Free Yeast Research Articles

Bacterial cellulose as an oleaginous yeast cell carrier for soybean oil refinery effluent treatment and pyrolysis oil production.

Bacterial cellulose produced from soybean oil refinery effluent is a good immobilization carrier because of the large pores in its fiber network, its high water-holding capacity, and its good biocompatibility. In this study, it was applied to immobilization of oleaginous yeasts for treating soybean oil refinery effluent. The immobilization percentage reached 50%, and the removal of chemical oxygen demand and oil content reached 92.1% and 93.1%, respectively, during dynamic immobilization using a mass percentage of bacterial cellulose of 30% and an immobilization time of 24h, which were significantly higher than those of free oleaginous yeasts or yeasts immobilized by bacterial cellulose from rich medium. The immobilized oleaginous yeasts facilitated the recovery of the yeasts and effectively treated three batches of soybean oil refinery effluent. The immobilized oleaginous yeasts recovered after soybean oil refinery effluent treatment were pyrolyzed to produce bio-oil, which contributed to more alkanes and a higher calorific value of bio-oil in the pyrolysis products as compared to those of free oleaginous yeasts. As bacterial cellulose used as an oleaginous yeast cell carrier is produced from soybean oil refinery effluent, no waste of immobilization materials is involved and an efficient waste-into-oil bioprocess is developed.

Significant enhancement of citric acid production by Yarrowia lipolytica immobilized in bacterial cellulose-based carrier

The aim of this study was to improve the yield of citric acid (CA), an industrially valuable metabolite, obtained during Yarrowia lipolytica yeast culturing. To this end, Y. lipolytica cells were immobilized on a novel bacterial cellulose (BC) based carrier and subjected to four subsequent cycles of fed-batch culturing. During the fermentation process, yeasts metabolic stability, glucose consumption and CA production were analyzed. The results of our study have shown that BC-immobilized yeasts utilized more glucose than free cells and that the metabolic activity of BC-immobilized cells and the resultant CA production remained on a stable level throughout 4 fermentation batches, while the drop in free cells’ metabolic stability and the consequent drop in CA production was observed with each subsequent batch. Also, the overall concentration of CA product was higher in immobilized vs. free yeasts (121−129 g/L vs. 99−110 g/L, respectively). The presented results indicate that the application of a BC carrier for Y. lipolytica culturing correlates not only with a higher yield of CA product but also with more stable and repeatable conditions of the biotechnological fermentation process. The results obtained in this study may find multiple biotechnological applications in which immobilization of various types of cells is required.

Effect of microencapsulation in whey protein and water-soluble chitosan derivative on the viability of the probiotic Kluyveromyces marxianus VM004 during storage and in simulated gastrointestinal conditions

The aim of this study was to evaluate the effect of the microencapsulation (by spray drying) of the whey-native probiotic yeast Kluyveromyces marxianus VM004 in matrices of whey protein concentrate (WPC) and water-soluble chitosan (WSCh) on the viability of the yeast during drying and storage and in simulated gastrointestinal conditions. The optimized outlet drying temperature was 68 °C. This temperature allowed obtaining an encapsulation efficiency of 91% for a suspension of 10% (w/v) WPC. Yeasts microencapsulated in WSCh showed a significantly improved tolerance to simulated gastrointestinal conditions in comparison to free yeasts and yeasts microencapsulated in WPC. Besides, the solids content showed a significant influence on the probiotic viability during storage, with a suspension with 30% (w/v) solids (29:1 WPC:WSCh) showing 95% of viability after passing through gastrointestinal conditions. The results allow expanding the development of mixtures of encapsulating materials to improve the probiotic aptitude of a food ingredient powder.

Volatile Composition and Sensory Properties of Mead.

Mead is a traditional beverage that results from the alcoholic fermentation of diluted honey performed by yeasts. Although the process of mead production has been optimized in recent years, studies focused on its sensory properties are still scarce. Therefore, the aim of this work was to analyse the sensory attributes of mead produced with free or immobilized cells of the Saccharomyces cerevisiae strains QA23 and ICV D47, and to establish potential correlations with its volatile composition. In the volatile composition of mead, the effect of yeast condition was more important than the strain. In respect to sensory analysis, the most pleasant aroma descriptors were correlated with mead obtained with free yeast cells, independently of the strain. Both sensory analysis and volatile composition indicates that the most pleasant mead was produced by free yeast cells. Although this study has provided a significant contribution, further research on the sensory quality of mead is still needed.

