Determination of Impurities in Bioproduced Succinic Acid

At present, significant research resources are directed towards development of renewable products for replacing petrochemicals such as succinic acid. The critical component of this research is the identification of impurities which have a detrimental impact on further processing of succinic acid. We have adapted derivatization with gas chromatography - mass spectrometry to identify and quantify more than 120 impurities in several succinic acid samples. This study focused on petroleum based succinic acid as well as bio-based samples that use a modified E. coli strain for fermentation. To enable an accurate quantification of both the target product and common impurities, we evaluated the acetonitrile extraction efficiency as an alternative to direct derivatization, and then compared several derivatization agents for trimethylsilylation. A prior acetonitrile extraction was shown to be essential to detect impurities in trace concentrations. N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) was most efficient for derivatization of saccharides and low molecular weight monocarboxylic acids. However, the presence of pyridine was necessary for derivatization of saccharides and polyalcohols with BSTFA, whereas low molecular weight acids had to be quantified without pyridine. Fourteen representative bioproduced succinic acid samples differing in production stage, and cultivation method were characterized. The screening of initial process (1st stage of synthesis) samples showed monocarboxylic acids as most abundant and suggested occurrence of saccharides. Thus we have developed method allowing for quantification of carboxylic acids and saccharides with limits of detection between 0.02-0.3 ng. In initial process bacterial samples and also petrochemical sample, formic, acetic, lactic, oxalic, benzoic, citric and malic acids as well as glycerol, butanediol, and glucose were found in a range of 0.02-1160 µg/g. In final processed samples, formic and acetic acid, and glucose were found in concentration lower than 0.001% demonstrating effectiveness of process as well as applicability of the method as quality control of the process

Morphological and chemical variations of sweet flag (Acorus calamus L.) in the Czech and Finnish gene bank collection

v2007okMTT Mikkel

Allium genetic resources

An overview of the developments in Allium genetic resources during the past 25 years is presented in this chapter. A first important development has been the introduction and further development of web-based genebanking information systems (e.g. GENESYS, PLANTSEARCH), which facilitated the exchange of data to a large extent between Allium collection holders worldwide. These information systems made it possible to obtain an overview of the Allium genetic resources managed worldwide and identify the gaps in collections which still need to be filled, especially in the face of the ongoing genetic erosion. A second important area of progress has been the development of new methods for the maintenance of Allium germplasm, especially cryopreservation. This method has made it possible to maintain Allium accessions in a cheap and effective way. The method is especially important for the conservation of vegetatively maintained germplasm. Other developments in Allium genebanking are the improvement of the health status of the germplasm kept in the collections and the continuing characterization and evaluation of germplasm, which stimulates the utilization of the Allium genetic resources held in genebanks. Significant changes could also be observed with respect to acquisition and exchange of plant genetic resources due to many and complex new regulations on the legal and organizational levels due to the adoption of the CBD and IT-PGRFA by many countries. It makes the handling of the plant accessions safer and more consistent but also more circumstantial. Finally, we need to underline that in an increasingly changing world with all the threats of genetic erosion and extinction due to disappearance of traditional cultivation methods, devastation of our environment and climatic change, the conservation of genetic resources is of prime importance for agriculture. Especially for breeders, a highly diverse genepool of a crop plant is an invaluable treasure. The importance to keep this treasure will no doubt become even more important in the future