Aerobic methane oxidizing bacteria (methanotrophs) can use methane as carbon source and energy source, eliminating 10%-20% of global methane. Methanotrophs can also effectively synthesize valuable methane-derived products. This article introduced the methane oxidizing mechanism of methanotrophs, and summarized the practical application and research hotspots of methanotrophs in the field of methane emission reduction in the landfill, ventilation air methane mitigation in coal mines, valuable chemicals biosynthesis, as well as oil and gas reservoir exploration. Main factors influencing the pollutant removal and the biosynthesis efficiency in various applications were also discussed. Based on the study of large-scale cultivation of methanotrophs, some measures to benefit the application and promotion of aerobic methane oxidizing biotechnology were proposed. This includes investigating the effect of intermediate metabolites on methanotrophs activity and population structure, and exploiting economical and efficient alternative culture media and culture techniques.
Biotechnology ; Carbon ; Culture Media/chemistry* ; Methane/metabolism* ; Methylococcaceae/metabolism* ; Oxidation-Reduction

Royal jelly (RJ) from honeybee has been widely used as a health promotion supplement. The major royal jelly proteins (MRJPs) have been identified as the functional component of RJ. However, the question of whether MRJPs have anti-senescence activity for human cells remains. Human embryonic lung fibroblast (HFL-I) cells were cultured in media containing no MRJPs (A), MRJPs at 0.1 mg/ml (B), 0.2 mg/ml (C), or 0.3 mg/ml (D), or bovine serum albumin (BSA) at 0.2 mg/ml (E). The mean population doubling levels of cells in media B, C, D, and E were increased by 12.4%, 31.2%, 24.0%, and 10.4%, respectively, compared with that in medium A. The cells in medium C also exhibited the highest relative proliferation activity, the lowest senescence, and the longest telomeres. Moreover, MRJPs up-regulated the expression of superoxide dismutase-1 (SOD1) and down-regulated the expression of mammalian target of rapamycin (MTOR), catenin beta like-1 (CTNNB1), and tumor protein p53 (TP53). Raman spectra analysis showed that there were two unique bands related to DNA synthesis materials, amide carbonyl group vibrations and aromatic hydrogens. These results suggest that MRJPs possess anti-senescence activity for the HFL-I cell line, and provide new knowledge illustrating the molecular mechanism of MRJPs as anti-senescence factors.
Animals ; Bees ; Cattle ; Cell Line ; Cell Proliferation ; Cellular Senescence/drug effects* ; Culture Media ; Dose-Response Relationship, Drug ; Fatty Acids/chemistry* ; Fibroblasts/drug effects* ; Humans ; Insect Proteins/chemistry* ; Lung/drug effects* ; Serum Albumin/metabolism* ; Spectrum Analysis, Raman ; Superoxide Dismutase-1/metabolism* ; TOR Serine-Threonine Kinases/metabolism* ; Tumor Suppressor Protein p53/metabolism* ; beta Catenin/metabolism*

Nocathiacin I, a glycosylated thiopeptide antibiotic, displays excellent antibacterial activities against multidrug resistant bacterial pathogens. Previously, a novel nocathiacin I formulation for intravenous administration has been successfully developed and its aqueous solubility is greatly enhanced for clinical application. The purpose of the present study was to increase the fermentation titer of nocathiacin I and reduce or eliminate analogous impurities by screening the medium ingredients using response surface methodology. After a sysmatic optimization, a water-soluble medium containing quality-controllable components was developed and validated, resulting in an increase in the production of nocathiacin I from 150 to 405.8 mg·L at 150-L scale. Meanwhile, the analogous impurities existed in reported processes were greatly reduced or eliminated. Using optimized medium for fermentation, nocathiacin I with pharmaceutically acceptable quality was easily obtained with a recovery of 67%. In conclusion, the results from the present study offer a practical and efficient fermentation process for the production of nocathiacin I as a therapeutic agent.
Actinobacteria ; growth & development ; metabolism ; Anti-Bacterial Agents ; biosynthesis ; chemistry ; Bioreactors ; Culture Media ; Fermentation ; Intercellular Signaling Peptides and Proteins ; Peptides ; chemistry ; metabolism ; Quality Improvement

Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.
Acetic Acid ; Biofuels ; Biomass ; Culture Media ; Fatty Acids ; Hydrolysis ; Industrial Microbiology ; Lignin ; chemistry ; Linoleic Acid ; Lipids ; biosynthesis ; Oleic Acid ; Rhodotorula ; metabolism

OBJECTIVETo investigate the inhibitory effect of high concentration insulin on K562 cell proliferation and its underlying mechanism.