Enhancing bioethanol productivity by a yeast-immobilized catalytically active membrane in a fermentation-pervaporation coupling process

Bioethanol is a promising substitute for fossil fuels and is mainly produced through yeast fermentation. However, in conventional batch fermentation process extracellular ethanol accumulation restricts yeast excretion of intracellular ethanol, and results in suppressed yeast viability and ethanol productivity. The present study reports a yeast-immobilized catalytically active membrane for efficient extracellular ethanol removal towards enhanced bioethanol productivity in pervaporation membrane reactor. The membrane was fabricated by immersion phase inversion through coating a porous yeast/polyethersulfone catalytic layer on a polydimethylsiloxane (PDMS) pervaporation membrane. Benefited from the high porosity of biocatalytic layer, the immobilized yeast exhibited superior fermentation capacity in high substrate concentration when compared with free yeasts. Most importantly, by comparing the fermentation performances in catalytically active membrane reactor (CAMR), inert membrane reactor and batch reactor, CAMR exhibited the highest ethanol productivity (3.05 g L−1 h−1) and yeast mass concentration (26.41 g L−1), indicating a superior yeast growth rate and viability in CAMR. We attribute this to a “genuine” in situ removal ability of the bio-catalytically active membrane: the extracellular ethanol was promptly removed from the vicinity of the yeast, promoting a more rapid excretion of the inhibitor (intracellular ethanol) and thus maximally eliminated undesirable inhibition of the intracellular ethanol.

Intranasal Inoculation of Cryptococcus neoformans in Mice Produces Nasal Infection with Rapid Brain Dissemination.

Cryptococcus neoformans is an important fungal pathogen, causing life-threatening pneumonia and meningoencephalitis. Brain dissemination of C. neoformans is thought to be a consequence of an active infection in the lung which then extravasates to other sites. Brain invasion results from dissemination via either transport by free yeast cells in the bloodstream or Trojan horse transport within mononuclear phagocytes. We assessed brain dissemination in three mouse models of infection: intravenous, intratracheal, and intranasal models. All three modes of infection resulted in dissemination of C. neoformans to the brain in less than 3 h. Further, C. neoformans was detected in the entirety of the upper respiratory tract and the ear canals of mice. In recent years, intranasal infection has become a popular mechanism to induce pulmonary infection because it avoids surgery, but our findings show that instillation of C. neoformans produces cryptococcal nasal infection. These findings imply that immunological studies using intranasal infection should assume that the initial sites of infection of infection are brain, lung, and upper respiratory tract, including the nasal airways.IMPORTANCECryptococcus neoformans causes an estimated 181, 000 deaths each year, mostly associated with untreated HIV/AIDS. C. neoformans has a ubiquitous worldwide distribution. Humans become infected from exposure to environmental sources, after which the fungus lays dormant within the human body. Upon AIDS-induced immunosuppression or therapy-induced immunosuppression (required for organ transplant recipients or those suffering from autoimmune disorders), cryptococcal disease reactivates and causes life-threatening meningitis and pneumonia. This study showed that upon contact with the host, C. neoformans can quickly (a few hours) reach the host brain and also colonizes the nose of infected animals. Therefore, this work paves the way to better knowledge of how C. neoformans travels through the host body. Understanding how C. neoformans infects, disseminates, and survives within the host is critically required so that we can prevent infections and the disease caused by this deadly fungus.

Yeast cells in double layer calcium alginate–chitosan microcapsules for sparkling wine production

This paper focuses on the use of a new type of yeast encapsulation procedure, applying the chitosan-calcium alginate double layer microcapsules, for the production of Riesling sparkling wine. Four different sparkling wines were produced by free or encapsulated yeasts. The four types of yeast used were adapted (Free EtOH-A, Encapsulated EtOH-A) and non-adapted to ethanol (Free, Encapsulated).The different yeast-inoculating formats had a significant impact on oxygen consumption and pressure increase rate in the bottle during the prise de mousse. Similarly to the free form, encapsulated yeast successfully completed the secondary fermentation. After an ageing period of 6 months, volatiles and sensory profiles of sparkling wines were compared. Although, some differences in volatile profiles were found among samples, sparkling wines produced by Encapsulated EtOH-A showed sensory properties, in terms of aroma, taste and body, similar to those produced by free yeast (both adapted and non-adapted to ethanol).

