RESUMO
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.
Assuntos
Proliferação de Células/efeitos dos fármacos , Hidrolisados de Proteína/metabolismo , Proteínas de Soja/farmacologia , Streptococcus thermophilus/efeitos dos fármacos , Streptococcus thermophilus/crescimento & desenvolvimento , Aminoácidos Essenciais/análise , Aminoácidos Essenciais/metabolismo , Contagem de Colônia Microbiana , Fermentação , Microbiologia de Alimentos , Peso MolecularRESUMO
<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>