Differences In Carbohydrate Content Research Articles

Evolutionary patterns in chemical composition and biomechanics of articulated coralline algae.

Seaweeds inhabiting wave-battered coastlines are generally flexible, bending with the waves to adopt more streamlined shapes and reduce drag. Coralline algae, however, are firmly calcified, existing largely as crusts that avoid drag altogether or as upright branched forms with uncalcified joints (genicula) that confer flexibility to otherwise rigid thalli. Upright corallines have evolved from crustose ancestors independently multiple times, and the repeated evolution of genicula has contributed to the ecological success of articulated corallines worldwide. Structure and development of genicula are significantly different across evolutionary lineages, and yet biomechanical performance is broadly similar. Because chemical composition plays a central role in both calcification and biomechanics, we explored evolutionary trends in cell wall chemistry across crustose and articulated taxa. We compared the carbohydrate content of genicula across convergently-evolved articulated species, as well as the carbohydrate content of calcified tissues from articulated and crustose species, to search for phylogenetic trends in cell wall chemistry during the repeated evolution of articulated taxa. We also analysed the carbohydrate content of one crustose coralline species that evolved from articulated ancestors, allowing us to examine trends in chemistry during this evolutionary reversal and loss of genicula. We found several key differences in carbohydrate content between calcified and uncalcified coralline tissues, though the significance of these differences in relation to the calcification process requires more investigation. Comparisons across a range of articulated and crustose species indicated that carbohydrate chemistry of calcified tissues was generally similar, regardless of morphology or phylogeny; conversely, chemical composition of genicular tissues was different across articulated lineages, suggesting that significantly different biochemical trajectories have led to remarkably similar biomechanical innovations.

CARBOHYDRAT BY DIFFERENT ANALYSIS OF DRAGON FRUIT LEATHER TEA

The key to managing blood sugar levels is managing carbohydrate intake. This is because carbohydrates are responsible for raising blood sugar levels. Managing the quantity of carbohydrates is the main goal, although choosing slow-digesting carbohydrates with high fiber content also helps. Apart from carbohydrates, people with diabetes need to also limit their intake of salt, saturated fat, and avoid trans fats. For people with diabetes, it is highly recommended to include fiber and healthy fats in the daily diet. The research aims to: 1. Know the differences in carbohydrate content consisting of starch, reduced sugar and crude fiber in dragon skin tea mechanically and manually, 2. Knowing the carbohydrate content different; 3. Knowing the number of calories in a 100 gram serving of tea. The treatments were carried out using two drying techniques, namely oven drying (mechanical) and manual drying (sunlight). The test carried out is proximate testing. The resulting product is a functional food processed product that has an additional function as a food processing product for health. The herbal tea is made from red dragon fruit skin as raw material. Red dragon fruit skin tea has a function as a medicine for type 2 diabetes mellitus. From the laboratory test results obtained by different carbohydrate values for dragon skin tea with mechanical treatment is 41.83% and the total calorie is 201.57 kcal per 100 grams.

The Effect of Magnetic Induction on Seeds Infected Fusarium Sp. Toward Generative Growth of Red Chili (Capsicum annuum. L)

Magnetic fields are proven to improve the quality of growth of various plants. In the study, it was examined whether the treatment of magnetic fields on chili seeds (Capsicum annuum. L) infected by Fusarium sp. could maintain plant growth to the generative phase. This research is two-factor research using a randomized block design. The first factor is the 0.2 mT magnetic field induction treatment consisting of 7 minutes 48 seconds (M7), 15 minutes 36 seconds (M15) and control (M0) as control and the second factor is the Fusarium oxysporum infection treatment consisting of 60 minutes infected (F60) and not infected (F0). Each treatment unit was repeated 5 times. Data obtained were analyzed for variance at a 5% significance level. The results of the analysis showed that the treatments in this study did not provide significant differences in carbohydrate content, flowering speed and number of flowers, as well as the fruiting rate of plants from seeds infected with Fusarium sp (M0F60, M7, F60, and M15F60), thus the magnetic field treatment could be causing plants to be resistant to Fusarium sp. so plants from seeds infected with Fusarium sp. able to flower and bear fruit at the same speed and produce the same amount of interest.