Isothermal calorimetry for monitoring of grape juice fermentation with yeasts immobilized on nylon-6 nanofibrous membranes

Isothermal microcalorimetry is often used to monitor microbiological activity and growth in various types of biological samples. Usually, it is useful to convert the isothermal microcalorimetry data into biologically meaningful data such as growth rate, lag phase or maximum growth. In this work, isothermal calorimetry was applied for monitoring of grape juice fermentation by Saccharomyces cerevisiae immobilized in nylon-6 nanofibrous membranes (NFM) prepared by electrospinning in comparison with freely dispersed yeasts. The resulting heat flow can be fitted using various approaches applying graphical, exponential, Gompertz, modified logistic and Michaelis–Menten models. Advantages and drawbacks of each approach for monitoring of the immobilized yeasts have been discussed in relation to the S. cerevisiae yeasts. Analysis of the fitting parameters showed that immobilized yeasts had the highest growth rate and maximum growth in comparison with freely dispersed yeasts. Parallel measurements of sugar and oxygen consumption rates for immobilized and free yeasts cells confirmed the calorimetric data. The results of this work demonstrate practical approach to analysis and modeling of calorimetric data in food analysis and advantages of application of NFM as solid support for yeast immobilization.

The effect of pitching rate on the production of higher alcohols by top-fermenting yeast in wheat beer fermentation

The level of higher alcohols on top-fermentation determines the flavor profile and is one of the most important elements dictating the favorable top-fermented wheat beer (Ale beer) development. The optimization of the pitching rate has been shown to be crucial for industrial beer brewing. This study focused on understanding the effect of the variable inoculum size on the synthesis of higher alcohols. We utilized sequencing to investigate the transcript changes under different inoculum sizes and link the results to fermentation performance. Variable cell inoculum density levels were linked with differences in higher alcohol production. Specifically, we observed significantly less higher alcohols produced at lower cell inoculum density during the stationary phase. Importantly, the accumulation of higher alcohols during the exponential growth phase was overall similar between different pitching rates. Moreover, free amino nitrogen (FAN) consumption and yeast cell viability were significantly decreased during stationary phase at the lowest inoculum density. Transcriptomic analysis revealed that amino acid metabolism genes ALD4, ALD6, ARO9, ARO10, and PUT1 were differentially expressed once the cells entered the declining growth phase at the lowest inoculum size. The results suggest that the variable accumulation of higher alcohols in the top-fermenting yeast at different inoculum sizes is mostly accounted for in the stationary phase. We discovered that lower pitching rate was associated with a negative effect on amino acid metabolism and synthesis of higher alcohols during the stationary phase, leading to the decrease in higher alcohol concentration at low inoculum densities. Overall, our study provides valuable insights that could benefit wheat beer production.

Encapsulation of Saccharomyces cerevisiae in alginate beads and its application for wine making

A study was carried out on encapsulation of wine yeast (Saccharomyces cerevisiae) and its use in wine making compared to free yeast. Rehydrated active dry yeast was encapsulated in a 2% sodium alginate solution, cross linked with different molar concentration of CaCl2 solution (0.1, 0.2, 0.3,0.4 and 0.5M) for 30 minutes. The molar concentration with minimum cell leakage (0.2M) was used for yeast encapsulation. Colony count (CFU/ml) was analyzed for both free yeast (FY) and encapsulated yeast (EY) so as to equilibrate the rate of yeast pitching in wine fermentation. Physico-chemical properties; total soluble solids (T.S.S.), acidity and pH of red and white grapes were analyzed and were found to be 16.4±0.10oBx, 0.38±0.02% and 3.90±0.02 for white grapes and 19±0.15oBx, 0.64±0.01% and 3.1±0.10 for red grapes. During the fermentation process in both wines, a gradual reduction in T.S.S. was noted while an alternate of increase and decrease trend in acidity was noted which finally stabilized after 12 days. The final T.S.S. of wines was not significantly different for yeast types but higher values were noted for red wine (FY, 7.11±0.26 & EY, 7.33±0.19) than for white wine (FY, 6.1±0.10 & EY, 6.2±0.10). Similar trend was noted for final acidity of red wine (FY, 0.83±0.01 & EY, 0.84±0.02%). Though, no significant effect of yeast type on alcohol production was noted, the average alcohol content of red (FY, 13.22±0.26% & EY, 13.72±0.44%) and white (FY, 9.21±0.21% & EY, 9.64±0.38%) wine were found to be significantly different. However, wine prepared from EY was less turbid (Red wine, 95 NTU & White wine, 140 NTU) and had higher clarity (L*) than wine from FY. So, from this study it was concluded that encapsulating wine yeast does not affect its fermenting capability but will aid in production of less turbid wine which will definitely simplify the filtration process.

