Effect of Glycerol, as Cryoprotectant in the Encapsulation and Freeze Drying of Microspheres Containing Probiotic Cells

It is reported that probiotics provide several health benefits as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. Ensuring adequate dosages of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants. In this study, probiotic cells (Bifidobacterium lactis 300B) were entrapped in alginate/pullulan microspheres. In the encapsulation formula glycerol was used as cryoprotectant in the freeze drying process for long time storage. It was observed that the survival of Bifidobacterium lactis 300B when encapsulated without cryoprotectant was higher than the formula with glycerol in the fresh obtained microspheres. The addition of glycerol was in order to reduce the deep freezing and freeze drying damages. In the chosen formulations, glycerol did not proved protection for the entrapped probiotic cells in the freeze drying process, for which the use of glycerol as cryoprotectant for alginate/pullulan Bifidobacterium lactis 300B entrapment is not recommended

The cyclin‐dependent kinase G group defines a thermo‐sensitive alternative splicing circuit modulating the expression of Arabidopsis ATU2AF65A

The ability to adapt growth and development to temperature variations is crucial to generate plant varieties resilient to predicted temperature changes. However, the mechanisms underlying plant response to progressive increases in temperature have just started to be elucidated. Here, we report that the Cyclin?dependent Kinase G1 (CDKG1) is a central element in a thermo?sensitive mRNA splicing cascade that transduces changes in ambient temperature into differential expression of the fundamental spliceosome component, ATU2AF65A. CDKG1 is alternatively spliced in a temperature?dependent manner. We found that this process is partly dependent on both the Cyclin?dependent Kinase G2 (CDKG2) and the interacting co?factor CYCLIN L1 resulting in two distinct messenger RNAs. Relative abundance of both CDKG1 transcripts correlates with ambient temperature and possibly with different expression levels of the associated protein isoforms. Both CDKG1 alternative transcripts are necessary to fully complement the expression of ATU2AF65A across the temperature range. Our data support a previously unidentified temperature?dependent mechanism based on the alternative splicing of CDKG1 and regulated by CDKG2 and CYCLIN L1. We propose that changes in ambient temperature affect the relative abundance of CDKG1 transcripts and this in turn translates into differential CDKG1 protein expression coordinating the alternative splicing of ATU2AF65AauthorsversionPeer reviewe

The Arabidopsis thaliana glycine-rich RNA binding proteins atGRP7 and atGRP2 are involved in early development

The glycine-rich RNA-binding proteins of Arabidopsis thaliana are of growing interest in the context of understanding how plants respond to biotic and abiotic stresses. In this study we focus on the phenotypic analysis of Arabidopsis knock-out mutants of genes that encode the glycine-rich proteins atGRP2 and atGRP7, comparing them to knock-out mutants of ABI3, ABI4 and ABI5, genes linked to cell signaling through the plant hormone abscisic acid (ABA). The results show that the abscisic acid insensitive (ABI) mutants developed faster than wild-type plants. In contrast the glycine-rich protein knock-out mutants (grp7-1 and grp2) did not grow as well, suggesting an involvement of these genes in key early developmental processes. There was a significant difference in the phenotype of the knock-out mutants grp2 and grp7-1, suggesting that atGRP7 and atGRP2 have overlapping yet distinct roles in development