Technical Glycerol Research Articles

Honey's Yeast-New Source of Valuable Species for Industrial Applications.

Honey is a rich source of compounds with biological activity; moreover, it is a valuable source of various microorganisms. The aim of this study was to isolate and identify yeast from a sample of lime honey from Poland as well as to assess its ability to biosynthesize value-added chemicals such as kynurenic acid, erythritol, mannitol, and citric acid on common carbon sources. Fifteen yeast strains belonging to the species Yarrowia lipolytica, Candida magnolia, and Starmerella magnoliae were isolated. In shake-flask screening, the best value-added compound producers were chosen. In the last step, scaling up of the culture in the bioreactor was performed. A newly isolated strain of Y. lipolytica No. 12 produced 3.9 mg/L of kynurenic acid growing on fructose. Strain Y. lipolytica No. 9 synthesized 32.6 g/L of erythritol on technical glycerol with a low concentration of byproducts. Strain Y. lipolytica No. 5 produced 15.1 g/L of mannitol on technical glycerol, and strain No. 3 produced a very high amount of citric acid (76.6 g/L) on technical glycerol. In conclusion, to the best of our knowledge this is the first study to report the use of yeast isolates from honey to produce valuable chemicals. This study proves that natural products such as lime honey can be an excellent source of wild-type yeasts with valuable production properties.

Application of Liquid Waste from Biogas Production for Microalgae Chlorella sp. Cultivation.

Microalgae biomass is a viable feedstock for a wide range of industries. Recently, there has also been interest in the ability of microalgae biomass applications for biofuel production. In the meantime, the cultivation of microalgae biomass requires high energy costs, and the application of microalgae for technical purposes is still problematic. A significant part of the cost of biomass arises from the nutrients used for cultivation. Chemical compounds included in the microalgae cultivation media can be replaced by suitable wastes containing nitrogen, phosphorus, and other elements. This could reduce the microalgae biomass cultivation price and allow cheaper biomass to be used for biofuel production. The aim of this work was to comprehensively investigate and optimize the growth process of microalgae using liquid waste (liquid waste after biogas production from sewage sludge and distillers’ grain) as a source of nitrogen and phosphorus, and technical glycerol as a carbon source. It was found that higher levels of waste in the cultivation media were found to inhibit the accumulation of microalgal biomass, with the optimum level corresponding to a nitrogen concentration of 0.08 g/L. The influence of technical glycerol from biodiesel production on the yield of microalgal biomass was investigated, and it was found that the addition of 6% glycerol allows an increase in the concentration of microalgal biomass in the cultivation media, from 18.1 to 20.6%.

What’s in a wine? – A spot check of the integrity of European wine sold in China based on anthocyanin composition, stable isotope and glycerol impurity analysis

ABSTRACT The international wine market has been repeatedly hit by cases of fraud in recent decades. While several studies attested a special vulnerability of the fast growing wine business in China, reports on chemical analyses of commercial wine samples are rare. We examined 50 predominantly red wines with European labelling, which were purchased on the Chinese market, for fraud-relevant parameters. More than 20% of the tested samples revealed anomalies in relation to the stable isotope ratios of D/H, 18O/16O and 13C/12C, contents of technical glycerol by-products or anthocyanin composition. These results strongly suggested watering of the wines, chaptalisation, glycerol addition or the use of non-Vitis anthocyanin sources, respectively. Some of these samples also showed suspicious spelling errors or other irregularities in the labelling, but the majority appeared genuine to the eye. Hence, this spot check demonstrates the importance of chemical authenticity analysis of market samples in order to detect fraudulent products. Moreover, we used the same sample set for an evaluation of the Chinese standard method for carbon stable isotope determination of wine ethanol in comparison to the current OIV (International Organisation of Vine and Wine) standard method. The results of a Bland-Altman analysis indicated that the methods can be applied interchangeably. As the two methods differ in their workflow and in the requested equipment, this might eventually enable more laboratories to perform 13C/12C analysis of wine and spirits.

