INFLUENCE OF BIOGENIC SUBSTANCES ADDING INTO MOLASSES SOLUTIONS ON THE EFFICIENCY OF BIOLOGICALLY ACTIVE SUBSTANCES SYNTHESIS

Побочный продукт сахарного производства – свекловичная меласса используется в микробиологической промышленности в качестве компонента высокопродуктивного субстрата для культивирования микроорганизмов, синтезирующих биологически активные вещества. На наш взгляд, перспективна предварительная подготовка мелассы путем ее насыщения биогенными веществами, повышающими эффективность жизнедеятельности микроорганизмов. Для подтверждения этого исследовано влияние внесения биогенных веществ в растворы свекловичной мелассы при их обработке на жизнедеятельность микроорганизмов, способствующих повышению синтеза витамина В2 и жиров. Объектами исследования были раствор свекловичной мелассы с массовой долей сухих веществ 78% и 3 штамма микроорганизмов – Bacillus subtilis B-501, Cryptococcus curvatus Y-2236 и Rhodotorula glutinis Y-332. Анализ исходного содержания макро- и микроэлементов в растворе свекловичной мелассы позволил установить, что содержащихся в мелассе биогенных веществ достаточно для жизнедеятельности Bacillus subtilis B-501 с удельной выработкой витамина В2 в количестве 0,019 г/г сахаров при степени утилизации сахаров 42,55%. Для повышения эффективности жизнедеятельности Rhodotorula glutinis Y-332 требуется внесение сульфатов железа FeSO4 и марганца MnSO4, которые способствуют увеличению удельной выработки жиров с 0,019 до 0,030 г/г сахара в каждом случае. Для повышения эффективности жизнедеятельности Cryptococcus curvatus Y-2236 требуется внесение сульфатов железа FeSO4 и марганца MnSO4, а также источников фосфора KH2PO4 и азота (NH4)2SO4. Внесение указанных биогенных веществ способствует повышению удельной выработки жиров с 0,011 до 0,015–0,020 г/г сахаров. A byproduct of sugar production – beet molasses is used in the microbiological industry as a component of a highly productive substrate for the cultivation of microorganisms that synthesize biologically active substances. In our opinion, the preliminary preparation of molasses by its saturation with biogenic substances to increase the efficiency of the vital activity of microorganisms is promising. To confirm this, the effect of introducing biogenic substances into the solution of beet molasses during their processing on the vital activity of microorganisms that contribute to the increase in the synthesis of vitamin B2 and fats has been studied. The objects of the study were a solution of beet molasses with a mass fraction of dry substances of 78% and 3 strains of microorganisms – Bacillus subtilis B-501, Cryptococcus curvatus Y-2236 and Rhodotorula glutinis Y-332. Analysis of the initial content of macro-and microelements in the solution of beet molasses allowed us to establish that the nutrients contained in the molasses are sufficient for the vital activity of Bacillus subtilis B-501 with a specific production of vitamin B2 in the amount of 0,019 g/g of sugars with a degree of sugar utilization of 42,55%. To improve the vital efficiency of the Rhodotorula glutinis Y-332, the addition of ferrous FeSO4 and manganese MnSO4 sulfates is required, which increase the fats specific production from 0,019 to 0,030 g/g of sugars in each case. To improve the vital efficiency of the Cryptococcus curvatus Y-2236 the addition of ferrous FeSO4 and manganese MnSO4 sulfates, as well as sources of phosphorus KH2PO4 and nitrogenium (NH4)2SO4is required. Adding these nutrients contributes the increase of fats specific production from 0,011 to 0,015–0,020 g/g of sugars.

Lipid Production by Yeasts Growing on Commercial Xylose in Submerged Cultures with Process Water Being Partially Replaced by Olive Mill Wastewaters

