This study investigates the twitching ability of 28 clinical and five environmental strains of S. maltophilia grown under iron-depleted condition through in-silico, phenotypic and proteomics approaches. Rapid Annotations using Subsystem Technology (RAST) analysis revealed the presence of 21 targets of type IV pilus shared across S. maltophilia strains K279a, R551-3, D457 and JV3. The macroscopic twitching assay showed that only clinical isolates produced a zone of twitching with a mean of 22.00 mm under normal and 25.00 mm under iron-depleted conditions. (p = 0.002). Environmental isolates did not show any significant twitching activity in both conditions tested. Isobaric Tags for Relative and Absolute Quantification (ITRAQ) analysis showed altered expression of twitching motility protein PilT (99.08-fold change), flagellar biosynthesis protein FliC (20.14-fold change), and fimbrial protein (0.70-fold change) in response to iron-depleted condition. Most of the strains that have the ability to twitch under the normal condition, exhibit enhanced twitching during iron limitation.
Crustacean molting is highly related to energy and lipid metabolism. This study was conducted to detect the changes of total lipids (TL), triacylglyceride (TAG), phospholipid (PL) and lipid droplets in hepatopancreas, and then to investigate the gene expression patterns related to hepatopancreatic lipid metabolism during the molting cycle of Chinese mitten crab Eriocheir sinensis. Hepatopancreatic TL and TAG increased significantly from post-molt stage to pre-molt stage, then decreased significantly from pre-molt stage to ecdysis stage, which is consistent to the changes of neutral lipid-rich adipocytes in hepatopancreas. By transcriptomic analysis, 65,325 transcripts were sequenced and assembled, and 28,033 transcripts were annotated. Most genes were related to energy metabolism, and the enriched genes were involved in carbohydrate and lipid metabolism and biosynthesis, especially in de novo synthesis of fatty acids and TAG, and ketone body production. Compared to the inter-molt stages, acetyl-CoA carboxylase, fatty acid synthase and other genes related to the synthesis of fatty acids were upregulated in the pre-molt stage. TAG synthesis related genes, including Glycerol-3-phosphate acyltransferase and 1-acylglycerol-3-phosphate acyltransferases, were upregulated in the post-molt stage compared to the inter-molt stage. The expression of ketone body-related genes had no significant changes during the molting cycle. Compared to the TAG synthetic pathway, ketone body biosynthesis may contribute less/secondarily to fatty acid metabolic processes, which could be involved in the other physiological processes or metabolism. In conclusion, these results showed that TAG is the major lipid deposition during inter- and pre-molt stages, and the most genes are related to the fatty acids and TAG metabolism in the hepatopancreas during the molting cycle of E. sinensis.
Understory plants in tropical forests often experience a low-light environment combined with high CO2 concentration. We hypothesized that the high CO2 concentration may compensate for leaf carbon loss caused by the low light, through increasing light-use efficiency of both steady-state and dynamic photosynthetic properties. To test the hypothesis, we examined CO2 gas exchange in response to an artificial lightfleck in Dipterocarpus sublamellatus Foxw. seedlings under contrasting CO2 conditions: 350 and 700 μmol CO2 mol(-1) air in a tropical rain forest, Pasoh, Malaysia. Total photosynthetic carbon gain from the lightfleck was about double when subjected to the high CO2 when compared with the low CO2 concentration. The increase of light-use efficiency in dynamic photosynthesis contributed 7% of the increased carbon gain, most of which was due to reduction of photosynthetic induction to light increase under the high CO2. The light compensation point of photosynthesis decreased by 58% and the apparent quantum yield increased by 26% at the high CO2 compared with those at the low CO2. The study suggests that high CO2 increases photosynthetic light-use efficiency under both steady-state and fluctuating light conditions, which should be considered in assessing the leaf carbon gain of understory plants in low-light environments.
Zingiber officinale Roscoe. (Family Zingiberaceae) is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin) and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid), and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara) with CO(2) enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO(2) enrichment from 400 to 800 µmol mol-1 CO(2). These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC) results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO(2) conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO(2) concentration was increased from 400 to 800 µmol mol-1, free radical scavenging power (DPPH) increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO(2) enrichment.
