Aromatic compounds are a class of organic compounds with benzene ring(s). Aromatic compounds are hardly decomposed due to its stable structure and can be accumulated in the food cycle, posing a great threat to the ecological environment and human health. Bacteria have a strong catabolic ability to degrade various refractory organic contaminants (e.g., polycyclic aromatic hydrocarbons, PAHs). The adsorption and transportation are prerequisites for the catabolism of aromatic compounds by bacteria. While remarkable progress has been made in understanding the metabolism of aromatic compounds in bacterial degraders, the systems responsible for the uptake and transport of aromatic compounds are poorly understood. Here we summarize the effect of cell-surface hydrophobicity, biofilm formation, and bacterial chemotaxis on the bacterial adsorption of aromatic compounds. Besides, the effects of outer membrane transport systems (such as FadL family, TonB-dependent receptors, and OmpW family), and inner membrane transport systems (such as major facilitator superfamily (MFS) transporter and ATP-binding cassette (ABC) transporter) involved in the membrane transport of these compounds are summarized. Moreover, the mechanism of transmembrane transport is also discussed. This review may serve as a reference for the prevention and remediation of aromatic pollutants.
Humans ; Adsorption ; Bacteria/metabolism* ; Organic Chemicals ; Biological Transport ; ATP-Binding Cassette Transporters ; Polycyclic Aromatic Hydrocarbons/metabolism*

Organic acids are organic compounds that can be synthesized using biological systems. They often contain one or more low molecular weight acidic groups, such as carboxyl group and sulphonic group. Organic acids are widely used in food, agriculture, medicine, bio-based materials industry and other fields. Yeast has unique advantages of biosafety, strong stress resistance, wide substrate spectrum, convenient genetic transformation, and mature large-scale culture technology. Therefore, it is appealing to produce organic acids by yeast. However, challenges such as low concentration, many by-products and low fermentation efficiency still exist. With the development of yeast metabolic engineering and synthetic biology technology, rapid progress has been made in this field recently. Here we summarize the progress of biosynthesis of 11 organic acids by yeast. These organic acids include bulk carboxylic acids and high-value organic acids that can be produced naturally or heterologously. Finally, future prospects in this field were proposed.
Saccharomyces cerevisiae/metabolism* ; Organic Chemicals ; Carboxylic Acids/metabolism* ; Metabolic Engineering ; Fermentation ; Acids

OBJECTIVETo study the hemostatic effect of chemical constituents from Callicarpa nudiflora.

METHODThe chemical constituents were isolated and purified via silica gel and Sephadex LH-20 column chromatography. Their structures were determined on the basis of spectral analysis. prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (FIB) of the constituents rabbit blood samples were tested with rabbit blood in vitro.

RESULTEleven compounds were isolated and identified as two diterpenens: 7alpha-hydroxy sandaracopimaric acid (1), 16, 17-dihydroxy-3-oxophyllocladane (2). Two phenoic glycosides: acteoside (3), samioside(4). Three triterpenes: 2alpha, 3alpha, 24-trihydroxy-ursa-12-en-28-oic acid (5), 2alpha, 3alpha, 19alpha-trihydroxyursa-12-en-28-oic acid-28-0-beta-D-glucopyranosyl ester (6), and 2alpha, 3alpha, 19alpha, 23-tetrahydroxy-ursa-12-en-28-oic acid-28-0-beta-D-glucopyranosyl ester (7). Four flavones: rhamnazin (8), 5-Hydroxy-3, 7, 4'-trimethoxy-flavone (9) , 5-Hydroxy-3, 7, 3', 4'-tetramethoxyflavone (10), and luteoloside (11). All Compounds cannot significantly shorten the PT (P < 0.01), compounds 3, 4, 7, 10 can remarkedly increase APTT (P < 0.01), compound 5 can prolong the T( P < 0.01) obviously, and compound 8 can significantly increase the contents of FIB (P < 0.01).

CONCLUSIONCompounds 2, 4 and 10 were isolated from this genus for the first time, and compounds 1, 3, 5, 6, 7 and 9 had been isolated from this plant for the first time. The hemostatic effect of C. nudiflora may be related to the activation of the intrinsic blood coagulation system.

