were the dominant species account for 28%. Eight strains showed antagonistic effect against C. gloeosporioides. Bacillus velezensis strain B-11 inhibited the growth of 6 different pathogenic fungi, with the hyphae inflated, deformed and branches increased. It can produce diverse antifungal substances including protease, β-gluconase and siderophore and lipopeptide. Inoculation experiment in vitro found that the cell-free culture of it had a control efficacy of 64% against C. gloeosporioides on D. officinale. [Conclusion] Endophytic bacterium strain B-11 in the rhizome of Curcuma wenyujin is an efficient biocontrol agent with potential for antibiotics development.

Abstract:[Background] Endophytic bacteria in crop roots are beneficial to fix nitrogen, secrete hormones and produce resistant substances to pathogenic fungi. The isolation and application of endophytic bacteria in roots has become one of the hotspots in environment-friendly prevention and control technology. Although the rice planting area in saline alkali soil is increasing, the isolation and application of endophytic bacteria from rice roots in saline-alkali soil are still limited. [Objective] To isolate endophytic bacteria from rice roots in saline-alkali soil in Daqing, to screen promoting-growth bacteria with antagonistic effect on plant fungal diseases, to investigate its bacteriostasis and promoting-growth effect, and to provide the bacteria resources for further studies on bacteriostasis and promoting mechanism. [Methods] Sterilized the root surface and then grinded the rice root, which were used to isolate the endophytic bacteria. Screened endophytic antagonistic strains and determined the ability of endogenous bacteria to secreting indole-3-acetic acid (IAA) by using confrontation culture method and modified Salkowski colorimetry method, respectively. The taxonomic status of the strains with broad-spectrum bacteriostatic effect was determined by using morphological identification, Gram staining, physiological and biochemical analysis, phylogenetic analysis of 16S rRNA structural genes and srfA/ituA/fenB functional genes. [Results] The SM13 strain was an candidate of endophytic bacterium isolated from rice roots, which showed broad-spectrum bacteriostatic effect. The bacteriostasis rates for Curvularia lunata, Sclerotinia sclerotiorum (Lib.) de Bary, Magnapporthe grisea, and Fusarium graminearum Schw were 59.38%, 78.13%, 53.12% and 37.50% respectively, and the ability to secrete IAA was 5.56±0.41 μg/mL (n=6). SM13 strain was identified as Bacillus subtilis by morphological, physiological and biochemical tests and phylogenetic analysis. The strain grew well in NA medium under pH 11.0 and salt concentration 10% condition, so it had higher salt tolerance and alkalinity tolerance. [Conclusion] The rice roots endophyte SM13 has the ability of tolerance to saline-alkaline, promoting-growth and biocontrol. It could be used as the material of microbial pesticides and biofertilizers.

Abstract:[Background] Endophytic bacteria can produce antagonistic and plant-growth promoting substances, which can not only inhibit host plants attacked by pathogens, but also promote the growth of plants. The endophytic bacteria from Seabuckthorn nodules are a kind of symbiotic microorganism. Studying endophytic bacteria with antagonistic and plant-growth promoting activity, which could be used as the basis of bacterial manure research. [Objective] To screen and identify efficient endophytic bacteria from Seabuckthorn nodules and study its activity of antagonistic and plant-growth promoting substances. [Methods] Antagonistic endophytes from Seabuckthorn nodules were screened by double agar layer piaque technique, agar diffusion assay, confrontation culture and oxford cup culture in vitro. The ability of indole acetic acid secretion were detected through the Salkowski colorimetric method, the production of siderphore were measured through the blue plate assay and phosphate solubilization were detected through Mo-Santispetrophotography method. The effects of growth promotion on cucumber seedlings were studied by using the fermentation broth of strain SR308. In addition, strain TT201 and SR308 were identified by morphological, culture, physiological and biochemical tests and 16S rRNA gene sequence analysis. [Results] Among 131 strains, 9 strains displayed the antagonistic and plant-growth promoting activity, especially strain TT201 displayed high antagonistic activity and broad antimicrobial spectrum; strain SR308 displayed high growth promoting activity. Pos tests showed that cucumber growth index treatment with SR308 fermentation broth were promoted significantly. Strain TT201 was identified as Brevibacillus laterosporus; strain SR308 was identified as Bacillus mycoides. [Conclusion] Two endophytic bacteria from Seabuckthorn nodules with antagonistic and plant-growth promoting activity are possible to be further developed as an excellent strain for microbial fertilizer and fungicide.

