scholarly journals Biodegradation of Polymeric Material and Adhesive Properties of Cells of Microorganisms

2010 ◽  
Vol 4 (4) ◽  
pp. 305-309
Author(s):  
Gennady Zaikov ◽  
◽  
Klara Gumargalieva ◽  
Marina Artsis ◽  
◽  
...  

The chemical composition of cell membranes of microscopic fungi destroying polymeric materials is analyzed. The concentrations of the major chemical components – phospholipids, glycans, and amines – in nine types of fungi are estimated. The measured ratios of these components provide an estimate of the hydrophobic properties of conidia, controlling microorganism adhesion to polymer surface and subsequent degradation of polymeric materials.

2018 ◽  
Vol 13 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Liang Peng ◽  
Yunhao Xiong ◽  
Mei Wang ◽  
Manman Han ◽  
Weilan Cai ◽  
...  

AbstractThe essential oil of Mosla chinensis Maxim cv. Jiangxiangru is known for its antibacterial ability. This study aimed to investigate the chemical composition of Jiangxiangru essential oil and its inhibitory effect on Staphylococcus aureus biofilm formation. Gas chromatography/mass spectrometry (GC–MS) was used to determine the chemical composition of Jiangxiangru essential oil. Subsequently, the eight major chemical components were quantitatively analyzed using GC– MS, and their minimum inhibitory concentration (MIC) values against S. aureus were tested. Biofilm formation was detected by crystal violet semi-quantitative method and silver staining. Of the 59 peaks detected, 29 were identified by GC–MS. Of these peaks, thymol, carvacrol, p-cymene, γ-terpinene, thymol acetate, α-caryophyllene, 3-carene, and carvacryl acetate were present at a relatively higher concentration. The results of the quantitative test showed that thymol, carvacrol, p-cymene, and γ-terpinene were the major components of the essential oil. Among the eight reference substances, only thymol, carvacrol, and thymol acetate had lower MICs compared with the essential oil. Essential oil, carvacrol, carvacryl acetate, α-caryophyllene, and 3-carene showed the better inhibition of S. aureus biofilm formation. When one fourth of the MIC concentrations were used for these substances (0.0625 mg/mL for essential oil, 0.0305 mg/mL for carvacrol, 1.458 mg/mL for carvacryl acetate, 0.1268 mg/mL for α-caryophyllene, and 2.5975 mg/mL for 3-carene), the inhibition rates were over 80%. However, thymol, γ-terpinene, thymol acetate, and p-cymene showed a relatively poor inhibition of S. aureus biofilm formation. When 1× MIC concentrations of these substances were used, the inhibition rates were less than 50%. In conclusion, Jiangxiangru essential oil and its major components, carvacrol, carvacryl acetate, α-caryophyllene, and 3-carene, strongly inhibited biofilm formation in S. aureus.


1969 ◽  
Vol 15 (7) ◽  
pp. 665-669 ◽  
Author(s):  
L. H. Knipp ◽  
J. R. Sokatch

The chemical composition of the cell envelope of the bacillary form of Streptobacillus moniliformis was investigated to determine if there were any unusual features which might account for the ability of this organism to produce L forms spontaneously. A procedure was developed for the preparation of particles of the cell envelope using sonic oscillation to disrupt the cells. Particles of the cell envelope of E. coli B prepared by this method were comparable to those preparations obtained by other methods. The percentages of the major chemical components of the cell envelope of S. moniliformis were 64% protein, 28% lipid, and 6% carbohydrate. Cell envelope preparations made from E. coli B contained 66% protein, 18% lipid, and 10% carbohydrate. All common amino acids were present in hydrolysates of the cell envelope of S. moniliformis with the exception of cysteine. The monosaccharides detected in hydrolysates of the cell envelope of S. moniliformis were glucose, galactose, heptose, glucosamine, and muramic acid. The amounts of glucosamine and muramic acid (and presumably therefore mucopeptide) present in the cell envelope of S. moniliformis were much less than those amounts detected in the cell envelope of E. coli B. It is suggested that the low content of mucopeptide may be related to the ability of S. moniliformis to produce L forms spontaneously.