Variation in Trembling Aspen and White Spruce Wood Quality Grown in Mixed and Single Species Stands in the Boreal Mixedwood Forest

The Canadian boreal forest is largely represented by mixed wood forests of white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuloides Michx). In this study, a total of 300 trees originating from three sites composed of trembling aspen and white spruce with varying compositions were investigated for wood quality traits: one site was composed mainly of aspen, one mainly of spruce and a third was a mixed site. Four wood quality traits were examined: wood density, microfibril angle (MFA), fibre characteristics, and cell wall chemistry. Social classes were also determined for each site in an attempt to provide a more in-depth comparison. Wood density showed little variation among sites for both species, with only significant differences occurring between social classes. The aspen site showed statistically lower MFAs than the aspen from the mixed site, however, no differences were observed when comparing spruce. Fibre characteristics were higher in the pure species sites for both species. There were no differences in carbohydrate contents across sites, while lignin content varied. Overall, the use of social classes did not refine the characterization of sites.

24-hour glucose profiles on diets varying in protein content and glycemic index.

Evidence is increasing that the postprandial state is an important factor contributing to the risk of chronic diseases. Not only mean glycemia, but also glycemic variability has been implicated in this effect. In this exploratory study, we measured 24-h glucose profiles in 25 overweight participants in a long-term diet intervention study (DIOGENES study on Diet, Obesity and Genes), which had been randomized to four different diet groups consuming diets varying in protein content and glycemic index. In addition, we compared 24-h glucose profiles in a more controlled fashion, where nine other subjects followed in random order the same four diets differing in carbohydrate content by 10 energy% and glycemic index by 20 units during three days. Meals were provided in the lab and had to be eaten at fixed times during the day. No differences in mean glucose concentration or glucose variability (SD) were found between diet groups in the DIOGENES study. In the more controlled lab study, mean 24-h glucose concentrations were also not different. Glucose variability (SD and CONGA1), however, was lower on the diet combining a lower carbohydrate content and GI compared to the diet combining a higher carbohydrate content and GI. These data suggest that diets with moderate differences in carbohydrate content and GI do not affect mean 24-h or daytime glucose concentrations, but may result in differences in the variability of the glucose level in healthy normal weight and overweight individuals.

Expression patterns, activities and carbohydrate-metabolizing regulation of sucrose phosphate synthase, sucrose synthase and neutral invertase in pineapple fruit during development and ripening.

Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion.

Seasonal changes of total carbohydrate contents in three varieties of apple (Malus sylvestris Miller) stem cuttings

Abstract Stems of apple ( Malus sylvestris Miller) varieties ‘Golden delicious’, ‘Starkrimson delicious’ and ‘Misket delicious’ were taken at different times of the year and investigated to find out seasonal changes of their total carbohydrate concentrations. All investigated varieties exhibited seasonal differences in carbohydrate contents. Total carbohydrate contents of these varieties reached at the highest value in February but the lowest in May. For all the three varieties, soluble sugars and starch contents in stem tissues were found to be similar and also soluble sugars contents of stems to be higher than starch through all the sampling period (August–May).

Effects of cultivar, root weight, storage and boiling on carbohydrate content in carrots (Daucus carota L)

The effects of cultivar (n = 4), root weight (n = 4), storage (5 months) and boiling (7 min) and their interactions on the content of dry matter and carbohydrates were studied and ranked in carrots. Boiling had the greatest effect and had an influence on all variables except the ratio between sucrose and the monosaccharides glucose and fructose. The choice of cultivar was also of great importance as regards glucose, fructose and sucrose content, while dietary fibre and dry matter were much less affected, or even unaffected, by this factor. Root weight and storage were consistently of less significance than boiling and cultivar. Thus dietary fibre solubility, fructose content and the ratio between sucrose and the monosaccharides glucose and fructose were independent of the root weight, while storage had no impact on the dry matter content. After storage the cultivar Lonto had lost more dry matter than the other cultivars (10% versus mean 1% for the others, P = 0.009) and the sugar ratio between sucrose and the monosaccharides glucose and fructose had increased in the cultivar Amarant, while it decreased in the other cultivars (P < 0.001). Furthermore, Amarant had a lower loss of sugars (35%) following boiling than the other cultivars (mean 39%, P = 0.002). Storage and boiling interacted concerning soluble and insoluble dietary fibre, fibre solubility and glucose content. It is concluded that the various factors (especially boiling and cultivar) gave rise to such differences in carbohydrate content and composition that they might be of nutritional importance. The results may thus provide a basis for selecting raw material when studying possible health effects of carrots. Copyright © 2004 Society of Chemical Industry