Abstract:[Background] Xanthomonas oryzae pv. oryzicola is a pathogen to cause rice bacterial leaf streak. Micromonospora carbonacea JXNU-1 with broad-spectrum antibacterial activities was isolated from soil previously, and its fermentation products (designated as “antibiotic JX”) show strong antibacterial activity against plant pathogenic bacteria. [Objective] The antibacterial activity of antibiotic JX against Xanthomonas oryzae pv. oryzicola and its mechanism were studied. [Methods] The size of the inhibition zone was measured with cylinder plate method, and the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was performed by serial tube double dilution. Additionally, the mechanism was elaborated through the investigations of cell morphology, electrical conductivity of bacterial suspension, macromolecule leakage, biosynthesis level of protein and nucleic acid and bacterial membrane potential. [Results] The average diameter of inhibition zones was 18.84±0.28 mm. The MIC and MBC was 1.39 μg/mL and 2.78 μg/mL, respectively. Complete sterilization was achieved within 12 hours, indicating a fast sterilization of antibiotic JX. In the presence of antibiotic JX, an obvious change was observed for the cell morphology of Xanthomonas oryzae pv. oryzicola. Moreover, the conductivity and macromolecule leakage of bacterial suspension as well as bacterial membrane potential increased with antibiotic concentration, but the protein content decreased. The down-regulated ef-p expression was detected by real-time fluorescence quantitative PCR. [Conclusion] The antibiotic JX exhibits a strong antibacterial ability against Xanthomonas oryzae pv. oryzicola by means of disturbing the integrity of bacterial membranes and inhibiting biosynthesis of proteins.

Abstract:[Background] Cucumber Fusarium wilt is a soil-borne fungal disease caused by Fusarium oxysporum f. sp. cucumerinum, which seriously restricts the development of cucumber industry. [Objective] Screening and identification antagonistic actinomycete strains with strongly inhibitory activity against Fusarium oxysporum f. sp. cucumerinum was isolated from saline-alkali soil in Hexi corridor. We identified the antagonistic actinomycete strain and optimized the fermentation conditions. [Methods] The method of dilution plate coating was applied to isolate actinomycetes; The methods of growth plate-confrontation and speed rate were applied to screen antagonistic actinomycetes; The morphological characteristics, physiological and biochemical characteristics, and 16S rRNA gene sequence of strain 16-3-10 were analyzed the taxonomic status. The conditions of fermentation and medium composition were optimized through single factor and orthogonal experiment. [Results] The result of identification revealed that strain 16-3-10 can be classified as Streptomyces sp., the optimum culture conditions of strain 16-3-10 were with a medium was as follows: millet 10.0 g/L, lactose 20.0 g/L, peptone 1.0 g/L, NaCl 5.0 g/L, CaCO3 6.0 g/L at 28 °C, liquid volume 50 mL in 250 mL flask, initial pH of 10.0 for 3 d, and inhibition rate of strain 16-3-10 to pathogen reached to 82.50% under this condition. [Conclusion] The result indicates that 16-3-10, strongly inhibitory activity against Fusarium oxysporum f. sp. cucumerinum, might act as a potential candidate for the application.