Ethanol was produced via the simultaneous saccharification and fermentation (SSF) of dilute sodium hydroxide treated corn stover. Saccharification was achieved by cultivating either Phanerochaete chrysosporium or Gloeophyllum trabeum on the treated stover, and fermentation was then performed by using either Saccharomyces cerevisiae or Escherichia coli K011. Ethanol production was highest on day 3 for the combination of G. trabeum and E. coli K011 at 6.68 g/100g stover, followed by the combination of P. chrysosporium and E. coli K011 at 5.00 g/100g stover. SSF with S. cerevisiae had lower ethanol yields, ranging between 2.88 g/100g stover at day 3 (P. chrysosporium treated stover) and 3.09 g/100g stover at day 4 (G. trabeum treated stover). The results indicated that mild alkaline pretreatment coupled with fungal saccharification offers a promising bioprocess for ethanol production from corn stover without the addition of commercial enzymes.
The biochemical events associated with the onset of lipid accumulation in Mucor circinelloides and Mortierella alpina, under conditions of nitrogen-limited growth, have been elucidated; they differ in key aspects from those described in oleaginous yeasts. The NAD+:isocitrate dehydrogenases of Mc. circinelloides and Mort. alpina were not absolutely dependent on AMP for activity. Furthermore, changes in the cellular adenine nucleotide pools and energy charge were different from those reported for oleaginous yeasts. In Mc. circinelloides ATP, ADP and AMP concentrations all decreased by 50% after nitrogen limitation, leading to a constant energy charge at the expense of the size of the total adenylate pool. Pyruvate carboxylase in Mc. circinelloides was cytosolic, having implications for the organization of lipid synthesis in filamentous fungi. As a result of the data obtained, a revised and more concerted mechanism for the initiation of storage lipid accumulation is put forward for filamentous fungi.
To isolate a bacterial strain capable of biotransforming ferulic acid, a major component of lignin, into vanillin and vanillic acid by a rapid colorimetric screening method.
Solubility and matrix play an important role in the gut lumen in delivering bioactive compounds to the absorptive surface of enterocytes. The purpose of this study was to determine the effect of certain commonly consumed lipids, soybean, olive and corn oil, on the transport and conjugation of flavonols (myricetin, quercetin, kaempferol and galangin) using the conjugation-competent co-cultured Caco-2/HT29-MTX intestinal cell monolayer model. To enable identification and quantification of conjugates, each flavonol was enzymatically glucuronidated or sulphated, then analysed by HPLC with triple quadrupole mass spectrometric detection. Quantification showed large differences in mass spectrometric peak area response factors between the aglycones and many of the conjugates, with galangin-sulphate for example ionising ∼15-fold better than galangin. Flavonol aglycones and conjugates were transported to the basolateral side of Caco-2/HT29-MTX co-cultures. The total amount of methyl, sulphate and glucuronide conjugates was in the order: galangin > quercetin > kaempferol > myricetin. All oils inhibited the transport and conjugation of galangin, the most hydrophobic flavonol, whereas they increased the sulphation, and to some extent glucuronidation, of quercetin and kaempferol. The results show that the lipid matrix has the potential to modify both transport and conjugation of dietary flavonols, but that the effect depends upon the structure and hydrophobicity.
In general, Cordyceps sinensis is much more popular than C. militaris, though both species contain quite similar bioactive ingredients and exhibit medicinal activities. Many bioactive ingredients have been isolated from C. militaris, such as adenosine, cordycepin, D-mannitol, and exopolysaccharides. C. militaris is claimed to have extensive pharmacological properties, such as: anti-inflammatory; anti-fatigue; anti-bacterial; anti-diabetic; improve lung, liver, and kidney functions; to be beneficial for treating cancer as well as male and female sexual dysfunctions. C. militaris is fast gaining momentum for its so-called health benefits, and it is often used as a substitute for C. sinensis. In view of the growing popularity of C. militaris, nowadays C. militaris cultivation for stroma is also done. There is a great diversity of compounds from different strains of Cordyceps and different artificially cultivated products. This study is to determine the optimum culture parameters integrated with substrate of choice to bring the indoor-cultivated C. militaris to a higher and more consistent level of quality. To achieve the above objective, the resultant products after growth were analyzed for adenosine, cordycepin, and D-mannitol using the high-performance liquid chromatography method. The optimum culture condition to produce a high level of adenosine is by using millet as solid substrate. It must be cultivated in the dark for the first 7 days and harvested on day 40. The optimum culture condition to produce a high level of cordycepin is by using soybean as solid substrate. It must be cultivated in the dark for the first 14 days and harvested on day 50. While a high level of D-mannitol is achieved with millet as the solid substrate. It must be kept in the dark for the first 7 days and harvested on day 50. The adenosine level decreased and cordycepin increased from day 40 of culture to day 50 generally.
