Abstract:[Objective] To develop a novel and efficient amino acid fertilizer, a liquid fermentation of waste feathers was established and optimized aiming at enhancing the degradation of waste feather and yield of amino acid. [Methods] Bacillus amyloliquefaciens 3-2 was used to ferment feathers. The influences of fermentation temperature, time, feathers content, sole carbon source, carbon-nitrogen complex and metal ions on the degradation of feather as well as the kinds and yield of amino acids were studied. [results] No positive correlation between degradation of waste feathers and yield of amino acid was observed. Increase of fermentation time contributed to the degradation of feathers. The optimal fermentation conditions of degradation of feathers were 37 °C, 1% feather, lactose as external carbon source and Mg2+ and the highest degradation of feathers was 81.92%. The increase of feathers content favored the yield of amino acids (less than 20%). The optimal conditions of kinds and yield of amino acids were 37 °C, 108 h, 10% feathers, 0.5% lactose and no carbon-nitrogen complex and metal ions with the kinds of 17 and highest yield of 20.861 g/kg amino acids. [Conclusion] The production of nutrient-rich amino acids fertilizer from waste feathers by fermentation of Bacillus amyloliquefaciens 3-2 is a reliable, eco-friendly and economical technology. The results will be a technological support to develop novel amino acids fertilizer.

Abstract:[Objective] This study was to explore the structure and dynamic of yeast community, and to analyze the potential key yeast species associated with urea metabolism and its regulation by environmental factors. It could provide potential clues for reducing ethyl carbamate in Chinese light-aroma liquor fermentation process. [Methods] The main precursor and microbial groups were identified by correlation analysis, and yeast community was revealed by high-throughput sequencing. Besides, the potential key species related with the urea metabolism were predicted by partial least squares regression. In addition, the effect of environmental factors on yeast community was analyzed by redundancy analysis. [Results] Urea was identified as the main precursor, and was associated with yeast population in Chinese light-aroma liquor fermentation. A total of 22 yeast species was identified by high-throughput sequencing at 97% sequence similarity. Hanseniaspora osmophila, Pichia fermentans and Saccharomyces cerevisiae were positively associated with urea formation, while Pichia kudriavzevii was positively associated with urea degradation. In addition, moisture, pH, ethanol and arginine were important environmental factors which associated with yeast community during liquor fermentation process. [Conclusion] Environmental factors could influence the potential key yeast species, which could provide strategies to decrease urea and ethyl carbamate in Chinese light-aroma liquor fermentation.

Abstract:[Objective] We researched the effects of inactivation of acetate synthetic pathway and expression of NADH oxidase on acetoin production in Corynebacterium glutamicum. [Methods] Heterologous expression of alsSD operon in C. glutamicum CGF2 resulted in acetoin production strain CGT1, and disruption of acetate synthetic pathway gene cat and pqo was investigated. Subsequently, NADH oxidase from Lactobacillus brevis was developed for acetoin production under optimal oxygen condition. [Results] CGT1 accumulated 6.27 g/L acetoin in flask cultivation. Deletion of cat increased acetion production by 30.94% compared with CGT1, which was 8.21 g/L. Deletion of cat and pqo had no improvement on production. Moreover, the production of acetoin enhanced 10.06 g/L by optimizing the concentration of dissolved oxygen. Under high dissolved oxygen, expression of NADH oxidase contributed to an increase in biomass and glucose consumption rate, but the titer of acetoin decreased slightly. In intermittent fed-batch fermentation, recombination strain produced 40.51 g/L acetoin with a productivity of 0.51 g/(L?h). [Conclusion] The inactivation of acetate synthetic pathway gene cat could efficiently increase the production of acetoin in C. glutamicum. However, expression of NADH oxidase had disadvantage of acetion, and its expression level required more regulation to confirm the effect.

