Synthesis of Duloxetine Intermediate (S)-3-Chloro-1-(2-thienyl)-1-propanol with Liquid-Core Immobilized Candida pseudotropicalis 104

The evaluation of kefir pure culture starter: Liquid-core capsule entrapping microorganisms isolated from kefir grains

The main purpose of this study was to develop a pure culture starter for producing kefir. In order to accomplish starter recycling, yeasts ( Kluyveromyces marxianus strain, Pichia kudriavzevii clone), lactic acid bacteria ( Lactobacillus kefiri strain F4Aa, Lactobacillus kefiri strain NM131-7, Lactobacillus kefiri strain NM132-3, Lactobacillus kefiri strain NM180-3, respectively), and acetic acid bacteria ( Acetobacter lovaniensis strain) were entrapped in liquid core capsules based on the distribution ratio in kefir grains. The microbiological, antimicrobial, and chemical properties of kefir made with capsules (M) and kefir grains (K) were measured and compared. According to the results of plate counts in different selective medium, the number of yeasts and bacteria in the liquid core capsules gradually increased and stabilized after eight fermentation cycles. The results of gas chromatography–mass spectrometry showed that almost all the aroma components existed in the two type of kefir, except the ethyl lactate. There was no significant difference in alcohol content, protein content, and fat content, except the acidity and sugar content. Water holding capacity of kefir K was higher than kefir M. There were 14 same free amino acids in kefir M and kefir K, and the content of most free amino acids was similar. In antimicrobial test, there was no significant difference in both kefirs.

Production of chiral compounds using immobilized cells as a source of biocatalysts

The importance of chiral compounds in all fields of technology and life sciences is shown. Small chiral molecules are mainly used as building blocks in the synthesis of more complex and functionalized compounds. Nature creates and imposes stereoselectivity by means of enzymes, which are highly efficient biocatalysts. The use of whole cells as a biocatalyst source is a promising strategy for avoiding some drawbacks associated with the use of pure enzymes, especially their high cost. The use of free cells is also challenging, since cell lysis can also occur under the reaction conditions. However, cell immobilization has been employed to increase the catalytic potential of enzymes by extending their lifetimes in organic solvents and non-natural environments. Besides, immobilized cells maintain their biocatalytic performance for several reaction cycles. Considering the above-mentioned arguments, several authors have synthesized different classes of chiral compounds such as alcohols, amines, carboxylic acids, amides, sulfides and lactones by means of immobilized cells. Our aim was to discuss the main aspects of the production of chiral compounds using immobilized cells as a source of biocatalysts, except under fermentation conditions.