Abstract:[Background] Cotton plays a key role in Xinjiang’s agriculture, but cotton production and fiber quality are seriously affected by Verticillium dahliae, effective prevention and control approaches are the primary tasks to be solved. [Objective] To study the ability of Bacillus velezensis BHZ-29, Bacillus atrophaeus SHZ-24, Bacillus subtilis SHT-15 and Bacillus vanillea SMT-24 to produce siderophore and siderophore’s effects on antibacterial activity. [Methods] MKB-CAS double-layer plate was used to detect siderophore, Arnow method and iron perchlorate method were used to identify the type of siderophore, CAS dye liquid quantitative siderophore and agar diffusion method was used to determine the effect of siderophore on antibacterial substances under low iron conditions. [Results] An orange-purple color appeared around the bacteria on the MKB-CAS solid plate, Solutions color of the four antagonistic antibiotics in the Arnow experiment was red and perchlorate reaction solutions was yellow. The maximum values of quantitative activity units of siderophore of BHZ-29, SHZ-24, SHT-15 and SMT-24 strains were 8.27%±0.61%, 31.80%±2.06%, 16.06%±3.61%, and 15.53%±0.51%, respectively, the absorbance values of As/Ar the smallest ratios were 0.917±0.092, 0.682±0.021, 0.845±0.005 and 0.846±0.008, respectively. No inhibitory zone appeared in the 0, 10 and 20 μmol/L iron ion treatment groups of BHZ-29, SHZ-24 and SMT-24 strains, in three treatment groups of SHT-15 strains had inhibition zones, but there was no difference in the diameter of the inhibition zone. [Conclusion] The four strains of antagonistic bacteria were all siderophore-producing, the type of siderophore was catechol, and the four antagonistic strains had low siderophore-producing ability, with a maximum of 31.80%±2.06%, when the siderophore-producting capacity of As/Ar ratio was higher than 0.682, BHZ-29, SHZ-24 and SMT-24 fermentation sterile filtrates with 0, 10 and 20 μmol/L iron ions, had no effect on the antibacterial activity, SHT-15 fermentation sterile filtrates with 0, 10 and 20 μmol/L had no significant difference in the effect of antibacterial substances.

Abstract:[Background] Apple blue mold rot is an important fruit post-harvest disease that caused by Penicillium expansum, which affects the quality of the fruit and leads to the rot of the apple resulting in economic losses. [Objective] To study the inhibitory effect and explore the inhibition mechanism of Pseudomonas sp. YL11 on P. expansum. [Methods] We studied the effects of cell-free fermentation filtrate of Pseudomonas sp. YL11 with different concentration on the growth colony diameter, spore germination, mycelial dry weight of P. expansum and the lesion diameter of wounded inoculated apple fruit; We also explored impact of the conductivity, nucleic acid and protein release, AKP content, SDH activity, ATPase activity and ATP content to reveal the inhibitory mechanism. [Results] Pseudomonas sp. YL11 sterile fermentation broth effectively inhibited the growth of P. expansum. The diameter of inhibition zone was 22.33±0.27 mm and the inhibition titer was 71.67 mm/mL. It also could effectively inhibit spore germination. The inhibition rate of 100% aseptic fermentation broth to germination reached 80.2%. It had certain inhibition effect on the biomass of P. expansum. The dry weight of mycelium was 4.7 mg/mL and the inhibition rate reached 39.74% when the volume fraction was 100%. Moreover, aseptic fermentation fluid effectively inhibited extension of lesion diameter of blue mold of apple. The maximum inhibitory rate reached 47.1% at 3 d. In addition, aseptic fermentation broth treatment increased electrical conductivity, intracellular nucleic acid, protein release, extracellular AKP content and decreased SDH activity, ATPase activity and ATP content. The effect was enhanced by the fermentation broth concentration. [Conclusion] Pseudomonas sp. YL11 disturbed the normal growth of P. expansum by significantly inhibited the growth of P. expansum, destroyed the structure of cell membrane and reduced the activity of energy metabolism enzyme. It had a good better biocontrol effect to against blue mold of apple and had a potential development value.

Abstract:[Background] Listeria monocytogenes is an important opportunistic pathogen. There are some differences in host range and virulence among different strains. Internalin gene inlA play an important role in host epithelial cells invasion. [Objective] Analyze the genomic characteristics of the Listeria monocytogenes STS477 isolate and investigate the genetic diversity of gene inlA. [Methods] Mutilocus sequence typing (MLST), single nucleotide polymorphism (SNP) and inlA genetic diversity were analyzed based on the sequencing data with software. [Results] MLST analysis showed that isolates from different countries have close relationship. Based on the SNP analysis, ST9 strains isolated from Canadian food owned the fewest mutation sites (91?93) by aligning six CC9 isolates against the chromosome of the ST477. The nucleotide homology of seven inlA gene sequences was 29.8%?100%. [Conclusion] We preliminarily analyzed the evolution of ST477 isolate and investigate the mutation type of inlA gene belonging to CC9. This study provides basic data for analysis of the evolution of ST477 strains and the virulence of L. monocytogenes.

