Effect Of Sorbose Research Articles

Zonal Soil Amendment with Simple Sugars to Elevate Soil C/N Ratios as an Alternative Disease Management Strategy for Rhizoctonia Damping-off of Sugar Beet.

Effects of monosaccharide-amended soils on suppression of Rhizoctonia damping-off of sugar beet were compared under controlled experiments. Suppressive effects of glucose, fructose, sorbose, and xylose were significantly (P < 0.001) greater than that of galactose or mannose but the effect of sorbose was reduced by soil treatments with antibiotics. Saprotrophic growth of Rhizoctonia solani in the laimosphere also was suppressed by glucose, fructose, sorbose, and xylose, whereas only sorbose repressed pericarp colonization. Sugar alcohols (mannitol, sorbitol, and xylitol) neither suppressed Rhizoctonia damping-off nor halted the saprotrophic growth of the pathogen. Seed germination was not affected by any of these six monosaccharides, whereas galactose and mannose inhibited seedling emergence significantly (P < 0.001) compared with the nontreated control or other monosaccharides. Soil fertilization with inorganic nitrogen at a C/N ratio of 20:1 negated the suppressive effects of glucose and fructose on both damping-off and saprotrophic colonization but improved seedling growth in carbonized soils. Obviously, microbial competition for mineral nitrogen was responsible for disease suppression; however, it delayed seedling growth after emergence. This paradox was resolved by adding glucose to the top 1-cm surface-soil zone at a C/N ratio of 50:1 or 125:1. This protected the laimosphere, resulting in effective disease suppression while complementarily enhancing seedling growth.

Production of extracellular enzymes by immobilizedTrichoderma reesei in shake flask cultures

Polyurethane foam and nylon-web carriers were compared for simultaneous production of endo-1, 4-β-glucanase and xylanase by immobilizedTrichoderma reesei on a medium based on lactose (27 g/l), cellulose (3 g/l) and sorbose (0.3 g/l). Nylon sheet with 1.2 cm2 carrier surface/ml medium was superior to the others, and it was selected for further studies. The carbon source had a marked effect on enzyme production by the immobilized fungus. With pure cellulose (10 g/l) as substrate, the maximum endoglucanase activity was 690 nkat/ml and xylanase activity 4800 nkat/ml. Supplementation with 0.5 g/l of sorbose resulted in an increase in both endoglucanase and xylanase activities in all media studied. A more detailed study on the effect of sorbose on a lactose(7 g/l)-and cellulose(3 g/l)-based medium revealed a clear optimum sorbose concentration of 1.5 g/l, with a maximum endoglucanase activity of 660 nkat/ml, xylanase activity of 3670 nkat/ml, and filter-paper activity (overall cellulolytic activity) of 2.0 filter-paper units/ml. However, the addition of 1.5 g/l sorbose to the pure-cellulose(10 g/l)-based medium resulted in a slight decrease in the enzyme production.

Feeding behavior in growing rats fed diets containing sorbose

The effect of dietary sorbose on food and water consumption was investigated in growing rats. Rats (26-day old) were fed diets containing 0, 100, 200 or 300 g sorbose/kg diet for 5 weeks in Experiment 1. Daily food and water intakes were measured at day 0, 7, 14, 21, 28 and 35. Absolute food intake (g) until day 21 decreased linearly with increasing sorbose levels and so did relative food intake (g/100 g b.wt.) until day 7. In contrast, relative water intake (ml/100 g b.wt.) and water:food intake ratio (ml/g) remained high by day 7 with increasing sorbose levels. In Experiment 2, the effect of sorbose on the short-term food intake was compared with those of glucose, sucrose and maltitol in growing rats (25-day old) at a level of 100 g/kg diet in order to investigate how quickly reduced food intake would be induced by sorbose consumption. Cumulative food intake was determined every hour for the first ten hours, then at two-hour intervals thereafter during the 24-hour period that followed feeding. As rapid as 6 hours after feeding, cumulative food intake significantly decreased in sorbose-fed animals compared with other dietary groups. It was concluded that sorbose consumption decreased the food intake of growing rats from 6 hours to a few weeks after feeding, but this inhibitory effect disappeared afterwards.

