Effect of different conditions on Saccaromyces cerevisiae immobilization onto sugar beet pulp in ethanol production

The use of yeast cells immobilized on sugar beet pulp as support for ethanol production employs a cheap and simple method of retaining high cells densities. The present work describes the effect of yeast concentration and ammount of support on immobilization of Saccharomyces cerevisiae onto sugar beet pulp (SBP). Further, the efficiency of immobilized biocatalyst for batch ethanol fermentation of sugar beet thin juice was investigated with goal to examine the optimum conditions of its potential application. The hvdratet SBP showed highes cells retention capacity of 0.117 g/g. A maximum sugar conversion of 97.69%, ethanol concentration of 75.66 g/I, ethanol yield per consumed sugar of 0.499 g/g (equal to 97.71% of its theoretical value) was achieved in the batch fermentation of thin juice substrate. This study demonstrates that the efficient ethanol fermentation from sugar beet thin juice using S. cerevisiae immobilized by natural adhesion on sugar beet pulp (SBP) is possible even without any nutrient supplementation. The novelty of the approach lies in the effectiveness of exploitation of thin juice and sugar beet pulp with purpose to obtain efficient ethanol production from and to lower high operating cost

Ethanol fermentation of molasses by Saccharomyces cerevisiae cells immobilized onto sugar beet pulp

Natural adhesion of Saccharomyces cerevisiae onto sugar beet pulp (SBP) is a very simple and cheap immobilization method for retaining high cells density in the ethanol fermentation system. In the present study, yeast cells were immobilized by adhesion onto SBP suspended in the synthetic culture media under different conditions such as: glucose concentration (100, 120 and 150 g/l), inoculum concentration (5, 10 and 15 g/l dry mass) and temperature (25, 30, 35 and 40°C). In order to estimate the optimal immobilization conditions the yeast cells retention (R), after each immobilization experiment was analyzed. The highest R value of 0.486 g dry mass yeast /g dry mass SBP was obtained at 30°C, glucose concentration of 150 g/l, and inoculum concentration of 15 g/l. The yeast immobilized under these conditions was used for ethanol fermentation of sugar beet molasses containing 150.2 g/l of reducing sugar. Efficient ethanol fermentation (ethanol concentration of 70.57 g/l, fermentation efficiency 93.98%) of sugar beet molasses was achieved using S. cerevisiae immobilized by natural adhesion on SBP. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

Ethanol production from sugar beet thin juice by immobilized Saccharomyces cerevisiae : characterization of volatile compounds

The potential of by-products and intermediate products of sugar beet processing as rawmaterials for bioethanol production in Serbia has a big scope in view of the demand of ethanol as an alternative for fossil fuels. The production of bioethanol from sugar beet thin juice by Saccharomyces cerevisiae immobilized on sugar beet pulp (SBP) enables one more opportunity for achieving the zerowaste goal, through a rational use of intermediate and by-products of sugar beet processing. The effect of inoculum concentration on volatile compounds content of distillate was examined. The increase of inoculum concentration from 2.0 g/1 to 2.6 g/l (dry mass basis) increased ethanol and aldehyde content of the distillate from 9.34 % v/v to 9.60 % v/v and from 238.6 mg/l a.a. to 301.5 mg/l a.a., but decreased methanol, acetic acid and ester content from 650.0 mg/l a.a. to 232.3 mg/l a.a., from 73.4 to 51.3 mg/l a.a., and from 272.0 mg/l a.a. to 220.8 mg/l a.a., respectively. The increase in inoculum concentration of SBP-immobilized yeast indicated improvement of distillate quality

Bioethanol production from milling industry by-product in a laboratory-scale bioreactor

Bioethanol produced by biomass fermentation is a renewable and environmentally friendly energy source and has significant potential as a replacement for liquid fossil fuels. Due to the world moving toward more sustainable energy sources, the production of bioethanol has been steadily increasing. This research aims to investigate the efficiency of bioethanol fermentation from a milling industry by-product in a laboratory-scale bioreactor. Prior to fermentation in a bioreactor, for preparation of a milling industry by-product, two different thermo-enzymatic procedures were investigated and compared, and based on the obtained results the more efficient procedure was selected and used for the experiment in a bioreactor. The bioethanol fermentation was carried out in a 14-litre bioreactor in batch mode under anaerobic conditions at 30°C. The obtained results showed that this by-product can be used for the production of bioethanol but that further optimization is necessary to improve the overall efficiency of the bioprocess

The application of sheet filters in treatment of fruit brandy after cold stabilization

Considering the common use of sheet filtration for clarification of fruit brandies, the aim of this study was to evaluate the influence of its application on the stability and composition of volatile compounds of apricot brandy after cold stabilisation. Cold stabilisation treatment involved holding of the brandy at -1°C during 24 hours. Five depth filter sheets with the nominal retention rate of 0.3 μm, 0.5-0.7 μm, 0.7-1.0 μm, 1.0-2.0 μm and 2.5-4.0 μm, were tested in the study. It was shown that all assessed filter sheets were efficient in removing chill haze by significantly reducing the content of fatty acid esters (primarily ethyl palmitate and ethyl laurate). Other volatile and aromatic compounds were not significantly influenced by the applied treatments. However, the filter sheets with higher nominal retention rate (> 0.7 μm), had a smaller impact on the sensory characteristics of the apricot brandy. The re-exposure to lower temperatures did not lead to chill haze formation in any sample obtained after sheet filtration. [Projekat Ministarstva nauke Republike Srbije, br. TR-31002