Animals ; Blood Coagulation Factors ; metabolism ; Callicarpa ; chemistry ; Hemostasis ; drug effects ; Male ; Organic Chemicals ; analysis ; pharmacology ; Rabbits

We studied cutinase production from short-chain organic acids by Thermobifida fusca WSH03-11 to evaluate the possibility of converting municipal sludge to high value-added products. The optimum organic acid (8.0 g/L) and nitrogen source (1.5 g/L) concentrations were determined by the single factor experiments with butyric acid, propionic acid and acetic acid as the carbon sources. When lactic acid was used as the carbon source, the optimum organic acid (3.0 g/L) and nitrogen source (1.0 g/L) concentrations were obtained. Cutinase production by T. fusca WSH03-11 was further improved with butyric acid (by 31.0%), propionic acid (by 13.3%), acetic acid (by 43.8%) and lactic acid (by 73.2%) as carbon source, respectively, with the optimized cutin concentrations. Among these four short-chain organic acids, the average specific consumption rate of acetic acid was the highest, higher than that of propionic acid 1.3-folds, butyric acid 2.0-folds and lactic acid 2.2-folds. The highest cutinase activity reached 52.4 u/mL with butyric acid (8 g/L) as the sole carbon source, higher than that of lactic acid (3 g/L) 1.7-folds, acetic acid (8 g/L) 2.5-folds and propionic acid (8 g/L) 3.2-folds. The yield of cutinase activity on lactic acid (12.70 u/mg) higher than that of butyric acid 1.4-folds, propionic acid 3.0-folds and acetic acid 3.8-folds. T. fusca WSH03-11 consumed acetic acid firstly in mixed acids carbon sources, and the consumption of butyric acid was inhibited. Further studies indicated that the consumption rate of butyrate was decreased by 66.7% in the presence of 0.5 g/L acetic acid in the mixed acids. This was the first report concerning the production of cutinase by T. fusca with mixed organic acids as the carbon sources. The results presented here provided a novel and efficient approach to produce high value-add products from municipal sludge, and also established a foundation for the industrial production of cutinase by T. fusca WSH03-11 with cheap carbon sources from the processing of municipal sludge.
Acetates ; metabolism ; Actinomycetales ; growth & development ; metabolism ; Butyric Acid ; metabolism ; Carboxylic Ester Hydrolases ; biosynthesis ; Fermentation ; Organic Chemicals ; metabolism ; Propionates ; metabolism

OBJECTIVES: To study the correlation of the expression of Lipin1 in visceral adipose tissue and Lipin2 in liver tissue with hepatic fat content in rats with intrauterine growth retardation (IUGR). METHODS: Pregnant rats were given a low-protein (10% protein) diet during pregnancy to establish a model of IUGR in neonatal rats. The pregnant rats in the control group were given a normal-protein (21% protein) diet during pregnancy. The neonatal rats were weighed and liver tissue was collected on day 1 and at weeks 3, 8, and 12 after birth, and visceral adipose tissue was collected at weeks 3, 8, and 12 after birth. The 3.0T ¹H-magnetic resonance spectroscopy was used to measure hepatic fat content at weeks 3, 8, and 12 after birth. Real-time PCR was used to measure mRNA expression levels of Lipin2 in liver tissue and Lipin1 in visceral adipose tissue. Western blot was used to measure protein levels of Lipin2 in liver tissue and Lipin1 in visceral adipose tissue. A Pearson correlation analysis was performed to investigate the correlation of mRNA and protein expression of Lipin with hepatic fat content. RESULTS: The IUGR group had significantly higher mRNA and protein expression levels of Lipin1 in visceral adipose tissue than the control group at weeks 3, 8, and 12 after birth (P<0.05). Compared with the control group, the IUGR group had significantly lower mRNA and protein expression levels of Lipin2 in liver tissue on day 1 after birth and significantly higher mRNA and protein expression levels of Lipin2 at weeks 1, 3, 8, and 12 after birth (P<0.05). At week 3 after birth, there was no significant difference in hepatic fat content between the IUGR and control groups (P>0.05), while at weeks 8 and 12 after birth, the IUGR group had a significantly higher hepatic fat content than the control group (P<0.05). The protein and mRNA expression levels of Lipin1 were positively correlated with hepatic fat content (r=0.628 and 0.521 respectively; P<0.05), and the protein and mRNA expression levels of Lipin2 were also positively correlated with hepatic fat content (r=0.601 and 0.524 respectively; P<0.05). CONCLUSIONS Upregulation of the mRNA and protein expression levels of Lipin1 in visceral adipose tissue and Lipin2 in liver tissue can increase hepatic fat content in rats with IUGR and may be associated with obesity in adulthood.
Adult ; Animals ; Female ; Fetal Growth Retardation ; Gene Expression ; Humans ; Liver/metabolism* ; Organic Chemicals ; Pregnancy ; RNA, Messenger/metabolism* ; Rats

