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.

Escherichia coli mutants possessing an Li+-resistant melibiose carrier.

Abstract: Escherichia coli K-12 strains in the absence of the lactose carrier grew on the disaccharide melibiose as the sole source of carbon. The presence of 0.1 mM Li+ in the medium strongly inhibited growth of such cells, and Li+-resistant mutants appeared after several days of incubation. These mutants showed altered cation coupling to melibiose transport via the melibiose carrier. Cotransport between H+ and melibiose was lost in the mutants, although Na+-melibiose cotransport was retained. We observed no Li+-melibiose cotransport. Therefore, these mutants represent a new type of cation-coupling mutants of the melibiose carrier.

Leminorella, a new genus of Enterobacteriaceae: identification of Leminorella grimontii sp. nov. and Leminorella richardii sp. nov. found in clinical specimens.

Abstract: Leminorella is proposed as a new genus for the group of Enterobacteriaceae formerly known as Enteric Group 57. Strains of Leminorella gave positive tests for H2S production, acid production from L-arabinose and D-xylose, and tyrosine clearing; they were negative for indole production, Voges-Proskauer, urea hydrolysis, phenylalanine deaminase, motility, gelatin liquefaction, lysine and ornithine decarboxylases, arginine dihydrolase, growth in KCN, and acid production from adonitol, D-arabitol, cellobiose, erythritol, D-galactose, myo-inositol, lactose, maltose, D-mannitol, D-mannose, melibiose, alpha-CH3-glucoside, raffinose, L-rhamnose, salicin, D-sorbitol, sucrose, and trehalose. By DNA hybridization, strains of Leminorella were only 3 to 16% related to other Enterobacteriaceae and were divided into three groups. Leminorella grimontii is proposed as the type species for the genus and strain CDC 1944-81, ATCC 33999, is designated as the type strain. There were four strains of L. grimontii from stool specimens and two from urine specimens. L. richardii is proposed as the name for the second species (type strain, CDC 0978-82, ATCC 33998). All four L. richardii strains were from stool specimens. L. grimontii can be distinguished from L. richardii because it produces gas from glucose (100%) and acid from dulcitol (83%) and is methyl red positive (100%). One strain, CDC 3346-72, was more related to L. grimontii by DNA hybridization than to L. richardii, but the lower relatedness to both of these species indicated that it may be a third species. Biochemically it could not be distinguished from L. grimontii. All Leminorella strains were resistant (no zone of inhibition) to ampicillin, carbenicillin, and cephalothin. Some of the Leminorella strains were sent to us for Salmonella serotyping, and two reacted weakly in Salmonella antisera. The clinical significance of Leminorella is unknown.

Degradation of polysaccharides and non-digestible oligosaccharides by Bacillus subtilis and Bacillus pumilus isolated from Soumbala, a fermented African locust bean (Parkia biglobosa) food Condiment

Abstract: In order to select starter cultures for controlled fermentation of African locust beans, Bacillus subtilis and B. pumilus from Soumbala were investigated for their ability to degrade arabinogalactan, stachyose, raffinose and sucrose—the main polysaccharides and oligosaccharides in African locust bean. The methods used were liquefaction of gels of galactomannan for screening, pH measurement and High Performance Anion Exhange Chromatography – Pulsed Amperometric Detection (HPAEC–PAD) for detailed degradation study of the carbohydrates. For B. subtilis isolates, liquefaction of galactomannan gels was observed and HPAEC–PAD showed that arabinogalactan and stachyose were partially degraded while raffinose was fully degraded after 48 h of fermentation. Melibiose, fructose and traces of galactose were detected as residual sugars. For B. pumilus isolates much weaker degradation of the carbohydrates was observed. Two isolates of B. subtilis showed strong ability to degrade the oligosaccharides and they are seen as promising starter cultures for fermentation of African locust bean.

Conventional taxonomy of lactobacilli surviving radurization of meat.

Abstract: All of the 113 catalase-negative, Gram-positive, rod-shaped strains isolated from radurized minced beef (5 kGy) were homofermentative, non-thermophilic, and belonged to the sub-genus Streptobacterium. The majority of the strains (100) were identified as Lactobacillus sake. These were divided into four sub-groups based on their sugar fermentation pattern: group IA1 (melibiose (+), maltose (-), amygdalin (-), 76 strains); group IA2 (melibiose (+), maltose (-), amygdalin (+), 14 strains); group IB1 (melibiose (+), maltose (+), amygdalin (+), four strains); group IB2 (melibiose (+), maltose (+), amygdalin (-), six strains). Of the remaining strains, two produced L(+)-lactic acid and were identified as L. farciminis, three were identified as L. curvatus and eight showed characteristics of both L. sake and L. curvatus and were designated 'L. sake/curvatus.' With one exception, all strains were aciduric and relatively insensitive to the chemical preservatives tested. Most L. sake strains produced significant amounts of H2O2. Electron microscopy confirmed a possible relationship between the thickness of the cells and radiation resistance. The problems and limitations of this type of taxonomic study and possible reasons for the predominance of L. sake species in radurized meat are discussed.