Biomedical subjects

Sun Ming

Publications and source records attributed to Sun Ming.

4 recordsLinked to original sources

PubMed2006

Complete nucleotide sequence of pBMB67, a 67-kb plasmid from Bacillus thuringiensis strain YBT-1520.

The complete nucleotide sequence of a large (67kb) cryptic plasmid pBMB67 from Bacillus thuringiensis strain YBT-1520 was determined. Of the 74 predicted open reading frames (ORFs), 25 (34%) were assigned putative functions, 18 (24%) encoded conserved hypothetical proteins, and 31 (42%) had no homology to any genes present in the current open databases. The ORFs with similar functions were organized in a modular structure; thus, the DNA sequence of pBMB67 could be functionally divided into three modules, including a 39kb transfer region encoding homologs of the Agrobacterium tumefaciens VirB/D4 system components VirB1, VirB4, VirB11, and VirD4, as well as homologs of Gram-positive conjugation proteins. We also found a potential operon that was analogous to the Rap-Phr cassettes from Bacillus subtilis, which are involved in cell-cell communication and transcriptional regulation. Thus, we suggest that pBMB67 is likely to be implicated in cell-cell signaling and plays a role in the regulation of several cellular processes, with the production of exoprotease being one of the candidates.

Amino Acid Sequence↗

PubMed2005

Medium optimization by response surface methodology for poly-gamma-glutamic acid production using dairy manure as the basis of a solid substrate.

Dairy manure, supplemented with agro-industrial materials, was used as the solid substrate for high yield of poly-gamma-glutamic acid (gamma-PGA) by Bacillus subtilis CCTCC202048. The solid-state fermentation medium was optimized by response surface methodology. In the first optimization step, a Plackett-Burman design was used to evaluate the influence of related factors. Wheat bran, soybean cake and glutamic acid were found to be more compatible supplement with dairy manure and positively influenced on gamma-PGA production. In the second step, the concentrations of the three supplemental nutrients above were further optimized using a Box-Behnken design. The average gamma-PGA yield (4.70%) in triplicate under optimal conditions was obtained on the laboratory scale, whereas it was 3.58% at compost experiment. These would lay a foundation for lessening the pollution of dairy manure, increasing fertilizer efficiency and exploring a late-model organic fertilizer that retains water and nutrients.

Animals↗

PubMed2003

Study of the thermokinetic properties of copper(II) on Escherichia coli growth.

By using an LKB2277 Bioactivity Monitor, stop-flow mode, the power-time curves of Escherichia coli at 37 degrees C affected by Cu(II) were determined. Some parameters, such as growth rate constants k, inhibitory ratio I, the heat output Qlog in the log phase, and the generation times G were obtained. According to these parameters, we found that a low concentration of Cu(II) (0-20 microg/mL) had an promoting action on the growth of E. coli, but a high concentration of Cu(II) (40-100 microg/mL) had an inhibitory action. The toxicity of Cu(II) can also be expressed as the half-inhibitory concentration IC50; the value is 69.7 microg/mL. The assay is quantitative, inexpensive, and versatile.

Algorithms↗

PubMed2003

Microcalorimetric investigation of the effect of manganese(II) on the growth of Tetrahymena shanghaiensis S199.

The heat output of and the effect of manganese (II) on Tetrahymena shanghaiensis S199 growth metabolism has been determined by means of a LKB-2277 BioActivity monitor. Different concentrations of manganese(II) ions have different effects on the growth of T. shanghaiensis. At low concentrations (0-40 microg/mL) culture growth is promoted, whereas high concentrations (60-800 microg/mL) slow growth. Furthermore, concentrations of 1200 microg/mL or greater stop the growth of this protozooa completely.

Algorithms↗