Search

Four polysaccharide fractions were isolated and purified from the culture supernatant and mycelium of Poria cocos, and differences in their immunomodulatory activity were investigated. The average molecular weights of EPS-0M, EPS-0.1M, IPS-0M, and IPS-0.1M were 1.77 × 10

Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for the repair of cracks in concrete. In order to improve the ability of microbial materials to repair concrete cracks, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate. Sporosarcina pasteurii ATCC 11859 was used as the starting strain to obtain the mutant with high urease activity by atmospheric and room temperature plasma (ARTP) mutagenesis. Then, the optimal biomineralization conditions and precipitation crystal form was studied using Plackett-Burman experimental design and response surface methodology (RSM). Biomineralization with 0.73 mol/L calcium chloride, 45 g/L urea, reaction temperature of 45°C, and reaction time of 22 h, significantly increased the amount of precipitated calcium carbonate, which was deposited in the form of calcite crystals. Finally, the repair of concrete using the optimized biomineralization process was evaluated. A comparison of water absorption and adhesion of concrete specimens before and after repairs showed that concrete cracks and surface defects could be efficiently repaired. This study provides a new method for the engineering of biocementing material for concrete repair.

Sarcopenia,an age-related disease caused by the imbalance in protein synthesis and degradation,can result in significant decreases in skeletal muscle mass and strength.Skeletal muscle loss during aging is inevitable and can affect the life quality of the elderly.Moreover,it may increase the risks of other age-related diseases in the elderly.However,the underlying molecular mechanism remains unclear in age-related skeletal muscle loss.Autophagy is a degradation pathway for the removal of dysfunctional organelles and damaged macromolecules during aging.Mitochondria also play a key role in skeletal muscle function.To maintain skeletal muscle mass,we should pay attention to autophagy and improve mitochondrial homeostasis through autophagy or other means.This paper summarizes the research progress of autophagy and mitochondrial quality control in sarcopenia,aiming to provide reference for exploring new therapies.

Two capsular polysaccharides (WL-CPS-1 and GLU-CPS-1) purified from Nostoc flagelliforme under normal and mixotrophic culture conditions were used to investigate the hypolipidemic activity and effect on intestinal flora in C57BL/6J mice respectively. Their molecular weight and monosaccharide composition have been determined in previous studies. They both improved the lipid level by affecting the expression of lipid metabolism genes. They down-regulated the TNF-α and IL-1β levels in serum and up-regulated the activity of antioxidant enzymes in liver thus decreased the atherosclerosis index and MDA content. They up-regulated the short chain fatty acids (SCFAs) synthesis. They decreased the abundance of pathogenic bacteria and increased the abundance of probiotics positively correlated with SCFAs. Compared with WL-CPS-1, GLU-CPS-1 exhibited higher in vivo activity and enriched Odoribacter and Alloprevotella correlating with the gene expression of lipid metabolism, suggesting that the bioactivity of polysaccharides could be regulated by culture conditions. These findings contributed to application of N. flagelliforme polysaccharides with higher activity in hypolipidemia by adjusting culture conditions.

Understanding the relation between land-use types and baseflow mean response time (BMRT) is important to explore the response mechanism of baseflow processes in watersheds. BMRT was determined using an instantaneous unit hydrograph. The instantaneous unit hydrograph parameters were estimated by autocorrelation functions. The relative importance of land-use types in determining BMRT dynamics was assessed by hydrological model and partial least-squares regression. Our study suggests greater effects of urban area on BMRT than the effects of forest and agricultural land. This may be because the urban interception impervious area may impede baseflow generation over a short timescale. The effects of agricultural land are greater than those of forest in areas with steeper hillslopes, but lower than those of the forest in areas with more plains, reflecting the varied ability of forest and agricultural lands with different topography to hinder overland flow. Variations of BMRT are strongly linked to land use in the watershed. Overall, our study provides insight into the BMRT and dominant factors of land-use types in watersheds, planning of sustainable water resource use, and ecological protection in watersheds.

