Dulcitol

Osmotic stress activates nif and fix genes and induces the Rhizobium tropici CIAT 899 Nod factor production via NodD2 by up-regulation of the nodA2 operon and the nodA3 gene.[Pubmed:30917160]

PLoS One. 2019 Mar 27;14(3):e0213298.

The symbiosis between rhizobia and legumes is characterized by a complex molecular dialogue in which the bacterial NodD protein plays a major role due to its capacity to activate the expression of the nodulation genes in the presence of appropiate flavonoids. These genes are involved in the synthesis of molecules, the nodulation factors (NF), responsible for launching the nodulation process. Rhizobium tropici CIAT 899, a rhizobial strain that nodulates Phaseolus vulgaris, is characterized by its tolerance to multiple environmental stresses such as high temperatures, acidity or elevated osmolarity. This strain produces nodulation factors under saline stress and the same set of CIAT 899 nodulation genes activated by inducing flavonoids are also up-regulated in a process controlled by the NodD2 protein. In this paper, we have studied the effect of osmotic stress (high mannitol concentrations) on the R. tropici CIAT 899 transcriptomic response. In the same manner as with saline stress, the osmotic stress mediated NF production and export was controlled directly by NodD2. In contrast to previous reports, the nodA2FE operon and the nodA3 and nodD1 genes were up-regulated with mannitol, which correlated with an increase in the production of biologically active NF. Interestingly, in these conditions, this regulatory protein controlled not only the expression of nodulation genes but also the expression of other genes involved in protein folding and synthesis, motility, synthesis of polysaccharides and, surprinsingly, nitrogen fixation. Moreover, the non-metabolizable sugar Dulcitol was also able to induce the NF production and the activation of nod genes in CIAT 899.

Development and validation of HILIC-UHPLC-ELSD methods for determination of sugar alcohols stereoisomers and its application for bioconversion processes of crude glycerin.[Pubmed:30621908]

J Chromatogr A. 2019 Mar 29;1589:56-64.

The recent increase in the production of crude glycerin through the manufacture of biodiesel has imputed a commercial issue, the excess of this raw material in the market and its constant devaluation, which resulted in the need for new technologies for its use. Crude glycerin can be used in biotechnological processes for the production of high value-added compounds. This study presents novel, simple and fast methods based on ultra-high performance liquid chromatography (UHPLC) using evaporative light scattering detection (ELSD) for simultaneous analysis of ten sugar alcohols with a hydrophilic interaction chromatography (HILIC) column. The selected compounds and their possible stereoisomers have major commercial importance and they can be obtained by biotechnological routes. Under optimized conditions, threitol, erythritol, adonitol, xylitol, arabitol, iditol, sorbitol, mannitol, Dulcitol and volemitol can be analyzed simultaneously within 15.0 min. The use of different column temperatures was a key parameter to reach the selectivity during the separation of some stereoisomers. Regression equations revealed a good linear relationship (R > 0.995) over the range from 50.0 to 800.0 ng. Limits of detection (LOD) and quantification (LOQ) ranged from 30.0 to 45.0 ng and 50.0-75.0 ng, respectively. The HILIC-UHPLC-ELSD methods showed good precision with low coefficient of variation (CV%) for the intra- and inter-assays experiments (

Sensitivity to antimicrobials of faecal Buttiauxella spp. from roe and red deer (Capreolus capreolus, Cervus elaphus)detected with MALDI-TOF mass spectrometry.[Pubmed:30468327]

Pol J Vet Sci. 2018 Sep;21(3):543-547.

Wild ruminants are an interesting topic for research because only limited information exists regarding their microbiota. They could also be an environmental reservoir of undesirable bacteria for other animals or humans. In this study faeces of the 21 free-living animals was sampled (9 Cervus elaphus-red deer, adult females, 12 Capreolus capreolus-roe deer, young females). They were culled by selective-reductive shooting during the winter season of 2014/2015 in the Strzalowo Forest District-Piska Primeval Forest (53 degrees 36 min 43.56 sec N, 21 degrees 30 min 58.68 sec E) in Poland. Buttiauxella sp. is a psychrotolerant, facultatively anaerobic, Gram-negative rod anaerobic bacte- rial species belonging to the Phylum Proteobacteria, Class Gammaproteobacteria, Order Entero- bacteriales, Family Enterobacteriacae and to Genus Buttiauxella. Buttiauxella sp. has never previ- ously been reported in wild ruminants. In this study, identification, antimicrobial profile and sensitivity to enterocins of Buttiauxella strains were studied as a contribution to the microbiota of wild animals, but also to extend knowledge regarding the antimicrobial spectrum of enterocins. Five strains were identified using the MALDI-TOF identification system (evaluation score value was up to 2.224) and allotted to the genus Buttiauxella including the species Buttiauxella gaviniae, B. ferragutiae, B. agrestis. Strains were DNase negative, and they hydrolysed esculin; fermentation of L-arabinose, D-mannitol and D-mannose was positive. Dulcitol, inositol reaction, urea and indol were negative. Buttiauxella strains did not form biofilm. They were resistant to at least one of the 13 antibiotics tested. B. agrestis 2/109/1 was resistant to amdinocillin, clindamycin and pen- icillin. However, Buttiauxella strains were sensitive to the enterocins used (inhibition activity ranged from 100 to 25 600 AU/ml).

Inhibitory effects of Dulcitol on rat C6 glioma by regulating autophagy pathway.[Pubmed:30445865]

Nat Prod Res. 2018 Nov 16:1-5.

In the study, we treated C6 rat glioma cells with 25 mg/ml Dulcitol for 24 h. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays were used to detect cellular growth. The measurements of the superoxide dismutase (SOD), malondialdehyde (MDA) and catalase (CAT) were used to assess oxidative stress level. Western was performed to detect the autophagy and apoptosis expression. The data showed that Dulcitol significantly decreased the cell viability, upregulated the Bax level in mitochondria and the Cytochrome C level in cytoplasm, and downregulated anti-apoptotic protein Bcl-xl. Moreover, it enhanced MDA level, reduced CAT and SOD activities, decreased LC3-II/LC3-I ratio, and increased P62 expression. However, rapamycin increased autophagy level and cell viability, and decreased ROS in Dulcitol treated C6 cells. Moreover, Dulcitol inhibited the glioma growth and enhanced survival in vivo. These results suggest that Dulcitol evidently increase cellular ROS levels and apoptosis in glioma cells, which can be significantly regulated by autophagy.