Abstract:[Objective] To study the effects and possible mechanism of exogenous addition of different amino acids and compatible solutes on the growth of Corynebacterium glutamicum under high sugar stress. [Methods] Various amino acids and compatible solutes were individually added into the indicated medium supplemented with high glucose or sucrose, and their potential effects on the growth of C. glutamicum were examined. The influences of exogenous arginine on the transcription levels of some key enzymes involved in sugar transport and metabolic pathways, as well as the fermentative production of amino acids under high glucose stress, were also explored. Moreover, the potential roles of basic amino acids in protecting against high glucose challenge were also analyzed in other Corynebacterium species. [Results] Under high glucose stress, the biomass of C. glutamicum increased by 54.7%, 50.0% and 37.6% by addition of exogenous lysine, arginine and histidine, respectively, while the addition of exogenous proline or ectoine increased the biomass of C. glutamicum more than 20% under high sucrose stress. Further studies revealed that exogenous arginine resulted in a nearly 2.5-fold higher glucose utilization rate, and the amount of L-glutamic acid by fermentation increased by 127.5% in the presence of arginine under high glucose stress. Additionally, the osmoprotective effects of basic amino acids in response to high glucose stress were also observed in other four Corynebacterium species. [Conclusion] Arginine plays an osmoprotective role for C. glutamicum under high glucose stress, which may be attributed to its ability to promote glucose transport and metabolism. Meanwhile, the osmoprotective effects of basic amino acids in response to high glucose were shown to be applicable to other Corynebacterium species.

Abstract:[Objective] to study the relationship between the tolerance of pH and ε-PL, oxidative stress and ε-poly-L-lysine (ε-PL) synthesis in ε-PL producing strain. [Methods] The fermentation activities, pH and ε-PL tolerance, and antioxidative abilities among Streptomyces sp. AF3-44, Streptomyces sp. AS32 and Streptomyces albulus F15 were compared, and the cause for reactive oxygen species generation was analyzed. [Results] AF3-44 had the best pH and ε-PL tolerance and antioxidative ability among three tested strains, and kept good cell activity with the highest ε-PL concentration. ε-PL caused the oxidative stress at the earlier but pH at the later stage of fermentation. [Conclusion] improvement of the antioxidative ability in ε-PL fermentation by Streptomyces could increase the cell activity and ε-PL level in fermentation.

Abstract:[Objective] To clarify the ability of Phyllobacterium myrsinacearum RC6b and its mutant strains to degrade diphenylarsinic acid (DPAA). [Methods] The conditions for the co-metabolic degradation of DPAA were optimized with P. myrsinacearum RC6b as the original strain and with sucrose, glucose and sodium acetate as different external carbon sources. Strain RC6b was chemically mutated using treatment with N-methyl-N′-nitro-N-nitrosoguanidine (NTG). The DPAA degradation rate was compared before and after chemical mutagenesis, and the metabolite of DPAA by RC6b mutants was also analyzed. [Results] The DPAA degradation rate was <2% after 28 days of incubation when using DPAA as the sole carbon source. After addition of sucrose, glucose and sodium acetate as external carbon sources the DPAA degradation rate increased significantly, by 14.08%, 15.21% and 15.05%, respectively. Three mutant strains of strain RC6b were obtained using 250 μg/mL NTG as chemical mutagen. All three RC6b mutants showed significantly higher DPAA degradation rates than did the original strain. Mutant strain N-RC6b2 showed the highest DPAA degradation rate of 36.71% after 28 days of incubation when using DPAA as the sole carbon source. The main degradation metabolite of DPAA by strain N-RC6b2 was identified as monohydroxylated DPAA. [Conclusion] The original RC6b strain grew only sparingly using DPAA as the sole carbon source. Addition of co-metabolic carbon sources such as sucrose, glucose and sodium acetate significantly enhanced the biodegradation of DPAA. The chemical mutagen NTG further enhanced the biodegradation of DPAA, with monohydroxylated DPAA as the main intermediate product.

Abstract:[Objective] To obtain efficient decoloration bacterial consortium, which were able to degrade azo dyes in high salt environment and to biodegrade the dyeing wastewater. [Methods] A moderately halophilic bacterial consortium degrading of acid scarlet GR was enriched from activated sludge of dyeing wastewater. The community structure of the bacterial consortium was studied by high-throughput sequencing method, and the decoloring performance was studied under static condition. [Results] The moderately bacterial consortium was mainly composed by Halomonas, Salinicoccus, Nitratireductor and Aequorivita, Halomonas was the main decoloring bacteria. The degradation was inhibited by high concentration of NaCl, Na2SO4 and NaNO3, of which the strongest inhibition is NaNO3. The optimal decolorization conditions were as follows: pH 7.0, 30 °C, 5% NaCl. The moderately halophilic bacterial consortium could also degrade direct black 19 and disperse deep blue S-3BG. After continuous bleaching for 5 rounds, the degradation rate still reached over 98%. [Conclusion] The moderately halophilic bacteria consortium has strong potential to treat azo dye contaminated wastewater.