A strategy by exogenous addition of quorum sensing molecule farnesol to improve the production, antioxidant activity and antitumor activity of extracellular polysaccharide (EPS) of Grifola frondosa by liquid fermentation was proposed in the study. The highest yield of EPS induced by farnesol was 1.25 g/L, which was 150% higher than that of the control. Four polysaccharides including EPS-C-0M, EPS-C-0.2M, EPS-F-0M and EPS-F-0.2M were extracted and purified under the conditions of control and farnesol respectively. The physicochemical properties, antioxidant activities and antitumor activities were studied. Their chemical composition differed in sugar, protein and uronic acid contents, and they were composed of six constituent monosaccharides with different ratios, with the average molecular weights of 1.12 × 103, 1.89 × 103, 1.41 × 103 and 2.02 × 103 kDa, respectively. They presented similar FT-IR spectra, but different surface morphology. Antioxidant experiments showed that they had strong scavenging activities on ABTS+, hydroxyl radical, O2− and DPPH radical. Antitumor experiments showed that they had strong inhibitory effects on human cervical cancer (HeLa) cells and human liver cancer cells (HepG2) cells. Among the four polysaccharides, EPS-F-0.2M showed the highest antioxidant and antitumor activities, indicating that farnesol could regulate the biological activity of EPS by affecting structure and properties. These results demonstrated that appropriate adjustment of culture conditions had potential application in the development of polysaccharides with high antioxidant and antitumor activity. It provided a new strategy to enhance the production and bioactivity of edible and medicinal fungal polysaccharides by using quorum sensing molecules.

Microbially induced calcium carbonate precipitation (MICP) has recently become an intelligent and environmentally friendly method for repairing cracks in concrete. To improve on this ability of microbial materials concrete repair, we applied random mutagenesis and optimization of mineralization conditions to improve the quantity and crystal form of microbially precipitated calcium carbonate.

Introduction: Pathological scar is the abnormal manifestation of skin fiber hyperplasia caused by the failure of normal healing after skin damage. At present, there are many clinical treatments for pathological scars. However, there is no cure for clinically effective pathological scars with high recurrence rate. In this study, we will use a combination of Chinese and western medicine treatment methods to evaluate the clinical efficacy and related indicators of young and middle-aged female patients who meet pathological scars, looking for an objective and effective treatment method for pathological scars. Methods/design: In this study, we will use our own front-to-back clinical research method. We plan to include 120 young and middle-aged female patients who meet the diagnostic criteria for pathological scars. The untreated pathological scars of the enrolled patients will be used as blank controls. The intervention group will be given conventional western medicine treatment and combined Chinese and western medicine treatment. The assessment of scar area, color, hardness, thickness, itching, and pain was recorded for 8 weeks of treatment. Discussion: This trial may provide evidence regarding the clinical effectiveness, safety, and cost-effectiveness of traditional Chinese medicine for patients with pathological scars. Trial registration: ClinicalTrials.gov, ChiCTR2000032187, Registered on April 22, 2020.

Three polysaccharides (WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1) were extracted and purified from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions respectively. Their physicochemical properties and antioxidant activities were investigated. WL-CPS-1, NaCl-CPS-1 and Glu-CPS-1 chemical composition differed in sugar and uronic acid contents, and they were composed of nine constituent monosaccharides and one uronic acid with different ratios, with the average molecular weights of 1.02 × 103, 1.12 × 103 and 1.33 × 103 kDa, respectively. They presented similar fourier transform infrared spectra, but different surface morphology, chain length and branching. Antioxidant assay showed that they all exhibited strong scavenging activity on ABTS+ and hydroxyl radicals and moderate activity on DPPH radical. Glu-CPS-1 exhibited the highest antioxidant activity suggested culture conditions could regulate the bioactivity through influencing the structure and properties. These findings demonstrated the potential application of proper regulation of culture conditions in the development of polysaccharides with high antioxidant activity.

A new Strandberg-type polyoxometalate compound [Co(L)2(H2O)2]2H2[P2Mo5O23]·2H2O (1), (L = pyridine-2-carboxamide) has been synthesized and structurally characterized by elemental analysis, spectroscopic methods (IR, UV-Vis) and X-ray powder diffraction (XRD), as well as single crystal X-ray diffraction. Compound 1 consists of one [P2Mo5O23]6–, two [Co(L)2(H2O)2]2+ and two dissociative water molecules. Biological studies indicated that compound 1 exhibited effective activities against both HepG2 (human hepatocellular carcinoma) cells and HCT-116 (human colorectal cancer) cells and lower toxicity against normal HL-7702 (human normal hepatocyte) cells. A synergistic effect involving L, metal ions and P2Mo5 cluster could probably explain the improved growth-inhibiting properties.

Different light qualities have been found to effectively promote polysaccharide production of cyanobacteria, to elucidate the underlying mechanism, the effects of four typical light qualities including ultraviolet radiation B (UVB), red light (R), blue light (B), and mixed light (R:B = 7:15) (RB) on polysaccharide production in Nostoc flagelliforme were comprehensively investigated with white fluorescent light as control. In this study, an iTRAQ-based proteomic approach was employed to explore the proteomes of N. flagelliforme, and 126, 177, 208, and 200 differentially expressed proteins were identified in UVB-, R-, B- and RB-treated N. flagelliforme. Functional classification analysis showed that differentially expressed proteins were mainly involved in photosynthesis, antioxidant activity, and carbohydrate metabolism. Analysis of differentially expressed proteins involved in polysaccharide synthesis revealed that different light qualities shared a common mechanism to promote polysaccharide production by altering carbon allocation and increasing carbon flow into sugar nucleotide synthesis pathway. Activity assay of selected enzymes further verified the proteomic analysis. Our results provide novel insights into the molecular mechanisms of light quality affecting polysaccharide production.