A split plot 3 by 3 experiment was designed to investigate and distinguish the relationships among production of primary metabolites (soluble sugar and starch), secondary metabolites (total phenolics, TP; total flavonoids, TF) and leaf gas exchange of three varieties of the Malaysian medicinal herb Labisia pumila Blume, namely the varieties alata, pumila and lanceolata, under three levels of CO₂ enrichment (400, 800 and 1,200 µmol mol⁻¹) for 15 weeks. The treatment effects were solely contributed by CO₂ enrichment levels; no varietal differences were observed. As CO₂ levels increased from 400 to 1,200 µmol mol⁻¹, the production of carbohydrates also increased steadily, especially for starch more than soluble sugar (sucrose). TF and TP content, simultaneously, reached their peaks under 1,200 µmol exposure, followed by 800 and 400 µmol mol⁻¹. Net photosynthesis (A) and quantum efficiency of photosystem II (f(v)/f(m)) were also enhanced as CO₂ increased from 400 to 1,200 µmol mol⁻¹. Leaf gas exchange characteristics displayed a significant positive relationship with the production of secondary metabolites and carbohydrate contents. The increase in production of TP and TFs were manifested by high C/N ratio and low protein content in L. pumila seedlings, and accompanied by reduction in cholorophyll content that exhibited very significant negative relationships with total soluble sugar, starch and total non structural carbohydrate.
Matched MeSH terms: Carbon Dioxide/metabolism*; Plant Leaves/metabolism*; Primulaceae/metabolism*; Seedlings/metabolism*; Photosystem II Protein Complex/metabolism
Consumption of probiotics has been associated with decreased risk of colon cancer and reported to have antimutagenic/ anti-carcinogenic properties. One possible mechanism for this effect involves physical binding of the mutagenic compounds, such as heterocyclic amines (HCAs), to the bacteria. Therefore, the objective of this study was to examine the binding capacity of bifidobacterial strains of human origin on mutagenic heterocyclic amines which are suspected to play a role in human cancers. In vitro binding of the mutagens Trp-p-2, IQ, MeIQx, 7,8DiMeIQx and PhIP by three bacterial strains in two media of different pH was analysed using high performance liquid chromatography. Bifidobacterium pseudocatenulatum G4 showed the highest decrease in the total HCAs content, followed by Bifidobacterium longum, and Escherichia coli. pH affects binding capacity; the highest binding was obtained at pH 6.8. Gram-positive tested strains were found to be consistently more effective than the gram-negative strain. There were significant decreases in the amount of HCAs in the presence of different cell concentrations of B. pseudocatenulatum G4; the highest decrease was detected at the concentration of 10(10) cfu/ml. The results showed that HCAs were able to bind with all bacterial strains tested in vitro, thus it may be possible to decrease their absorption by human intestine and increase their elimination via faeces.
Pre-eclampsia or pregnancy induced hypertension (PIH) affects 6-8% of all pregnancies. Although the underlying mechanism of PIH is still unknown, it is widely believed that the placenta plays an important role. It was thought that an ischemic placenta due to poor perfusion can precipitate the signs and symptoms of PIH. This study aims to investigate the possible role of Type 1(AT1) and Type 2 (AT2) angiotensin II receptor subtypes in the mechanism of PIH. AT1 receptor stimulation causes vasoconstriction and AT2 receptor stimulation causes vasodilatation. Investigating the interactions of these two receptors in the placenta provides an insight as to the balance that may exist between AT1 and AT2 receptors in normal pregnancy. Any disruption to the balance might cause a disruption of the blood flow in the placenta, leading to PIH. Placentas were collected from 11 PIH patients and 11 normal patients. Immunohistochemistry techniques were performed on the placental tissue to determine the distribution of AT1 and AT2 receptors in the placental tissue qualitatively and quantitatively. It was observed that in normal patients, the balance between AT1 and AT2 receptors is that the level of AT2 receptors is higher than the level of AT1 receptors. However in the PIH patient, it was observed that the normal balance was disrupted. In PIH patients the level of AT1 receptors was observed to be higher than the level of AT2 receptors. This study suggests that disruption of the balance between AT1 and AT2 receptors observed in PIH placentas might cause a decrease in blood flow to the placenta, causing it to be poorly perfused. This may cause placental ischemia which may lead to PIH.
