Biosynthesis of Applicable Levan by a New Levan Producing Moderately Halophilic Strain Chromohalobacter salexigens and its Biological Activities (original) (raw)
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Biological Activity of Chemically Modified Levan Produced by Moderately Halophilic
2016
Levan (Lev-KT7) produced by a moderately halophilc strain Chromohalobacter salexigens KT7 was chemically modified into two derivatives, sulphated (SA-KT7) and carboxymethylated levan (CM-KT7). Modification process was confirmed by Fourier Transform Infra-Red (FTIR) spectroscopy. Three types of biological activities were assayed for levan and its derivatives; anti-tumor activity (for Lev-KT7, SA-KT7 and CMKT7), fibtinolytic activity (for Lev-KT7 and SA-KT7) and prebiotic activity (for lev-KT7 and CM-KT7). FT-IR spectroscopy results confirmed the success of modification processes. Anti-tumor activity indicated that SA-KT7 was promising compared with Lev-KT7 and CM-KT7 which showed no activity as anti-tumor agents. SA-KT7 exhibited 64 % fibrinolytic activity comparing with (57%) caused by the same amount of standard heamoclar “pentosan sulfuric polyester” at the same concentration. On the other hand, Lev-KT7 showed 50% fibrinolytic activity on plasma clot. It was found that prebiotic a...
High level synthesis of levan by a novel Halomonas species growing on defined media
Carbohydrate Polymers, 2009
A novel halophilic isolate from soil samples taken from Çamaltı Saltern area in Turkey, Halomonas sp. AAD6 (JCM 15723) strain, was found to produce high levels of exopolysaccharides (EPS), in the presence of sucrose in defined media, by flasks and bioreactor condition yielded 1.073 g L À1 and 1.844 g L À1 , respectively. Sugar analysis, methylation studies and NMR analysis of EPS indicated the repeating unit of this polysaccharide was composed of b-(2,6)-D-fructofuranosyl residues. Hence with this work, Halomonas sp. has been described as a levan producer microorganism for the first time. Biocompatibility studies showed this EPS did not affect cellular viability and proliferation of osteoblasts and murine macrophages. The protective effect of the polymer against the toxic activity of avarol implied its additional use as an anti-cytotoxic agent. Halomonas sp. AAD6 could represent an alternative cheap source of levan polymer when grown on defined media hypothesizing its larger employment in industrial application being non pathogenic microorganism.
Production, Purification and Characterization of Levan Polymer from Bacillus lentus V8 Strain
British Microbiology Research Journal, 2015
Aims: To optimize fermentation conditions for microbial production of levan polymer on a low-price productive medium. Also to purified levan from Bacillus lentus V8 strain, characterization the levan polymer by 13 C NMR spectroscopy and physicochemical properties. Study Design: Optimization of environmental factors for levan production. Polymer purification and identification. Place and Duration of Study: Methodology: Bacillus lentus V8 strain was used as producer of levan. This strain was grown on productive medium. Cell dry weight and levan polymer were determined in all the samples at the end of the fermentation period. Study on optimal levan production conditions such as initial pH, incubation temperatures, shaking speed, inoculum size. The parameters of growth and levan were calculated from the exponential phase. Isolation and identification of levan polymer. Results: Effect of some environmental factors on growth and levan production by Bacillus lentus BMRJ, 5(1): 22-32, 2015; Article no. BMRJ.2015.003 23 V8 strain on medium supplemented with sucrose or black strap sugar cane molasses was investigated. Results indicated that the productive medium with initial pH 6.5, 10% inoculum size, incubated at 30ºC, 150rpm shaking speed gave 51.40 or 45.34gL -1 of levan dry weight on medium supplemented with sucrose or black strap sugar cane molasses, respectively. With respect to biological activity of Bacillus lentus V8 strain on modified medium supplemented with sucrose or black strap sugar cane molasses using shake flasks as a batch culture, results reveal that the fermentation period for highest cell dry weight 2.99 or 2.89gL -1 was obtained after 48 h or 66 h, respectively. The highest levan dry weight (57.95 or 49.86gL -1 ) and biopolymer yield (23.18 or 36.93%) on modified medium supplemented with sucrose or black strap sugar cane molasses were achieved after 60 h, respectively. A highly positive correlation coefficient between incubation period and cell dry weight, levan dry weight, polymer dry weight yield, effective yield and Y p/x , R 2 values ranged from (0.91 to 0.97) and (0.89 to 0.96) on medium supplemented with sucrose or black strap sugar cane molasses, respectively. The levan produced by tested strain was identified by 13 C NMR and characterized by being white color, soluble in water and precipitated with alcohol, it contains 40.86% carbon and 0.98% ash. Conclusion: The highest amount of levan was produced by Bacillus lentus V8 strain on productive medium supplemented with sucrose [or] black strap sugar cane molasses with pH 6.5, 10% inoculum size and incubated at 30ºC for 60h at 150rpm. Characterization the levan polymer by 13 C NMR spectroscopy and physicochemical properties.