Four metal complexes based on 2-benzoylpyridine N,N-dimethylthiosemicarbazone (Bp44mT) were designed. Free ligand and zinc(ii), diorganotin(iv), gallium(iii) and cadmium(ii) complexes all demonstrated pronounced activity, which was indicated using the growth inhibition test in vitro. Interestingly, most of the compounds were found to be selective against hepatocellular carcinoma (HepG2) cells but had little effect on normal hepatocyte (QSG7701) cells. In particular, Zn(Bp44mT)2 (1) exhibited toxicity on QSG7701 cells which approximately 12-fold lower than that on HepG2 cells. The studies of mechanisms of action indicated that 1 induced reactive oxygen species (ROS) generation in a dose-dependent manner via the mitochondria transduction pathway. Protein analyses showed that 1 significantly promoted p21 and p53 gene expression, causing caspase-3 activation.

Nostoc flagelliforme is a pioneer organism in the desert and exerts important ecological functions. The habitats of N. flagelliforme are characterized by intense solar radiation, while the ultraviolet B (UV-B) tolerance has not been fully explored yet. To evaluate the physiological responses of N. flagelliforme to UV-B radiation, three intensities (1 W m−2, 3 W m−2 and 5 W m−2) were used, and the changes in photosynthetic pigments, cell morphology, mycosporine-like amino acids (MAAs) synthesis and cell metabolism were comparatively investigated. Under high UV-B intensity or long term radiation, chlorophyll a, allophycocyanin and phycocyanin were greatly decreased; scanning electron microscope observations showed that cell morphology significantly changed. To reduce the damage, cells synthesized a large amount of carotenoid. Moreover, three kinds of MAAs were identified, and their concentrations varied with the changes of UV-B intensity. Under 1 W m−2 radiation, cells synthesized shinorine and porphyra-334 against UV-B, while with the increase of intensity, more shinorine turned into asterine-330. Metabolite profiling revealed the contents of some cytoprotective metabolites were greatly increased under 5 W m−2 radiation. The principal component analysis showed cells exposed to UV-B were metabolically distinct from the control sample, and the influence on metabolism was particularly dependent on intensity. The results would improve the understanding of physiological responses of N. flagelliforme to UV-B radiation and provide an important theoretical basis for applying this organism to control desertification.

Three Strandberg-type polyoxometalate compounds [Cu(L)2(H2O)2]2H2[P2Mo5O23]·2CH3OH (1), [Cu(L)2(H2O)]H2[Cu(L)2(P2Mo5O23)]·4H2O (2), [Cd(L)2(H2O)2]2H2[P2Mo5O23]·2CH3OH (3), (L = pyridine-2-carboxamide) have been synthesized and structurally characterized by elemental analysis, spectroscopic methods (IR and UV–vis) as well as single crystal X-ray diffraction. Single-crystal X-ray structural analyses indicate that 1 and 3 are isostructural and crystallized in monoclinic, space group I2/a. Biological studies have indicated that compounds 1–3 exhibit broad and effective activities against the tested cells. A synergistic effect involving L, metal and P2Mo5 could probably explain the improved growth-inhibiting properties. Both coordination mode and the type of metal ion play significant roles in these compounds cytotoxicity.

The relationship between monosaccharide composition of Nostoc flagelliforme extracellular polysaccharide (EPS) and activities of EPS synthesis enzymes under various carbon sources, nitrogen sources and light culture condition was investigated. Culture conditions showed significant influences on both monosaccharide composition and related enzyme activities. Under both carbon and nitrogen sources conditions, mannose mole percentage was increased with the increase of initial mole ratio of C/N and positively related to fructose-1, 6-bisphosphatase activity, and glucuronic acid and galactose mole percentages were positively correlated with UDP-glucose dehydrogenase, while arabinose and rhamnose mole percentages were negatively associated with UDP-glucose pyrophosphorylase. Different correlation between monosaccharide composition and enzymes activity from carbon and nitrogen sources conditions was found under light condition. These findings will be helpful to establish a novel fermentation process aimed to produce the N. flagelliforme EPS with desired monosaccharide composition.