Antibiofilm and Antivirulence Activities of 6-Gingerol and 6-Shogaol Against Candida albicans Due to Hyphal Inhibition.

Candida albicans is an opportunistic pathogen and responsible for candidiasis. C. albicans readily forms biofilms on various biotic and abiotic surfaces, and these biofilms can cause local and systemic infections. C. albicans biofilms are more resistant than its free yeast to antifungal agents and less affected by host immune responses. Transition of yeast cells to hyphal cells is required for biofilm formation and is believed to be a crucial virulence factor. In this study, six components of ginger were investigated for antibiofilm and antivirulence activities against a fluconazole-resistant C. albicans strain. It was found 6-gingerol, 8-gingerol, and 6-shogaol effectively inhibited biofilm formation. In particular, 6-shogaol at 10 μg/ml significantly reduced C. albicans biofilm formation but had no effect on planktonic cell growth. Also, 6-gingerol and 6-shogaol inhibited hyphal growth in embedded colonies and free-living planktonic cells, and prevented cell aggregation. Furthermore, 6-gingerol and 6-shogaol reduced C. albicans virulence in a nematode infection model without causing toxicity at the tested concentrations. Transcriptomic analysis using RNA-seq and qRT-PCR showed 6-gingerol and 6-shogaol induced several transporters (CDR1, CDR2, and RTA3), but repressed the expressions of several hypha/biofilm related genes (ECE1 and HWP1), which supported observed phenotypic changes. These results highlight the antibiofilm and antivirulence activities of the ginger components, 6-gingerol and 6-shogaol, against a drug resistant C. albicans strain.

Preservative effects of fish gelatin coating enriched with CUR/βCD emulsion on grass carp (Ctenopharyngodon idellus) fillets during storage at 4 °C

This study investigated the effects of a novel edible coating combining fish gelatin with curcumin/β-cyclodextrin (CUR/βCD) emulsion on the quality of grass carp fillets (GCFs) during storage at 4 °C. For all samples, the quality parameters, including weight loss, pH, total volatile basic nitrogen (TVB-N), peroxide value (PV), thiobarbituric acid (TBA) value, SDS-PAGE, free amino acids (FAA), microbiological (total viable counts (TVC), Pseudomonas counts, yeasts and molds, and H2S-producing bacteria), color and sensorial characteristics, were tested periodically. The coatings containing CUR/βCD emulsions exhibited better preservative effects than gelatin/βCD coating. Therefore, fish gelatin coating enriched with CUR/βCD emulsion can be used as an effective way to maintain the quality of GCF and extend its shelf life during storage at 4 °C.

Enhanced biodegradation of phenol by magnetically immobilized Trichosporon cutaneum

Aromatic compounds are abundant in aqueous environments due to natural resources or different manufacturer’s wastewaters. In this study, phenol degradation by the yeast, Trichosporon cutaneum ADH8 was compared in three forms namely: free cells, nonmagnetic immobilized cells (non-MICs), and magnetically immobilized cells (MICs). In addition, three different common immobilization supports (alginate, agar, and polyurethane foams) were used for cell stabilization in both non-MICs and MICs and the efficiency of phenol degradation using free yeast cells, non-MICs, and MICs for ten consecutive cycles were studied. In this study, MICs on alginate beads by 12 g/l Fe2O3 magnetic nanoparticles had the best efficiency in phenol degradation (82.49%) and this amount in the seventh cycle of degradation increased to 95.65% which was the highest degradation level. Then, the effect of magnetic and nonmagnetic immobilization on increasing the stability of the cells to alkaline, acidic, and saline conditions was investigated. Based on the results, MICs and non-MICs retained their capability of phenol degradation in high salinity (15 g/l) and acidity (pH 5) conditions which indicating the high stability of immobilized cells to those conditions. These results support the effectiveness of magnetic immobilized biocatalysts and propose a promising method for improving the performance of biocatalysts and its reuse ability in the degradation of phenol and other toxic compounds. Moreover, increasing the resistance of biocatalysts to extreme conditions significantly reduces costs of the bioremediation process.

