Release Of Carbohydrates Research Articles

Glycaemic Impact Regulation Based on Progressive Geometric Changes in Solid Starch-Based Food Particles During Digestion

Glycaemic impact is an important health-related property of foods which may be controlled by regulating glycaemic carbohydrate release during digestion. Equations were derived for designing surface-digested particles of defined glycaemic impact. They related the proportion (P) of a particle digested after T minutes of digestion to the initial particle diameter (D0 millimetres) and the mean rate of superficial volume erosion (E cubic millimetres per minute): (a) Spherical particles: $$ P = 6TE{{{\pi }}^{{ - 1}}}D_0^{{ - 3}} $$ (b) Cylindrical particles of initial length L0: $$ P = 4TE{{{\pi }}^{{ - 1}}}{L_0}{\,^{{ - 1}}}D_0^{{ - 2}} $$ (c) Flat structures of depth D, length L0 and width W0 $$ P = TE{L_0}^{{ - 1}}D_0^{{ - 1}}W_0^{{ - 1}} $$ Using spreadsheets based on the equations, erosion rate was continuously adjusted from its initial value in response to non-linear and progressive reduction in particle surface area during digestion. Then, for a given digestibility, the particle dimensions required to deliver the time-dependent proportions of nutritionally distinct carbohydrate fractions, rapidly digested, slowly digested and inaccessible digestible starch, could be determined. The results were confirmed by in vitro digestion. The glycaemic impact of starch may potentially be manipulated using the relationship between time, digestibility and particle dimensions, by delivering it in the form of solid food particles whose rates of digestion depend on surface area predetermined by their geometry.

Development of a Photolabile Carbonyl-Protecting Group Toolbox

New salicyl alcohol derived photolabile carbonyl protecting groups have been developed, and the effect of substituents on the photochemical properties of photolabile protecting groups (PPGs) has been studied. The 3-(dimethylamino)phenyl groups at the α position prove to be important to the efficiency of the deprotection reactions, as shown in the photo reactions of the acetal 9. On the other hand, expansion of the salicyl alcohol's benzene skeleton to naphthalene does not improve the photochemical properties of PPGs. A neutral protecting protocol has been generalized to new PPGs with α,α-diaryl salicyl alcohol backbone. Thus, installation of PPGs onto aldehydes is readily achieved at 140 °C without using any other chemical reagents. These PPGs are stable under acidic conditions typical for hydrolyzing acetals and constitute orthogonal protecting groups with traditional 1,3-dioxane/1,3-dioxolane for carbonyl compounds. Highly efficient release of carbohydrate molecules is demonstrated, which can be potentially useful in site-specific release and immobilization of carbohydrates for preparation of high-density microarrays. With the enriched PPG toolbox, PPGs are divided into three subgroups based on their UV absorption profiles. PPGs from different subgroups can be sequentially removed by using different UV irradiation wavelengths. For PPGs absorbing UVA (λ >315 nm), photochemical deprotection can be carried out with sunlight in high yields.

Synergistic Effect of Abrasive and Sonication for Release of Carbohydrate and Protein from Algae

While algae have demonstrated significant potential as a raw material due to the high intracellular concentration of carbohydrates and proteins, a primary limitation as a biofuel feedstock is due to the fact that an economically feasible method of extraction has yet to be offered. Algae samples, acquired from a local waste treatment facility, were combined with abrasive materials and subjected to ultrasonication for specific time intervals. It was found that the synergistic effect of sonication in the presence of abrasive material, such as silicon beads or sand, could extract adequate protein and carbohydrate to be utilized in fermentation processes.

Effects of sea surface warming on the production and composition of dissolved organic matter during phytoplankton blooms: results from a mesocosm study

An experimental study was conducted to test the effects of projected sea surface warming (according to the IPPC scenarios) on the accumulation and composition of dissolved organic matter (DOM) during marine phytoplankton blooms in cold seas (<4°C). Eight mesocosms (∼1400 L) were filled with natural seawater, and two replicate mesocosms each were incubated by raising temperature by +0, +2, +4 and +6°C, respectively. The enclosed water was initially fertilized with inorganic nutrients to induce the development of phytoplankton blooms, which were then dominated by diatoms. Over a 4-week period, dissolved combined carbohydrates (DCCHO) and dissolved amino acids (DAA) were determined as major components of freshly produced, labile to semi-labile DOM. In all mesocosms, the increase in DCCHO concentration occurred sharply after the peak of chlorophyll a concentration, when nutrients became depleted. Rising temperature resulted in an earlier, faster and higher accumulation of DCCHO and of combined glucose predominantly. DCCHO yielded a maximum percentage of 35, 40, 49 and 59% of total combined carbohydrates in the +0, +2, +4 and +6°C treatments, respectively. Accumulation of DAA occurred more continuously and at an average rate of 0.79 ± 0.20 nmol L−1 h−1, but was not affected by rising temperature. Owing to the higher accumulation of DCCHO, the C:N ratio of DOM increased strongly during the course of the bloom, with higher ratios in the warmer treatments. Our study suggests that warming increases the extracellular release of carbohydrates from phytoplankton and, therefore, may affect the bottom-up control of the microbial loop in cold seas in the future.