Cyanobacteria have evolved a number of photosynthetic strategies by adjusting the properties of the light-harvesting pigments to cope with changes in the light environment. Nostoc flagelliforme is a terrestrial filamentous cyanobacterium that has distinct phycobilisome composition consisting of phycocyanin (PC) and allophycocyanin (APC). The photoregulation process of N. flagelliforme was explored by investigating the effects of different light colors on photosynthetic pigments, which were determined after photoautotrophic growth with red (RL), yellow (YL), green (GL), blue (BL), purple (PL) and white (WL) light of same photosynthetically active photon flux density. Compared with WL, YL, GL, BL and PL changed the amounts of pigments but did not alter the cellular ratio of PC/APC; while RL altered both the amounts and proportions of PC and APC. The observations by confocal laser scanning microscope and transmission electron microscope showed that PC, APC and chlorophyll a were distributed throughout the cells under GL, BL, PL, and WL illumination but located in the outermost layer in RL and YL-grown cells. Further study revealed that changing RL intensity would not influence the ratio of PC/APC but the distribution of pigments shifted from central cytoplasmic region to the periphery of the cells with the increase of intensity. These results implied that N. flagelliforme responded to RL by regulating the composition and location of phycobilisomes and these findings would be of importance to develop the high-efficient process of N. flagelliforme culture.

We report a novel “anchor–shield” approach for synthesizing a yolk–shell-structured biocatalytic system that consists of a phenylalanine ammonia lyase (PAL) protein particle core and a hollow silica shell with large mesopores by a combination of CaCO3 microtemplates and biomimetic silicification. The method is established upon filling porous CaCO3 cores with PAL via co-precipitation, controlled self-assembly and polycondensation of silanes, cross-link of the PAL molecules, and subsequent CaCO3 dissolution. During this process, the self-assembled layer of cetyltrimethylammonium bromide served as a structure-directing agent of the mesostructure and directed the overgrowth of the mesostructured silica on the external surface of PAL/CaCO3 hybrid microspheres; after CaCO3 dissolution, the cross-linked PAL particles were encapsulated in the hollow silica shell. The hollow silica shell around the enzyme particles provided a “shield” to protect from biological, thermal, and chemical degradation for the enzyme. As...

Cross-linked enzyme aggregates (CLEAs) have recently emerged as a promising method for enzyme immobilization due to its simplicity and low cost. However, a lack of good size and morphological control over the as-prepared CLEAs has limited their practical applications in some cases. Here, monodisperse spherical CLEAs of phenylalanine ammonia lyase (PAL microspheres) were prepared based on CaCO3 microtemplates. The preparation procedure involves filling porous CaCO3 microtemplates with the protein by salt precipitation, glutaraldehyde crosslinking, and dissolution of the microtemplates. The formulation of CaCO3 templates with controlled size was studied in detail. Characterization of the prepared PAL microspheres was investigated. The results showed that the PAL microspheres with high immobilization efficiency (79%) exhibited excellent stability, including increased tolerance to proteolysis, low pH, and denaturants, and excellent mechanical properties. For example, free PAL almost lost all activity after they were incubated in the presence of trypsin for 2min, whereas PAL microspheres still retained 95% of their initial activity. Moreover, scanning electron microscope, transmission electron microscope, and N2 adsorption-desorption isotherms revealed that the resultant PAL microspheres possessed good monodispersity and mesoporous structure instead of the amorphous clusters of conventional CLEAs with few pores. Compared with conventional CLEAs, the monodisperse PAL microspheres with mesoporous make them more potentially useful for biomedical and biotechnological applications.

Culture conditions significantly influence extracellular polysaccharide (EPS) production of Nostoc flagelliforme, however, the key enzyme controlling EPS synthesis has not been fully explored yet. The influence of different culture conditions including light quality, carbon source and nitrogen source on EPS production of N. flagelliforme and activities of EPS synthesis enzymes was investigated. Three experimental groups produced higher amounts of EPS than the control group, including the carbon source group with 1.26 g L−1 NaHCO3, the nitrogen source group with 0 g L−1 NaNO3 and the light quality group with blue light. Activities of seven related enzymes phosphoglucose isomerase (PGI), fructose-1,6-bisphosphatase (FBPase), UDP-glucose pyrophosphorylase (UGPase), UDP-galactose-4-epimerase (UGE), UDP-glucose dehydrogenase (UGDH), phosphomannose isomerase (PMI), and phosphofructokinase (PFK) were significantly influenced by culture conditions. Partial least-squares analysis and correlation analysis methods were used to analyze the relationship between the activities of these enzymes and EPS production, and a correlation between the production of EPS and the activities of PGI, PMI, FBPase, UGDH, and UGPase was found under different culture conditions. Subsequent analysis of the transcription level of genes encoding the five enzymes showed genes pgi and fbp1 in three experimental groups were significantly up regulated. The results revealed PGI and FBPase might be important enzymes positively influencing the biosynthesis of N. flagelliforme EPS. The findings would be helpful to further understand the pathway of EPS biosynthesis aimed to improve the EPS production of N. flagelliforme.

