scholarly journals Effect of the initial glycerol concentration in the medium on the xanthan biosynthesis

2014 ◽  
pp. 239-246 ◽  
Author(s):  
Zorana Roncevic ◽  
Bojana Bajic ◽  
Jovana Grahovac ◽  
Sinisa Dodic ◽  
Jelena Dodic
Keyword(s):  
Xanthomonas Campestris ◽  
Average Molecular Weight ◽  
Process Efficiency ◽  
Glycerol Concentration ◽  
Agitation Rate ◽  
Nitrogen And Phosphorus ◽  
Experimental Conditions ◽  
Batch Mode ◽  
Residual Content ◽  
Xanthan Production

This study is concerned with the effect of different initial glycerol concentrations in the medium on xanthan production by Xanthomonas campestris ATCC 13951. Xanthan biosynthesis was carried out in batch mode under aerobic conditions at a temperature of 30oC and agitation rate of 150 rpm for 7 days. The process efficiency was estimated based on the values of raw xanthan yield, average molecular weight of the polymer and residual content of glycerol, total nitrogen and phosphorus. Based on these results, the initial concentration of glycerol as a carbon source in the production medium was suggested. In the applied experimental conditions, high raw xanthan yield (12.15 g/l) of good quality (Mw = 2.86?105 g/mol) and the lowest amount of residual nutrients (glycerol 2.75 g/l, nitrogen 0.46 g/l and phosphorus 0.67 g/l) was achieved in the medium with the initial glycerol content of 20 g/l. The obtained results are the basis for optimization of xanthan production on glycerol containing media in order to increase the product yield and quality.

scholarly journals The biotechnological production of xanthan on vegetable oil industry wastewaters. Part I: Modelling and optimization

2017 ◽  
Vol 23 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Bojana Bajic ◽  
Damjan Vucurovic ◽  
Sinisa Dodic ◽  
Zorana Roncevic ◽  
Jovana Grahovac ◽  
...  
Keyword(s):  
Carbon Source ◽  
Vegetable Oil ◽  
Xanthomonas Campestris ◽  
Phosphorus Content ◽  
Oil Industry ◽  
Raw Material ◽  
Nitrogen And Phosphorus ◽  
Biotechnological Production ◽  
Xanthan Production ◽  
Industry Wastewater

The aim of this research was to examine the possibility of using the vegetable oil industry wastewater as the basis of the cultivation media for xanthan production, using Xanthomonas campestris ATCC 13951, in order to reuse the wastewater obtained in one industry as a raw material in another. Furthermore, the aim was to optimize the composition of wastewater based media in terms of carbon, nitrogen, and phosphorus content. Experiments were carried out in accordance with the Box-Behnken design with three factors on three levels (glucose: 10.00- -30.00 g/L; nitrogen: 0.02-0.20 g/L; phosphorus: 0.0045-0.045 g/L) and three repetitions at the central point. The success of biosynthesis was assessed by analysing broths to determine xanthan yield, cultivation broth apparent viscosity, residual carbon, nitrogen, and phosphorus content. Graphical and numerical optimization using response surface methodology was performed to determine the optimal content values of the carbon source, nitrogen, and phosphorus content. The results of graphical optimization suggest that for the defined response interval values, the defined model predicts that the xanthan production is possible when 15.00-16.00 g/L of the carbon source, 0.02-0.09 g/L of nitrogen and 0.01-0.02 g/L of phosphorus are added to the media that as a basis contains vegetable oil industry wastewater.

scholarly journals The effect of cultivation time on xanthan production by Xanthomonas spp. on glycerol containing medium

2021 ◽  
pp. 173-187
Author(s):  
Ida Zahovic ◽  
Jelena Dodic ◽  
Jovana Grahovac ◽  
Mila Grahovac ◽  
Zorana Trivunovic
Keyword(s):  
Molecular Weight ◽  
Sole Carbon Source ◽  
Reference Strain ◽  
Average Molecular Weight ◽  
Quality Parameter ◽  
Submerged Cultivation ◽  
Experimental Conditions ◽  
Cultivation Time ◽  
Pepper Leaves ◽  
Xanthan Production