Abstract:[Objective] To explore secondary metabolites and new bioactive substances, the diversity, functional enzyme activity and antimicrobial activity of halophilic bacteria from Aiding Lake were studied. [Methods] A total of 20 sugars and sugar derivatives were selected as the sole carbon source of medium, and 298 halophilic bacteria were isolated from 5 samples of Aiding Lake. Based on the morphological characteristics, 62 representative strains were selected for 16S rRNA gene sequencing and phylogenetic analysis. Twenty-two halophilic bacteria were chosen from different species to screen functional enzyme activity and antimicrobial activity. Activity for 3 functional enzyme were tested by noculating single colony method. Antimicrobial activity for 12 pathogenic bacteria and fungus were tested by plate confront method. [Results] There were 221, 54, 23 halophilic bacteria isolated from 5%, 10%, 15% salt concentration respectively. They were distributed in 9 families, 18 genera. Actinobacteria were distributed in 4 genera, and bacteria were distributed in 14 genera. Nocardiopsis and Pontibacillus were dominant groups of culturable halophilic bacteria from Aiding Lake, comprising 17.7% and 16.1% respectively. The 16S rRNA gene sequence similarity of 15 halophilic bacteria were lower than 98.5%, which may present potential novel species. Among the 22 representative strains, 68.2%, 22.7%, 72.7% of them showed positive result for protease activity, amylase activity and asterase activity respectively. And 45.5% of the tested strains showed at least one kind of microbial activity against 12 pathogenic bacteria and fungus. Especially, one Nocardiopsis strain exhibited extensive antagonism against 9 pathogenic bacteria and fungus. [Conclusion] The halophilic bacteria of Aiding Lake in Xinjiang has abundant diversity and good biological activity, which provides the basis for further study on secondary metabolites.

Abstract:[Objective] This study was aimed to investigate the optimal Nile Red fluorescence staining method to quickly determine the quantification of total lipid in Nannochloropsis. [Methods] We systematically adjusted the excitation wavelength, emission wavelength and optimized the dimethyl sulfoxide (DMSO) concentration, Nile Red concentration, staining time and cell density range. Meanwhile, we evaluated the relationship between the florescence intensity of Nile Red staining and the lipid contents of gravimetric method and Triolein standard method, respectively. [Results] The relationship between the Nile Red fluorescence intensity and the lipid content of green algae Nannochloropsis was obtained. The results showed that the optimal dyeing conditions are as follows: DSMO concentration was 5%, the final concentration of Nile Red was 1 mg/L, staining time was 6 min and the cell number ranged from 0.5×106 to 3.0×106 cells/mL, under the excitation and emission wavelengths was 515 nm and 570 nm. The correlation between the lipid content from gravimetric method and Triolein standard indicated that the Nile Red fluorescence staining method can be used to rapidly and exactly detect the lipid content in Nannochloropsis. The lipid content was positively correlated with the fluorescence intensity, and the correlation coefficient R2 was 0.997 3. The detection limit of lipid content reached 2 μg after the optimization of Nile Red staining, which greatly reducing the amount of cells required for the determination of lipid content. [Conclusion] These results indicated that the Nile Red fluorescence staining method can be used to determine the lipid content rapidly and exactly in the Nannochloropsis with a microdose cell, and be applied in screening Nannochloropsis mutants with higher lipids content in large scale, conveniently.