Crude glycerol gasification in a fixed bed gasifier

The purpose of this work was the study of crude glycerol gasification, using steam as oxidant. The results were compared with those obtained for technical glycerol gasification. The producer gas composition and the gasification parameters were evaluated. Tests were performed in a fixed bed reactor and the producer gas samples were analysed by gas chromatography. The results using crude glycerol showed higher H2/CO ratio and cold gas efficiency values than the ones obtained using technical glycerol while no significant differences were observed for the remaining evaluated parameters. The results reveal that gasification is a possibility of crude glycerol valorisation.

Антимікробна та антиадгезивна активність поверхнево-активних речовин, синтезованих Acinetobacter calcoaceticus ІМВ В-7241 на технічному гліцерині

Антимікробна та антиадгезивна активність поверхнево-активних речовин, синтезованих Acinetobacter calcoaceticus ІМВ В-7241 на технічному гліцерині

Improvement of Impact Toughness of Biodegradable Poly(butylene succinate) by Melt Blending with Sustainable Biobased Glycerol Elastomers

Poly(butylene succinate) (PBS) was melt blended with glycerol based polyesters (PGS) synthesized from pure and technical glycerol aiming to improve the impact strength of PBS. It was found that after addition of 30 wt% PGS to PBS its impact strength was significantly increased by 344% (from 31.9 to 110 J/m) and its elongation at break was maintained at 220%. Infrared spectra of the blends showed the presence of hydroxyl groups from the PGS phase suggesting that hydrogen bonding between the phases could be responsible for a good stress transfer and an efficient toughening in the PBS/PGS blends. Scanning electron microscopy imaging showed a good dispersion of PGS phase into PBS with a PGS particle size of 10 μm and less and no agglomeration. Addition of PGS to PBS was shown to be an effective strategy for improvement of PBS impact resistance without serious detrimental effects on its thermal and rheological properties.

Біологічні властивості поверхнево-активних речовин Nocardia vaccinii ІМВ В-7405, синтезованих на відходах виробництва біодизелю

Comparison of antimicrobial and anti-adhesive activity of Nocardia vaccinii ІMV B-7405 surfactants synthesized on purified and technical glycerol (byproduct of biodiesel production). Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). Antimicrobial against bacteria and yeast properties of the surfactant was determined by index of the minimum inhibitory concentration (MIC). The number of attached cells was determined spectrophotometrically. The dependence of surfactant antimicrobial and anti-aghesive activity on the degree of glycerol purification (purified, technical), as well as the duration of N. vaccinii IMV B-7405 cultivation on these substrates was established. MIC against studied test cultures surfactants, synthesized on technical glycerol during 5 days, was 15–121 μg/ml, that lower than MIC of surfactant obtained on purified substrate (22.5−180 μg/ml). Increasing duration of N. vaccinii ІMV B-7405 cultivation accompanied by rise the MIC against some test cultures surfactants synthesized on both technical and purified glycerol. Adhesion of the bacteria Escherichia coli ІEM-1, Bacillus subtilis BT-2 (vegetative cells and spores) and the yeast Candida albicans Д-6 on abiotic surfaces treated with surfactants synthesized on technical glycerol for both 5 and 7 days, was an average of 11−12 % less than after materials treatment with surfactants obtained on the purified substrate. Increasing activity of NADP+-dependent glutamate dehydrogenase − key enzyme of aminolipids biosynthesis (effective antimicrobial and anti-adhesion agents) in the presence of K+ and Na+ may indicate the possibility of biosynthesis intensification of these components of surfacrants complex under N. vaccinii ІMV B-7405 cultivation on technical glycerol, which is characterized by a high content of sodium and potassium cations. Replacing refined glycerol on byproduct of biodiesel production will not only reduce the cost of N. vaccinii ІMV B-7405 surfactant biosynthesis, but also to obtain the final product with high antiadhesive and antimicrobial activity.

