Aims: To optimize the transformation conditions and improve the transformation efficiency of Bacillus subtilis WB800 and DB104.
Methods and Results: Trehalose, which could decrease the damage of electric shock to the cells, was added to the electroporation medium containing sorbitol and mannitol. The factors affecting the transformation efficiency, such as the growth phase of bacteria, cell concentration, electric field strength and plasmid variety, were examined and improved. The new method increased the transformation efficiency of B. subtilis by nearly 100‐fold compared with the conventional one.
Conclusions: With the optimized method, the transformation efficiency came up to 3·64 × 105 transformants μg−1 DNA for WB800, and 2·10 × 105 transformants μg−1 DNA for DB104.
Significance and Impact of the Study: This improvement in transformation efficiency will be largely attributed to the research of expression of exogenous genes in B. subtilis, gene library construction for directed evolution and transformation of wild‐type B. subtilis strains.
A gene (named BcFLC1) homologous to the AtFLC gene, which encodes a floral repressor, was isolated from the nonheading Chinese cabbage (Brassica campestris L. ssp. chinensis) cv. NJ074. The gene showed high similarity to AtFLC. For studying the gene function, we designed to introduce the BcFLC1 gene into Arabidopsis thaliana. The results showed that BcFLC1 had effects on flowering time similar to AtFLC. We also found that Arabidopsis cold-tolerance was enhanced by BcFLC1 overexpression. Under low temperature stress, the BcFLC1 transgenic plants exhibited stronger growth than wild-type plants. The elevated cold tolerance of the BcFLC1 over-expressing plants was also confirmed by the changes of electrolyte leakage and malonyldialdehyde and proline content.
In this paper, four TiO 2 /β-FeOOH photocatalysts were synthesized by a simple deposition-precipitation method and characterized by X-ray diffraction, fourier transform infrared, scanning electron microscope and transmission electron microscope. The characterization showed the presence of nano-sized β-FeOOH particles on the TiO 2 support. The photocatalytic efficiency of the catalysts was examined on the Cr(VI) reduction under ultraviolet irradiation in aqueous suspension. The photocatalyst denoted as 25TiO 2 /β-FeOOH appeared to be most efficient, which is due to effectively inhibiting the recombination of photoinduced electrons and holes. A 2 4 factorial design methodology was employed to evaluate the statistically important operating conditions (pH of the solution, loading of catalyst, Cr(VI) concentration and reaction time) and their interactions on the photocatalytic reduction efficiency of Cr(VI) over 25TiO 2 /β-FeOOH.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.