Two new threonine-containing metabolites from fungus Curvularia inaequalis strain HS-FG-257.

Two new threonine-containing metabolites, N-[4-hydroxy-3-prenyl-benzoyl]-L-threonine (1) and N-[2,2-dimethyl-2H-chromene-6-carbonyl]-L-threonine (2), were isolated from the fermentation broth of the soil fungus Curvularia inaequalis strain HS-FG-257. Their structures were elucidated through the interpretation of HR-ESIMS and extensive NMR spectroscopic data. Both compounds exhibited no cytotoxic activity against the test cell lines A549 and HCT-116.

Comparative analysis of maca (Lepidium meyenii) proteome profiles reveals insights into response mechanisms of herbal plants to high-temperature stress.

BACKGROUND: High-temperature stress (HTS) is one of the main environmental stresses that limit plant growth and crop production in agricultural systems. Maca (Lepidium meyenii) is an important high-altitude herbaceous plant adapted to a wide range of environmental stimuli such as cold, strong wind and UV-B exposure. However, it is an extremely HTS-sensitive plant species. Thus far, there is limited information about gene/protein regulation and signaling pathways related to the heat stress responses in maca. In this study, proteome profiles of maca seedlings exposed to HTS for 12 h were investigated using a tandem mass tag (TMT)-based proteomic approach. RESULTS: In total, 6966 proteins were identified, of which 300 showed significant alterations in expression following HTS. Bioinformatics analyses indicated that protein processing in endoplasmic reticulum was the most significantly up-regulated metabolic pathway following HTS. Quantitative RT-PCR (qRT-PCR) analysis showed that the expression levels of 19 genes encoding proteins mapped to this pathway were significantly up-regulated under HTS. These results show that protein processing in the endoplasmic reticulum may play a crucial role in the responses of maca to HTS. CONCLUSIONS: Our proteomic data can be a good resource for functional proteomics of maca and our results may provide useful insights into the molecular response mechanisms underlying herbal plants to HTS.

Effect of complexes of cyanidin-3-diglucoside-5-glucoside with rutin and metal ions on their antioxidant activities.

Studies have enabled a molecular understanding of the anthocyanin copigmentation phenomenon over several decades. However, the effect of combinations of, or even supramolecular assemblies of, anthocyanins with other phenols and/or metal ions on their antioxidative activity was unclear. In this study, anthocyanin complexes of cyanidin-3-diglucoside-5-glucoside (CY3D5G), rutin and Mg(II)/Fe(III) were constructed, analyzed, and evaluated for their antioxidant effects. The CY3D5G-rutin-Fe(III) exhibited supramolecular properties via visible, CD and FTIR spectra among complexes. The interaction of CY3D5G-rutin, CY3D5G-rutin-Mg(II), or CY3D5G-rutin-Fe(III) was synergistic (P<0.05) in the ORAC assay. On cellular ROS levels, the median effective concentration of the CY3D5G-rutin-Mg(II) was 7.76µmol QE/L and exhibited a synergistic interaction (CI=0.67, P<0.05), whereas the CY3D5G-rutin-Fe(III) (CI=0.79, P=0.074) was additive. The results indicate that the antioxidant properties were affected by the molecular combination. Additionally, Fe(III) might exhibit a negative effect, since the CY3D5G-Fe(III) required a greater concentration than CY3D5G to achieve the same effect on cells.

Characterization of the transcriptome of Achromobacter sp. HZ01 with the outstanding hydrocarbon-degrading ability.

Microbial remediation has become one of the most important strategies for eliminating petroleum pollutants. Revealing the transcript maps of microorganisms with the hydrocarbon-degrading ability contributes to enhance the degradation of hydrocarbons and further improve the effectiveness of bioremediation. In this study, we characterized the transcriptome of hydrocarbon-degrading Achromobacter sp. HZ01 after petroleum treatment for 16h. A total of 38,706,280 and 38,954,413 clean reads were obtained by RNA-seq for the petroleum-treated group and control, respectively. By an effective de novo assembly, 3597 unigenes were obtained, including 3485 annotated transcripts. Petroleum treatment had significantly influenced the transcriptional profile of strain HZ01, involving 742 differentially expressed genes. A part of genes were activated to exert specific physiological functions, whereas more genes were down-regulated including specific genes related to cell motility, genes associated with glycometabolism, and genes coding for ribosomal proteins. Identification of genes related to petroleum degradation revealed that the fatty acid metabolic pathway and a part of monooxygenases and dehydrogenases were activated, whereas the TCA cycle was inactive. Additionally, terminal oxidation might be a major aerobic pathway for the degradation of n-alkanes in strain HZ01. The newly obtained data contribute to better understand the gene expression profiles of hydrocarbon-degrading microorganisms after petroleum treatment, to further investigate the genetic characteristics of strain HZ01 and other related species and to develop cost-effective and eco-friendly strategies for remediation of crude oil-polluted environments.