METHODSK562 cells were treated by different concentration of insulin and/or anti-IGF-1R antibody (IGF-1R-Ab), MTT assay and flow cytometry were used to detect the K562 cells proliferation and apoptosis, respectivety; Western blot was used to measure the expression and phosphorylation level of IGE-IR, Akt, Erk1/2 in K562 cells under the different concentration of insulin.

RESULTSMTT assay showed that less than 40 mU/ml insulin could promote K562 cell proliferation, while high concentration (> 40 mU/ml) insulin has been shown to inhibit K562 cell proliferation; Flow cytometry showed that 40 mU/ml insulin suppressed K562 cell apoptosis (P < 0.05), while 200 mU/ml insulin could significantly induce K562 cell apoptosis (P < 0.01); 0.01 to 1.0 µg/ml IGF-1R-Ab has significantly enhanced the inhibitory and inducing effects of high concentration (> 40 mU/ml) of insulin on K562 cell proliferation and apoptosis respectively (r = 0.962, P < 0.001); Western blot showed that after K562 cells were treated with different concentrations of insulin ERK, and the p-ERK expression did not change significantly, after K562 cells were treated with 200 mU/ml insulin, the expression of IGF-1R and AKT also not were changed obviously, while the phosphorylation level of IGF-1R and AKT increased.

CONCLUSIONHigh concentration (>40 mU/ml) of insulin inhibits K562 cell proliferation and induces its apoptosis, and its mechanism may be related with the binding IGF-1R by insulin, competitively inhibiting the binding of IGF-1 and IGF-1R, the blocking the transduction of PI3K/AKT signal pathway.

Antibodies ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Culture Media ; chemistry ; Humans ; Insulin ; pharmacology ; Insulin-Like Growth Factor I ; metabolism ; K562 Cells ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptors, Somatomedin ; immunology ; Signal Transduction ; drug effects

OBJECTIVETo investigate the optimal starvation conditions of human umbilical vein endothelial cells (HUVECs) and establish a highly efficient and stable method for separating HUVECs.

METHODSHUVECs harvested from human umbilical cords by digestion with 0.1% collagenase II for 15 min were cultured in endothelial culture medium (ECM) containing 5% fetal bovine serum (FBS), 1% endothelial cell growth factor (ECGS) and 1% penicillin/streptomycin solution(P/S) at 37 degrees celsius; in 5% CO2. The cells were observed for cell morphology under an inverted microscope and identified with immunofluorescence assay. The purity of HUVECs was detected using flow cytometry (FCM). The cell cycles of HUVECs cultured in the presence of 0, 0.1%, 0.5%, and 1% FBS for 0, 6, 12, 18, and 24 h were analyzed with flow cytometry.

RESULTSs The purity of HUVECs harvested by digestion with 0.1% collagenase II reached 99.67%. The primary HUVECs showed a cobblestone or volute appearance in vitro. Immunocytochemistry showed that HUVECs highly expressed VIII-related antigen. Cell culture in the presence of different concentrations of FBS for 6 h resulted in 70% G0/G1 phase cells, which increased to 80%-90% at 12 h of cell culture, and further to around 95% at 18 and 24 h.

CONCLUSIONDigestion with 0.1% collagenase II can obtain high-purity primary HUVECs. Culturing HUVECs in serum-free medium for 12 h can result in a high purity (over 80%) of G0/G1 phase cells.

Cell Culture Techniques ; Cell Cycle ; Cells, Cultured ; Culture Media ; chemistry ; Flow Cytometry ; Human Umbilical Vein Endothelial Cells ; cytology ; Humans ; Matrix Metalloproteinase 8 ; chemistry ; Serum

OBJECTIVETo investigate the effect of prostaglandins E2 (PGE2) in enhancing vascular endothelial growth factor (VEGF) expression in a rat macrophage cell line and the effect of the media from PGE2-inuced rat macrophages on angiogenetic ability of human umbilical vein endothelial cells (HUVECs) in vitro.

