Abstract: The invention provides a process for the production of aspartic acid poly-condensate from a carbohydrate comprising the steps of: fermenting a carbohydrate-containing medium by means of a fumaric acid-producing microorganism, whereby a fumarate-containing fermentation liquor is formed; forming a purified ammonium fumarate solution from the fumarate-containing fermentation liquor; enzymatically converting the purified ammonium fumarate into purified ammonium aspartate; heating an aqueous solution of an aspartate salt derived from the purified ammonium aspartate whereby water is removed, an aspartic acid condensate is formed and a second product is formed, which second product is basic and contains the cation of the aspartate salt; and removing and using the basic second product as a reagent in another step of the process.

Abstract: The present invention relates to a process for integration of a chosen gene or of a specific DNA sequence in a DNA sequence such as the chromosome or episome of a bacterium, wherein: a) the said chosen gene or the chosen DNA sequence is cloned inside a defective transposon outside the essential parts of the transposon, b) the said transposon is integrated in the DNA sequence such as the chromosome or the episome of the said bacterium, and also the bacterium strains obtained by implementation of this process.

Abstract: The invention provides a process for the preparation of aspartic acid via a fermentation process for the preparation of ammonia fumarate, wherein the pH of the fermentation broth is controlled by the addition of a calcium base to produce a calcium fumarate precipitate, characterized in that ammonium fumarate is produced by separating the precipitated calcium fumarate from the fermentation broth, and reacting the same with a reagent selected from ammonia, ammonium carbonate, ammonia in combination with CO.sub.2 and mixtures therefore, to form ammonium fumarate and a co-product selected from calcium carbonate and calcium hydroxide, wherein the energy of indirect neutralization of fumaric acid by ammonia serves as the driving force for the conversion of calcium fumarate to the desired ammonium fumarate product and for the regeneration of a calcium base reagent, and wherein diammonium fumarate is enzymatically converted to ammonium aspartate and acidulated to from aspartic acid.

Abstract: The present invention relates to a process for integration of a chosen gene or of a specific DNA molecule into the chromosome or episome of a bacterium by cloning the gene or DNA molecule into a defective transposon which is then integrated into the chromosomal or episomal DNA of the bacteria. The defective transposon is incapable of transposition autonomously but can be induced to transpose when properly complemented. The complementation to induce transposition can be limited so that the defective transposon produces a specific number of copies and thereafter is stable. The number of copies of the defective transposon produced during the period of transposition can be estimated by the level of expression of a marker gene contained within the defective transposon.