Morphological Observations and Fatty Acid Composition of Indoor-Cultivated Cordyceps sinensis at a High-Altitude Laboratory on Sejila Mountain, Tibet.

Cordyceps sinensis, a caterpillar entomopathogenic fungus-host larva complex, is a rare medicinal herb found in the Qinghai-Tibetan Plateau and its surrounding high-altitude areas. The alternation of generations in the life cycle, whatever the fungus or its host insect, requires special growth conditions. However, it is difficult to simulate the growth conditions of C. sinensis, which hinders its artificial cultivation. In this work, the life cycle from the host larva to C. sinensis was observed in an indoor-cultivation laboratory at 4,200 m a.s.l. on Sejila Mountain, Tibet. Comparative examinations between indoor-cultivated and wild C. sinensis demonstrated that the indoor-cultivated C. sinensis preferred to germinate multiple long, slim stromata at diverse positions on dead larvae, including but not limited to their heads. Their fatty acid composition shows a significant difference in the levels of polyunsaturated fatty acids (PUFAs). In indoor-cultivated C. sinensis, PUFAs constituted 24.59% and 49.43%, respectively, of neutral and polar lipids; meanwhile, in wild C. sinensis, PUFAs represented 34.34% and 61.25% of neutral and polar lipids, respectively. These observations and fatty acid data suggest that environmental factors, particularly temperature, soil pressure and light intensity, strongly affect the growth of C. sinensis. Our new findings may provide important information for improving techniques for the large-scale artificial cultivation of C. sinensis.

Depth-related coupling relation between methane-oxidizing bacteria (MOBs) and sulfate-reducing bacteria (SRBs) in a marine sediment core from the Dongsha region, the South China Sea.

The vertical distributions of methane-oxidizing bacteria (MOBs) and sulfate-reducing bacteria (SRBs) in the marine sediment core of DH-CL14 from the Dongsha region, the South China Sea, were investigated. To enumerate MOBs and SRBs, their specific genes of pmoA and apsA were quantified by a culture-independent molecular biological technique, real-time polymerase chain reaction (RT-PCR). The result shows that the pmoA gene copies per gram of sediments reached the maximum of 1,118,679 at the depth of 140-160 cm. Overall considering the detection precision, sample amount, measurement cost, and sensitivity to the seepage of methane from the oil/gas reservoirs or gas hydrates, we suggest that the depth of 140-160 cm may be the optimal sampling position for the marine microbial exploration of oils, gases, and gas hydrates in the Dongsha region. The data of the pmoA and apsA gene copies exhibit an evident coupling relation between MOBs and SRBs as illustrated in their vertical distributions in this sediment core, which may well be interpreted by a high sulfate concentration inhibiting methane production and further leading to the reduction of MOBs. In comparison with the numbers of the pmoA and apsA copies at the same sediment depth, we find out that there were two methane-oxidizing mechanisms of aerobic and anaerobic oxidation in this sediment core, i.e., the aerobic oxidation with free oxygen dominantly occurred above the depth of 210-230 cm, while the anaerobic oxidation with the other electron acceptors such as sulfates and manganese-iron oxides happened below the depth of 210-230 cm.

Isolation and characterization of a novel hydrocarbon-degrading bacterium Achromobacter sp. HZ01 from the crude oil-contaminated seawater at the Daya Bay, southern China.