Abstract:[Objective] In order to understand the relationships between arbuscular mycorrhizal fungi (AMF) and soil nutrients and soil enzyme activities in Angelica sinensis field, the AMF spore densities, soil nutrient and soil enzyme activities of rhizosphere soil were investigated at its different growing stages. The results will provide a theoretical basis for the application of AMF in A. sinensis production. [Methods] Rhizosphere soil samples were taken at different growing stages of A. sinensis. The rhizosphere soil nutrients, soil enzyme activities, AMF spore densities, and glomalin were measured and the correlative analysis and principal component analysis (PCA) were also conducted based on the measurements for further understanding the dynamic metabolism. [Results] With the completion of the A. sinensis growth period, the AMF spore density of its rhizosphere soil decreased at early growth stages and then increased continuously in the following growth stages. And the easy extractable glomalin (EEG) and total glomalin (TG) had significant positive correlation with soil organic matter, total nitrogen, acid and neutral phosphatase activities (P<0.01), and the contents of EEG and TG in rhizosphere soil were significantly increased with A. sinensis growth (P<0.05). Soil organic matter and total nitrogen also show an increasing trend with A. sinensis growth. The available phosphorus content remained constant during the early growth stages, decreased significantly at the middle stage and gradually increased at the later stage, while the available potassium content increased significantly at the first and middle growth stages and decreased at late growth stages. Acidity and neutral phosphatase activities of rhizosphere soil increased gradually, while urease activity increased at the early growth stage, and decreased significantly in the middle and later stages. pH value fluctuated during different growth stages of A. sinensis. The correlation analysis shows that AMF spore density is significantly positively correlated with acid phosphatase activity, while the acid phosphatase activity significantly positively correlated with total nitrogen, organic matter, EEG and TG in rhizosphere soil, but significantly negative correlation between available phosphorus and available potassium, indicating that AMF could affect rhizosphere soil nutrients and enzyme activities. The correlative analysis refracts the relationships among the indexes. In particular, the PCA shows that the A. sinensis growth stage is the main factor for affecting the physical and chemical indexes of rhizosphere soil. [Conclusion] The AMF spore densities at the rhizosphere of A. sinensis mainly reflect the ability of AMF to secrete glomalin and its contribution to the storage of carbon and nitrogen in rhizosphere soil, and the glomalin also affects the soil enzyme activities and nutrients metabolic cycle, and plays an important role in improving the soil quality and promoting the growth of A. sinensis.

Abstract:[Objective] Biosurfactant-producing strains were screened from an oil-shale environment for the biodegradation of kerogen in oil shale. [Methods] Wastewater samples of the Fushun oil-shale mine were collected and used for the primary screening of biosurfactant-producing strains using the blood-agar plate method. Oil spreading, emulsification activity, and surface tension methods were further used to re-screen the biosurfactant-producing strains. The target strain was identified by 16S rRNA gene sequencing and phylogenetic analysis, as well as by determining its physiological and biochemical characteristics. Surface-active components in the zymotic fluid of the target strain were analyzed by thin-layer chromatography. The culture conditions were optimized for biosurfactant production by the target strain, and its biodegradation of oil-shale kerogen was examined preliminarily. [Results] A glycolipid biosurfactant-producing strain, B-1, was screened and identified preliminarily as a Pseudomonas sp., and it showed the advantages of good oil displacement and emulsifying ability, and low surface tension. Strain B-1 used alkanes, unsaturated fatty acids, and carbohydrates as carbon sources. In a glucose-containing culture medium (pH 7.0) with 0.3% NaCl, strain B-1 grew well at 30?34 °C, and the surface tension of the zymotic fluid exhibited its lowest value (27 mN/m). After 30 d, the kerogen degradation rate of strain B-1 in the glucose-containing medium was 2.85%, compared with 1.04% in a control medium without glucose. [Conclusion] Strain B-1 is a good glycolipid biosurfactant-producing bacterium with the potential to degrade kerogen.

Abstract:[Objective] We studied resources, diversity and taxonomic information of the genus Hirsutella. [Methods] We identified two fungal samples GZUIFR-dj14 and GZUIFR-dy1 from Guizhou Province, which parasitized adult of Cercopidae (Homoptera) and Dioryctria splendidella (Lepidoptera) through morphological characteristics and phylogenic analyses based on tef1, ITS and 28S rDNA sequences. [Results] The two fungi were identified as Hirsutella changbeisanensis and Hirsutella leizhouensis. [Conclusion] Two new fungal isolates were studied with their information of hosts, habitats, molecular sequences and phylogenetics.

Abstract:[Objective] To analyze the intestinal microbiota of healthy Li cohort in Baisha of Hainan Province, study the profiles of intestinal microbiota of Li cohort and its correlation with their diet. [Methods] Morning faeces of 22 volunteers in Baisha of Hainan Province were selected as the study object, high-throughput sequencing technology based on 16S rRNA gene V3–V4 variable region was used to research the intestinal microbiota of Li cohort. Then, compared and analyzed the intestinal microbiota between Li cohort and other ethnic groups. At the same time, the nutrient intake of 22?volunteers of Li cohort was recorded in detail to study the profiles in intestinal microbiota of Li cohort and its correlation with their diet. [Results] Bacteroidetes (58.96%) and Firmicutes (37.77%) were the most abundant phylum in the gut of Li cohort. Meanwhile, at the genus level, Prevotella (49.38%) was the predominant genus. We compared the differences in gut microbiota between the Li cohort and other ethnic groups in China. Based on the analysis of α and β diversity in microbiota communities, the gut microbiota of Li cohort was significantly differences with other ethnic groups in China, and the α diversity in Li cohort was significantly lower than other ethnic groups. And the structure difference could be attributed to the genera of Catenibacterium, Prevotella, Megasphaera, Megamonas, Phascolarctobacterium and Blautia. The correlation between core microbiota and nutrients showed that Faecalibacterium prausnitzii was significantly positively related to the intake of dietary fiber, Cu, Mg and Mn, and negatively related to the intake of fat and VB2, while the Lactobacillus rogosae was significantly positively related to the intake of dietary fiber, Zn and Fe, and negatively related to the intake of niacin. [Conclusion] Present research reflected the differences in the gut microbiota among different regions and ethnic groups, and provided a theoretical basis for further understanding the balance in host’s intestinal microecology.