Seasonal Changes in Carbohydrate Accumulation for Two Creeping Bentgrass Cultivars

Controlled‐environment studies suggest that turf quality decline of creeping bentgrass [Agrostis stolonifera var. palustris (Huds.) Farw.] under heat stress is associated with decreases in carbohydrate availability in plants. The study was designed to examine and compare seasonal changes of carbohydrate status and C allocation pattern for two creeping bentgrass cultivars, ‘Penncross’ and ‘L‐93’, that differ in heat tolerance under field conditions. The experiment was conducted from May to November in 1999 and 2000. Grasses were managed under putting green conditions with daily irrigation and mowing at a 4‐mm height. Turf quality of both cultivars declined from May and reached the lowest level in August and September, and recovered in October. The content of total nonstructural carbohydrates (TNC), sucrose, and fructans in shoots and roots exhibited a similar seasonal pattern as turf quality for both cultivars in both years. Reducing sugar content decreased during the summer, but did not recover in October, except in shoots of L‐93 in 2000. The decreases in carbohydrate content were more pronounced in roots than in shoots for both cultivars. Carbon allocation to roots also decreased during summer for Penncross. Cultivar differences in carbohydrate content were not consistent between fractions of carbohydrate and times of the year. The decline in carbohydrate availability, particularly in roots, and limited C allocation to roots during summer could contribute to quality decline under field conditions; however, cultivar variation in carbohydrate content was not related to the differences in turf quality decline between two cultivars.

Differences in carbohydrate content of waiting-bed strawberry plants during development in the nursery

During three seasons (1996–1997, 1997–1998 and 1998–1999), the evolution of starch and soluble sugars content in crown tissue of strawberry waiting-bed plants (cultivars ‘Camarosa’ and ‘Pajaro’) was determined. The study was carried out using plants from three nurseries located at different altitudes (10, 284 and 703 m) and plants were sampled from mid-September to mid-March. Starch accumulation tended to be higher in plants from the high elevation nursery, with no difference being recorded between the medium or low elevation nurseries, where the starch content depended on the temperatures of the year. Thus, only the use of high elevation waiting-beds is recommended for long-term cold-storage of plants. Starch content was higher in ‘Camarosa’ than in ‘Pajaro’ during the second part of the sampling period, but starch started to accumulate earlier in ‘Pajaro’. Positive correlations between starch accumulation and the number of hours below 7 °C were found in both cultivars. With the same number of chilling hours, ‘Camarosa’ plants accumulated more starch than ‘Pajaro’ plants (on average for the three seasons and the three nursery locations), which implies that in a given season and/or nursery, ‘Camarosa’ plants could be lifted earlier than ‘Pajaro’ plants. No great variations in soluble sugar content were found between cultivars or locations.

Single-step isolation method for six glycoforms of human α 1-acid glycoprotein by hydroxylapatite chromatography and study of their binding capacities for disopyramide

A single-step isolation method for the glycoforms of human serum α 1-acid glycoprotein (AAG) using a hydroxylapatite column under a gradient elution program was developed. The concentrations of N-acetylneuraminic acid and monosaccharides (fucose, N-acetylglucosamine, galactose and mannose) of six AAG glycoforms were determined by the pulsed-amperometric detection method. For each AAG glycoform, significant sex-related differences in carbohydrate content have been observed only for AAG glycoforms two and six, and not for each AAG glycoform. The relationship between the extent of the branch in the glycan chain and the binding capacity to disopyramide were examined. Female AAG contained highly sialylated AAG glycoforms compared to male glycoforms. Conversely, male AAG was rich in the lower sialylated AAG glycoform. Furthermore, it was found that the drug binding capacity decreases with increasing branching of the glycan chain. This suggests that the binding sites of AAG are hindered by a relatively large carbohydrate moiety, such as tetraantennary structures.