OBJECTIVETo study the possibility of removing nitrogen, phosphorus, and organic pollutants using seeding type immobilized microorganisms.

METHODSLakes P and M in Wuhan were chosen as the objects to study the removal of nitrogen, phosphorus, and organic pollutants with the seeding type immobilized microorganisms. Correlations between the quantity of heterotrophic bacteria and the total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in the two lakes were studied. The dominant bacteria were detected, inoculated to the sludge and acclimated by increasing nitrogen, phosphorus and decreasing carbon source in an intermittent, time-controlled and fixed-quantity way. The bacteria were then used to prepare the seeding type immobilized microorganisms, selecting diatomite as the adsorbent carrier. The ability and influence factors of removing nitrogen, phosphorus, and organic pollutant from water samples by the seeding type immobilized microorganisms were studied.

RESULTSThe coefficients of the heterotrophic bacterial quantity correlated with TOC, TP, and TN were 0.9143, 0.8229, 0.7954 in Lake P and 0.9168, 0.7187, 0.6022 in Lake M. Ten strains of dominant heterotrophic bacteria belonging to Pseudomonas, Coccus, Aeromonas, Bacillus, and Enterobateriaceae, separately, were isolated. The appropriate conditions for the seeding type immobilized microorgansims in purifying the water sample were exposure time=24 h, pH=7.0-8.0, and quantity of the immobilized microorganisms=0.75-1 g/50 mL. The removal rates of TOC, TP, and TN under the above conditions were 80.2%, 81.6%, and 86.8%, respectively.

CONCLUSIONThe amount of heterotrophic bacteria in the two lakes was correlated with TOC, TP, and TN. These bacteria could be acclimatized and prepared for the immobilized microorganisms which could effectively remove nitrogen, phosphorus, and mixed organic pollutants in the water sample.

Bacteria ; metabolism ; Environmental Pollutants ; isolation & purification ; Nitrogen ; isolation & purification ; Organic Chemicals ; isolation & purification ; Phosphorus ; isolation & purification ; Water Microbiology

With the rapid development of socialization and industrialization, more and more pollutes were produced and discharged into natural environment. It is harmful to human health and life. These pollutes included refractory degradation organic compounds like PAHs, RDX, HMX, CL-20, PCBs and alkanes and their relative substances. Various compounds exist in nature with long life span. They are the most hazardous than other organics. The impact of pollutes can be treated by microorganisms. Results showed that it is an effective way for bioremediation of these pollutes with microbial metabolism or cometabolism. A few key enzymes, mainly oxidative and reductive enzymes, connected with the first step of initial degradation. Normally, enzymes grouped with other active fraction on the cell membrane are composed of one oxidative and reductive system for substrates oxidation. The metabolic intermediates can be used with TCA by microorganisms. The pathways of metabolism and the key enzymes were summarized. The further research topics should be focused on microorganism screen and its relative enzyme, pathway and mechanism of metabolism or cometabolism for such compounds degradation, and the result was hoped for the environmental protection.
Bacteria ; enzymology ; metabolism ; Biodegradation, Environmental ; Environmental Pollutants ; metabolism ; Nitroreductases ; metabolism ; Organic Chemicals ; isolation & purification ; metabolism ; Oxidation-Reduction ; Oxidoreductases ; metabolism ; Polychlorinated Biphenyls ; metabolism ; Polycyclic Aromatic Hydrocarbons ; metabolism