Abstract:[Objective] An indigo-producing gene was cloned and expressed, and its application in indigo production was investigated. [Methods] An indigo-producing gene from Burkholderia sp. IDO3 was cloned and heterogeneously expressed in Escherichia coli BL21(DE3). Recombinant strain was able to produce blue pigments. HPLC and LC/MS were applied to analyze the reaction product. The conditions for indigo production, such as rotary speed, temperature, and growth medium components were optimized, and indigo-producing curve was also determined under the optimal conditions. [Results] Recombinant strain IND_AB was successfully constructed and could produce blue pigment in LB medium. Product analysis revealed the blue pigment was indigo. Strain IND_AB could generate 22.9 mg/L indigo when incubated at 30 °C and 150 r/min. The indigo yield was improved to 25.4 mg/L and 35.1 mg/L after optimization of environmental parameters and medium components. The indigo yield was subsequently enhanced to 57.7 mg/L and 64.4 mg/L with the addition of 50 mg/L indole and 0.1 g/L tryptophan, which rose by 152.0% and 181.2% compared with initial yield. Time-course analysis indicated that there was no indigo production in the previous 6 h, and indigo was exponentially produced between 6?15 h and reached the maximum at 18 h. [Conclusion] Recombinant strain IND_AB could produce relatively pure indigo, and present study provided efficient genetic resource for indigo microbial production.

Abstract:[Objective] The structure and diversity of soil microbial community and their changes reflect the quality of soil. To study the effects of a fertilizer synergist, we analyzed fungal communities from potato rhizosphere soil. [Methods] We used high throughput sequencing technology to sequence the fungi metagenomic DNA of the fungal internal transcribed spacer 1 (ITS 1) in the roots of potatoes. With the aid of RDP classifier, all rhizosphere soil fungi were identified from the reads of OTUs. [Results] Sequencing data suggested that after the quality control, 437 375 reads were remained. Cluster similarity analysis was performed with threshold of 97% sequence similarity, yielding 633 OTUs from the 12 samples. Phylogenetic analysis showed that Ascomycota were predominant in all samples (relative abundance from 56.95% to 97.23%). Ascomycota in all samples but Haiyuan with Novel Fertilizer Synergist increased. However, Basidiomycota decreased. Alpha diversity analysis showed that the fungal community diversity of the rhizosphere soil in the same site was different after fertilizer synergist application. however, in beta diversity analysis, no significant differences were observed with respect to fungal community composition, which could be attributed to the discrepancy in soil properties from different sampling sites. [Conclusion] Soil characteristics are one of the important factors in explaining the variation of microbial diversity. Fungal communities could be greatly changed by using Novel Fertilizer Synergist.

Abstract:[Objective] To understand the effect of the Morchella white mold on soil fungal community structure. [Methods] Illumina MiSeq high throughput sequencing technology was used to analyze the fungal community structure of control soil, rhizosphere soil of diseased and healthy Morchella. [Results] The results showed that a total of 393 347 valid sequences were obtained from 9 samples collected. The fungal abundance and diversity of control soil were the highest among all the samples, followed by that of diseased Morchella, which were significantly higher than that of healthy Morchella. The community composition and dominant taxa of different samples varied significantly. [Conclusion] The diversity of soil fungi decreased in the field of cultivated Morchella. While, the occurrence of white mold disease lead the abundance of rhizosphere fungi increased, the community structure changed, and the dominant fungi groups varied.

