Photocatalytic degradation of tetracycline hydrochloride with g-CN/Ag/AgBr composites.

Graphite carbon nitride (g-CN), as a polymer semiconductor photocatalyst, is widely used in the treatment of photocatalytic environmental pollution. In this work, a Z-scheme g-CN/Ag/AgBr heterojunction photocatalyst was prepared based on the preparation of a g-CN-based heterojunction loading through photoreduction method. The g-CN/Ag/AgBr composite showed an excellent photocatalytic performance in the degradation of tetracycline hydrochloride pollutants.

Characterisation of mutagenised acid-resistant alpha-amylase expressed in Bacillus subtilis WB600.

Based on the original thermostable alpha-amylase gene from Bacillus licheniformis, two amino acids were site-directed mutagenised by polymerase chain reaction to obtain a new gene. This gene, with Leu134-->Arg and Ser320-->Ala, was substituted for acid-resistant capability previously. To favor purification of the product, high-level expression and secretion of mature, authentic and stable recombinant mutagenised alpha-amylase were achieved with protease-deficient strain Bacillus subtilis WB600 as the host.