Author(s):  
Miss. Patil Shivani Navnath

Abstract: The Presenace study investigation oil isolation form cyperus rotundus and the chemical composition of essential oil of root's of Cyprus rotundus.In india it's commonly known as nagarmotha.and it belongs to the family cyperacea.the major chemical components of this herb are essential oils.flavonoids, terpenoids, sesauiterpenes, cyproten, cyperene, aselinene, rotundene, valencene, cyperol, gurjunene, transcalamenenene, cad'Alene, cyperoutundone, mustskone, isocyperol, acyperone etc. Reserch studies have shown that it possesses various Pharmacological activity Such as diuretic,carmenative emmenagogue, anthelmintic, analgesic, anti-inflammatory, anti-dysentery, anti-rheumatic activities.an extensive review of the ancient traditional literature and madern research revealead that the drug has numerous therapeutic action. Several of which have been established scientifically, which may help the reserchers to set their minds for approaching the utility efficiency and potency of nagarmotha. Keywords: cyperus rotundus, cyprotene flavanoids nagarmotha.


2013 ◽  
Vol 64 (4) ◽  
Author(s):  
N. Baharin ◽  
Y. Z. Arief ◽  
W. A. Izzati ◽  
M. Z. H. Makmud ◽  
Z. Adzis ◽  
...  

Surface discharge is a common electrical discharge that normally occurs on the surface of outdoor insulators and also causes the failure in the electrical insulation system. One of the causes of surface discharge is the presence of high voltage stress. Experimental works had been carried out to examine the surface discharge characteristics on polymeric samples as insulation material. The IEC (b) electrode configuration had been used to investigate the surface discharges phenomena of different types of polymeric materials with controlled of air relative humidity (RH). In these experimental works, three types of polymeric sample were selected, namely high-density polyethylene (HDPE), ethylene-vinyl acetate (EVA), and polystyrene (PS), respectively. The characteristics of the discharge are critically depending on the types of polymer. Surface discharges intensity, number of discharge occurrence, and surface morphology of each polymeric material were also investigated. Comparisons of these electrical characteristics were conducted among the samples. Results from the experiment showed that the EVA samples experienced severe degradation as compared to HDPE and PS samples.


2018 ◽  
Vol 15 (1) ◽  
pp. 21-33
Author(s):  
Ying Wei ◽  
Yongqiao Liu ◽  
Yifan Hele ◽  
Weiwei Sun ◽  
Yang Wang ◽  
...  

Background: Gentianella acuta (Michx.) Hulten is an important type of medicinal plant found in several Chinese provinces. It has been widely used in folk medicine to treat various illnesses. However, there is not enough detailed information about the chemical constituents of this plant or methods for their content determination. Objective: The focus of this work is the isolation and characterization of the major chemical constituents of Gentianella acuta, and developing an analytical method for their determination. Methods: The components of Gentianella acuta were isolated using (1) ethanol extraction and adsorption on macroporous resin. (2) and ethyl acetate extraction and high speed countercurrent chromatography. A HPLC-DAD method was developed using a C18 column and water-acetonitrile as the mobile phase. Based on compound polarities, both isocratic and gradient elution methods were developed. Results: A total of 29 compounds were isolated from this plant, of which 17 compounds were isolated from this genus for the first time. The main components in this plant were found to be xanthones. The HPLC-DAD method was developed and validated for their determination, and found to show good sensitivity and reliability. Conclusion: The results of this work add to the limited body of work available on this important medicinal plant. The findings will be useful for further investigation and development of Gentianella acuta for its valuable medicinal properties.


2018 ◽  
Vol 46 (2) ◽  
pp. 258-267
Author(s):  
J.M. Alonso Vega ◽  
Pedro H. Toledo

Lessonia berteroana (ex L. nigrescens) is kelp freely harvested from Open Access Areas (OAA), and to some extent controlled, from Management and Exploitation Areas for Benthic Resources (MEABR). Harvesting pressures can change population dynamics, mainly in OAAs. In particular, harvesting may alter the chemical components of plants. Therefore, the aim of this study was to determine the harvesting effects on the chemical composition of L. berteroana from MEABR and OAA sampled during different seasons (spring and fall) and at two sites (Talquilla and Lagunillas) near Coquimbo (30°S), Chile. The crude protein (13.5 ± 1.0%), total lipids (0.9 ± 0.2%), crude fiber (16.3 ± 1.6%), ash (30.1 ± 1.5%), and nitrogen-free extract (39.2 ± 2.0%) contents of L. berteroana were within reference values for Laminariales species. Population descriptors and chemical analyses showed that harvesting had local effects, rather than being affected by a resource management strategy (OAA vs MEABR). The seasonal anticipator nature of L. berteroana may explain the detected seasonality of it's chemical composition. Regarding functional morphological structures, chemical composition in the fronds was more variable than in the stipes and perennial holdfast, probably since leaves are ephemeral structures susceptible to environmental changes and that play a functional, rather than structural, role in kelp. In the context of Chilean kelp resource management, monitoring chemical composition is useful for determining optimal harvesting periods to local scale and for deciding when commercially valuable compounds, such as alginate, should be extracted. These data also complement harvesting pressure indicators based on L. berteroana demographic parameters.