Abstract:[Objective] To isolate and identify lipopeptides in metabolites of Bacillus subtilis subsp. natto Bna05 and to assess antifungal activity of the identified lipopeptides. [Methods] Primers specific for lipopeptide synthetases were used to amplify DNA fragments from strain Bna05 by PCR. The amplified DNA fragments were sequenced and analyzed using BLAST against GenBank database. The antifungal metabolites were obtained from the inhibition zone formed between Bna05 and Aspergillus niger on modified PDA plate and separated by RP-HPLC. Antifungal activity of fractions separated by RP-HPLC was determined by micro-dilution method and the active molecules were identified by mass spectrum analysis. [Results] Genes for srfAA and sfp were identified in strain Bna05. However, genes encoding for ituC, ituD, fenD, fenACE, bymB and bymC were not detected. Three active fractions F2, F3 and F4 were isolated by RP-HPLC. Lipopeptide was not detected in F2. Two kinds of surfactin variants were identified from F3 and F4: V7-surfactin variants in F3 and I/L7-surfactin variants in F4. Synergistic effect against Aspergillus niger was observed when F2 was used together with either V7-surfactins or I/L7-surfactins. The best antifungal activity was obtained when all three fractions were used together. [Conclusion] V7-surfactins and I/L7-surfactins were the main lipopeptides secreted by B. subtilis natto Bna05. Synergistic antifungal effect was found against Aspergillus niger when surfactins were used together with other active compounds such as F2. The greatest synergistic effect was obtained when both V7-surfactins and I/L7-surfactins were used together with F2.

Abstract:[Objective] To understand the complete genome sequence information of Mycoplasma mycoides subsp. capri str. PG3 (Mmc str. PG3) and offer help for screening of main antigenic genes. [Methods] The high flux Illumina HiSeq 2000 technology was used for genome sequencing and annotation of Mmc str. PG3. [Results] The genome of Mmc str. PG3 consisted of a circular chromosome of 1 025 065 bp with an overall molar G+C% content of only 23.6%. The chromosome of Mmc str. PG3 contained 846 predicted coding sequences. The majority of genes were associated with protein translation, ribosome synthesis and structure, DNA replication and repair, glycometabolism and environment transfer and conversion processes. The Mmc-specific maltodextrin/maltose gene cluster was also identified in the genome of Mmc str. PG3. Comparative genomic analysis showed that Mmc str. PG3 should have significant genomic synteny with Mmc str. 95010. Three genes (GL000459, GL000461, GL000462) were identified as variable lipoprotein genes in the genome of Mmc str. PG3 by genomic information analysis. [Conclusion] Complete genome sequence of Mmc str. PG3 provided in this study might facilitate genome-wide structural annotation to assess genes associated with pathogen virulence. The results of this study would provide a theoretical basis for further research on the role of variable surface lipoprotein of the pathogenesis of mycoplasmose and development of biological engineering vaccine.

Abstract:[Objective] As a metabolic syndromes disease, obesity has become an epidemic hazard and a major problem for health care systems worldwide. It is well documented that n-3 polyunsaturated fatty acids (n-3 PUFAs), especially docosahexaenoic acid (DHA), could effectively prevent and treat obesity and related diseases. Aim to study the effect of DHA from Schizochytrium sp. on high-fat-induced obesity in male C57BL/6J mice, including the weight of body and adipose tissue of the mice and the content of blood lipid, pharmacological changes in liver and fat tissue, and the expression level of lipid metabolism related gene. [Methods] Mice were fed with high fat diet for nine weeks, and mice whose weight gain was 15% higher than the control were selected for the follow-up experiment. Mice were divided into five groups: (1) low fat diet as the control; (2) high fat diet as the model control; (3) high fat diet + microalgal oil with 50 mg DHA/kg body weight; (4) high fat diet + microalgal oil with 100 mg DHA/kg body weight; (5) high fat diet + microalgal oil with 200 mg DHA/kg body weight. Mice in groups of (1) and (2) were gavaged with isovolumetric corn oil, and mice in groups of (3), (4) and (5) were gavaged with microalgal oil with different dosage adjusted by corn oil. After nine weeks treatment, the mice were anesthetized, and blood samples were obtained from venosus plexus of fundus oculi. The total triglyceride, total cholesterol and high-density lipoprotein cholesterol in the serum were measured. Body, adipose tissue and liver of the mice were weighted, and the morphological changes of fat and liver were observed and the lipid metabolism related gene was examined. [Results] Microalgal oil DHA from Schizochytrium sp. significantly decreased the abnormal fat accumulation and blood lipid levels of the obesity mice, improved liver and fat tissue morphology, and promoted the expression of hormone sensitive lipase gene in white tissue fat. [Conclusion] Microalgal oil DHA from Schizochytrium sp. might have prospective applications in obesity therapy.