Improved utilization of crude glycerol from biodiesel industries: Synthesis and characterization of sustainable biobased polyesters

The present work describes the synthesis of biobased polyesters using glycerol of different purities and sources with the aim of understanding how glycerol composition can influence the resulting structure and properties of biobased polyesters. Glycerol and succinic acid based polyesters were synthesized using crude and technical grade glycerol obtained from biodiesel producing facilities. It was shown that the presence of impurities in crude glycerol can greatly decrease the yield of reaction and also lead to products with different chemical structure and composition than those derived from pure glycerol. In particular, the presence of fatty acids and soaps was shown to produce incorporation of fatty acid residues and formation of carboxylate residues in the polymer backbone respectively. The products synthesized from industrial technical grade glycerol with 95wt% purity were similar to those formulated from pure glycerol, showing rubbery behavior at room conditions. The materials synthesized from crude glycerol showed different thermal and chemical properties due to incorporation of impurities from the glycerol source to the polymer backbone. It was concluded that technical glycerol could be used as an alternative to pure glycerol on the synthesis of polyesters without inducing major changes on the synthesis products.

Identification of two mutations increasing the methanol tolerance of Corynebacterium glutamicum.

BackgroundMethanol is present in most ecosystems and may also occur in industrial applications, e.g. as an impurity of carbon sources such as technical glycerol. Methanol often inhibits growth of bacteria, thus, methanol tolerance may limit fermentative production processes.ResultsThe methanol tolerance of the amino acid producing soil bacterium Corynebacterium glutamicum was improved by experimental evolution in the presence of methanol. The resulting strain Tol1 exhibited significantly increased growth rates in the presence of up to 1 M methanol. However, neither transcriptional changes nor increased enzyme activities of the linear methanol oxidation pathway were observed, which was in accordance with the finding that tolerance to the downstream metabolites formaldehyde and formate was not improved. Genome sequence analysis of strain Tol1 revealed two point mutations potentially relevant to enhanced methanol tolerance: one leading to the amino acid exchange A165T of O-acetylhomoserine sulfhydrolase MetY and the other leading to shortened CoA transferase Cat (Q342*). Introduction of either mutation into the genome of C. glutamicum wild type increased methanol tolerance and introduction of both mutations into C. glutamicum was sufficient to achieve methanol tolerance almost indistinguishable from that of strain Tol1.ConclusionThe methanol tolerance of C. glutamicum can be increased by two point mutations leading to amino acid exchange of O-acetylhomoserine sulfhydrolase MetY and shortened CoA transferase Cat. Introduction of these mutations into producer strains may be helpful when using carbon sources containing methanol as component or impurity.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-015-0558-6) contains supplementary material, which is available to authorized users.

TECHNOLOGIES OF SYNTHESIS OF ORGANIC SUBSTANCES BY MICROORGANISMS USING WASTE BIODIESEL PRODUCTION

We describe here literature and our experimental data concerning microbial synthesis using waste biodiesel production, mono- and dihydric alcohols (1,3-propanediol, 2,3-butanediol, butanol, ethanol), polyols (mannitol, erythritol, arabitol), organic acids (citric, succinic, lactic, glyceric), polymers and compounds with a complex structure (polysaccharides, polyhydroxyalkanoates, surfactants, cephalosporin, cyanocobalamin). In some mentioned cases recombinant producer strains were used. It was shown that due to the presence of potential inhibitors in the composition of technical (crude) glycerol (methanol, sodium and potassium salts), the efficiency of synthesis of most microbial products on such a substrate is lower than on the purified glycerol. However, the need of utilization of this toxic waste (storage and processing of crude glycerol is a serious environmental problem due to the high alkalinity and the content of methanol in it), compensates the lower rates of synthesis of the final product. Furthermore, currently considering the volumes of crude glycerol formed during the production of biodiesel, microbial technologies are preferred for its utilization, allowing realizing biosynthesis of practically valuable metabolites in the environment with the highest possible concentration of this waste. Using of crude glycerol as a substrate will reduce the cost of products of microbial synthesis and increase the profitability of biodiesel production.

