35 research outputs found

    Efficiency of natural oils as antifoaming agents in bioprocesses

    No full text
    The effectiveness and efficiency of nine different natural oils were investigated using simulated fermentation media and several dimensionless coefficients were derived to provide a means for quantitative comparison. Furthermore, correlations between the physical and chemical properties of natural oils and of media and foam-suppression efficiencies of natural oils were sought. It was concluded that the effectiveness of a natural oil in foam suppression greatly varies with the type of medium. Copyright © 1988 Society of Chemical Industr

    Photo-bioproduction of hydrogen by Chlamydomonas reinhardtii using a semi-continuous process regime

    No full text
    Photo-bioproduction of hydrogen by using green algae, Chlamydomonas reinhardtii, was investigated in batch and semi-continuous process regimes, in a continuous stirred type photobioreactor. Batch cultivation was carried out for 35 days which was one of the longest cited in literature. Total hydrogen production with batch culture reached 316 ml. The observations from the batch culture provided useful data about the production process. Three important observations were made from the batch cultivation. One was the requirement of a 2 day-lag time for the start of the hydrogen production. Second one was the fact that the maximum hydrogen production is reached at around day 4. Third one was the decline of hydrogen production after a week. Semi-continuous regime was preferred rather than a continuous one based on these data. Semi-continuous cultivation was continued for 127 days yielding a total hydrogen production of 1108 ml. In the semi-continuous process, the effects of parameters such as dilution ratio, dilution frequency and fresh medium addition were studied. The range of these parameters was also decided, based on the batch cultivation data. Each experiment testing for different parameters lasted for 7 days and thus five consecutive sets were completed in 35 days. The results showed a direct correlation between the amount and frequency of dilution and hydrogen production. Semi-continuous regime gave the opportunity of dividing the continuous production in consecutive batches and the process was in good relation with batch regime. © 2009 Professor T. Nejat Veziroglu

    Downstream processes for plant cell and tissue culture

    No full text
    Biotechnological cultivation of plant cells and tissues is one of the most challenging fields of recent scientific researches. The requirements of pharmaceutical and food industries in terms of value-added phytochemicals have increased rapidly in the last few years. Therefore, cost-effective and technically sound downstream processes have to be developed in order to supply standardized end-products. Depending on the utilization of the biomass or the culture broth, different types of facilities are needed for the recovery and quali-quantitative analysis. The aim of this chapter is to summarize mass transfer considerations and critically outline the developments in downstream processing of plant cell and tissue cultures by presenting fundamental knowledge as well as the advantages and disadvantages of some conventional and novel techniques such as supercritical fluid and membrane processes. Furthermore, state of the art for recovery and purification of secondary metabolites were discussed in the light of patents via Espacenet database covering US, Japan, European, Korean, and Chinese issued and applied patents and WIPO publications. Innovative downstream processes in combination with hyphenated techniques representing a modern approach to perform fast and reproducible analytical methods for quantification and quality assurance of secondary metabolites are major challenges for industrial-scale applications of plant cell and tissue cultures. © 2013 Springer-Verlag Berlin Heidelberg. All rights are reserved

    An Engineering approach to bioinformatics and its applications

    No full text
    [No abstract available
    corecore