Controlling beer filtration process through implementation of enzymatic and microbiological techniques

Abstract The best practice for filtration optimization process is to control biological and non biological particles at every stage of beer chain production. There are several processes that can be used to control beer filtration process, such as settlement of non-biological and biological particles through sedimentation, centrifugation, extended stabilization periods, addition of flocculants and clarifiers to reduce both, yeast and haze loadings etc. Filtration process is controlled by yeast, proteins and carbohydrates. Cell yeast number in suspension determines which is going to dominate filtration process. If yeast cell number is less than a million, filterability is dependent mainly from physico-chemical beer characteristics, otherwise biological phase control filtration process. In this paper we have proposed some enzymatic and yeast management techniques to improve filtration process. Experiments were carried out in laboratory and industrial scale. There were used free and immobilized enzymes and yeast. It was noticed a good correlation between laboratory and industrial application findings. Immobilized yeast in batch processes not only make easier yeast management but also increase beer filterability, excluding some energy consuming processes like centrifugation and long conditioning time

BIO-ETHANOL PRODUCTION FROM ENVIRONMENTAL WASTE FOLLOWED BY POLYMERIC SEPARATION OF FORMED ETHANOL/WATER MIXTURE

Recent studies are concerned by future energy shortage that projected to occur as a result of fossil fuel depletions. Our study was interested to use the environmental wastes as a raw material for bio-ethanol production. Kitchen wastes are one of the most distributed wastes all over the world. Starchy ingredients in the form of rice mainly are the major component of such wastes. Crude alpha amylase enzyme has been applied to convert the starch molecules into simple units of glucose. Saccharomyces cerevisiae has been subsequently used to ferment the produced glucose units into bioethanol anaerobically. The obtained results showed that 40% rice substrate is the optimum concentration to produce the highest glucose units at 417.9 mg/dl. However, the higher concentration of the substrate (rice) was recorded as a blocking agent for glucose production. On the other hand, the higher percentage of alpha amylase (100 μl) was recorded as the most preferable one to produce the most elevated glucose concentration of approximately 482.5 mg /dl. The highest bioethanol production of 423.5 mg/dlwas obtained after anaerobic fermentation of the free yeast cells at 30oC without shaking. The produced bio-ethanol compared with standard 25% ethanol was separated by using amicon cell ultra-filtration at different nitrogen pressures. Chitosan and sodium alginate membranes were prepared to be used in the bio-ethanol/water separation process. Chitosan and sodium alginate membranes were characterized by SEM and IEC. The hydrophilicity/hydrophobicity of the prepared membranes were investigated using contact angle.

Immobilization of Saccharomyces cerevisiae on nylon-6 nanofibrous membranes for grape juice fermentation

Nylon-6 nanofibrous membranes (NFM) prepared by electrospinning have been used as solid state support for the immobilization of the yeast Saccharomyces cerevisiae and then applied for the fermentation of grape juice. The membranes were characterized by scanning electron microscopy. The resulting metabolic activity was characterized by microcalorimetry. Sugar and ethanol changes during fermentation were monitored by HPLC. The results showed that the fermentation performance of immobilized yeasts on NFM is equal or even superior to the traditional fermentation process with yeasts freely dispersed in the medium. From calorimetry, free and immobilized yeasts showed the same enthalpy value in model solution, regardless to the amount of yeast loaded (52.2 ± 5.9 kJ mol−1 of glucose). Instead, immobilization of yeasts resulted in shorter lag time. Moreover, the maximum growth rate of immobilized yeasts was the same as with free yeasts in model solutions. However, the growth rate of immobilized yeasts was even higher, when performed in grape juice. In addition, the immobilization of yeasts on NFM exhibits the evident possibility of multiple reuse. Three consecutive fermentations were performed without significant loss of the overall performance. These findings support the development of nanostructured solid support for biocatalytic processes like fermentation of alcoholic beverages.

