Melibiose

About: Melibiose is a research topic. Over the lifetime, 1002 publications have been published within this topic receiving 27300 citations. The topic is also known as: Melibiose.

Purification and characterization of a CIostfidium perfringens α‐galactosidase

Abstract: Of 21 strains of C. perfringens tested for hydrolysis of α-galactosides, 10 utilized either raffinose or melibiose while 2 utilized both sugars. Spore production in Duncan Strong medium was superior in the presence of raffinose as opposed to starch in 12 out of 21 strains. C. perfringens M34 yielded 1.2 units of α-galactosidase/g washed cells. This enzyme had an isoelectric point of 5.6 and a pH optimum for hydrolysis of PNPG of 6.3. Native and monomer molecular weights were 96,000 and 46,000 daltons respectively. Km was 0.20 ± 0.02mM PNPG. Heat stability of the enzyme decreased as purity increased. This trend was partially reversed by addition of 2-mercaptoethanol, NADH, cysteine, and/or bovine serum albumin to reaction mixture.

Morphological and physiological variants among isolates of saccharomyces cerevisiae from palmwine and other sources

Abstract: Using 34 carbon and four nitrogen compounds, and 12 standard yeast identification tests, eight isolates of Saccharomyces cerevisiae Hansen from Raphia Beaur (Palmae) palmwine and other sources were evaluated comparatively for morphological and physiological characteristics. Differences among the isolates were found mainly in their formation of pseudomycelium and blastospores, and in the fermentative utilisation of galactose, maltose, melibiose, raffinose, trehalose and α-methyl-D-galactoside. The wine isolates varied primarily in their assimilatory capabilities for lactic acid and maltose. Observed fermentative and assimilative differences among the wine isolates confirmed the presence of physiological races of S cerevisiae in Raphia palmwine, and suggest that physiological races of S cerevisiae in palmwine may influence the wine's organoleptic and aromatic qualities.

Characterization of the $\alpha$ -Galactosidase Gene from Leuconostoc mesenteroides SY1

Abstract: Leuconostoc mesenteroides SY1, an isolate from kimchi, was able to ferment -galactosides, such as melibiose and raffinose. -Galactosidase (-Gal) activity was higher in cells grown on melibiose and raffinose than cells grown on galactose, sucrose, and fructose. -Gal activity was not detected in cells grown on glucose, indicating the operation of carbon catabolite repression (CCR). A 6 kb DNA fragment was PCR amplified using a primer set based on the nucleotide sequence of a putative -galactosidase gene (aga) from L. mesenteroides ATCC 8293. Nucleotide sequencing of the 6 kb fragment confirmed the presence of aga and other genes involved in the galactosides utilization, and the gene order was galR (transcriptional regulator)-aga-gaIK (galactokinase)-gaIT (galactose-1-phosphate uridylyltransferase). Northern blotting experiment showed that aga, gaIK, and gaIT constituted the same operon, that the transcription was induced by galactosides, such as melibiose and raffinose, whereas gaIR was independently transcribed as a monocistronic gene, and that the level of transcription was fairly constant. The aga was overexpressed in E. coli BL21 (DE3) using pET26b(+) vector, and -Gal was accumulated in E. coli as an inclusion body.