In this study, the influence of cultivation time on xanthan biosynthesis by different Xanthomonas strains, reference strain and crucifers? and pepper leaves? isolates, was examined. Biopolymer was produced by submerged cultivation of fourteen producing strains on medium with glycerol as a sole carbon source. Each experiment was performed at a laboratory level under aerobic conditions at 30?C and 150 rpm for 168 h and 240 h. Bioprocess efficacy was estimated based on the xanthan quantity and its average molecular weight that was selected as quality parameter. According to the obtained results, it can be concluded that all applied strains have a statistically significant effect on xanthan concentration in medium and on its average molecular weight, while cultivation time significantly affect the bioprocess efficacy only when biosynthesis is performed by Xanthomonas strains isolated from crucifers. Further, when only Xanthomonas strains isolated from crucifers are observed, statistically obtained data suggest that the largest amount of the best quality xanthan in applied experimental conditions can be accomplished by the cultivation of CB strain for 240 h. On the other hand, when it comes to Xanthomonas strains isolated from pepper leaves, the highest productivity is shown by PL 2, PL 4 and PL 5 strains regardless of the cultivation time, while the PL 3 strain was responsible for the synthesis of biopolymers with the highest average molecular weight. The results obtained in this study represent valuable information for development of biotechnological process for xanthan production on glycerol containing media using new producing strain.

scholarly journals Potential of different Xanthomonas campestris strains for xanthan biosynthesis on waste glycerol from biodiesel production

2020 ◽  
Vol 24 (2) ◽  
pp. 62-66
Author(s):  
Zorana Rončević ◽  
Ida Zahović ◽  
Nikolina Danilović ◽  
Siniša Dodić ◽  
Jovana Grahovac ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Crude Glycerol ◽  
Rapid Expansion ◽  
Raw Material ◽  
Biodiesel Production ◽  
Nitrogen And Phosphorus ◽  
Sustainable Solutions ◽  
Waste Glycerol ◽  
Xanthan Production ◽  
The Media

A rapid expansion of the biodiesel industry has created various ecological issues relative to crude glycerol disposal. Xanthan biosynthesis is considered one of the sustainable solutions for minimizing the adverse effects of waste crude glycerol on the environment. The initial phase of xanthan production on crude glycerol entails the screening of producing microorganism. Therefore, the purpose of this study is to examine the possibility of xanthan production on a crude glycerol-based medium using different Xanthomonas campestris strains. The bioprocesses performed were assessed according to the rheology of the media considered, amounts of xanthan produced and conversion degrees of the most important nutrients present. The pseudoplastic behavior of all the media considered, the amounts of xanthan produced (5.22-7.67 g/L) and the degrees of crude glycerol, total nitrogen and phosphorus conversion (34.44-57.61 %, 23.04-30.35 % and 18.20-22.28 %, respectively) suggest that crude glycerol, after additional bioprocess optimization, can be a suitable raw material for the industrial production of xanthan.

scholarly journals Xanthan production on wastewaters from wine industry

2017 ◽  
Vol 71 (2) ◽  
pp. 145-153 ◽  
Author(s):  
Zorana Roncevic ◽  
Bojana Bajic ◽  
Damjan Vucurovic ◽  
Sinisa Dodic ◽  
Jovana Grahovac ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Sugar Content ◽  
Wine Industry ◽  
Raw Material ◽  
Experimental Conditions ◽  
Wine Production ◽  
Xanthan Production ◽  
Valuable Product ◽  
Rosé Wine ◽  
Sugar Conversion

Wine industry generates large volumes of wastewaters resulting from numerous cleaning operations that occur during the different stages of winemaking. Disposal of these effluents in the environment causes huge problems due to their high organic and inorganic load and seasonal variability. The bioconversion of winery wastewaters in valuable product, such as xanthan, is an important alternative to overcome environmental problems. In this research, the possibility of xanthan production using Xanthomonas campestris on blended wastewaters from different stages of white and rose wine production with initial sugar content of 50 g/L was investigated. In addition to the media parameters (content of sugars, total and assimilable nitrogen, phosphorus, total dissolved salts and apparent viscosity), raw xanthan yield and degree of sugar conversion into product were determined in order to examine the success of xanthan biosynthesis. In applied experimental conditions, xanthan yield of 20.92 and 30.64 g/L and sugar conversion into product of 40.23 and 60.73% were achieved on wastewaters from white and rose wine production, respectively. The results of these experiments suggest that winery wastewaters, after additional optimization of the process in terms of the substrate composition and the cultivation conditions, may be a suitable raw material for industrial xanthan production.

scholarly journals Application of Bar Adsorptive Microextraction for the Determination of Levels of Tricyclic Antidepressants in Urine Samples

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3101
Author(s):  
Mariana N. Oliveira ◽  
Oriana C. Gonçalves ◽  
Samir M. Ahmad ◽  
Jaderson K. Schneider ◽  
Laiza C. Krause ◽  
...  
Keyword(s):  
Tricyclic Antidepressants ◽  
Matrix Effects ◽  
Activated Carbons ◽  
Process Efficiency ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Experimental Conditions ◽  
Analytical Methodology ◽  
Low Efficiency