The strategy of light environment control was applied to improve biomass and extracellular polysaccharides (EPS) production of the cyanobacterium Nostoc flagelliforme by adjusting multiple wavelengths (red 660 nm, blue 460 nm, green 520 nm) and light intensity assisted by nitrogen source optimization. A mixed wavelength with low light intensity was more suitable for cell growth. Wavelength shift approach, i.e., manipulation of light wavelength at appropriate culture stages, increased both biomass and EPS production, and optimum shift time was at 9 days. The effects of four nitrogen sources under different light conditions were subsequently evaluated, and urea showed the best performance. The optimized wavelength shift approach (9-day illumination with white light followed by 9-day culture with mixed wavelengths of red/blue/green = 12:5:5) with urea as nitrogen source improved the biomass from 0.72 ± 0.02 to 1.20 ± 0.02 g L−1 (i.e., by 66 %) and EPS production from 27.31 ± 1.00 to 86.65 ± 2.56 mg L−1 (i.e., by 217.3 %). These results provide information on novel culture strategies for microalgal biotechnology by applying light environment control.

e-Poly- l -lysine (e-PL) is a natural antimicrobial poly-cationic peptide, and it has been widely used as a food preservative. However, the detailed antimicrobial mechanism of e-PL remains unclear. Currently, it is widely accepted that membrane disruption is its main antimicrobial mode of action, but its effect on the cell membrane composition and fluidity remains unclear. In this study, we investigated the effect of e-PL on ergosterol and fatty acids as well as fluidity of the cell membrane of Saccharomyces cerevisiae. Compared with the control, the level of ergosterol increased significantly by e-PL. e-PL also caused changes in the membrane fatty acid composition. A slight increase in the fluidity of cell membrane and plasmolysed cells as well as some membrane curvature changes were observed under a transmission electron microscope. e-PL also induced osmotic stress by breaking ionic balance between inside and outside of the membrane.

Introduction: Hypertrophic scars are a common disease in plastic surgery, which is the reaction of skin connective tissue to trauma beyond the normal range. Although scholars around the world have explored the tissue structure and formation mechanism of HS for decades, they are not satisfactory the result of. No effective treatment has been found. Therefore, the search for safe and effective treatments for HS has always been the focus of medical attention and research. Acupuncture therapy has a definite effect on HS and has unique advantages. Methods/design: In this study, we will use our own front-to-back clinical research method. We plan to include 120 young and middle-aged female patients who meet the diagnostic criteria for HS. The untreated HS of the enrolled patients will be used as blank controls. The intervention group will be given acupuncture treatment. The assessment of scar area, color, hardness, thickness, itching and pain will be recorded for 30 days of treatment. Discussion: This trial may provide evidence regarding the clinical effectiveness, safety, and cost-effectiveness of Acupuncture for patients with HS. Trial registration: ClinicalTrials.gov, ChiCTR2000032624, Registered on 04 May 2020.

Nostoc flagelliforme is a pioneer organism in the desert and highly resistant to ultraviolet B (UV-B) radiation, while the involved adaptive mechanism has not been fully explored yet. To elucidate the responsive mechanism, two doses of UV-B radiation (low: 1 W/m2 and high: 5 W/m2) were irradiated for 6 h and 48 h, respectively, and their effects on global metabolism in N. flagelliforme were comprehensively investigated. In this study, we used iTRAQ-based proteomic approach to explore the proteomes of N. flagelliforme, and 151, 172, 124 and 148 differentially expressed proteins were identified under low and high UV-B doses for 6 h and 48 h, respectively. Functional classification analysis showed these proteins were mainly involved in photosynthesis, amino acid metabolism, antioxidant activity and carbohydrate metabolism. Further analysis revealed that UV-B imposed restrictions on primary metabolism including photosynthesis, Calvin cycle, and amino acid metabolism, and cells started defense mechanism through repair of DNA and protein damage, increasing antioxidant activity, and accumulating extracellular polysaccharides to minimize the damage. Moreover, high UV-B dose imposed more severe restrictions and activated stronger defense mechanism compared with low dose. The results would improve the understanding of molecular mechanisms of UV-B-stress adaption in N. flagelliforme.