Optimization of mixotrophic cultivation of microalgae Chlorella sp. for biofuel production using response surface methodology

Microalgae invite the attention of scientists due to their unique properties, including their ability to grow quickly, accumulate lipids and other valuable materials, fix carbon dioxide and treat wastewater. Several studies have aimed to identify cost-effective production methods for microalgae biomass. In this paper, several potential inexpensive waste materials for microalgae Chlorella sp. biomass production rate were investigated, including technical glycerol and liquid waste (i.e., the liquid fraction of the digestate after biogas production). In addition, the cultivation of microalgae biomass was optimized using these materials. The optimization procedure was performed using response surface methodology. Biomass cultivation process was optimized depending on the amount of technical glycerol and the nitrogen concentrations in the growth medium, which was prepared using liquid waste. The highest Chlorella sp. biomass concentration of 2.41gL−1 was achieved in the growth medium that contained 0.114gL−1 nitrogen and 2.70gL−1 technical glycerol.

OPPORTUNITIES FOR REDUCTION OF ENERGY CONSUMPTION IN THE LIFE CYCLE OF BIODIESEL OBTAINED FROM MICROALGAE SCENEDESMUS SP.

The article considers the opportunities for reduction of energy consumption in the life cycle of biodiesel obtained from microalgae oil. Results show that by introducing technical glycerol and substrate leftover after production of biogas into the microalgae growth media energy consumption can be significantly reduced. Production of biogas from de-oiled microalgae improves the energy balance of the life cycle of biodiesel obtained from microalgae oil. It is impossible to obtain fuel containing more energy than would be used in the process of production if microalgae for biodiesel production are cultivated in conventional growth media. Only by subjecting microalgal biomass for production of gaseous and liquid biofuel (biodiesel and biogas) the total energy consumption is lower and equals to 65802.03 MJt-1 than energy value of biofuel, i.e. 79083.32 MJt-1. In this case the fossil energy ratio (FER) for biodiesel reaches 1.2.

Biosurfactant synthesis by Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 on byproduct of biodiesel production

The possibility of using technical glycerol (waste product of biodiesel production) as a substrate for the synthesis of the extracellular surfactants by Acinetobacter calcoaceticus IMV B-7241, Rhodococcus erythropolis IMV Ac-5017 and Nocardia vaccinii IMV In-7405 was investigated. When the components of glycerol fraction (potassium and sodium salts – 2.5%, methanol and ethanol – 0.3%) were introduced into the medium with purified glycerol (1%, v/v) an increase in conditional surfactant concentration by 11–68% was established when compared to a medium without these salts and alcohols. The maximum concentration of surfactants synthesized by R. erythropolis IMV Ac-5017 (1.6g/L), N. vaccinii IMV B-7405 (4.2g/L), and A. calcoaceticus IMV B-7241(5.6g/L) was reached in the medium with technical glycerol (4–6%, v/v). The possibility of intensifying surfactants synthesis by R. erythropolis IMV Ac-5017 and N. vaccinii IMV B-7405 can be established as a result of exogenous precursors (organic acids, sunflower oil, glucose, 0.05–0.1%) introduction into the medium with technical glycerol (2.2%, v/v). The increased amount of product was obtained when R. erythropolis IMV Ac-5017 and A. calcoaceticus IMV B-7241 were grown on a mixture of technical glycerol and n-hexadecane in a molar ratio of 1:8.

Biomass and oil content of Chlorella sp., Haematococcus sp., Nannochloris sp. and Scenedesmus sp. under mixotrophic growth conditions in the presence of technical glycerol

The growth of algae strains Chlorella sp., Haematococcus sp., Nannochloris sp. and Scenedesmus sp. under mixotrophic conditions in the presence of different concentrations of technical glycerol was investigated with the aim of increasing biomass growth and algae oil content. The highest concentration of lipid obtained in media with 5 g L−1 glycerol for Chlorella sp., Scenedesmus sp., Nannochloris sp. and Haematococcus sp. was 17.77, 22.34, 27.55 and 34.22 % larger than during the autotrophic growth of these species. Increases in triacylglycerols of up to ten times was observed for Scenedesmus sp. under mixotrophic conditions (using 10 g L−1 glycerol), whereas an increase of 2.28 times was found for Haematococcus sp. The content of saturated fatty acids of Scenedesmus, Chlorella, Haematococcus and Nannochloris was 67.11, 34.63, 23.39 and 24.23 %, and the amount of unsaturated fatty acids was 32.9, 65.06, 79.61 and 75.78 % of total fatty acids, respectively. Growth on technical glycerol of these strains with light produced higher biomass concentrations and lipid content compared with autotrophic growth. The fatty acid content of oils from these species suggests their potential use as biodiesel feedstock.