LWT ◽  
2021 ◽  
Vol 142 ◽  
pp. 111055
Author(s):  
Chunhui Xu ◽  
Lu Liang ◽  
Yuhao Li ◽  
Tianming Yang ◽  
Yunxue Fan ◽  
...  

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingzhong Chen ◽  
Xiaolong Huang ◽  
Bingli Tong ◽  
Deng Wang ◽  
Jiming Liu ◽  
...  

Abstract Background This study examined how rhizosphere fungi influence the accumulation of chemical components in fruits of a small population species of Cinnamomum migao. Results Ascomycota and Basidiomycota were dominant in the rhizosphere fungal community of C. migao. Pestalotiopsis and Gibellulopsis were associated with α-Terpineol and sabinene content, and Gibellulopsis was associated with crude fat and carbohydrate content. There were significant differences in rhizosphere fungal populations between watersheds, and there was no obvious change between fruiting periods. Gibberella, Ilyonectria, Micropsalliota, and Geminibasidium promoted sabinene accumulation, and Clitocybula promoted α-Terpineol accumulation. Conclusion The climate-related differentiation of rhizosphere fungal communities in watershed areas is the main driver of the chemical composition of C. migao fruit. The control of the production of biologically active compounds by the rhizosphere fungal community provides new opportunities to increase the industrial and medicinal value of the fruit of C. migao.


2015 ◽  
Vol 85 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Ricardo Carvalho Bueno ◽  
Roberta Tarkany Basting

ABSTRACT Objective:  To evaluate the proliferation and morphology of human osteoblasts cultured on two brands of mini-implants after 24, 48, and 72 hours, in addition to the chemical composition found on their surface. Materials and Methods:  Two brands of mini-implant (Morelli and Neodent) were evaluated; polystyrene was used as a control group (n  =  3). Osteoblasts were cultured on the surface of sterilized mini-implants in a CO2 incubator at different time periods (24, 48, and 72 hours). Osteoblast proliferation was quantified by scanning electron microscopy using up to 5000× magnification, and cell morphology was analyzed by a single observer. For the chemical analysis, spectroscopy X-ray fluorescence was used to identify and quantify chemical components on the surface of the mini-implants. Results:  Two-way ANOVA showed no significant interaction between the factors studied (P  =  0.686). A Tukey test revealed no significant difference in osteoblast proliferation between the mini-implants at all studied periods; however, a difference in cell proliferation was detected between the Neodent and the control group (P  =  .025). For all groups, time had a direct and positive effect on osteoblast proliferation (P < .001). The significant elements present in both brands of mini-implants were titanium, aluminum, vanadium, and iron. Conclusions:  Osteoblast proliferation was present on the mini-implants studied, which increased over time; however, no significant difference between brands was observed. No difference was seen between the mini-implants evaluated in terms of chemical composition. Cell adhesion after 72 hours suggests that areas of bone remodeling can be achieved, thus initiating the process of mini-implant anchorage.


2017 ◽  
Author(s):  
Huanbo Wang ◽  
Mi Tian ◽  
Yang Chen ◽  
Guangming Shi ◽  
Yuan Liu ◽  
...  

Abstract. To investigate the characteristics of PM2.5 and its major chemical components, formation mechanisms, and geographical origins in the two biggest cities, Chengdu (CD) and Chongqing (CQ) in Sichuan Basin, the most densely populated basin in China, daily PM2.5 samples were collected simultaneously at one urban site in each city from October 2014 to July 2015. Annual mean concentrations of PM2.5 were 67.0 ± 43.4 and 70.9 ± 41.4 μg m−3 at CD and CQ, respectively. Secondary inorganic aerosols (SNA) and organic matter (OM) accounted for 41.1 % and 26.1 %, respectively, of PM2.5 mass at CD, and 37.4 % and 29.6 % at CQ. Seasonal variations of PM2.5 and its major chemical components were significant, usually with the highest values in winter and the lowest in summer. SNA and OM were 1.7–3.4 times higher on polluted days than on clean days at both sites, whereas their percentage contributions to PM2.5 varied differently among the components and between the two sites. Gas-phase oxidation probably played an important role on the formation of secondary aerosols when PM2.5 mass varied in the range of 75–150 μg m−3, while heterogeneous transformation was likely the major mechanism on the heavy polluted days. Geographical regions causing high PM2.5 were identified to mainly distribute within the basin at both sites based on potential source contribution function (PSCF) analysis.


Sign in / Sign up

Export Citation Format

Share Document