DOES LIGHT QUALITY AFFECT THE SINKING RATES OF MARINE DIATOMS?1

ABSTRACTAlthough the spectral quality of light in the ocean varies considerably with depth, the effect of light quality on different physiological processes in marine phytoplankton remains largely unknown. In cases where experiments are performed under full spectral irradiance, the meaning of these experiments in situ is thus unclear. In this study, we determined whether variations in spectral quality affected the sinking rates of marine diatoms. Semicontinuous batch cultures of Thalassiosira weissflogii (Gru.) Fryxell et Hasle and Ditylum brightwellii (t. West) Grunow in Van Huerk were grown under continuous red, white, or blue light. For T. weissflogii, sinking rates (SETCOL method) were twice as high (∼0.2 m·d−1)for cells grown under red light as for cells grown under white or blue light (∼0.08 m·d−1), but there were no significant differences in carbohydrate content (∼105 fg·μm−3) or silica content (∼ 17 fg·μ−3) to account for the difference in sinking rates. Thalassiosira weissflogii grown under blue light was significantly smaller (495 μm3) than cells grown under red light (661 μm3), which could contribute to its reduced sinking rate. However, cells grown under white light were similar in size to those grown under red light but had sinking rates not different from those of cells grown under blue light, indicating the involvement of factors other than size. There were no significant differences in sinking rate (∼0.054 m·d−1) or silica content (∼20 fg·μm−3) in D. brightwellii grown under red, white, or blue light, but cells grown under red light were significantly (20%) larger and contained significantly (20%) more carbohydrate per μm3 than cells grown under white or blue light. Spectral quality had no consistent effect on sinking rate, biochemical composition (carbohydrate or silica content), or cell volume in the two diatoms studied. The similarity in sinking rate of cells grown under white light compared to those grown under blue light supports the ecological validity of sinking rate studies done under white light.

Influence of CPPU on carbohydrate accumulation and metabolism in fruits of Actinidia deliciosa (A. Chev.)

A trial was carried out to evaluate the influence of N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU), a diphenylurea derivative cytokinin, on kiwi productivity, on carbohydrate accumulation and metabolism and on post-harvest fruit performance. CPPU (20 ppm) was sprayed on fruitlets inside the canopy 2 weeks after full bloom (AFB). CPPU influenced fruit growth soon after treatment and, at harvest, treated fruit weight and, consequently, yield per vine were about 25% higher than the control. During fruit growth, soluble sugars (glucose, fructose and sucrose) were higher in treated fruits than in the control ones. In the first period of fruit development glucose was the most abundant carbohydrate and CPPU treatment increased the fruit glucose content significantly. During the period of starch accumulation, treated fruits showed a higher starch content and a higher ADP-glucose pyrophosphorylase activity. Starch accumulation started earlier in treated fruits than in the control ones. At the end of the growing season the degradation of starch in treated fruits started earlier and/or was faster than in the control ones, so that at harvest treated and control fruits contained the same amount of starch. As a consequence, treated fruits at harvest had higher contents of soluble sugars. This indicates that CPPU induced faster and/or advanced fruit ripening. The chlorophyll content was higher in CPPU treated fruits. During storage, the differences in carbohydrate content disappeared and treated fruits performed as well as control ones, maintaining good quality for up to 6 months.

Effects of Formula Change on Intestinal Hydrogen Production and Crying and Fussing Behavior

To determine whether incomplete carbohydrate absorption plays a role in mediating the effects of formula change on babies' crying, breath hydrogen excretion and behavior were measured in 17 normal formula-fed infants who entered a feeding trial at 28 days of life. The trial permitted two comparisons between (1) lactose and reduced lactose soy-based formulae, and (2) the infant's usual pretrial formula and the subsequent soy-based variable-carbohydrate formulae. Reduced lactose formula was associated with a small reduction in H2 excretion (from a mean of 15 to 7 ppm, p = .07) but no difference in crying or fussing. However, compared with their usual pretrial formula, the change to soy-based variable-carbohydrate formulae was associated with a substantial and sustained reduction in H2 excretion (mean 32 to 11 ppm, p less than .03) and a modest 21% decline in fussing (90.4 to 71.5 min/24 hr, p less than .08). By 8 days after the formula change, there was a 40% decline (90.4 to 53.9 min/24 hr) in fussing. These results suggest that, although behavioral changes due to differences in carbohydrate content are unlikely in normal infants, formula changes involving protein and carbohydrate can reduce colonic gas production and may have some effect on crying. Such effects may be implicated when feeding changes occur in normal infants, but their potential role in treatment of crying problems (colic) is yet to be demonstrated.