Abstract:[Background] Stropharia rugosoannulata and Hypsizigus marmoreus are rare edible and medicinal fungi with great development potential. The medium plays an important role in mycelial growth and fruit body development. Optimizing the medium of the two mushroom is particularly important. [Objective] Screen out the new medium more suitable for S. rugosoannulata and H. marmoreus cultivation. [Methods] Using new media containing trehalose for the cultivation of S. rugosoannulata and H. marmoreus. The mycelial growth status, growth rate and biomass, cellulase and laccase activities were measured and analyzed in different culture media. [Results] Trehalose-added media promoted the growth rate of mycelia and increased the biomass compared with PDA medium. The proportion of trehalose content had a great effect on cellulase and laccase activity. Trehalose-added media could significantly promote the growth of hyphae, but the protein composition did not change. [Conclusion] PTA-5 was more suitable for the cultivation of S. rugosoannulata mycelia; PDTA was more suitable for the cultivation of H. marmoreus mycelia.

Abstract:Bioelectrochemical systems (BESs) couple energy generation with biodegradation and bioconversion of a wide range of contaminants. BESs have increasingly attracted research attentions and would have a broad application prospect in the treatment of environmental pollutants. Recently, BESs are used to treat waste gases. Due to the combined electrochemical and biological processes, BESs generally show higher efficiency and promising application in the treatment of waste gases. Here, we summarize gas types, treatment efficiencies and reactor structures of BESs for waste gas treatment. Moreover, the functional microorganisms and the possible bioelectrochemical mechanisms in those systems are summarized. The main problems needing to be solved in the future are also proposed, with the aim to promote BESs in waste gas treatment.

Abstract:Biogenic coal-bed methane (CBM), a kind of unconventional gas resources, has been observed in different coal-rank basins. The composition and the diversity of microbial community involved in biogenic CBM have been investigated by metagenomics and high-throughput sequencing. It is fundamental for unravelling the mechanism of biogenic CBM. This review focuses on recent advances in microbial diversity, metabolic pathway, and the function of microbial community in biogenic CBM production. The associations between coal ranks and microbial diversity are further discussed and analyzed.

Abstract:Lectin can bind with carbohydrate specifically, non-covalently and reversibly, known as a kind of carbohydrate-binding proteins. The presence of a large number of glycoprotein molecules on the surface of food-borne pathogens makes it possible that lectin bind with food-borne pathogens with high affinity, making lectin been widely used in the rapid detection of food-borne pathogens. When applied as a recognition agent for the separation and detection of food-borne pathogens, lectin harbors the merits of improving the practicability of the new detection methods, eliminating matrix interference, improving sensitivity and shortening sample processing time. In this article, the basic information of the lectins and the mechanism of carbohydrate specificity recognition were introduced, and the application progress of lectin used in the field of rapid detection of food-borne pathogens were reviewed.

Abstract:Accumulating literatures indicate that intestinal microflora, known as the second human genome, can affect glycolipid metabolism, and then regulate the corresponding diseases. In this review, we introduce the distribution, species and influencing factors of intestinal microflora. We mainly address the relationship between intestinal microflora and glycolipid metabolic diseases, and the mechanism how intestinal microflora regulates the glycolipid metabolism. Moreover, the potential use of glycolipid metabolism for clinical diagnosis and treatment of diseases is also discussed.