Production of biomass, carotenoid and other lipid metabolites by several red yeast strains cultivated on waste glycerol from biofuel production – a comparative screening study

This study was focused on a comparison of growth and production properties of seven red yeast strains of the genus Rhodotorula, Sporobolomyces and Cystofilobasidium cultivated on glycerol substrate. Production of enriched yeast biomas and specific yeast metabolites (carotenoids, ergosterol, lipids) was evaluated on medium with glucose, pure technical glycerol and/or waste glycerol from biofuel production (40 g/L) and mixture of glycerol and glucose (1:3, 1:1, 3:1; C/N ratio 57 in all cultivations). All tested strains were able to utilize glycerol as the only carbon source. Production of biomass on waste glycerol was in most strains higher than in control as well as in medium with pure technical glycerol and reached 15.97–21.76 g/L. Production of carotenoids and ergosterol was better in glucose medium than in medium with glycerol only. Nevertheless, using glycerol medium with addition of glucose, higher yields of total carotenoids, beta-carotene and ergosterol were obtained than in control. The highest yields of total pigments were reached by Sporobolomyces roseus (3.60 mg/g cell dry weight (CDW); glycerol:glucose 1:3), Sporobolomyces salmonicolor (2.85 mg/g CDW; glycerol:glucose 1:3) and Rhodotorula glutinis (2.80 mg/g CDW; glycerol:glucose 3:1) In glucose medium, most tested strains except Cystofilobasidium capitatum (22.6 %) produced neutral lipids in the range of 11–15 %. Production of triacylglycerols in all strains was in 10–30 % better in glycerol medium, in which Rhodotorula aurantiaca and Sporobolomyces shibatanus also reached intracellular triacylglycerol concentrations up to 20 % of biomass. This study has shown that oleaginous red yeasts could have great potential for converting crude glycerol to valuable lipids and carotenoids in respect of efficient bioresources utilization.

Biomass and Oil Production of Green Microalgae Scenedesmus sp. Using Different Nutrients and Growth

Biofuel is mostly produced from oleaginous crops, such as rapeseed, sunflower, soybean. The search for new technologies and new feedstock for biofuel production is becoming an increasingly important issue for researchers. Special attention is turned to the raw materials which do not compete with food industry. Microalgae ability, due to their rapid growth, to accumulate oil, to treat wastewater and waste, seems to be a very attractive new object to be used for biofuel production. In this study we have investigated different microalgae growth conditions, including both autotrophic cultivation by means of nitrogen deprivation mode and mixotrophic cultivation by applying liquid waste and technical glycerol for determining the best growth and oil production conditions. It is found that applying nitrogen deprivation mode and mixotrophic growth conditions, microalgae Scenedesmus sp. have grown faster and accumulation of their oil has increased 10.88 times compared to that under autotrophic growth conditions using the usual amount of nitrogen. The highest biomass concentration (2.16 gL -1 ) is obtained by adding 5 gL -1 glycerol into the growth medium, whereas the highest oil concentration (15.12 %) is reached when using 10 gL -1 technical glycerol. In addition, the elemental composition of microalgae biomass has been analyzed. Results indicate that the usage of glycerol for cultivation of microalgae increases C : N ratio to optimum (19.25) for biogas production, and algae biomass could be used for this biofuel production without adding any other co-substratum. The results of our study show that addition of cheap products: liquid waste and technical glycerol can effectively adjust the composition of microalgae biomass, making it more suitable for biofuel production. DOI: http://dx.doi.org/10.5755/j01.erem.62.4.2318

Esterification of By-products of Biodiesel Fuel Production with Methanol and Technical Glycerol Using Biocatalysts