Understanding the response of flood frequency to impact factors could help water resource managers make better decisions. This study applied an integrated approach of a hydrological model and partial least squares (PLS) regression to quantify the influences of rainfall and forest landscape on flood frequency dynamics in the Upper Honganjian watershed (981 km2) in China. The flood events of flood seasons in return periods from two to 100 years, wet seasons in return periods from two to 20 years, and dry seasons in return periods from two to five years show similar dynamics. Our study suggests that rainfall and the forest landscape are pivotal factors triggering flood event alterations in lower return periods, that flood event dynamics in higher return periods are attributed to hydrological regulations of water infrastructures, and that the influence of rainfall on flood events is much greater than that of land use in the dry season. This effective and simple approach could be applied to a variety of other watersheds for which a digital spatial database is available, hydrological data are lacking, and the hydroclimate context is variable.

Both static and agitated culture methods have their own disadvantages on producing bacterial cellulose (BC). To reveal the metabolic differences between these two culture methods, the intracellular metabolic profile characterization of Gluconacetobacter xylinus was investigated using gas chromatography coupled with mass spectrometry. A total of 79 intracellular metabolites in G. xylinus were detected and quantified. Trehalose was mainly responsible for the discrimination among different cultural groups. Coupled with metabolic network, BC production was divided into two stages in agitated culture. At the first stage, glucose was more converted to gluconic acid at high rotational speeds, resulting in a low conversion rate of glucose to BC. At the second stage, gluconic acid acted as carbon source pool for BC synthesis under glucose-limited conditions. However, the accumulation of self-protection metabolites (trehalose, amino acids and gluconic acid) on the 2nd day at 280 rpm branches much carbon source from BC synthesis, resulting in the inhibition of BC synthesis. The highest conversion rate of glucose to BC was observed in static culture, attributing to the inhibition of Glucose-6-phosphate dehydrogenase and the accumulation of by-products. These might be the possible reasons that G. xylinus in static and agitated cultures gave distinct BC yields.

Filamentous Nostoc flagelliforme form colloidal complex, with beaded cells interacting with other bacteria embedded in the complex multilayer sheath. However, the species of bacteria in the sheath and the interaction between N. flagelliforme and associated bacteria remain unclear. In this study, PCR-denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial communities of N. flagelliforme from three regions of China. DGGE patterns showed variations in all samples, exhibiting 25 discrete bands with various intensities. The diversity index analysis of bands profiles suggested the high similarity of bacterial communities to each other but also the dependence of microbial composition on each location. Phylogenetic affiliation indicated that the majority of the sequences obtained were affiliated with Actinobacteria, Cyanobacteria, Proteobacteria, Acidobacteria, Bacteroidetes, of which Cyanobacteria was dominant, followed the Proteobacteria. Members of the genus Nostoc were the most abundant in all samples. Rhizobiales and Actinobacteria were identified, whereas, Craurococcus, Caulobacter, Pseudomonas, Terriglobus and Mucilaginibacter were also identified at low levels. Through comparing the bacterial composition of N. flagelliforme from different regions, it was revealed that N. flagelliforme could facilitate the growth of other microorganisms including both autotrophic bacteria and heterotrophic ones and positively contributed to their harsh ecosystems. The results indicated N. flagelliforme played an important role in diversifying the microbial community composition and had potential application in soil desertification.

Light quality strongly affects cell growth and polysaccharide production of cyanobacteria, however, the metabolic mechanism of polysaccharide biosynthesis upon light quality has not been fully explored yet. The effects of light quality on the metabolic changes of Nostoc flagelliforme were comprehensively investigated using red, yellow, green, blue, purple light emitting diodes for illumination. The principal component analysis revealed that red, yellow, green, blue, and purple light-grown cells were metabolically distinct from those illuminated with white fluorescent light, and the influence of light quality on metabolism was particularly dependent on light wavelength. Significant correlations between the metabolic profile and extracellular polysaccharide (EPS) and capsular polysaccharide (CPS) production were revealed by partial least-squares to latent structure analysis respectively, and analysis of key metabolites showed that CPS production was closely related with cell growth while the biosynthesis of EPS was more closely related with light conditions. Furthermore, as the influence pattern of red light on cellular metabolism and polysaccharide production was quite different from other light conditions, the effects of intensity of red light on photosynthesis and polysaccharide production were evaluated, and the results revealed that red light induced photoinhibition and therefore stimulated polysaccharide production. Manipulation of red light was thus proposed to profitably enhance polysaccharide productivity of N. flagelliforme.

Two inorganic-organic hybrid materials, [Co(L)2]2Na2[β-Mo8O26]·9H2O (1) and [Fe(L)2]2Na2[β-Mo8O26]·9H2O (2) (HL = 2-acetylpyrazine N4-methyl thiosemicarbazone) have been synthesized and characterized by elemental analyses, infrared (IR) spectroscopy, thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. The hybrids 1 and 2 were explored in the oximation of aldehydes and ketones with in situ generated hydroxylamine by a one-pot procedure. In the crystal structures of 1 and 2, N-containing thiosemicarbazide ligands, Lewis acid, and oxidation catalyst octamolybdate coexist within a confined space providing a promising synergistic catalytic way. Hybrids 1 and 2 displayed high catalytic activity and selectivity for the oximation of aldehydes and ketones.