Previous studies have shown that enhanced biological phosphorus removal (EBPR) performance under continuous aerobic conditions always eventually deteriorates; however, the speed at which this happens depends on the carbon source supplied. The published data suggest that propionate is a better carbon source than acetate is for maintaining operational stability, although it is not clear why. A lab-scale sequencing batch reactor was run initially under conventional anaerobic/aerobic conditions with either acetate or propionate as the carbon source. Chemical and microbiological analyses revealed that both sources performed as expected for such systems. When continuous aerobic conditions were imposed on both these established communities, marked shifts of the "Candidatus Accumulibacter" clades were recorded for both carbon sources. Here, we discuss whether this shift could explain the prolonged EBPR stability observed with propionate.
Abundant lignocellulosic biomass from various industries provides a great potential feedstock for the production of value-added products such as biofuel, animal feed, and paper pulping. However, low yield of sugar obtained from lignocellulosic hydrolysate is usually due to the presence of lignin that acts as a protective barrier for cellulose and thus restricts the accessibility of the enzyme to work on the cellulosic component. This review focuses on the significance of biological pretreatment specifically using ligninolytic enzymes as an alternative method apart from the conventional physical and chemical pretreatment. Different modes of biological pretreatment are discussed in this paper which is based on (i) fungal pretreatment where fungi mycelia colonise and directly attack the substrate by releasing ligninolytic enzymes and (ii) enzymatic pretreatment using ligninolytic enzymes to counter the drawbacks of fungal pretreatment. This review also discusses the important factors of biological pretreatment using ligninolytic enzymes such as nature of the lignocellulosic biomass, pH, temperature, presence of mediator, oxygen, and surfactant during the biodelignification process.
Esterification of succinic acid with oleyl alcohol catalyzed by immobilized Candida antarctica lipase B (Novozym 435) was investigated in this study. Response surface methodology (RSM) based on a five-level, four-variable central composite design (CCD) was used to model and analyze the reaction. A total of 21 experiments representing different combinations of the four parameters including temperature (35-65°C), time (30-450 min), enzyme amount (20-400 mg), and alcohol:acid molar ratio (1:1-8:1) were generated. A partial cubic equation could accurately model the response surface with a R(2) of 0.9853. The effect and interactions of the variables on the ester synthesis were also studied. Temperature was found to be the most significant parameter that influenced the succinate ester synthesis. At the optimal conditions of 41.1°C, 272.8 min, 20 mg enzyme amount and 7.8:1 alcohol:acid molar ratio, the esterification percentage was 85.0%. The model can present a rapid means for estimating the conversion yield of succinate ester within the selected ranges.
The potential significance of the previously reported papaya (Carica papaya L.) beta-galactosidase/galactanase (beta-d-galactoside galactohydrolase; EC 3.2.1.23) isoforms, beta-gal I, II and III, as softening enzymes during ripening was evaluated for hydrolysis of pectins while still structurally attached to unripe fruit cell wall, and hemicelluloses that were already solubilized in 4 M alkali. The enzymes were capable of differentially hydrolyzing the cell wall as evidenced by increased pectin solubility, pectin depolymerization, and degradation of the alkali-soluble hemicelluloses (ASH). This enzyme catalyzed in vitro changes to the cell walls reflecting in part the changes that occur in situ during ripening. beta-Galactosidase II was most effective in hydrolyzing pectin, followed by beta-gal III and I. The reverse appeared to be true with respect to the hemicelluloses. Hemicellulose, which was already released from any architectural constraints, seemed to be hydrolyzed more extensively than the pectins. The ability of the beta-galactanases to markedly hydrolyze pectin and hemicellulose suggests that galactans provide a structural cross-linkage between the cell wall components. Collectively, the results support the case for a functional relevance of the papaya enzymes in softening related changes during ripening.