Abstract:[Objective] Box Behnken design response surface methodology was used to optimize the colony count of IgY against Porphyromonas gingivalis in oral simulation environment in order to find the appropriate dose of IgY, initial density of P. gingivalis and culture time. [Methods] Final colony count was used as the evaluation index, on the basis of single factor tests. Box Behnken RSM was used with three factors such as number of colonies at different dose of IgY, initial density of P. gingivalis and culture time in the artificial saliva. The experiment was repeated three times under the optimal conditions to verify the accuracy of the model. [Results] The results of single factor test showed that IgY had the best effect on the reproduction of P. gingivalis by the dose of 180 mmol/L IgY, the initial amount of 2×106 CFU/mL P. gingivalis and the incubation at 37 °C for 4 h. The optimum culture conditions were as follows: dose of IgY was 165 mmol/L, the initial amount of P. gingivalis was 2×106 CFU/mL, culture time was 4.5 h. Under these conditions the final number of colonies was 5.92×105 CFU/mL. Compared with the predicted value of 5.85×105 CFU/mL, the relative error with the theoretical value was 1%. Analysis of Variance showed the P value of the model was significant, and the missing P value was not significant. The theoretical value was in good agreement with the measured value. [Conclusion] The number of colonies of P. gingivalis in the simulated oral environment was significantly decreased, which indicated that the regression model could be a good predictor of the response of P. gingivalis in the oral cavity.

Abstract:[Objective] To study the optimal fermentation conditions of antagonistic strain B16 isolated from ginseng root for improving the quantity and antibacterial activity of the bacteria, and test its control effect on ginseng disease. [Methods] The single factor test and orthogonal test were used in optimizing the fermentation media and the conditions, and the strain’s antagonistic effects to ginseng pathogenic fungus Cylindrocarpon destructans were tested with pot trails. [Results] Optimum fermentation media for B16 was: sucrose 1.00%, yeast extract 0.50%, MgSO4·7H2O 0.05%, FeSO4·7H2O 0.06% and NaCl 1.00%; and the optimum conditions are: pH 7.5, 35 °C, 5% 108?CFU/mL bacterium suspension, 40 mL/250 mL, 170 r/min and 48 h fermentation. The B16 fermentation broth shows antagonistic effect to ginseng pathogenic fungus C. destructans, the protection effect and curation effect are 64.8% and 58.6%, respectively. [Conclusion] Strain B16 has potential for C. destructans biocotrol.

Abstract:[Objective] To build a simple method for rapidly obtaining the full-length genome sequence of adenovirus type 55 (HAdV-55). [Methods] 12 pairs of primers were designed which covered the whole genome sequence of HAdV-55. HAdV-55 DNA was used as the template for PCR and twelve PCR products were obtained, which were sequenced respectively. Resulting sequences were assembled together and then the whole gene sequence was obtained. [Results] A strain of HAdV-55 (SF04/SC/2016) was isolated from throat swab specimens of a patient with acute upper respiratory tract infection. Twelve PCR products and their sequences were obtained. The sequences were assembled which yield the full-length genomic sequence. Sequence analysis was performed between this HAdV-55 strain and previous reported HAdV-55 virus in China. Phylogenetic tree was constructed by neighbor-joining method and this virus is in the same branch with previous reported HAdV-55 strains, which confirmed that this pathogen is HAdV-55. [Conclusion] The primer sequences and methods published in this study could facilitate the rapid sequencing of adenovirus, which will be contribute to reveal the evolutionary characteristics of HAdV-55 and the prevention and control of adenovirus type 55 related disease.

Abstract:[Objective] To provide the basis for the activity of activated sludge, as an important index in activated sludge, adenosine triphosphate (ATP) is detected to study the activity of activated sludge in the research. [Methods] The research used the method of TCA and microwave to detect ATP in activated sludge. Influencing factors (such as the concentration of TCA, time of immerging in an ice bath, pH, frequency of microwave and treatment time with microwave) are also discussed. [Results] The optimal concentration of TCA in the activated sludge is 2.5% with the concentration of TCA of 1.0%?7.0%; during 2?60 min immerging time in an ice bath, the optimal time using ice bath is 10 min; the optimal pH of Tris-EDTA buffer is 7.5. The suitable conditions for the method of microwave are: 800 W and 15 s for microwave irradiation. [Conclusion] The method of TCA and microwave can detect ATP in activated sludge. However, compared with the method of microwave, the method of TCA can guarantee the integrity of ATP, thus, the method of TCA is more suitable for detecting ATP in activated sludge.