Abstract:Biomass resources, such as lignocellulose fermentation by industrial yeasts to produce various compounds including alcohol, ketone, aldehyde, and so on, contribute to solving non-renewable energy crisis. Thereinto, abundance and low price lignocellulose fermentation and environmentally friendly and energy efficient high gravity fermentation have attracted a lot of attention. However, inhibition of cell growth and metabolism by toxic compounds formed during pretreatment of lignocellulose, high concentration of substrate and product, osmotic stress, and elevating temperature, is a bottleneck problem in the fermentation industry. Here, we introduce the effect of osmolarity, temperature, and toxic compounds on cell growth, and review recent advances in stress tolerance mechanisms of industrial yeasts for these harmful factors at intracellular homeostasis, molecular level and so on.

Abstract:With the booming of the genome era, the whole genome sequencing of important filamentous fungi has been basically completed and is widely used in the fields of industry, agriculture and medicine. However, the genetic transformation efficiency of filamentous fungi is extremely low. In order to ensure that positive transformants can be picked out from a large number of non-transformed colonies. Therefore appropriate selectable markers are particularly important. At present, the commonly used selectable markers in the genetic transformation of filamentous fungi can be divided into two categories: drug-resistance selectable markers and auxotrophic selectable markers. However, both of them have distinct limitations. For this reason, researchers use the latest genome editing technology to modify the selectable markers for better genetic selection. This article reviews the current genetic selection system and new screening marker theory modified by genome editing technology, which lays a foundation for a broader application prospect of filamentous fungi in various fields.

Abstract:Lumazine synthase (LS) is widely distributed in animals, plants and microbes, and is one of the important synthesizing enzymes that catalyze the biosynthesis of riboflavin. One of the most remarkable characteristics of LS is that it has different spatial structures in different species. Brucella lumazine synthase (BLS), which has a stable structure of decamer consisting of two pentamers, is a dominant antigen of Brucella. BLS is a common antigen existing in both smooth type and rough type Brucella, and it can improve the sensitivity of diagnostic assays for Brucellosis; BLS is capable of stimulating antigen-specific cellular responses, resulting in production of IFN-γ, which consequently provides protection for the host. Therefore, BLS is an ideal candidate protein for development of subunit vaccine against Brucellosis. In this paper, the structural features of BLS protein and its application are reviewed, aiming at providing reference for in-depth studies and application of BLS.

Abstract:This article mainly reviewed the research progress of bacteria using carbon, nitrogen as co-substrate degrading and decolorizing azo dyes. The results of the comprehensive literature showed that there was a great difference in the efficacy of the bacteria under different co-substrate conditions, such as with single carbon source, single nitrogen source, and composite of carbon and nitrogen sources. The main influencing factors included the type of carbon source, the type of nitrogen source, concentration, composite ratio of carbon and nitrogen source, etc. Among them, the type of carbon and nitrogen sources had the most significant impact. For degradation and decolorization of azo dyes, the performance could be promoted only by providing suitable type of carbon and nitrogen sources. At the same time, under different carbon and nitrogen co-substrate conditions, the bacterial community structure and dominant functional bacteria species differed greatly. Different carbon and nitrogen co-substrates were used as electron donors for azo dye reduction and decolorization, and with significant differences. Finally, the research direction was forecasted. It was considered that suitable carbon and nitrogen sources had great potential for improving the degradation and decolorization efficiency of bacterial flora. On the other hand, the microbiological mechanism of carbon and nitrogen as co-metabolism substrates, the enzymatic mechanisms, the interaction mechanism between functional strains and functional proteins had to be further studied.

Abstract:Microalgae are widely distributed in nature, which are easy to culture, grow fast and have high application value. They are widely used in biofuels, medical raw materials, high-quality food sources and animal husbandry. In recent years, the production of microalgae has been improved by the modification of photo-bioreactor, the screening of high yield algae and the transformation of metabolic pathway genes, and the research and innovation in the downstream process of microalgae treatment are not enough, especially the harvest of microalgae biomass has become the bottleneck of its industrial development. This paper summarizes the function of flocculation on the harvest of microalgal biomass, focus on the flocculation activity of flocculating microorganisms to harvest algal biomass, and the flocculation mechanism of flocculating microorganisms on microalgae is also discussed, Hopefully, it will provide some useful information and guidelines for the harvest of microalgal biomass by flocculating microorganisms.