In production of biodiesel fuel several by-products, such as glycerol and free fatty acids, are formed. The options for applying biochemical methods to process these by-products have been studied. The process of free fatty acid esterification with methanol using Lipozyme RM IM is to be performed in steps, with gradual addition of methanol into the reaction media. In 4 hours of a multi-step process it is possible to esterify up to 60% of free fatty acids. Novozym 435 is not inactivated by methanol, therefore, esterification with methanol of free fatty acids can be performed in one step. Free fatty acid esterification with glycerol is slowed down by admixtures present in by-products of biodiesel fuel production. After 7 hours of reaction, only 82.2% of free fatty acids react when using Novozym 435, and only 41.7% do in a case of Lipozyme RM IM, whereas in the case of esterification of pure oleic acid with pure glycerol the amounts reach 97.7% and 84.8%, respectively. Efficiency of ferment preparation Novozym 435is almost twice higher compared to Lipozyme RM IM. However, taking into account the prices of ferment preparations, it is possible to conclude that Lipozyme RM IM has future prospects in industrial synthesis.

Acetalisation of bio-glycerol with acetone to produce solketal over sulfonic mesostructured silicas

Sulfonic acid-functionalized mesostructured silicas have demonstrated excellent catalytic behaviour in the acetalisation of glycerol with acetone to yield 2,2-dimethyl-1,3-dioxolane-4-methanol, also known as solketal. This molecule constitutes an excellent compound for the formulation of gasoline, diesel and biodiesel fuels. The activity achieved with arenesulfonic acid-functionalized silica is comparable to that displayed by Amberlyst-15. Optimal production of solketal over arenesulfonic acid mesostructured silica has been established for a reaction system consisting of three consecutive 2-step batches (30 min under reflux and an evaporation step under vacuum), and using a 6/1 acetone/glycerol molar ratio. The use of lower grades of glycerol, such as technical (purity of 91.6 wt%) and crude (85.8 wt%) glycerol, has also provided high conversions of glycerol over sulfonic acid-modified heterogeneous catalysts (84% and 81%, respectively). For refined and technical glycerol the catalysts have been reused, without any regeneration treatment, up to three times, keeping the high initial activity. However, the high sodium content in crude glycerol deactivates the sulfonic acid sites by cation exchange. This deactivation is readily reversed by simple acidification of the catalyst after reaction.

Effect of Temperature and pH on the Growth Kinetics and Carotenoid Production by Sporobolomyces ruberrimus H110 Using Technical Glycerol as Carbon Source

A new isolated strain of Sporobolomyces ruberrimus H110 was cultivated on technical glycerol as carbon source and effect of different temperatures and pH on the growth and pigmentation was studied. The maximum concentration of total carotenoid was 3.84 mgg -1 including torularhodin (3.70 mgg -1 ) and β-carotene (0.14 mgg -1 ) using 19oC at pH 6, but the highest amount of the maximum specific growth rate was obtained (µmax = 0.094 h -1 ) at 27oC. The growth yield (Yx/s ) was equal to 0.52 ± 0.01 g g -1 with a correlation coefficient value of 0.98.

Accumulation of a cocoa-butter-like lipid by Yarrowia lipolytica cultivated on agro-industrial residues.

Yarrowia lipolytica was cultivated on mixtures of saturated free fatty acids (an industrial derivative of animal fat called stearin), technical glycerol (the main by-product of bio-diesel production facilities), and glucose. The utilization of technical glycerol and stearin as co-substrates resulted in higher lipid synthesis and increased citric acid production than the combination of glucose and stearin. The lipids produced contained significant amounts of stearic acid (50-70%, wt/wt) and lower ones of palmitic (15-20%, wt/wt), oleic (7-20%, wt/wt), and linoleic (2-7%, wt/wt) acid. Single-cell oil having a composition similar to cocoa-butter up to 3.4 g/L was produced, whereas in some cases relatively increased citric acid quantities (up to 14 g/L) were excreted into the growth medium. The microorganism presented a high specificity for lauric, myristic, and palmitic acid, while a discrimination for the stearic acid was observed. As a conclusion, microbial metabolism could be directed by using mixtures of inexpensive saturated fats, glycerol, and glucose as co-substrates, in order to accumulate lipids with predetermined composition, e.g., cocoa-butter equivalents.