Nostoc flagelliforme is an edible cyanobacterium with excellent food and herbal values. It has been used as food in China for more than 2000 years. Many studies have been focused on improving the yield and bioactivity of Nostoc flagelliforme polysaccharides although these have ignored the functional properties. In this study, we extracted and purified three polysaccharides (WL-CPS, NaCl-CPS and Glu-CPS) from Nostoc flagelliforme under normal, salt stress and mixotrophic culture conditions, respectively, in order to change the physicochemical properties of polysaccharides with the aim of obtaining better functional properties. Both salt stress and mixotrophic culture conditions increased the specific yield of polysaccharides. Their functional properties were comparatively investigated and the results showed that NaCl-CPS exhibited the highest emulsification activity and flocculation capability, which was also higher than that of some commercial products. In contrast, Glu-CPS exhibited the highest water and oil holding capacities, foaming property, intrinsic viscosity and bile acids binding capacity. Our results indicated that both NaCl-CPS and Glu-CPS could be considered to be functional polysaccharides according to their respective characteristics, which have great potential in numerous applications, such as food, pharmaceutical, cosmetic, chemical and mineral industries. These findings also demonstrated the potential application of the proper regulation of culture conditions in the development of polysaccharides with desired functional properties.

As one of the important parameters of dynamic soft reduction technology, reduction position seriously affects the using effect of this technology to decrease center segregation and porosity of continuous casting slabs. According to the actual production conditions, a two-dimensional solidification and heat transfer model was established. In order to obtain more accurate model, the heat transfer coefficient was amending by the pin shooting technique in measuring shell thickness. The laws of the effect of casting speed, superheat degree and specific water flow on reduction position were analyzed respectively and reduction positions were predicted in different working conditions based on the model. The experimental results show that the center segregation and porosity decreased obviously when it produces at the reduction position predicted by the model.

Four diesel fuel degrading microorganisms were isolated from soil and sea water from Crude Oil Terminal at Tianjin Port using diesel fuel as sole carbon source, and they all could degrade diesel fuel. The initial diesel fuel concentration in the culture medium was optimized and was 1.5 g/L. The ability of the four strains to degrade diesel was compared by spectrophotometer with the initial diesel concentration at 1.5 g/L. The results showed that the strain C1 had the highest degrading activity, which could degrade 32.59% of diesel in 7 days. The strain C1 was further identified by 16S rDNA sequence analysis as Rhodococcus erythropolis, and the phylogenetic tree of the strain C1 was constructed.

Two desulfurizing strains S1 and S2 were isolated from sea water from Crude Oil Terminal at Tianjin Port. The ability of the two strains to convert dibenzothiophene (DBT) to 2-dihydroxybiphenyl (HBP) was tested by Gibbs assay, which indicated that 2-HBP existed in the metabolite. The strains S1 and S2 were identified by both 16S rDNA sequence analysis and MALDI BioTyper system as Agrobacterium tumefaciens and Acinetobacter radioresistens respectively, which could degrade 22.3% and 22.4% of DBT in 46 hours respectively.

Metabolic flux analysis was used to reveal the metabolic distributions in Gluconacetobacter xylinus (CGMCC no. 2955) cultured on different carbon sources. Compared with other sources, glucose, fructose, and glycerol could achieve much higher bacterial cellulose (BC) yields from G. xylinus (CGMCC no. 2955). The glycerol led to the highest BC production with a metabolic yield of 14.7 g/mol C, which was approximately 1.69-fold and 2.38-fold greater than that produced using fructose and glucose medium, respectively. The highest BC productivity from G. xylinus CGMCC 2955 was 5.97 g BC/L (dry weight) when using glycerol as the sole carbon source. Metabolic flux analysis for the central carbon metabolism revealed that about 47.96 % of glycerol was transformed into BC, while only 19.05 % of glucose and 24.78 % of fructose were transformed into BC. Instead, when glucose was used as the sole carbon source, 40.03 % of glucose was turned into the by-product gluconic acid. Compared with BC from glucose and fructose, BC from the glycerol medium showed the highest tensile strength at 83.5 MPa, with thinner fibers and lower porosity. As a main byproduct of biodiesel production, glycerol holds great potential to produce BC with superior mechanical and microstructural characteristics.