Six yeast strains belonging to Rhodosporidium toruloides, Lipomyces starkeyi, Rhodotorula glutinis and Cryptococcus curvatus were shake-flask cultured on xylose (initial sugar—S0 = 70 ± 10 g/L) under nitrogen-limited conditions. C. curvatus ATCC 20509 and L. starkeyi DSM 70296 were further cultured in media where process waters were partially replaced by the phenol-containing olive mill wastewaters (OMWs). In flasks with S0 ≈ 100 g/L and OMWs added yielding to initial phenolic compounds concentration (PCC0) between 0.0 g/L (blank experiment) and 2.0 g/L, C. curvatus presented maximum total dry cell weight—TDCWmax ≈ 27 g/L, in all cases. The more the PCC0 increased, the fewer lipids were produced. In OMW-enriched media with PCC0 ≈ 1.2 g/L, TDCW = 20.9 g/L containing ≈ 40% w/w of lipids was recorded. In L. starkeyi cultures, when PCC0 ≈ 2.0 g/L, TDCW ≈ 25 g/L was synthesized, whereas lipids in TDCW = 24–28% w/w, similar to the experiments without OMWs, were recorded. Non-negligible dephenolization and species-dependent decolorization of the wastewater occurred. A batch-bioreactor trial by C. curvatus only with xylose (S0 ≈ 110 g/L) was performed and TDCW = 35.1 g/L (lipids in TDCW = 44.3% w/w) was produced. Yeast total lipids were composed of oleic and palmitic and to lesser extent linoleic and stearic acids. C. curvatus lipids were mainly composed of nonpolar fractions (i.e., triacylglycerols).

Single Cell Oil Production with Cutaneotrichosporon curvatus (syn, Cryptococcus curvatus) PY39 and Its Use for Biodiesel Preparation

Background: Microorganisms including yeasts that are capable of accumulating lipids above 20 to 70% of their dry biomass are collectively named oleaginous. The oil produced from such microorganisms can be used as alternative sources of oils for human consumption, feedstocks for production of biodiesel, components in paints, coatings, detergents, cleaning products, cosmetics, plastics, rubber and intermediate products.Results: In this study Cutaneotrichosporon curvatus (Cryptococcus curvatus) PY39, an oleaginous yeast, isolated from flower surface in Ethiopia, was grown under nitrogen-limited media. The capacity of this strain with respect to biomass production, lipid yield and lipid content was evaluated. To determine the optimal culture conditions for this oleaginous yeast, different carbon and nitrogen sources, carbon to nitrogen (C/N) ratio, pH, incubation temperature, shaking speed and incubation period were investigated. The optimal fermentation conditions were obtained as follows: 70 g/L of glucose as carbon source; combinations of ammonium sulphate and yeast extract as nitrogen sources at, respectively, 0.50 g/L and 0.47 g/L; initial pH of 5.0; temperature at 30oC, shaking speed of 225 rpm, and cultivated for 144 h. Under the optimized conditions, C.curvatus PY39 accumulated lipids up to 7.22±0.26 g/L on dry biomass basis. Such values correspond to lipid content of 48.66±0.60%. This strain was further grown on media containing peel mixtures of papaya and mango. Under the optimized conditions, C. curvatus PY39 exhibited a lipid yield and lipid content of 3.95±0.67 g/L and 35.02±1.63%, respectively. The fatty acid profiles were analyzed using gas chromatography. Data revealed the presence of significant amount of oleic acid (54.40±1.15%), palmitic acid (17.39±0.47%), stearic acid (13.16±0.93%) and low amount of other fatty acids in the extracted yeast oils which indicate that the fatty acid profiles were very similar to that of conventional vegetable oils.Conclusion: The results of fatty acid profiles showed that the microbial lipids from the studied yeast can be good feedstocks for biodiesel production.

Sugarcane Distillery Spent Wash, a New Resource for Third-Generation Biodiesel Production

Industrial production of biodiesel from microbial catalysts requires large volume of low-cost feedstock for lipid production. Vinasse, also known as distillery spent wash (DSW), is a liquid waste produced in large amounts by ethanol distilleries. This effluent is particularly rich in organic matter, and may be considered as a potential resource for the production of fungal lipids. The present study aimed at evaluating the potential of vinasse from a distillery located in Reunion Island for yeast and fungal growth, lipid production, and suitability for biodiesel requirements. Among the 28 different strains tested, we found that Aspergillus niger grown on pure vinasse allowed biomass production of up to 24.05 g/L (dry weight), whereas Aspergillus awamori produced the maximum amount of lipid, at 2.27 g/L. Nutrient removal and vinasse remediation were found to be the best for A. niger and Cryptococcus curvatus, reaching a maximum of 50% for nitrogen, and A. awamori showed 50% carbon removal. Lipids produced were principally composed of C16:0, C18:1 (n-9), and C18:2 (n-6), thus resembling the vegetal oil used in the biodiesel production. This work has shown that vinasse can support production of biomass and lipids from fungi and yeast suitable for energetic use and that its polluting charge can be significantly reduced through this process.