Ｓｏｒｂｏｓｅの基質としてのう蝕原性

Sorbose is a 2-ketohexose, differing from fructose in configuration at C-3 and C-4. It is obtained through a cultivation of sorbitol and Gluconobacter (Acetobacter) suboxydans. The sugar is about 80-90% as sweet as sucrose and is also non-hygroscopic. The effect of sorbose on the cariogenicity of mutans streptococci (serotype a-h) and certain oral microorganisms was studied. Sorbose was not utilized as a substrate for the growth, lactic acid production, and plaque formation of mutans streptococci (serotype a-h). It did not serve as a substrate for cellular aggregation of mutans streptococci and was not utilized in water-insoluble glucan synthesis and cellular adherence by glucosyltransferase from Streptococcus mutans PS-14 (c) or S. sobrinus 6715 (g). Sorbose was also not utilized for the growth and lactic acid production of certain oral microorganisms although some growth was seen with Lactobacillus casei and L. acidophilus. Two groups of SPF SD rats infected with S. mutans PS-14 were fed with a diet containing 30% sorbose and 30% sucrose for 58 days. A significantly (p<0.01) lower caries score (mean±SE; 17.5±2.0) was obtained in the rats fed with a diet containing 30% sorbose than in the rats fed with a diet containing 30% sucrose (82.1±4.4). The caries inhibition rate was 78.7%.

The haemolytic effect of sorbose in dogs.

The ingestion of L-sorbose, a sugar of the keto-hexose group, causes haemolysis in dogs, but not in rats. Heinz bodies were not found after sorbose administration in either animal species nor were the animals examined deficient in glucose-6-phosphate-dehydrogenase.

The effect of sorbose on metabolism and morphology of neurospora

1. 1. In the presence of sorbose Neurospora grows with colonial morphology, fails to conidiate, and loses up to 60% of its dry weight after depletion of the glucose from the medium. 2. 2. After a long period of adaptation Neurospora metabolizes sorbose, apparently via sorbitol. It then grows well on sorbose, although still with colonial morphology. 3. 3. In the presence of sorbose Neurospora utilizes glucose less efficiently. Less dry weight and more CO 2 are produced, more O 2 is consumed per mg glucose used, and the incorporation of labelled glucose into cell-wall polymers and into trehalose is lower. 4. 4. This evidence suggests that the effects of sorbose on the growth and morphology of Neurospora involves a general metabolic disturbance resulting from a partial uncoupling of respiration and oxidative phosphorylation.

THE UTILIZATION OF THE MIXTURES OF MONOSACCHARIDES BY SOME MUCORALES.

The utilization of mixtures of monosaccharides byBlakeslea trisporaThaxter,Choanephora circinans (Naganish &Kawakami)Hesseltine &Benjamin,Gilbertella persicaria var.indicaMehrotra &Mehrotra andHelicostylum piriformeBainier was studied. The effect of sorbose on the utilization of other sugars present in the mixtures was also studied. It was found that all the mixtures of sugars in combination with asparagine or ammonium chloride were valueless for all the organisms exceptHelicostylum piriforme. Growth ofHelicostylum piriforme on the mixtures with asparagine as the nitrogen source was better than on the mixtures with ammonium chloride as the source of nitrogen. Asparagine being a favourable source counteractecd sorbose inhibition, while ammonium chloride failed to do so. On the other hand, both of the nitrogen sources failed to counteract sorbose inhibition in the rest of the organisms. None of the organisms could finish sorbose and rhamnose from any of the mixtures within the specified period.

The Effect of Sorbose on the Utilization of Different Monosaccharides by Certain Fungi Causing “Leaf‐Spot” Diseases

The Effect of Sorbose on the Utilization of Different Monosaccharides by Certain Fungi Causing “Leaf‐Spot” Diseases

The inhibitory effect of sorbose on fungi.

The inhibitory effect of sorbose on fungi.