METHODSWestern blotting and qPCR were employed to investigate the expressions of VEGF protein and mRNAs in rat macrophage cell line NR8383 stimulated by PGE2 in the presence or absence of EP2 receptor inhibitor (AH6809) and EP4 receptor inhibitor (AH23848). Conditioned supernatants were obtained from different NR8383 subsets to stimulate HUVECs, and the tube formation ability and migration of the HUVECs were assessed with Transwell assay.

RESULTSPGE2 stimulation significantly enhanced the expression of VEGF protein and mRNAs in NR8383 cells in a dose-dependent manner. The supernatants from NR8383 cells stimulated by PGE2 significantly enhanced tube formation ability of HUVECs (P<0.05) and promoted the cell migration. Such effects of PGE2 were blocked by the application of AH6809 and AH23848.

CONCLUSIONPGE2 can dose-dependently increase VEGF expression in NR8383 cells, and the supernatants derived from PGE2-stimulated NR8383 cells can induce HUVEC migration and accelerate the growth of tube like structures. PGE2 are essential to corpus luteum formation by stimulating macrophages to induce angiogenesis through EP2/EP4.

Animals ; Cell Line ; Cell Movement ; Cells, Cultured ; Culture Media, Conditioned ; pharmacology ; Dinoprostone ; pharmacology ; Human Umbilical Vein Endothelial Cells ; cytology ; drug effects ; Humans ; Macrophages ; chemistry ; Neovascularization, Pathologic ; RNA, Messenger ; Rats ; Receptors, Prostaglandin E, EP2 Subtype ; metabolism ; Receptors, Prostaglandin E, EP4 Subtype ; metabolism ; Vascular Endothelial Growth Factor A ; Xanthones ; pharmacology

OBJECTIVETo investigate the effects of oxygen concentration and reactive oxygen species (ROS) on the biological characteristics of hematopoietic stem cells (HSC) and to analyzed the relationship among the oxygen concentration, ROS and the biological characteristics of mouse HSC through simulation of oxygen environment experienced by PB HSC during transplantation.

METHODSThe detection of reactive oxygen species (ROS), in vitro amplification, directional differentiation (BFU-E, CFU-GM, CFU-Mix), homing of adhesion molecules (CXCR4, CD44, VLA4, VLA5, P-selectin), migration rate, CFU-S of NOD/SCID mice irradiated with sublethal dose were performed to study the effect of oxgen concentration and reactive oxygen species on the biological characteristics of mouse BM-HSC and the relationship among them.

RESULTSThe oxygen concentrations lower than normal oxygen concentration (especially hypoxic oxygen environment) could reduce ROS level and amplify more Lin(-) c-kit(+) Sca-1(+) BM HSC, which was more helpful to the growth of various colonies (BFU-E, CFU-GM, CFU-Mix) and to maintain the migratory ability of HSC, thus promoting CFU-S growth significantly after the transplantation of HSC in NOD/SCID mice irradiated by a sublethal dose. BM HSC exposed to oxygen environments of normal, inconstant oxygen level and strenuously thanging of oxygen concentration could result in higher level of ROS, at the same time, the above-mentioned features and functional indicators were relatively lower.

CONCLUSIONThe ROS levels of BM HSC in PB HSCT are closely related to the concentrations and stability of oxygen surrounding the cells. High oxygen concentration results in an high level of ROS, which is not helpful to maintain the biological characteristics of BM HSC. Before transplantation and in vitro amplification, the application of antioxidancs and constant oxygen level environments may be beneficial for transplantation of BMMSC.

Animals ; Cell Differentiation ; Culture Media ; chemistry ; Erythroid Precursor Cells ; cytology ; Granulocyte-Macrophage Progenitor Cells ; cytology ; Hematopoietic Stem Cells ; cytology ; metabolism ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Oxygen ; chemistry ; Reactive Oxygen Species ; metabolism

OBJECTIVETo compare several schemes of inducing and expanding the antibody-mediated high efficiency CIK (AMHE-CIK) in vitro, so as to find out a method that can acquire a large number of cells capable to kill the tumor cells in a short time.