Confronted with the gradual exhaustion of the earth's fossil energy resources and the grimmer environmental deterioration, the bio-based process to produce high-value added platform chemicals from renewable biomass is attracting growing interest. Escherichia coli has been chosen as a workhouse for the production of many valuable chemicals due to various advantages, such as clear genetic background, convenient to be genetically modified and good growth properties with low nutrient requirements. Rational strain development of E. coli achieved by metabolic engineering strategies has provided new processes for efficiently biotechnological production of various high-value chemical building blocks. This review focuses on recent progresses in metabolic engineering of E. coli that lead to efficient recombinant biocatalysts for production of high-value organic acids such as succinic acid, 3-hydroxypropanoic acid and glucaric acid as well as alcohols like glycerol and xylitol. Besides, this review also discusses several other platform chemicals, including 2,5-furan dicarboxylic acid, aspartic acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxy-gamma-butyrolactone and sorbitol, which have not been produced by E. coli until now.
Acids ; metabolism ; Alcohols ; metabolism ; Biocatalysis ; Escherichia coli ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; methods ; Metabolic Networks and Pathways ; genetics ; Organic Chemicals ; metabolism

A novel reaction-enzymatic ammonolysis discovered in the mid of 1990s has been demonstrated to be a very promising alternative in the preparation of optically pure compounds. The effects of organic solvent, initial water activity, temperature and additives on lipase Novozym435-catalyzed enantioselective ammonolysis of racemic phenylglycine methyl ester were investigated systematically in this paper. Enzymatic reaction of ammonolysis showed higher activity and enantioselectivity than the corresponding reaction of hydrolysis and alcoholysis.
Alcohols ; Ammonia ; Catalysis ; Dimethylformamide ; pharmacology ; Esters ; Glycine ; analogs & derivatives ; metabolism ; Hexoses ; pharmacology ; Hydrolysis ; Lipase ; drug effects ; metabolism ; Organic Chemicals ; Solvents ; Surface-Active Agents ; pharmacology ; Temperature ; Water

OBJECTIVETo establish and optimize a real time RT-PCR system for determining the transcript levels of CatSper1 in human and mouse mature spermatozoa containing microamount of RNA.

METHODSTotal RNA of human and mouse mature spermatozoa was isolated by using TRIzol reagent and reversely transcribed to complementary DNA respectively. Primers for real time RT-PCR were designed in the homologous area of the human and mouse CatSper1 mRNAs. Human sperm complementary DNA was used as the template to the optimize the conditions for SYBR Green I real time RT-PCR, including annealing temperature, Mg2+ concentration, fluorescence measurement temperature and the ratio between forward and reverse primers. The standard curve was constructed with serial dilutions of complementary DNA from human sperm to ascertain the amplification efficiency of SYBR Green I real time PCR and to quantitate the CatSper1 mRNA levels in the human and mouse mature spermatozoa.

RESULTSThe optimal conditions for real time RT-PCR, that is, annealing temperature, Mg2+ concentration and the ratio between forward and reverse primers were 63 degrees C, 3.0 mmol/L and 1:1 respectively. The fluorescence measurement temperature was 88 degrees C. The standard curves were Y = -3.402 log (X) + 25.99 and Y = -3.409 log(X) + 24.09 in the human sperm cDNA and mouse sperm cDNA as the template, with amplification efficiency of 96.8% and 96.5% respectively. The R2 value (an indicator of the quality of the fit of the standard curve to the standard data points plotted) of both standard curves was 0.998. The CatSper1 mRNA levels in the human and mouse mature spermatozoa could be determined according to the standard curve.

CONCLUSIONThe general RT-PCR system, by adding SYBR Green I and optimizing its conditions, could be used to quantitate the mRNA levels in both human and mouse mature spermatozoa.

Animals ; Calcium Channels ; genetics ; Humans ; Male ; Mice ; Organic Chemicals ; chemistry ; RNA, Messenger ; genetics ; metabolism ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Spermatozoa ; metabolism