Biotecnología Aplicada, 2012
Bacterial levan (β(2,6)-linked polyfructan) has potential applications in the food, bio-energetic, medical, pharma- ceutical, and other industries. The lack of technically and economically feasible large-scale production systems limits the commercial exploitation of levan. Gluconacetobacter diazotrophicus secretes a levansucrase (LsdA, EC 2.4.1.10) that synthesizes high levels of levan and fructooligosaccharides from sucrose. This bacterium is not attractive for the cost-effective production of LsdA. In this research, we used Pichia pastoris and Nicotiana tabacum as hosts for LsdA production and direct levan synthesis, respectively. The recombinant yeast constitutively expressing the lsdA gene acquired saccharolytic capacity and secreted LsdA to a yield 9-fold higher than the value reported for the natural host. The occurrence of N-glycosylation in the yeast-produced LsdA did not affect the catalytic efficiency, substrate specificity, or product profile compared to the native non-gl...
Levan is an exopolysaccharide produced by various microorganisms and has a variety of applications. In this research, the aim was to demonstrate the biological activity of levan which produced from B. phenoliresistens KX139300. These were done via study the antioxidant, anti-inflammatory, anticancer and antileishmanial activities in vitro. The antioxidant levan was shown 80.9% activity at 1250 µg/mL concentration. The efficient anti-inflammatory activity of 88% protein inhibition was noticed with levan concentration at 35 µg/mL. The cytotoxic activity of levan at 2500 µg/mL concentration showed a maximum cytotoxic effect on L20B cell line and promastigotes of Leishmani tropica. Levan has dosedependent anticancer and antileishmanial activities. An addition to the antioxidant, anti-inflammatory and anticancer potential activities of levan, it can be concluded that levan produced from B. phenoliresistens can efficiently be applied as an antileishmanial agent.
Microbial levan from Brachybacterium phenoliresistens: Characterization and enhancement of production, 2017
Levan producing bacteria was isolated from rhizosphere soil. The molecular identification of this isolate was conducted using 16S rRNA, which resulted in a sequenced region of 1298 base pairs. The sequence alignment in the gene bank indicated that this isolate has a high percentage of similarity (99%) to the retrieved consensus sequence of Brachybacterium phenoliresistens strain phenol-A. The produced levan was characterized using TLC, FTIR, 1H NMR and 13C NMR spectroscopy techniques. The effects of nutritional and physical factors on this isolate’s levan production were investigated. The results demonstrated that the optimal sources for carbon and casein during levan production were sucrose and casein, yielding 7.88 g/land 8.12 g/l of levan, respectively. The highest levan yield (7.97 g/l) was obtained at a sucrose concentration of 300 g/l. At an initial pH of 7.8, this bacterium yielded their highest levan production of 7.88 g/l. The optimal incubation period was 72 h with a yield of 8.58 g/l, the optimal temperature was 30 °C and resulted in 7.87 g/l, and the highest levan production yield was obtained at 150 rpm and yielded 8.12 g/l.
International Journal of Biological Macromolecules, 2020
Levan is a fructose polymer with β-(2 → 6) glycosidic linkages. It is produced by several microorganisms, and due to its potential biotechnological and industrial applications, various levan-producing bacteria with different levels of production efficiencies have been reported. We investigated the levan-producing ability of the acetic acid bacterium, Tanticharoenia sakaeratensis. The exopolysaccharides produced by the bacterium under a sucrose environment were characterized as levan by FT-IR, and 1 H and 13 C NMR. The molecular weight of levan thus produced range from 1.0 × 10 5-6.8 × 10 5 Da. The maximum yield of levan from T. sakaeratensis is 24.7 g•L −1 in a liquid medium containing 20% (w/v) sucrose and incubated at 37°C, 250 RPM for 35 h. The levan produced by T. sakaeratensis can promote nitric oxide production in RAW264.7 macrophage cells in a concentrationdependent manner, suggesting it has immunomodulatory effects. Our study reveals that T. sakaeratensis can be potentially employed as a new source of levan for industrial applications.
Co-production of polyhydroxyalkanoates and levan by Halomonas smyrnensis AAD6T
Research, Society and Development
The simultaneous production of microbial polymers levan and poly[3-hydroxybutyrate] (PHB), a type of polyhydroxyalkanoates, was investigated in this work. The study involved the fermentation of sucrose and molasses by H. smyrnensis AAD6T (BAE2 strain) to produce PHB (intracellular) and levan (extracellular). Both polymers were isolated and characterized by FTIR. Levan was also characterized by thin-layer chromatography (TLC) and viscosimetric analysis. The amount of biomass was 25 g until the end of fermentation. The PHB rate was 0.015 g in both media and the average PHB productivity was 6.0 x 10-4 g PHB/g biomass. The highest rate of levan was 9 g/L in the range of 72–80 h, in the molasses-based medium. The FTIR spectra showed specific signals for each of the polymers, such as the peak at 1700 for the carbonyl group of esters for the PHB and signals at 900 and 800, which are typical signals for levan fructose rings. Furthermore, acid hydrolysis of levan revealed that it was formed ...
Cosmeceutical properties of levan produced by Zj/momonas mobilis
Levan, a polysaccharide that can be produced by both plants and microorganisms, is a sugar polymer composed of fructose, with [3-2,6 linkages. Here, we have attempted to assess the possible use of levan produced by Zymomonas mobilis as a cosmeceutical ingredient. In service of this goal, we assessed a host of levan's properties, including its moisturizing effects, cell cytotoxicity, cell proliferation effects, and antiinflammation effects.
Structural elucidation and interfacial properties of a levan isolated from Bacillus mojavensis
Food Chemistry, 2021
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