Nutrient release from extracted activated sludge cells using the microwave enhanced advanced oxidation process

This study investigates the effectiveness of the microwave enhanced advanced oxidation process (MW/H2O2-AOP) for nutrient release and cell destruction of the extracted activated sludge cells that are EPS-free. The concentrations of ammonia and soluble chemical oxygen demand increased with an increase of microwave temperature and hydrogen peroxide dosage. Orthophosphate could be released from these extracted cells at lower microwave temperatures and lower H2O2 dosages compared to our previous studies using activated sludge. Higher concentrations of carbohydrate were released into the solution with an increase of microwave temperature. For the same microwave temperatures, carbohydrate release was first increased with the addition of H2O2, and then decreased as the H2O2 dosages increased further. The amount of DNA in solution was a good indicator of the extent of cell damage; the high concentration of DNA released into solution after treatment indicated significant cell damage.

Targeting expression of a fungal ferulic acid esterase to the apoplast, endoplasmic reticulum or golgi can disrupt feruloylation of the growing cell wall and increase the biodegradability of tall fescue (Festuca arundinacea)

In the cell walls of grasses, ferulic acid is esterified to arabinoxylans and undergoes oxidative reactions to form ferulates dimers, trimers and oligomers. Feruloylation of arabinoxylan is considered important not only because it leads to cross-linked xylans but also because ferulates may act as a nucleating site for the formation of lignin and hence link arabinoxylans to lignin by forming a lignin-ferulate-arabinoxylan complex. Such cross-linking is among the main factors inhibiting the release of fermentable carbohydrates from grasses either for ruminant nutrition or for biofuel production. We have found that significant reductions in the levels of monomeric and dimeric phenolics can be achieved in the growing cell walls during plant development in leaves of Festuca arundinacea by constitutive intracellular targeted expression of Aspergillus niger ferulic acid esterase (FAEA). We propose that this occurred by directly disrupting ester bonds linking phenolics to cell wall polysaccharides by apoplast targeting or by preventing excessive feruloylation of cell wall carbohydrates prior to their incorporation into the cell wall, by targeting to the Golgi membrane system. Plants with lower cell wall ferulate levels, which showed increased digestibility and increased rates of cellulase-mediated release of fermentable sugars, were identified. Targeting FAE to the Golgi was found to be more effective than targeting to the ER, which supports the current theories of the Golgi as the site of feruloylation of arabinoxylans. It is concluded that targeting FAEA expression to the Golgi or apoplast is likely to be an effective strategy for improving wall digestibility in grass species used for fodder or cellulosic ethanol production.

RELEASE OF CARBOHYDRATES AND PROTEINS BY A SUBTROPICAL STRAIN OF RAPHIDIOPSIS BROOKII (CYANOBACTERIA) ABLE TO PRODUCE SAXITOXIN AT THREE NITRATE CONCENTRATIONS(1).

Raphidiopsis brookii P. J. Hill (cyanobacteria) was isolated from a small subtropical eutrophic pond (Biguá Pond) located in the grounds of Rio Grande University in the extreme south of Brazil, following a toxic bloom of this species. Growth, saxitoxin production, and release of carbohydrates and protein were monitored at three sodium nitrate concentrations (500, 1,000, and 1,500 μM), from inoculation up to the stationary growth phase. Growth was monitored by determining the biovolume, chl content, and trichome count. Growth was better described in terms of biovolume and chl measurements, because trichome fragmentation was observed to increase at the stationary growth phase. Carbohydrates and proteins were released in small amounts during most of the experiment, with a significant increase during the stationary phase. Extracellular polysaccharides were essentially composed of glucose, galactose, N-acetyl-glucosamine, mannose, xylose, rhamnose, arabinose, and fucose. The relative proportions of these units showed no significant variation during growth. Small quantities of extracellular free carbohydrates were also detected, and only fucose was released in significant amounts at the lowest nitrate concentration (500 μM). R. brookii produced both saxitoxin and dc-saxitoxin, the former at four times the rate of the latter. This was the first study demonstrating saxitoxin production and the release of both carbohydrate and protein by R. brookii.