Differences in carbohydrate content of low density lipoproteins associated with low density lipoprotein subclass patterns

The neutral carbohydrate content of both the protein (apoB) and lipid fractions of low density lipoproteins (LDL) from subjects with a predominance of small, dense LDL (subclass pattern B) was found to be lower than in subjects with larger LDL (subclass pattern A): 45 +/- 12 versus 64 +/- 13 mg/g apoLDL, and 58 +/- 8 versus 71 +/- 8 mg/g apoLDL (P less than 0.0005 for both). Sialic acid content of LDL lipids, but not apoB, was also reduced in subclass pattern B. ApoB and glycolipid carbohydrate content of total LDL and LDL density subfractions declined with increasing LDL density and decreasing particle diameter. Moreover, in LDL subfractions from pattern B subjects, carbohydrate content of LDL apoB, but not LDL glycolipid, was significantly lower in comparison with particles of similar size from pattern A subjects. Thus, in LDL subclass pattern B, reductions in LDL carbohydrate content are associated both with reduced concentrations of larger carbohydrate-enriched LDL subclasses, and with reduced glycosylation of apoB in all LDL particles. LDL glycolipids may vary with overall lipid content of LDL particles, but variation in apoB glycosylation may indicate differences in pathways for LDL production, and reduced apoB glycosylation may reflect the altered metabolic state responsible for LDL subclass pattern B.

An Analysis of the Carbohydrate Status of Mefluidide‐Treated Annual Bluegrass

AbstractThe intense spring seedhead production of annual bluegrass (Poa annua L.) is a major factor limiting its quality as a turfgrass. Developing seeds are unsightly, and monopolization of assimilates by developing seeds may be partially responsible for the shallow root system and poor stress tolerance of annual bluegrass. A greenhouse study was conducted to determine if seedhead suppression resulting from the plant growth regulator mefluidide [N(2,4‐dimethyl‐5‐{[(trifluoromethyl)sulfonyl]amino} phenyl) acetamide] would result in a redistribution of carbohydrates to the roots of annual bluegrass. Mefluidide was applied prior to seedhead emergence at rates ranging from 0 to 0.21 kg a.i. ha−1. Complete seedhead suppression associated with the 0.14 and 0.21 kg a.i. ha−1 rates resulted in greater concentrations of fructose and glucose in annual bluegrass roots compared to roots of untreated plants during peak seedhead emergence. Redistribution of carbohydrates was short lived, with no differences in carbohydrate content occurring among treatments after peak seedhead emergence. Mefluidide had little effect on leaf and stem carbohydrates. Regardless of mefluidide rate, concentrations of fructose, sucrose, and fructans were considerably greater in leaf and stem tissue than in roots. Annual bluegrass stems were the major storage organ for fructans, with only minor fructan storage occurring in roots. The carbohydrate content of mefluidide‐treated annual bluegrass decreased substantially in leaf, stem, and root tissue following growth inhibition due to a post‐inhibition growth surge.

Genetic and phenotypic adaptation of intestinal nutrient transport to diet in fish.

1. Herbivores have higher rates of intestinal sugar transport and lower rates of amino acid transport than carnivores, if each are studied while eating their respective natural diets. It was unclear whether these species differences involve a genetic contribution, since when omnivores are switched from a high-protein to a high-carbohydrate diet they reversibly increase sugar transport and suppress amino acid transport. Hence we studied eight fish species of differing natural diets while all were eating the same manufactured diet. 2. Na+-dependent L-proline uptake and active D-glucose uptake, measured in vitro by the everted intestinal sleeve technique, followed Michaelis-Menten kinetics. Values of the apparent Michaelis-Menten constant increased with values of the maximal transport rate, probably as a result of unstirred layer effects. 3. The ratio of proline to glucose uptake decreased in the sequence: carnivores greater than omnivores greater than herbivores. The intestine's uptake capacity for the non-essential nutrient glucose was much higher in herbivores than in carnivores, correlated with species differences in carbohydrate content of the natural diet. Proline uptake varied much less among species, since species with different natural diets still have similar protein requirements. 4. Since all species were studied while eating the same diet, these species differences in uptake are not phenotypic but genetic adaptations to the different natural diets. 5. In two fish species which normally switch from carnivory towards herbivory or omnivory as they mature, we observe a 'hard-wired' developmental change in intestinal uptake. Larger animals had lower proline uptake relative to glucose uptake than did smaller animals, even though both were being maintained on the same diet in the laboratory. 6. Carnivorous fish tend to allocate absorptive tissue to pyloric caeca or a thick mucosa, while herbivorous fish tend towards a long thin intestine.