FERMENTATION CHARACTERISTICS OF CAMPBELL EARLY GRAPE WINE INOCULATED WITH INDIGENOUS KOREAN WINE YEASTS ENCAPSULATED IN CA-ALGINATE BEADS AFTER AIR-BLAST DRYING

The aim of this study was to test the possibility of using yeast cells encapsulated in calcium alginate (Ca-alginate) beads as a starter for wine fermentation. Characteristics of Korean Campbell Early wines fermented by five free yeast cell types and those encapsulated in 2% Ca-alginate beads were compared using physicochemical analyses and sensory evaluation tests. The encapsulated yeast cells were shown to ferment Korean Campbell Early grapes with a similar efficiency as that exhibited by the five free yeast cell-types. After fermentation, the characteristics of free cells and encapsulated cells did not show significant differences in terms of content of reducing sugars, soluble solids, total acids, organic acids, and free sugars, as well as in terms of viable cell numbers and other physicochemical properties. The encapsulated cells did, however, produce more alcohol than the free cells. Encapsulation in 2% Ca-alginate beads was furthermore found to decrease the production of negative volatile compounds. The sensory evaluation of wines fermented by free cells compared with those fermented by Ca-alginate bead-encapsulated cells yielded similar scores for the following properties: color, taste, flavor, and overall preference. Overall, no significant differences were observed between the two grape wines, and yeast cells encapsulated in 2% Ca-alginate beads therefore showed high stability and served as an effective yeast starter for wine fermentation.

Yeast Immobilization Systems for Alcoholic Wine Fermentations: Actual Trends and Future Perspectives.

Yeast immobilization is defined as the physical confinement of intact cells to a region of space with conservation of biological activity. The use of these methodologies for alcoholic fermentation (AF) offers many advantages over the use of the conventional free yeast cell method and different immobilization systems have been proposed so far for different applications, like winemaking. The most studied methods for yeast immobilization include the use of natural supports (e.g., fruit pieces), organic supports (e.g., alginate), inorganic (e.g., porous ceramics), membrane systems, and multi-functional agents. Some advantages of the yeast-immobilization systems include: high cell densities, product yield improvement, lowered risk of microbial contamination, better control and reproducibility of the processes, as well as reuse of the immobilization system for batch fermentations and continuous fermentation technologies. However, these methods have some consequences on the behavior of the yeasts, affecting the final products of the fermentative metabolism. This review compiles current information about cell immobilizer requirements for winemaking purposes, the immobilization methods applied to the production of fermented beverages to date, and yeast physiological consequences of immobilization strategies. Finally, a recent inter-species immobilization methodology has been revised, where yeast cells are attached to the hyphae of a Generally Recognized As Safe fungus and remain adhered following loss of viability of the fungus. The bio-capsules formed with this method open new and promising strategies for alcoholic beverage production (wine and low ethanol content beverages).

Encapsulation of Saccharomyces cerevisiae in hydrogel particles based gellan ionically cross-linked with zinc acetate

The purpose of this study is to obtain ionically cross-linked gellan particles containing immobilized yeast cells. The zinc acetate was chosen as a cross-linking agent due to its beneficial role in the growth and nutrition of yeast cells and also due to the advantages of its use in fermentation processes. The physicochemical and morphological properties as well as the fermentative activity of the obtained particles were studied. The zinc acetate concentration has an influence on particles stability in water, on the mechanical stability and also on the swelling degree. The morphology of the obtained particles was analyzed by SEM and proves that the yeast cells are immobilized in large numbers in the polymeric matrix. The cell viability is maintained at high values after several fermentation cycles. These obtained micro-bioreactors were tested in terms of fermentative activity and the fermentation process was optimized by studying the influence of several factors. The gellan gum particles can be easily recovered by filtration and they can be reused in repeated fermentation cycles. The results obtained in the presence of these cross-linked particles are comparable to those achieved in the free yeast fermentation.

A novel method for bioethanol production using immobilized yeast cells in calcium-alginate films and hybrid composite pervaporation membrane

Fermentation of sugar for production of ethanol was carried out using Saccharomyces cerevisiae cells immobilized in calcium alginate films. Thin films of calcium alginate casted on a microchannel surface were used instead of the typical spherical bead configuration. Yeast immobilized on alginate films produced a higher ethanol yield than free yeast cells under the same fermentation conditions. Also, a silicalite-1/poly dimethyl siloxane composite pervaporation membrane was synthesized for ethanol separation, and characterized with flux and separation factor. The composite membrane synthesized with a 3–1 ratio of silicalite-1 to poly dimethyl siloxane showed promising results, with a flux of 140.6g/m2h±19.3 and a separation factor of 37.52±3.55. Thus, the performance of both the alginate film with immobilized cells and the customized hybrid membrane suggests they could have an interesting potential application in an integrated reaction-separation device for the production and purification of bioethanol.