Abstract:Harmful algal blooms (HABs) pose a serious threaten to water environment because of the released toxic substances and dramatic underwater light reduction. How to control HABs is attractive and has attracted worldwide attentions. Among them, microorganisms show great application potential in prevention and control of HABs because of the fast growth, easy propagation and rapid metabolism. Here, we summarized the distribution and diversity of isolated algicidal bacteria and the underlying algicidal mechanisms (algicidal mode, cell morphology, photosynthesis, and oxidative damage).

Abstract:In order to cultivate backup outstanding engineers with the abilities of process optimization, technological innovation and conformation to the demand of fermentation industry, reform in teaching methods of bioengineering specialty curricula was carried out and experimental teaching contents and extracurricular professional contests were developed to improve students’ practical and innovative abilities. By these measures, good results have been gained, showing that students’ interest in the bioengineering has been enhanced and the abilities of fermentation process optimization and innovation have been improved.

Abstract:Environmental Microbiology is an important professional course for environmental specialty undergraduates. In view of the practical problems that affect teaching effect in the traditional teaching process, an innovative teaching mode is developed by introduction small private online course (SPOC) and Problem orientation into Environmental Microbiology using the intelligent tools of Rain Classroom. This blended teaching mode mainly consists of three parts: production of online teaching content, teaching implementation and effectiveness assessment, evaluation and feedback. This blended teaching mode takes into account the psychology of the students. Problem-oriented teaching can fully stimulate students’ interest in learning, giving students more personalized experience and enhancing the interaction between teachers and students. Thus, the preliminary exploration showed that the innovative teaching mode of SPOC and Problem orientation can effectively improve the teaching quality and effectiveness by improving teaching process. The blended teaching mode helps to cultivate innovative talents in the field of environmental protection with professional knowledge and skills of environmental microbiology. It can also provide a reference for improving the teaching quality and effectiveness of other courses.

Abstract:[Background] Mycotoxins produced by different species of fungi may coexist in single cereal or feed samples, which could become highly toxic for humans and animals. In this context, a dual flow immunochromatographic assay for rapid monitoring mixed mycotoxin contamination has become a necessity. [Objective] Development of the colloidal gold dual immunoassay for simultaneous detection of ochratoxin A and zearalenone in cereal and feed samples. [Methods] Mycotoxins monoclonal antibodies were labeled with colloidal gold nanoparticles. After optimizing the materials, reagents as well as the experimental conditions, a dual flow immunochromatographic assay was developed and tested for determining the ochratoxin A and zearalenone in cereal and feed samples. [Results] The detection limit for ochratoxin A and zearalenone was 0.625 ng/mL and 1.25 ng/mL, respectively. Naturally contaminated cereal and feed samples were analyzed using both immunochromatographic assay and LC-MS/MS, and showed a good agreement between these two methods. [Conclusion] This immunoassay could detect ochratoxin A and zearalenone in cereal and feed samples rapidly and accurately, more easily and at a lower cost.

Abstract:[Background] Pseudomonas aeruginosa is an important water- and food-borne pathogenic bacterium causing acute enteritis, meningitis, sepsis and skin inflammation. It is important to detect rapidly P. aeruginosa for food safety. [Objective] A rapid and simple method for detection of P. aeruginosa using polymerase spiral reaction (PSR) technique was established. [Methods] The primers were designed according to the P. aeruginosa exotoxin A gene—ETA gene (toxA), the visual PSR method for rapid detection of P. aeruginosa comprised primer screening, accelerated primer introduction, reaction conditions optimization and color indicator screening. The specificity, sensitivity and reliability of the method were evaluated. [Results] The PSR assay to detect toxA of P. aeruginosa could fulfill within 40?min at 65 °C, and visualize the results by Calcein and HNB. This method specifically detected P. aeruginosa without showing cross-reaction with closely related Pseudomonas species or other bacteria. The sensitivity of the method was high, with detection limit 20 CFU/mL bacteria and 1.011 5 pg/μL genomic DNA. The detection of isolated strain of packaged drinking water showed that the PSR method was consistent with the results of traditional biochemical methods for the P. aeruginosa detection. [Conclusion] The established visual PSR method provides a potential method to be used for rapid detection in the field.