Angiotensin II receptors and mechanisms of action in adrenal glomerulosa cells

The plasma-membrane receptors, coupling mechanisms, and effector enzymes that mediate target-cell activation by angiotensin II (All) have been characterized in rat and bovine adrenal glomerulosa cells. The All holoreceptor is a glycoprotein of Mr∼125,000 under non-denaturing conditions. Photoaffinity labeling of All receptors with azido-AII derivatives has shown size heterogeneity among the All binding sites between species and target tissues, with Mr values of 55,000 to 79,000. Such variations in molecular size probably reflect differences in carbohydrate content of the individual receptor sites. The adrenal All receptor, like that in other tissues, is coupled to the inhibitory guanine nucleotide inhibitory protein (N i). However, studies with pertussis toxin have shown that stimulation of aldosterone production by All is not mediated by N i but by a pertussis-insensitive nucleotide regulatory protein of unidentified nature. Although N i is not involved in the stimulatory action of All on steroidogenesis, it does mediate the inhibitory effects of high concentrations of All upon aldosterone production. The actions of All on adrenal cortical function are thus regulated by at least two guanine nucleotide regulatory proteins that are selectively activated by increasing All concentrations. The principal effector enzyme in All action is phospholipase C, which is rapidly stimulated in rat and bovine glomerulosa after All receptor activation. All-induced breakdown of phosphatidylinositol bisphosphate (PIP 2) and phosphatidylinositol phosphate (PIP) leads to formation of inositol 1,4,5-trisphosphate IP 3) and inositol 1,4-bisphosphate (IP 2). These are metabolized predominantly to inositol-4-monophosphate, which serves as a marker of polyphosphoinositide breakdown, whereas inositol-1-phosphate is largely derived from phosphatidylinositol hydrolysis. The All-stimulated glomerulosa cell also produces inositol 1,3,4-trisphosphate, a biologically inactive IP 3 isomer formed from Ins-l,4,5-trisphosphate via inositol tetrakisphosphate (IP 4) during ligand activation in several calcium-dependent target cells. The Ins-l,4,5-P3 formed during All action binds with high affinity to specific intracellular reeceptors that have been characterized in the bovine adrenal gland and other All target tissues, and may represent the sites through which (IP 3) causes calcium mobilization during the initiation of cellular responses.

Studies on Salivary Gland Ribonucleases. III. Purification and Properties of Three Ribonucleases from Bovine Parotid Gland

Three alkaline ribonucleases [EC 3.1.4.22] were purified 4,500- to 7,850-fold from bovine parotid gland by repeated CM-Sephadex C-25 chromatography and Sephadex G-50 gel filtration, with a total recovery of about 33%. They were designated as RNase BP1, BP2, and BP3, based on their order of elution from a CM-Sephadex C-25 column. The molecular weights of these enzymes were estimated by gel electrophoresis to be 18,500, 18,000, and 14,000, respectively. These enzymes are very similar to RNase A in that they are inhibited by heparin, show preferential hydrolysis of C5'-O-P linkages adjacent to a cytosine nucleotide rather than a uracil nucleotide, and in their antigenic properties. Spermine was found to stimulate the activities of these enzymes; the degree of stimulation was in the order of RNase BP3 greater than BP2 greater than BP1. The stimulation by spermine is mainly due to the increased cleavage of C5'-O-P linkages adjacent to cytosine nucleotides. From the results of amino acid analysis, glycosidase digestion and amino-terminal sequencing, it was suggested that the differences in molecular weights of RNase BP1, BP2, and BP3 are due to the differences in carbohydrate contents. In addition, it was suggested that RNase BP3 is identical with RNase A.

Growth, survival and macronutrient composition of Penaeus monodon Fabricius larvae fed with Chaetoceros calcitrans and Tetraselmis chuii

Penaeus monodon larvae were reared from zoea 1 (Z 1) to mysis 3 (M 3) using two different algal feeds, Chaetoceros calcitrans and Tetraselmis chuii. Artemia nauplii were added to both treatments at mysis 2. Mean survival and growth rates in both treatments were different at 5% level of significance on the second and third day of culture, but did not differ during the mysis stage and the end of the 8-day culture period. Z 3 and M 3 larvae fed with C. calcitrans had a lower crude protein but a higher lipid content than T. chuii-fed larvae. Differences in carbohydrate content were noticed in M 3 larvae. The implication of the findings are discussed.