Dissociated cells separated from a natural colony of Nostoc flagelliforme were cultivated heterotrophically in the darkness on glucose under fed-batch culture conditions. The effects of carbon sources (glucose, fructose, xylose, and sucrose) and concentrations on cell growth and extracellular polysaccharide (EPS) production were investigated. At harvest, the culture contained 1.325 g L−1 of biomass and 117.2 mg L−1 of EPS, respectively. The gravimetric EPS production rate was 16.7 mg g−1 cell dry weight day−1, which was 2.1 times higher than previously reported. Using sigmoid model, batch fermentation of N. flagelliforme was kinetically simulated to obtain equations including substrate consumption, biomass growth, and EPS accumulation. Results from a simulation correlated well with the experimental ones, indicating that this method could be useful in studying EPS production from batch and fed-batch cultures.

The open culture is a simple, low-cost way for microalage cultivation, and the great advantage of which is that it can be easily used for mass production. This culture system is primarily used for the alga that can survive under bad or extreme conditions. N. flagelliforme is a kind autotrophic alga having the property of alkali-resistance, which makes open culture of N. flagelliforme become possible. In this study, the cultivation of N.flagelliforme with an open, 60×40×30cm rectangular glass reactor was conducted. Firstly, the open culture of N.flagelliforme was carried on without new nutrient elements supplemented into pond intermittently. During the whole process of cultivation, the pH maintained at 8-9 in order to avoid the contamination of other green alga. At the end of the cultivation, the cell density reached 0.802 g•L-1 and the exopolysaccharide concentration was 97mg•L-1. Secondly, the fed-batch cultivation was employed to increase biomass and exopolysaccharide production. At the end of the fed-batch cultivation, the biomass and exopolysaccharide of N.flagelliforme increased distinctly to 1.16 g•L-1 and 124 mg•L-1, respectively.

Nostoc flagelliforme is a kind of terrestrial cyanobacterium with high economic value. Dissociated cells, which separated from a natural colony of N. flagelliforme, could be cultivated heterotrophically in the darkness on xylose and glucose under fed-batch culture conditions. Growth and extracellular polysaccharides (EPS) production in different cultures are investigated. At harvest time, the cultures contain 1.215 g•L-1 of biomass and 122.5 mg•L-1 of EPS respectively. The gravimetric EPS production rate is 17.5 mg•g-1•day-1, which is 1.65 times higher than previously reported results for heterotrophic Nostoc flagelliforme grown on xylose batch culture.

Plant cell culture has been developed as an alternative method for the production of an anticancer drug, paclitaxel. However, the sensitivity of plant cells to shear stress has been one of the main obstacles to the scale-up of the plant cell culture. To gain a better understanding of the mechanism of plant cells' response to hydrodynamic mechanical stress, lipid profiling of suspension-cultured Taxus chinensis (Chinese yew) var. mairei cells under shear stress was carried out using liquid chromatography―tandem MS and gas chromatography―time-of-flight MS. T chinensis var. mairei cells cultured in a Couette-type shear reactor responded with an increase of cell membrane permeability compared with control cells, which indicated that the adaptation to shear stress altered membrane lipid composition. The main changes of lipid profiles in the shear-stress-induced cells were the following: (a) the total phospholipid content decreased, especially that of structural phospholipids such as phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine; (b) cells showed increased stigmasterol at the expense of sitosterol and campesterol; (c) the stigmasterol/phospholipid ratio increased; (d) the mono-unsaturated-fatty-acid content increased; (e) the shear-stress-induced cells accumulated very-long-chain saturated fatty acids (C 22:0 , C 23:0 , C 24:0 and C 25:0 ). These findings suggested alterations in membrane composition and hinted at a possible molecular basis for the mechanotransduction processes induced by shear stress in T. chinensis var. mairei cells.

Lipid signaling involved in mechanotransduction processes in response to shear stress in plants remained elusive. To understand the responses of phospholipids in shear stress-induced mechanotransduction, a lipidomic approach was employed to profile phospholipid species of Taxus cuspidata cells under laminar shear stress. A total of 99 phospholipid species were profiled quantitatively, using the LC/ESI/MS(n) procedure. Potential biomarkers were found by the principal component analysis (PCA) as well as partial least squares (PLS) combined with variable influence in the projection (VIP). Phosphatidic acid (PA) and lysophosphatidylcholine (LysoPC) were two important lipid groups that were responsible for the discrimination between shear stress induced and control cells. Further research revealed that shear stress enhanced the activation of phospholipase D (PLD) and phospholipase C (PLC) compared with control cells and consequently increased PA content in shear stress induced T. cuspidata cells. These results demonstrate that phospholipids and related phospholipases play important roles in mechanotransduction of T. cuspidata cells in response to shear stress.