Biomedical subjects

G Sreeramulu

Publications and source records attributed to G Sreeramulu.

4 recordsLinked to original sources

PubMed2000

Kombucha fermentation and its antimicrobial activity.

Kombucha was prepared in a tea broth (0.5% w/v) supplemented with sucrose (10% w/v) by using a commercially available starter culture. The pH decreased steadily from 5 to 2.5 during the fermentation while the weight of the "tea fungus" and the OD of the tea broth increased through 4 days of the fermentation and remained fairly constant thereafter. The counts of acetic acid-producing bacteria and yeasts in the broth increased up to 4 days of fermentation and decreased afterward. The antimicrobial activity of Kombucha was investigated against a number of pathogenic microorganisms. Staphylococcus aureus, Shigella sonnei, Escherichia coli, Aeromonas hydrophila, Yersinia enterolitica, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermis, Campylobacter jejuni, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Helicobacterpylori, and Listeria monocytogenes were found to be sensitive to Kombucha. According to the literature on Kombucha, acetic acid is considered to be responsible for the inhibitory effect toward a number of microbes tested, and this is also valid in the present study. However, in this study, Kombucha proved to exert antimicrobial activities against E. coli, Sh. sonnei, Sal. typhimurium, Sal. enteritidis, and Cm. jejuni, even at neutral pH and after thermal denaturation. This finding suggests the presence of antimicrobial compounds other than acetic acid and large proteins in Kombucha.

Bacteria↗

PubMed1998

Purification and characterization of beta-1,4-glucosidase from Clostridium papyrosolvens.

Clostridium papyrosolvens CFR-1010 was selected for the anaerobic extracellular production of beta-1,4-glucosidase. The enzyme was purified by alcohol precipitation and DEAE ion-exchange chromatography. Its homogeneity was confirmed by SDS/PAGE. The enzyme had a molecular mass of 85 kDa. The maximum enzyme activity was observed at pH 5.0 and 50 degrees C. The enzyme activity was inhibited by Ca2+, Co2+, Cu2+, Zn2+, Fe2+, Mg2+ and Na+ ions. However, the activity increased (158%) in the presence of MnCl2, whereas it decreased by 80% in the presence of N-bromosuccinimide, suggesting the presence of tryptophan residues at the active site of enzyme. The enzyme had a K(m) of 15 mg/ml and Vmax of 125 units/min per mg of protein.

Clostridium↗

PubMed1997

Genetic and biochemical characterization of novel low molecular weight glutenin subunits in wheat (Triticum aestivum L.).

Two novel low molecular weight subunits of glutenin with relative molecular mass (M(r) values) of 30 and 32 kDa were isolated from the seeds of hexaploid wheat and characterized at genetic and biochemical levels. Among 115 Indian bread wheat cultivars analysed, 40 had a narrow doublet of the new protein bands, 69 had a wide doublet, 3 had only the faster moving band of the doublet, and the remaining 3 cultivars had only the slower moving band. These subunits could be seen in the alkylated glutenin preparations only and the genes for the faster (designated Glu-D4) and slower (designated Glu-D5) moving protein bands of the doublet were located on chromosomes 1D and 7D, respectively. Amino acid composition of the two new subunits was quite different from those of the other well-characterized gluten proteins, as the new subunits have lower amounts of proline and relatively higher amounts of glycine, aspartic acid-asparagine, cysteine, and lysine. Polyclonal antibodies raised against these polypeptides cross-reacted strongly with the major low molecular weight subunits of wheat glutenin (Glu-3 subunits), but did not cross-react with the high molecular weight glutenin subunits or monomeric gliadins. Furthermore, preliminary results on the N-terminal amino acid sequences of the new subunits show homology with the major low molecular weight glutenin subunits, suggesting an evolutionary link between the two.

Amino Acids↗

PubMed1995

Destaining of Coomassie Brilliant Blue R-250-stained polyacrylamide gels with sodium chloride solutions.

A novel method for destaining of polyacrylamide gels, stained with Coomassie Brilliant Blue R-250, is described, based on the use of 0.5 M NaCl in water as the destainer, requiring only 2-3 h. Concentrated (> 2 M) or dilute (< 0.1 M) salt solutions were unsuitable. The method affords the advantage that expensive organic solvents, such as methanol, acetic acid or trichloroacetic acid, are not needed. Furthermore, salt destaining results in darker purple-blue protein bands as compared to the pale blue color with e.g. methanol/acetic acid destaining.

Acrylic Resins↗