Protease-induced solubilisation of carbohydrates from brewers' spent grain

The impact of microbial proteases on the release of carbohydrates from BSG was studied. The proteases were able to release the non-cellulosic glucose, a portion of feruloylated arabinoxylan and over 50% of the protein from brewers' spent grain (BSG) after 24 h hydrolysis. The non-cellulosic glucose was derived from residual starch-derived products persisting in BSG after mashing. The proteases did not cleave the hydroxycinnamate ester linkages present on the arabinoxylan backbone, and thus do not behave as feruloyl esterases. However, the material solubilised from spent grain by the proteases contained up to 198 μg bound ferulic acid/g extract, which represented 8.6% of the total ferulic acid present in BSG. These results suggest that a portion of water-extractable feruloylated arabinoxylan and starch is trapped within the BSG matrix by a proteinaceous barrier.

Protonophore‐ and pH‐insensitive glucose and sucrose accumulation detected by FRET nanosensors in Arabidopsis root tips

Although soil contains only traces of soluble carbohydrates, plant roots take up glucose and sucrose efficiently when supplied in artificial media. Soluble carbohydrates and other small metabolites found in soil are in part products from exudation from plant roots. The molecular nature of the transporters for uptake and exudation is unknown. Here, fluorescence resonance energy transfer (FRET) glucose and sucrose sensors were used to characterize accumulation and elimination of glucose and sucrose in Arabidopsis roots tips. Using an improved image acquisition set-up, FRET responses to perfusion with carbohydrates were detectable in roots within less than 10 sec and over a wide concentration range. Accumulation was fully reversible within 10-180 sec after glucose or sucrose had been withdrawn; elimination may be caused by metabolism and/or efflux. The rate of elimination was unaffected by pre-incubation with high concentrations of glucose, suggesting that elimination is not due to accumulation in a short-term buffer such as the vacuole. Glucose and sucrose accumulation was insensitive to protonophores, was comparable in media differing in potassium levels, and was similar at pH 5.8, 6.8 and 7.8, suggesting that both influx and efflux may be mediated by proton-independent transport systems. High-resolution expression mapping in root tips showed that only a few proton-dependent transport of the STP (Sugar Transport Protein) and SUT/SUC (Sucrose Transporter/Carrier) families are expressed in the external cell layers of root tips. The root expression maps may help to pinpoint candidate genes for uptake and release of carbohydrates from roots.

Carbohydrate and Ethane Release with Erwinia carotovora Subspecies betavasculorum –Induced Necrosis

Erwinia carotovora subspecies betavasculorum, also known as E. betavasculorum and Pectobacterium betavasculorum, is a soil bacterium that has the capacity to cause root rot necrosis of sugarbeets. The qualitatively different pathogenicity exhibited by the virulent E. carotovora strain and two avirulent strains, a Citrobacter sp. and an Enterobacter cloacae, was examined using digital analysis of photographic evidence of necrosis as well as for carbohydrate, ethane, and ethylene release compared with uninoculated potato tuber slices. Visual scoring of necrosis was superior to digital analysis of photographs. The release of carbohydrates and ethane from potato tuber slices inoculated with the soft rot necrosis-causing Erwinia was significantly greater than that of potato tuber slices that had not been inoculated or that had been inoculated with the nonpathogenic E. cloacae and Citrobacter sp. strains. Interestingly, ethylene production from potato slices left uninoculated or inoculated with the nonpathogenic Citrobacter strain was 5- to 10-fold higher than with potato slices inoculated with the pathogenic Erwinia strain. These findings suggest that (1) carbohydrate release might be a useful measure of the degree of pathogenesis, or relative virulence; and that (2) bacterial suppression of ethylene formation may be a critical step in root rot disease formation.

