Characterization of soybean protein hydrolysates able to promote the proliferation of Streptococcus thermophilus ST.

How soybean protein hydrolysates (SPHs) to favor the growth of S. thermophilus ST were investigated. Hydrolyzed soybean protein was fractionated to 4 fragments, that is, SPH-I, SPH-II, SPH-III, and SPH-IV according to their molecular weight sizes. SPHs can improve the growth of strain ST, in which SPH-IV, with the molecular weight of less than 5 kD, significantly promoted the growth of strain ST. The cell counts of strain ST grew quickly from 7.71 to 9.78 (log CFU/mL) when the concentrations of SPH-IV ranging from 0% to 1%. Moreover, 2 chemically defined media (CDMs) were used to test their roles in maintaining the viability of strain ST. CDMs only maintained the survival of strain ST, but SPH-IV had the promotional effects on proliferation of the bacteria. SPH-IV was further characterized to be oligopeptides that contain 2 to 8 amino acids and free amino acids by high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. The amino acid compositions showed that SPH-IV contained more essential amino acids, which were necessary for the growth of S. thermophilus ST. Clearly, SPH-IV could be used as an exogenous nitrogen supplement to enhance the proliferation of S. thermophilus ST and other lactic acid bacteria, and the data from small scale-up fermentation also supported this point.

The value of gamma-glutamyltransferase in the diagnosis of chronic hepatitis B / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the change of serum gamma-glutamyltransferase (GGT) and its diagnosis value in chronic hepatitis B (CHB) patients with different degrees of liver damage.</p><p><b>METHODS</b>Alanine-aminotransferase (ALT), aspartate-aminotransferase (AST) and GGT were measured in 221 CHB patients. Liver biopsy was conducted simultaneously to determine the inflammation grade and fibrosis stage of the liver tissues.</p><p><b>RESULTS</b>The rate of normal GGT in pathologically diagnosed mild and severe CHB patients was 90.4% and 12.3%, respectively (P<0.01). Increased level of GGT was parallel to the degree of liver pathological change (P<0.01). In active CHB patients, GGT rose with the ALT increase with a positive linear correlation between them (r=0.464, P<0.001). In pathologically diagnosed mild CHB patients, GGT had a tendency of rapidly declining to normal levels with ALT. In moderate CHB patients, GGT fluctuated at a relatively high level, and in severe CHB patients GGT exhibited a deviation from GGT.</p><p><b>CONCLUSIONS</b>GGT is conducive to improve the coincident rate between the clinical and pathological diagnosis of CHB.</p>