Thermo-Acid pretreatment of starch based kitchen waste for ethanol production

Recently, research on the alcoholic fermentation of kitchen waste has been accelerating for both ecological and economical reasons, primarily for ethanol use as renewable biofuel. Present work deals with the fermentative production of ethanol from different starch based kitchen waste. Kitchen waste from local students restaurant was separated by basic component as: peas, green beans, beans, rice, potato, wheat bread and corn. Thermo-acidic pretreatment of these raw materials was conducted by the addition of HCl up to pH of 1, and by autoclaving at 120 oC for 30 min. From the experimental result, maximum ethanol yield was obtained from wheat bread (0.11 g/g). The highest ethanol yield per starch of 0.36 g/g, which equals to 64% of the theoretical value, was obtained for peas. From the overall analysis, the examined thermo-acid pretreatment was the most efficient for hydrolysis of wheat bread, while it was least efficient for green beans. In order to enhance the efficiency of conversion of starch from kitchen waste into ethanol, pH lower than 1 is highly recommended. The results demonstrated the potential of different food waste as a promising biomass resource for the production of ethanol

Production of ethanol from Kantata wheat variety

Processing parameters of Kantata wheat variety indicate that it is not suitable for bread making. Therefore, an investigation was carried out to evaluate the suitability of the variety for ethanol production. Wheat was cultivated at the following sites: Kovin, Zrenjanin, Pančevo and Vrbas. Ethanol yields depend on the location on which the samples were grown and on the temperature during thermal and enzymatic preparation of flour samples. Wheat sample cultivated on the Vrbas site gave the highest ethanol yield

Thermo-acid pretreatment of starch based kitchen waste for ethanol production

Recently, research on the alcoholic fermentation of kitchen waste has been accelerating for both ecological and economical reasons, primarily for ethanol use as renewable biofuel. Present work deals with the fermentative production of ethanol from different starch based kitchen waste. Kitchen waste from local students restaurant was separated by basic component as: peas, green beans, beans, rice, potato, wheat bread and corn. Thermo-acidic pretreatment of these raw materials was conducted by the addition of HCl up to pH of 1, and by autoclaving at 120oC for 30 min. From the experimental result, maximum ethanol yield was obtained from wheat bread (0.11 g/g). The highest ethanol yield per starch of 0.36 g/g, which equals to 64% of the theoretical value, was obtained for peas. From the overall analysis, the examined thermo-acid pretreatment was the most efficient for hydrolysis of wheat bread, while it was least efficient for green beans. In order to enhance the efficiency of conversion of starch from kitchen waste into ethanol, pH lower than 1 is highly recommended. The results demonstrated the potential of different food waste as a promising biomass resource for the production of ethanol

Removal of acridine orange dye from aqueous solution by adsorption onto dried sugar beet pulp

A simple, low cost, and effective method for the removal of acridine orange (AO), a mutagenic cationic dye, from aqueous model solutions by adsorption onto dried sugar beet pulp (SBP) was evaluated in the present study. The AO removal was enhanced along with the increase of the initial solution pH and dye concentration. It was found that the adsorption process closely follows a pseudo-second-order chemisorption kinetics. The obtained equilibrium data obey both the Freundlich and Langmuir isotherm models. The SBP was proved to be very promising adsorbent for AO removal. Maximum adsorption capacity of the Langmuir monolayer of SBP for AO was found to be 5.37, 34.6, 89.62, 144.53 and 324.58 mg/g, at 25°C for the solution pH of 2, 4, 5, 6, and 8, respectively. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31002

Ethanol production using Saccharomyces cerevisiae cells immobilised on corn stem ground tissue

Cell immobilisation in alcoholic fermentation has been extensively studied during the past few decades because of its technical and economical advantages over those of free cell systems. A biocatalyst was prepared by immobilising a commercial Saccharomyces cerevisiae strain (baker yeast) on corn stem ground tissue for use in alcoholic fermentation. For this purpose, the yeast cells were submitted to the batch tests 'in situ' adsorption onto pieces of the corn stem ground tissue. Cells immobilisation was analysed by optical microscopy. It was determined that the addition of the corn stem ground tissue led to an increase of the pH value, total dissolved salts content, and sugar content in fermentation medium. The addition of 5 and 10g of the corn stem ground tissue per liter of medium, increased ethanol yield, decreased amount of residual sugar and the cells immobilisation was effective. Corn stem is one of the abundant, available, inexpensive, stable, reusable, nontoxic celulosic biomaterial with high porosity, which facilitates the transmission of substrates and products between carrier and medium. The prepared immobilised biocatalyst showed higher fermentation activity than free cells. The results indicate that corn stem might be an interesting support for yeast cell immobilisation, and also a cheap alternative recourse of mineral components with possibility of application for improving ethanol productivities