METHODSPeripheral blood mononuclear cells (PBMNC) from healthy volunteers was isolated and activated with CD3 antibody, then were cultured with the addition of different cytokines (IL-2, IL-4, G-CSF, GM-CSF, IFN-γ, TNF-α) for 14 days in vitro. The morphological changes of cells were observed by light microscopy. Based on the immunophenotypes of cells in each groups analyzed by flow cytometry, the cytokines capable to induce the dendritic cells and killer cells were screened out, respectively. According to different combination of cytokines, the cells were divided 4 groups: control, IL-2, group 1 (componant A included IL-2, IL-4, and GM-CSF. Componant B included IL-2, G-CSF, IFN-γ, and TNF-α), and group 2 (componant A included IL-2, IL-4, and GM-CSF. Componant B included IL-2, IL-4, G-CSF, IFN-γ, and TNF-α). The proliferation and differentiation of CD3(+) CD8(+) and CD3(+) CD56(+) cells were measured by flow cytometry after culture in vitro for 7 days.

RESULTSAfter inducing and expanding in vitro for 7 days, the cell proliferation rate of control group, IL-2 group, group 1 and group 2 were 1.57 ± 0.01, 4.17 ± 0.16, 5 ± 0.47, 7.17 ± 0.24-folds, respectively. The differences between IL-2 group, group 1, group 2 and control group were statistically significant (P < 0.05). The immunophenotype analysis showed that the proportion of CD3(+) CD8(+) induced by each protocol was 13.96 ± 0.23%, 26.33 ± 0.55%, 36.83 ± 0.34% and 35.88 ± 0.16%, respectively. The proportion of CD3(+) CD8(+) in group 1 and 2 was higher than that in IL-2 group (P < 0.05), but the difference between them was not significant (P < 0.05). The proportions of CD3(+) CD56(+) induced by each protocol were 11.03 ± 0.28%, 29.31 ± 0.60%, 39.96 ± 0.38% and 29.33 ± 0.54%, respectively, the proportion of group 1 was higher than that of IL-2 group and group 2 (P < 0.05), but the difference between IL-2 group and group 2 was not significant (P < 0.05).

CONCLUSIONThe group 1 protocol obtained from this study can promote the proliferation of DC-CIK and also increase the proportion of the tumor killing cells (CD3(+) CD8(+) and CD3(+) CD56(+)).

Cell Culture Techniques ; Cells, Cultured ; Culture Media ; chemistry ; Cytokine-Induced Killer Cells ; cytology ; Granulocyte Colony-Stimulating Factor ; pharmacology ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Immunophenotyping ; Interferon-gamma ; pharmacology ; Interleukin-2 ; pharmacology ; Interleukin-4 ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo investigate the effect of MiR-200b on human retinal endothelial cells (hRECs) cultured in high glucose and explore the mechanism.

METHODShRECs cultured in high glucose or in normal media were examined for MiR-200b mRNA expression using real-time PCR. The effect of MiR-200b transfection on hREC proliferation in high-glucose culture was evaluated with MTT assay, and real-time PCR and Western blotting were performed to determine vascular endothelial growth factor (VEGF) and transforming growth factor β1 (TGFβ1) expression in the transfected cells.

RESULTSThe cells in high-glucose culture showed significantly decreased MiR-200b expression and active proliferation. Compared with those in normal control cells, VEGF and TGFβ1 mRNA and protein expressions increased markedly in cells cultured in high glucose (P<0.05). MiR-200b transfection of the cells caused significantly increased cellular expression of MiR-200b but decreased expression levels of VEGF and TGFβ1 mRNA and protein, and suppressed hREC proliferation in high glucose culture (P<0.05).

CONCLUSIONMiR-200b can regulate REC growth and proliferation by changing VEGF and TGFβ1 expressions and thus play a role in the pathogenesis and progression of diabetic retinopathy.

Blotting, Western ; Cell Proliferation ; Cells, Cultured ; Culture Media ; chemistry ; Diabetic Retinopathy ; Endothelial Cells ; cytology ; Glucose ; chemistry ; Humans ; MicroRNAs ; metabolism ; RNA, Messenger ; Real-Time Polymerase Chain Reaction ; Retina ; cytology ; Transfection ; Transforming Growth Factor beta1 ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism