Continuous production of pectic oligosaccharides from sugar beet pulp in a cross flow continuous enzyme membrane reactor

Bioprocess and Biosystems Engineering - Sugar beet pulp pectin is an attractive source for the production of pectic oligosaccharides, an emerging class of potential prebiotics. The main aim of the...     

Detection of <Emphasis Type="Italic">Streptococcus pyogenes</Emphasis> virulence genes in <Emphasis Type="Italic">Streptococcus dysgalactiae</Emphasis> subsp. <Emphasis Type="Italic">equisimilis</Emphasis> from Vellore,India

Streptococcus dysgalactiae subsp. equisimilis (SDSE), belonging to the group C and G streptococci, are human pathogens reported to cause clinical manifestations similar to infections caused by Streptococcus pyogenes. To scrutinize the distribution of gene coding for S. pyogenes virulence factors in SDSE, 255 isolates were collected from humans infected with SDSE in Vellore, a region in southern India, with high incidence of SDSE infections. Initial evaluation indicated SDSE isolates comprising of 82.35% group G and 17.64% group C. A multiplex PCR system was used to detect 21 gene encoding virulence-associated factors of S. pyogenes, like superantigens, DNases, proteinases, and other immune modulatory toxins. As validated by DNA sequencing of the PCR products, sequences homologous to speC, speG, speH, speI, speL, ssa and smeZ of the family of superantigen coding genes and for DNases like sdaD and sdc were detected in the SDSE collection. Furthermore, there was high abundance (48.12% in group G and 86.6% in group C SDSE) of scpA, the gene coding for C5a peptidase in these isolates. Higher abundance of S. pyogenes virulence factor genes was observed in SDSE of Lancefield group C as compared to group G, even though the incidence rates in former were lower. This study not only substantiates detection of S. pyogenes virulence factor genes in whole genome sequenced SDSE but also makes significant contribution towards the understanding of SDSE and its increasing virulence potential.     

Milk-Clotting Enzymes From Microorganisms

A total of 230 cultures of fungi and 43 cultures of bacteria, isolated from such sources as soil, butter, and milk, were screened for their milk-clotting activity. The fungi were cultivated on semisolid media, and the bacteria were grown in milk media in shake culture. Phytic acid, added as calcium phytate, was found to stimulate production of the enzyme in most of the bacterial isolates. Proteolytic activity was invariably found to be associated with the milk-clotting enzyme in bacterial isolates. There was considerable variation in the ratio of the two enzymes from strain to strain.     

Molecular mapping and transfer of a novel brown planthopper resistance gene bph42 from Oryza rufipogon (Griff.) To cultivated rice (Oryza sativa L.)

Molecular Biology Reports - Brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests of rice accounting for 52% of annual yield loss. The breakdown of...     

Effect of undernutrition and hormone treatments on the absorption of proteins in suckling rat intestine.

The absorption of 125I-labeled BSA and gamma-globulin was significantly (P less than 0.01) elevated in UN pups compared to the controls. Administration of pharmacological doses of cortisone, thyroxine, and insulin markedly (P less than 0.001) reduced the absorption of BSA and gamma-globulin in UN pups. There was no significant difference in the binding of 125I-labeled BSA and gamma-globulin to microvillus membrane in the control and experimental animals. However, the degradation of labeled BSA and gamma-globulin by luminal content was considerably higher (55-70%) in controls compared to UN pups. This suggested that observed increase in the absorption of proteins in nutritionally deprived pups was unrelated to their binding to the microvillus surface but presumably it is a consequence of reduced luminal degradation together with delayed maturational development as suggested by the pattern of brush border enzymes in the UN intestinal tissue.     

Induction of androgenesis and callus formation inin vitro cultured anthers of a myrtaceous fruit tree (Psidium guajava L.)

Anthers ofPsidium guajava cultivated on either Murashige-Skoog's or Nitsch's basal medium (BM) or the BM supplemented with 10⁻⁶ M benzylaminopurine (BAP) were observed to contain microspores undergoing androgenic segmentations as well as a few multicellular microscopic embryoids. However, final morphogenic response from such cultured anthers was the development of calli. These calli had restricted growth accompanied by their early browning. Suspecting the browning to be due to accumulation of polyphenols, the culture medium was fortified with polyvinylpyrrolidone (PVP). PVP, increased sucrose concentration in the medium and cold pretreatment of anthers decreased the proportion of anthers turning brown as well as delayed the browning of calli, but it was not possible to maintain the calli for differentiation. Cold pretreatment significantly increased the percentage of callusing anthers and also resulted in the early emergence of calli.     

Taxol binds to polymerized tubulin in vitro

Taxol, a natural plant product that enhances the rate and extent of microtubule assembly in vitro and stabilizes microtubules in vitro and in cells, was labeled with tritium by catalytic exchange with (3)H(2)O. The binding of [(3)H]taxol to microtubule protein was studied by a sedimentation assay. Microtubules assembled in the presence of [(3)H]taxol bind drug specifically with an apparent binding constant, K(app), of 8.7 x 19(-7) M and binding saturates with a calculated maximal binding ration, B(max), of 0.6 mol taxol bound/mol tubulin dimer. [(3)H]Taxol also binds and assembles phosphocellulose-purified tubulin, and we suggest that taxol stabilizes interactions between dimers that lead to microtubule polymer formation. With both microtubule protein and phosphocellulose- purified tubulin, binding saturation occurs at approximate stoichiometry with the tubulin dimmer concentration. Under assembly conditions, podophyllotoxin and vinblastine inhibit the binding of [(3)H]taxol to microtubule protein in a complex manner which we believe reflects a competition between these drugs, not for a single binding site, but for different forms (dimer and polymer) of tubulin. Steady-state microtubules assembled with GTP or with 5’-guanylyl-α,β-methylene diphosphonate (GPCPP), a GTP analog reported to inhibit microtubule treadmilling (I.V. Sandoval and K. Weber. 1980. J. Biol. Chem. 255:6966-6974), bind [(3)H]taxol with approximately the same stoichiometry as microtubules assembled in the presence of [(3)H]taxol. Such data indicate that a taxol binding site exists on the intact microtubule. Unlabeled taxol competitively displaces [(3)H]taxol from microtubules, while podophyllotoxin, vinblastine, and CaCl(2) do not. Podophyllotoxin and vinblastine, however, reduce the mass of sedimented taxol-stabilized microtubules, but the specific activity of bound [(3)H]taxol in the pellet remains constant. We conclude that taxol binds specifically and reversibly to a polymerized form of tubulin with a stoichiometry approaching unity.     

Maternal nutrition and development of intestinal functions: II--Effect of feeding high protein and high fat diets to lactating rats

Effects of feeding high-protein (HP) and high-fat (HF) diets to lactating rats have been studied on the development of microvillus membrane enzymes and glycosylation in suckling rats. The activities of sucrase and lactase were significantly (P less than 0.01) decreased in the pups reared on HP fed dams. Alkaline phosphatase (AP), leucine aminopeptidase (LAP) and gamma-glutamyl-transpeptidase (gamma-GTP) activities were essentially similar in HP and pair-fed groups. Pups reared on dams fed HF-diet, revealed nearly a 20% increase in disaccharidase levels and a significant (P less than 0.05) decrease in AP activity compared to the pair-fed controls. The activities of LAP and GTP were unaffected under these conditions. Sialic acid content was unaltered, however, fucose level of the membranes was significantly reduced in pups nursed by mothers fed HP-(P less than 0.05) or HF-(P less than 0.01) diet. The binding of 125I-labelled wheat germ agglutinin and Ulex europeus agglutinin was in agreement to the data on sialic acid and fucose contents of the membranes. The binding of peanut agglutinin to microvillus membranes was enhanced by 31% and 21% in HP and HF groups, respectively. These findings suggest that the quality of maternal nutrition affects the enzymes and glycosylation of brush-borders in developing rat intestine.