This work entailed the development, optimization, validation, and application of a novel analytical approach, using the bar adsorptive microextraction technique (BAμE), for the determination of the six most common tricyclic antidepressants (TCAs; amitriptyline, mianserin, trimipramine, imipramine, mirtazapine and dosulepin) in urine matrices. To achieve this goal, we employed, for the first time, new generation microextraction devices coated with convenient sorbent phases, polymers and novel activated carbons prepared from biomaterial waste, in combination with large-volume-injection gas chromatography-mass spectrometry operating in selected-ion monitoring mode (LVI-GC-MS(SIM)). Preliminary assays on sorbent coatings, showed that the polymeric phases present a much more effective performance, as the tested biosorbents exhibited low efficiency for application in microextraction techniques. By using BAμE coated with C18 polymer, under optimized experimental conditions, the detection limits achieved for the six TCAs ranged from 0.2 to 1.6 μg L−1 and, weighted linear regressions resulted in remarkable linearity (r2 > 0.9960) between 10.0 and 1000.0 μg L−1. The developed analytical methodology (BAμE(C18)/LVI-GC-MS(SIM)) provided suitable matrix effects (90.2–112.9%, RSD ≤ 13.9%), high recovery yields (92.3–111.5%, RSD ≤ 12.3%) and a remarkable overall process efficiency (ranging from 84.9% to 124.3%, RSD ≤ 13.9%). The developed and validated methodology was successfully applied for screening the six TCAs in real urine matrices. The proposed analytical methodology proved to be an eco-user-friendly approach to monitor trace levels of TCAs in complex urine matrices and an outstanding analytical alternative in comparison with other microextraction-based techniques.

scholarly journals New Culture Medium to Xanthan Production by Xanthomonas campestris pv. campestris

2011 ◽  
Vol 51 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Cíntia Regina Rodrigues Carignatto ◽  
Kassandra Sussi Mustafé Oliveira ◽  
Valéria Marta Gomes de Lima ◽  
Pedro de Oliva Neto
Keyword(s):  
Xanthomonas Campestris ◽  
Culture Medium ◽  
Xanthan Production ◽  
Xanthomonas Campestris Pv Campestris

Studies on fluorescence of cellulosics

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 504-508 ◽  
Author(s):  
Alain Castellan ◽  
Reinaldo Ruggiero ◽  
Elisabete Frollini ◽  
Ludmila A. Ramos ◽  
Christine Chirat
Keyword(s):  
Solid State ◽  
Microcrystalline Cellulose ◽  
Woody Plants ◽  
Average Molecular Weight ◽  
Homogeneous Medium ◽  
Fluorescence Emission ◽  
Excitation Wavelength ◽  
Experimental Conditions ◽  
Fluorescence Emission Spectra ◽  
Cotton Linters

Abstract Steady-state fluorescence emission spectra of various celluloses were measured at an excitation wavelength of 320 nm. Various spectra recorded in the solid state were compared: (1) ECF bleached papers made of hardwood, the anhydroglucose units of which were chemically modified at C1 and C6 or C2 and C3 positions with carboxylic groups; (2) microcrystalline cellulose; (3) cotton linters; and (4) delignified sisal fibers (mercerized or not). Fluorescence emission was quite independent of the carboxylic acid content and average molecular weight (determined by viscosimetry) of the cellulose polymers. Microcrystalline cellulose (Avicel), cotton linters, and mercerized delignified sisal cellulose were acetylated in homogeneous medium (DMAc/LiCl as solvent system) to obtain soluble polymers in dichloromethane for comparison of spectra recorded in the solid and liquid states. Fluorescence of cellulose acetates in solution (CH2Cl2) and in the solid state was compared under similar experimental conditions to non-esterified celluloses in the solid state. The importance of the solid state for fluorescence emission could be demonstrated. Fluorophores are present in minute amounts in the polymer and their favorable energy transfer for excitation in the solid state likely enhances fluorescence emission. Among numerous fluorophores, dityrosine appeared to be a good candidate for fluorescence because it displayed emission in the fluorescence range of cellulose. Dityrosine is an amino acid involved in the lignification of non-woody plants. Mercerized sisal impregnated with tyrosine in the presence of peroxidase and hydrogen peroxide did not show enhanced emission, in contrast to para-hydroxycinnamic acid (coumaric acid), which is also involved in the lignification process at least for non-woody plants. The origin of cellulose fluorescence remains uncertain and appears to have several origins. This study clearly underlines the importance of the solid state for enhancing fluorophore emission.

Xanthan production by Xanthomonas campestris in batch cultures

2001 ◽  
Vol 37 (1) ◽  
pp. 73-80 ◽  
Author(s):  
M Papagianni ◽  
S.K Psomas ◽  
L Batsilas ◽  
S.V Paras ◽  
D.A Kyriakidis ◽  
...  
Keyword(s):  
Xanthomonas Campestris ◽  
Batch Cultures ◽  
Xanthan Production
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