Microorganisms play an important role in the biodegradation of petroleum contaminants, which have attracted great concern due to their persistent toxicity and difficult biodegradation. In this paper, a novel hydrocarbon-degrading bacterium HZ01 was isolated from the crude oil-contaminated seawater at the Daya Bay, South China Sea, and identified as Achromobacter sp. Under the conditions of pH 7.0, NaCl 3% (w/v), temperature 28 °C and rotary speed 150 rpm, its degradability of the total n-alkanes reached up to 96.6% after 10 days of incubation for the evaporated diesel oil. Furthermore, Achromobacter sp. HZ01 could effectively utilize polycyclic aromatic hydrocarbons (PAHs) as its sole carbon source, and could remove anthracene, phenanthrene and pyrence about 29.8%, 50.6% and 38.4% respectively after 30 days of incubation. Therefore, Achromobacter sp. HZ01 may employed as an excellent degrader to develop one cost-effective and eco-friendly method for the bioremediation of marine environments polluted by crude oil.

An effective method for the detoxification of cyanide-rich wastewater by Bacillus sp. CN-22.

The biodetoxification of cyanide-rich wastewater has become increasingly popular because of its cost-effectiveness and environmental friendliness. Therefore, we have developed an effective method, optimised by response surface methodology, for detoxifying cyanide-rich wastewater using Bacillus sp. CN-22, which was newly isolated from a cyanide-contaminated electroplating sludge and could tolerate a CN⁻ concentration of 700 mg L⁻¹. The concentration of CN⁻ in the treated wastewater decreased from 200 to 6.62 mg L⁻¹ after cultivation with 2.38 % inocula for 72 h on the medium, consisting of 0.05 % KH2PO4, 0.15 % K2HPO4, 1.0 mM MgCl2, 1.0 mM FeCl3, 0.1 % NH4Cl, and 0.1 % glycerol. The CN⁻ degradability of 96.69 % is similar to the predicted value of 96.82 %. The optimal cultivation conditions were controlled as follows: initial pH, 10.3; temperature, 31 °C; and rotary speed, 193 rpm. The maintenance of higher pH in the overall treatment procedures may avoid the production of volatile HCN and the risk associated with cyanide detoxification. Additionally, the bacterial strain Bacillus sp. CN-22, with its potent cyanide-degrading activity at the initial CN⁻ concentration of 200 mg L⁻¹, may be employed to effectively treat cyanide-rich wastewater, especially electroplating effluent.

Fucoxanthin, a marine carotenoid present in brown seaweeds and diatoms: metabolism and bioactivities relevant to human health.

The marine carotenoid fucoxanthin can be found in marine brown seaweeds, the macroalgae, and diatoms, the microalgae, and has remarkable biological properties. Numerous studies have shown that fucoxanthin has considerable potential and promising applications in human health. In this article, we review the current available scientific literature regarding the metabolism, safety, and bioactivities of fucoxanthin, including its antioxidant, anti-inflammatory, anticancer, anti-obese, antidiabetic, antiangiogenic and antimalarial activities, and its protective effects on the liver, blood vessels of the brain, bones, skin, and eyes. Although some studies have shown the bioavailability of fucoxanthin in brown seaweeds to be low in humans, many studies have suggested that a dietary combination of fucoxanthin and edible oil or lipid could increase the absorption rate of fucoxanthin, and thus it might be a promising marine drug.

Establishment of hypoglycemic agent screening method based on human glucokinase.

OBJECTIVE: To establish a reliable platform for screening glucokinase activators (GKAs) in vitro. METHODS: Pancreatic glucokinase (PGK) protein expressed in a prokaryotic expression system as a histidine-tagged fusion protein from Homo sapiens was produced. Then, response surface methodology (RSM) was used to optimize the microplate-based GKA screening platform. In the first step of optimization with Plackett-Burman design (PBD), initial pH, reaction time and MgCl2 were found to be important factors affecting the activity ratio of GKA (RO-28-1675) significantly. In the second step, a 2(3) full factorial central composite design (CCD) and RSM were applied to the optimal condition determination of each significant variable. A second-order polynomial was determined by a multiple regression analysis of the experimental data. RESULTS: The following optimal values for the critical factors were obtained: initial pH 0 (7.0), reaction time-0.63 (13.7 min) and MgCl2 0.11 (2.11 mmol/L) with a predicted value of the maximum activity ratio of 34.1%. CONCLUSION: Under the optimal conditions, the practical activity ratio is 34.8%. The determination coefficient (R2) is 0.9442, ensuring adequate credibility of the model. LLAE3, extracted from Folium nelumbinis in our laboratory, has prominently activated effects on PGK.