Akkermansia muciniphila Cell-Free Supernatant Improves Glucose and Lipid Metabolisms in Caenorhabditis elegans.

To explore the mechanism by which Akkermansia muciniphila cell-free supernatant improves glucose and lipid metabolisms in Caenorhabditis elegans, the present study used different dilution concentrations of Akkermansia muciniphila cell-free supernatant as an intervention for with Caenorhabditis elegans under a high-glucose diet. The changes in lifespan, exercise ability, level of free radicals, and characteristic indexes of glucose and lipid metabolisms were studied. Furthermore, the expression of key genes of glucose and lipid metabolisms was detected by qRT-PCR. The results showed that A. muciniphila cell-free supernatant significantly improved the movement ability, prolonged the lifespan, reduced the level of ROS, and alleviated oxidative damage in Caenorhabditis elegans. A. muciniphila cell-free supernatant supported resistance to increases in glucose and triglyceride induced by a high-glucose diet and downregulated the expression of key genes of glucose metabolism, such as gsy-1, pygl-1, pfk-1.1, and pyk-1, while upregulating the expression of key genes of lipid metabolism, such as acs-2, cpt-4, sbp-1, and tph-1, as well as down-regulating the expression of the fat-7 gene to inhibit fatty acid biosynthesis. These findings indicated that A. muciniphila cell-free supernatant, as a postbiotic, has the potential to prevent obesity and improve glucose metabolism disorders and other diseases.

Australobiustracheoperspicuus sp. n., the first subterranean species of centipede from southern China (Lithobiomorpha, Lithobiidae).

Australobiustracheoperspicuus sp. n. (Lithobiomorpha: Lithobiidae) was recently discovered from the Cave of the brickyard of Gaofeng village, in the Guizhou Province, southwest China, and it is described here. Morphologically the new species is similar to A.magnus (Trozina>, 1894) from north-western China. The new species can be easily distinguished from those by the trachea connected to the valve of the TIII clearly visible from the dorsal side, the absence of ocelli on each side of the cephalic plate, the DaC spine being only present on the XIIIth-XVth legs. Numbers of examined specimens, distribution and the main morphological characters and an identification key to the known Chinese species of genus Australobius based on adult specimens is given.

The Native Plasmid pML21 Plays a Role in Stress Tolerance in Enterococcus faecalis ML21, as Analyzed by Plasmid Curing Using Plasmid Incompatibility.

To investigate the role of the native plasmid pML21 in Enterococcus faecalis ML21's response to abiotic stresses, the plasmid pML21 was cured based on the principle of plasmid incompatibility and segregational instability, generating E. faecalis mutant strain ML0. The mutant and the wild strains were exposed to abiotic stresses: bile salts, low pH, H2O2, ethanol, heat, and NaCl, and their survival rate was measured. We found that curing of pML21 lead to reduced tolerance to stress in E. faecalis ML0, especially oxidative and osmotic stress. Complementation analysis suggested that the genes from pML21 played different role in stress tolerance. The result indicated that pML21 plays a role in E. faecalis ML21's response to abiotic stresses.

[Construction and expression of the soybean isoflavonoid biosynthetic pathway in Escherichia coli].

The natural isoflavones biosynthetic pathway is only limited in legumes plant. To study the isoflavone in bacteria by metabolic engineering requires transformation of multi-gene of the whole pathway into the host strain to resembling the expression and metabolism of the genes. The multi-gene transformation and expression strategy become necessary because of this. This article talks about the multi-gene transformation strategy using one or many vectors, taking the five genes of isoflavonoid biosynthetic pathway to E. coli. The recombinant bacteria carry five genes with two vectors, the whole Isoflavonoid biosynthetic pathway was constructed into E. coli. Fermented with L-tyrosine as substrate and IPTG as an inducer, the recombinant bacteria can produce a new isoflavone related metabolite showed on HPLC analysis profile.