Bacteria-derived enzymes that can modify specific lignin substructures are potential targets to engineer plants for better biomass processability. The Gram-negative bacterium Sphingobium sp. SYK-6 possesses a Cα-dehydrogenase (LigD) enzyme that has been shown to oxidize the α-hydroxy functionalities in β-O-4-linked dimers into α-keto analogues that are more chemically labile. Here, we show that recombinant LigD can oxidize an even wider range of β-O-4-linked dimers and oligomers, including the genuine dilignols, guaiacylglycerol-β-coniferyl alcohol ether and syringylglycerol-β-sinapyl alcohol ether. We explored the possibility of using LigD for biosynthetically engineering lignin by expressing the codon-optimized ligD gene in Arabidopsis thaliana. The ligD cDNA, with or without a signal peptide for apoplast targeting, has been successfully expressed, and LigD activity could be detected in the extracts of the transgenic plants. UPLC-MS/MS-based metabolite profiling indicated that levels of oxidized guaiacyl (G) β-O-4-coupled dilignols and analogues were significantly elevated in the LigD transgenic plants regardless of the signal peptide attachment to LigD. In parallel, 2D NMR analysis revealed a 2.1- to 2.8-fold increased level of G-type α-keto-β-O-4 linkages in cellulolytic enzyme lignins isolated from the stem cell walls of the LigD transgenic plants, indicating that the transformation was capable of altering lignin structure in the desired manner.
The oriental fruit fly, Bactrocera dorsalis (Handel) is one of the most destructive pests of fruits. The discovery of methyl eugenol (ME) as a potent male attractant for this species has led to its successful use in area-wide fruit fly control programs such as male annihilation. While the antenna is recognized as primarily responsible for male flies' detection of attractants such as ME, little is known of the involvement of the maxillary palp. Using behavioral assays involving males with intact and ablated antennae and maxillary palp structures, we seek to ascertain the relative involvement of the maxillary palp in the ability of the male fly to detect ME. In cage bioassays (distance of ≤40 cm from the source), >97% of unmodified males will normally show a response to ME. Here, we showed that 17.6% of males with their antennae ablated were still attracted to ME versus 75.0% of males with their palps ablated. However, none of the antennae-ablated males were able to detect ME over a distance of >100 cm. Furthermore, wind tunnel bioassays showed that maxillary palp-ablated males took a significantly longer time compared to unablated males to successfully detect and eventually feed on ME. These results suggest that although the antennae are necessary for detection of ME over longer distances, at shorter distances, both antennae and maxillary palps are also involved in detecting ME. Hence, those palps may play a larger role than previously recognized in maneuvering males toward lure sources over shorter ranges.
Matched MeSH terms: Chemoreceptor Cells/metabolism*; Eugenol/metabolism; Sex Attractants/metabolism*; Tephritidae/metabolism*; Sensilla/metabolism*
Champedak (Artocarpus integer) lectin-M is a lectin with high specificity and affinity for the core-mannosyl residues of the N-linked oligosaccharides of glycoproteins. We have studied the interaction of the champedak seed lectin with human serum glycoproteins that were resolved by 2-dimensional (2-D) gel electrophoresis. The lectin demonstrated strong interaction with haptoglobin beta chain, orosomucoid, alpha1-antitrypsin, alpha2-HS glycoprotein, transferrin, hemopexin, alpha1B-glycoprotein, and the heavy chains of IgA, IgM and IgG of the human serum. With exceptions of the heavy chains of the immunoglobulins and alpha1B-glycoprotein, all the other lectin-M-probed glycopeptides are acute-phase proteins. The use of champedak lectin-M to probe for serum glycoproteins that were separated in a 2-D gel electrophoresis and Western blotting technique may be conveniently applied to analyse the acute-phase and humoral immune responses simultaneously. Subjecting human serum to immobilised-lectin-M affinity chromatography was able to isolate intact haptoglobin, alpha1-antitrypsin, alpha1B-glycoprotein, hemopexin and IgA.
Activated microglial cells play an important role in immune and inflammatory responses in central nervous system and neurodegenerative diseases. Many pro-apoptotic pathways are mediated by signaling molecules that are produced during neuroinflammation. In glial cells, NF-κB, a transcription factor, initiates and regulates the expression of several inflammatory processes during inflammation which are attributed to the pathology of the several neurodegenerative diseases. In this review, we discuss the most important neuroinflammatory mediators with their pathways. Attenuating cytokines production and controlling microglial inflammatory response, which are the result of understanding neuroinflammation pathways, are considered therapeutic strategies for treating neurodegenerative diseases with an inflammatory component.