Zhang Lanwei

Cheese whey protein recovery by ultrafiltration through transglutaminase (TG) catalysis whey protein cross-linking

In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking was investigated under different conditions to find out the best treatment. We found that the optimal conditions for protein recovery involved catalyzing whey protein cross-linking with TG (40U/g whey proteins) at 40°C for 60min at pH 5.0. Under these conditions, the recovery rate was increased 15-20%, lactose rejection rate was decreased by 10%, and relative permeate flux was increase 30-40% compared to the sample without enzyme treatment (control). It was noticeable that the total resistance and cake resistance were decreased after enzyme catalysis. This was mainly due to the increased particle size and decreased zeta potential. Therefore, membrane coupling enzyme catalysis protein cross-linking is a potential means for further use.

Complete genome sequence of Enterococcus faecalis LD33, a bacteriocin-producing strain

Enterococcus faecalis LD33 strain was originally isolated from traditional naturally fermented cream in Inner Mongolia of China. Its complete genome sequence was carried out using the Illumina Hiseq and the PacBio RSII platform. The genome only has a circular chromosome and a GC content of 37.58%. Other core information shown in the genome sequencing results further insight on this bacteriums genetic elements for bacteriocin production and the genes related to respiratory chain.