Abstract:Dimorphism refers to the peculiar capacity of several fungi to shift morphologically between yeast and mycelial forms in response to environmental factors. Various signaling pathways connect external stimuli and cell morphological changes. Although the dimorphism transition is usually related to pathogenicity, it also greatly affects cell behavior during fermentation. Investigating the morphogenetic shifts of those fungi not only builds the foundation for elucidating pathogenic mechanisms, but may also help identify novel regulation strategies for biotechnological applications. The present work focuses on the latest researches aimed at understanding the environmental factors and their underpinning molecular mechanisms, discusses potential biotechnological applications, and provides a comprehensive basis for further research.

Abstract:Bacillus strains are safe for human and animal, of no environmental pollution, not easy to be resisted by plant pathogen, of strong stress resistance and helpful of promoting plant growth. Due to these advantages, Bacillus strains are important bacteria in bio-control of rice blast. The main bio-control mechanisms of Bacillus include competitive effect, antagonism and the induced disease-resistance. Bacillus strains can colonize in rice plant, produce antifungal active substance to inhibit growth of Magnaporthe oryzae, induce rice disease-resistance, promote rice plant growth and save the rice yield loss. Bacillus strains could be used as bio-control agents against rice blast in Southern and Northern regions of China. It has a guiding significance for the protection of rice blast in rice sustainable development. This article summarized the application progresses of Bacillus strains in bio-control of rice blast, the mechanism of Bacillus strains in bio-control of rice blast, influence factors of bio-control efficiency about Bacillus strains in bio-control of rice blast.

Abstract:The first bacterial cytoskeletal protein FtsZ, a bacterial tubulin homologue, was found in 1992. After these 25 years of research, more bacterial cytoskeletal proteins were identified. The prokaryotic tubulin homologues include FtsZ, CetZ, TubZ and BtubA/B. X-ray crystal structures have confirmed that they have similar structures. In the presence of GTP, they assemble into different polymers, such as single filaments, double helix filaments or bundles. These filaments conduct many different important functions including cell division, controlling cell shape and plasmid partition.

Abstract:Environmental microbiology is a compulsory course for environmental engineering major, this course is very important for cultivating student’s applied technology ability and improving the comprehensive quality. The traditional teaching mode has limited the applied technology talents cultivation. The teaching reform ideas and measures of environmental microbiology have been detailed mainly from the theory teaching, experiment teaching, teaching form and teaching construction. This exploration aims at improving student’s applicability understanding for this course and providing the exploration and practice for enhancing the applied technology talents cultivation.

Abstract:Environmental Engineering Microbiology is one of the core subjects in the environmental engineering major. It is also one of the pre-subjects for its professional subjects. In order to improve the teaching effect, the comprehensive experiments, the productive practice experiments, and the research experiments were added based on the verification experiments. Combined with the course practice and graduation project, the practice teaching system had been gradually reformed and improved. As a result of this, a teaching mode of “Integrated Practical Teaching System (IPTS)” was constructed. It had been proved that this model could stimulate students’ interest in learning, practical ability, innovation consciousness, and ability to analyze and solve problems.

Abstract:[Objective] To determine the resistance of urea hydrolytic bacteria to Hg2+ using single injection isothermal titration calorimetry (SIITC). [Methods] The tolerance of urea hydrolytic bacterium Staphylococcus succinus to Hg2+ toxicity was assessed by SIITC in comparison with the traditional cell growth curves and pH change curves. The correlation between SIITC and the traditional methods was examined. [Results] The maximum heat flux rate and the accumulated heat of adsorption and hydrolysis of urea by S. succinus decreased with increasing Hg2+ concentration up to 10 μmol/L. The maximum heat flux rate decreased from ?45 μJ/s for the control to ?20 μJ/s for 10 μmol/L Hg2+ treated cells and the accumulated heat decreased from ?1 291.90 μJ for the control to ?535.75 μJ for 10 μmol/L Hg2+ treated cells. The decreases of heat flux rate and accumulated heat well correlated with the change of solution pH (r=0.928) and cell growth rate OD600 (r=0.955). [Conclusion] SIITC is a potential method to detect tolerance of bacteria to Hg2+.