ZM 226600

Low nitrogen stress stimulating the indole-3-acetic acid biosynthesis of Serratia sp. ZM is vital for the survival of the bacterium and its plant growth-promoting characteristic.[Pubmed:27803972]

Arch Microbiol. 2017 Apr;199(3):425-432.

Serratia sp. ZM is a plant growth-promoting (PGP) bacterial strain isolated from the rhizospheric soil of Populus euphratica in northwestern China. In this study, low nitrogen supply significantly stimulated the production of indole-3-acetic acid (IAA) in Serratia sp.ZM. The inoculation of the bacterium to wheat seedlings improved plant growth compared with the uninoculated group, and the stimulating effect was more prominent under low nitrogen stress. Inactivation of the predicted key gene in the IAA biosynthesis pathway impaired IAA production and significantly hampered mutant growth in poor medium. Furthermore, the IAA-deficient mutant lost the PGP effect under either normal or low nitrogen conditions in plant experiments. This study revealed the significant impact of environmental nitrogen levels on IAA production in the PGP strain and the vital effect of IAA on resistance physiology of both the bacterium and host plant. The characteristics of Serratia sp. ZM also indicated its application potential as a biofertilizer for plants, especially those suffering from poor nitrogen soil.

ZM-66, a new podophyllotoxin derivative inhibits proliferation and induces apoptosis in K562/ADM cells.[Pubmed:25264886]

Chin Med Sci J. 2014 Sep;29(3):174-9.

OBJECTIVE: To investigate the anti-tumor effect of ZM-66 on multidrug-resistant leukemic cell line K562/ADM. METHODS: The K562/ADM cells were treated with varying concentrations (0, 1, 2, 4 x 10(-)(3) mmol/L) of ZM-66 or etoposide for 24 hours. The proliferation was detected by Sulforhodamine B Sodium Salt (SRB) assay and apoptosis was detected by flow cytometry analysis and fluorescent staining. In addition, the expression levels of p53 and bax genes in K562/ADM cells were detected by RT-PCR analysis. The level of P-glycoprotein (P-gp), P53 and Bax protein in K562/ADM cells were detected by Western blot assay. RESULTS: SRB assay demonstrated that etoposide had little inhibitory effect on K562/ADM cells, whereas ZM-66 (1, 2, 4 x 10(-)(3) mmol/L) had significantly inhibitory effect on K562/ADM cells (all P<0.01). The acridine orange/propidium iodide dual staining showed that there were typical condensation of chromatin and nuclear fragmentation nuclei with red color in ZM-66 treated cells. Flow cytometric analysis showed that there was a significantly increase of apoptotic cells in K562/ADM cells after treated with ZM-66. RT-PCR showed that the p53 and bax mRNA expression levels in K562/ADM cells treated with ZM-66 at 1, 2, 4 x 10(-)(3) mmol/L were higher than those in the cell without treatment. Western blot showed that the P53 and Bax protein expression levels in K562/ADM cells treated with ZM-66 at 2, 4 x 10(-)(3) mmol/L were higher than those in the cell without treatment. But the P-gp protein expression level in K562/ADM cells treated with ZM-66 at 2, 4 x 10(-)(3) mmol/L was gradually lower than those in the cell without treatment. CONCLUSION: ZM-66 is able to induce cell death by apoptosis in vitro, as a result of the reverse of the apoptosis resistance in drug-resistant K562/ADM cells by modulating expression of key factors associated with apoptosis induction.

[New metalloendopeptidase of Morganella morganii ZM].[Pubmed:25895364]

Bioorg Khim. 2014 Nov-Dec;40(6):682-7.

Proteolytic activity which is inhibited in the presence of o-phenanthroline was found in M. morganii ZM. Intracellular proteases of M. morganii ZM unlimited split musculoskeletal actin in contrast to grimelysin. Several proteolitic proteins of M. morganii ZM cells were identified by zymography with gelatin. Metalloproteinase of M. morganii ZM cell lysate was purified by hydrophobic chromatography fractionation. The molecular weight of the protein was 35 kDa.