Comparison of different production processes for bioethanol

In this study, ethanol was produced with the microorganism Saccharomyces cerevisiae by using sucrose as a substrate. Batch processes were tested by using the same substrate, microorganism and medium composition. Saccharomyces cerevisiae, used in the free form in the first group of experiments, was immobilized by different methods. in the second group of experiments agar, sponge and a natural material called luffa cylindrica fiber were Used as support materials. the batch processes with free and immobilized microorganisms were compared with respect to efficiency and yield

Aeration-enhanced bioethanol production

WOS: 000344825400008In recent years, growing attention has been devoted to maximize the product yield for the conversion of biomass into ethanol. In this study, microaerated conditions were established to enhance the ethanol yield by Eschericia coli KO11. According to the results, limited aeration was found to be an important factor to increase the ethanol yield by improving the consumption of sugars and the production of biomass. The best result was obtained using oxygen transfer rate (OTR) of 5 mmol/L/h, reaching 19.66 g/L of ethanol at 48 h using quince pomace as substrate. The assays showed that less than 5% of the initial sugar remained at the end of the fermentation, achieving a biomass concentration of 7.3 g/L. In conclusion, we successfully carried out lab-scale production of bioethanol from quince pomace using the ethanologenic E. coli KO11. In particular, microaerobic ethanol fermentation at OTR = 5 mmol/L/h is suggested for the efficient utilization of sugars in quince pomace. Considering the abundance of raw material and the ease of large-scale production, this improvement will have a considerable impact on the total cost of bioethanol. (C) 2014 Elsevier B.V. All rights reserved.COST Action of the European Union [FP0602]; The Scientific and Technical Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107M650]This study was a part of COST Action of the European Union, FP0602, and the authors wish to thank The Scientific and Technical Research Council of Turkey (TUBITAK with the grant number of 107M650) for the financial support

Evaluation of scale-up parameters of bioethanol production from Escherichia coli KO11

WOS: 000351543800008Objective: In recent years, increased attention has been devoted to the conversion of biomass into fuel ethanol, as one of the cleanest liquid fuel alternatives to fossil fuels. However, industrial production of bioethanol is related with successful scaling-up studies. Methods: In this study, the experimental designs of scale-up procedures based on constant mixing time, impeller tip speed and oxygen mass transfer coefficient were performed in 8 L stirred tank reactor and were compared in terms of product yield and productivity with those obtained from 2 L stirred tank reactor using quince pomace as a substrate for bioethanol production by Escherichia coli KO11. Results: Scale-up based on constant mixing time yielded a maximum ethanol concentration of 23.42 g/L which corresponded to 0.4 g ethanol/ g reduced sugar in 8 L stirred tank reactor. Moreover, shear stress increased only 1.1 fold which resulted in low cell damage and high cell viability. Conclusion: Constant mixing time was identified as the most important key parameter especially for scaling-up of viscous fermentation broths of bioethanol production due to the significance of the homogeneity.Scientific and Technical Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107M650]; Cost Action of the European Union [FP0602]This study was a part of Cost Action of the European Union, FP0602 and the authors wish to thank The Scientific and Technical Research Council of Turkey (TUBITAK with the grant number of 107M650) for the financial support

Influences of different stress media and high light intensities on accumulation of astaxanthin in the green alga Haematococcus pluvialis

WOS: 000272267400014PubMed ID: 19712763Haematococcus pluvialis Flotow is used in the aquaculture, pharmaceutical and cosmetic industries. The aim of this study was to compare the effect of various stress media and high light intensities on astaxanthin accumulation. The experimental design was achieved by four different stress media and two different light intensities for 14 days of induction period. The astaxanthin concentrations of 29.62 mg g(-1) and 30.07 mg g(-1) were obtained in distilled water with CO(2) and N-free medium, respectively, with no significant difference between them at 546 mu mol photons m(-2)s(-1). Because of the morphological changes of H. pluvialis, microscopic observation was considered during the induction period to facilitate the selection of stress medium. It was clear that the rate of astaxanthin accumulation was much faster in distilled water with the addition Of CO(2). The main point is that, this medium is more economical than others, especially for the large-scale productions.Ege University Scientific Research FundEge UniversityWe wish to thank Ege University Scientific Research Fund for financial support

Patents on Biosurfactants and Future Trends

WOS: 00046829820001