Nutritional characterization and measurement of dietary carbohydrates

Dietary carbohydrate characterization should reflect relevant nutritional and functional attributes, and be measured as chemically identified components. A nutritional classification based on these principles is presented, with a main grouping into 'available carbohydrates', which are digested and absorbed in the small intestine providing carbohydrates for metabolism, and 'resistant carbohydrates', which resist digestion in the small intestine or are poorly absorbed/metabolized. For the available carbohydrates, the chemical division into the starch and total sugars categories does not adequately reflect the physiological or nutritional attributes of foods. Characterizing carbohydrate release from starchy foods provides insight into some of the inherent mechanisms responsible for the varied metabolic effects. Also, a pragmatic approach to product signposting consistent with guidelines to limit free (or added) sugars is proposed. The most prominent of the resistant carbohydrates are the non-starch polysaccharides (NSP) from plant cell walls, which are characteristic of the largely unrefined plant foods that provide the evidence base for the definition and measurement of dietary fibre as 'intrinsic plant cell-wall polysaccharides' as proposed in conjunction with this paper and endorsed by the scientific update. Indigestibility in the small intestine was not considered to be an adequate basis for the definition of dietary fibre, as there is insufficient evidence to establish public health policy by this approach and concerns have been raised about potential detrimental effects of high intakes of rapidly fermentable resistant carbohydrates. Functional ingredients such as resistant starch and resistant oligosaccharides should therefore be researched and managed separately from dietary fibre, using specific health or function claims where appropriate. This structured approach to the characterization of nutritionally relevant features of dietary carbohydrates provides the basis for establishing population reference intakes, nutrition claims and food labelling that will assist the consumer with properly informed dietary choices.

Metabolic Footprinting: A New Approach to Identify Physiological Changes in Complex Microbial Communities upon Exposure to Toxic Chemicals

Metabolic footprinting coupled with statistical analysis was applied to multiple, chemically stressed activated sludge cultures to identify probable biomarkers that indicate community stress. The impact of cadmium (Cd), 2,4-dinitrophenol (DNP), and N-ethyl-maleimide (NEM) shock loads on the composition of the soluble fraction of activated sludge cultures was analyzed by gross biomolecular analyses and liquid chromatography-mass spectrometry (LC-MS). Fresh mixed liquor from four distinct treatment plants was each divided in four different batches and was subjected to no chemical addition (control) and spike additions of the stressors Cd, DNP, or NEM. The results indicate that chemical stress caused a significant release of proteins, carbohydrates, and humic acids from the floc structure into the bulk liquid. Using discriminant function analysis (DFA) with genetic algorithm variable selection (GA-DFA), the samples subjected to the different stress conditions plus control could be differentiated, thereby indicating that the footprints of the soluble phase generated by LC-MS were different for the four conditions tested and, therefore, were toxin-specific but community-independent. These footprints, thus, contain information about specific biomolecular differences between the stressed samples, and we found that only a limited number of m/z (mass to charge) ratios from the mass spectra were needed to differentiate between the control and each stressed sample. Since the experiments were conducted with mixed liquor from four distinct wastewater treatment plants, the discriminant m/z ratios may potentially be used as universal stress biomarkers in activated sludge systems.

Vapor-phase diethyl oxalate pretreatment of wood chips: Part 2. Release of hemicellulosic carbohydrates

Abstract Wood chips of pine, spruce, aspen, and maple were treated at 135–140°C with diethyl oxalate (DEO) and analyzed for extractable and residual carbohydrates. Under these conditions, DEO hydrolyzes to ethanol and oxalic acid (OA). The amount and identity of carbohydrates released from the chips were species-dependent. For all wood species, increasing the amount of chemical, time, or temperature resulted in an increment in carbohydrates released. Approximately 50% (by wt) of extracted carbohydrates were monosaccharides. In addition, acetic acid was detected in the water extracts. When extracts were subsequently alkaline-treated, more acetate was released, indicating the presence of acetyl esters. The composition of water extracts and of wood chips after treatment indicates that these treatments primarily affect hemicelluloses. In summary, treatment of wood chips with DEO or OA releases carbohydrates suitable for fermentation, with no evidence of cellulose degradation.

Mechanical sludge disintegration for the production of carbon source for biological nutrient removal

The primary driver for a successful biological nutrient removal is the availability of suitable carbon source, mainly in the form of volatile fatty acids (VFA). Several methods have been examined to increase the amount of VFAs in wastewater. This study investigates the mechanism of mechanical disintegration of thickened surplus activated sludge by a deflaker technology for the production of organic matter. This equipment was able to increase the soluble carbon in terms of VFA and soluble chemical oxygen demand (SCOD) with the maximum concentration to be around 850 and 6530 mg l −1, for VFA and SCOD, respectively. The particle size was reduced from 65.5 to 9.3 μm after 15 min of disintegration with the simultaneous release of proteins (1550 mg l −1) and carbohydrates (307 mg l −1) indicating floc disruption and breakage. High performance size exclusion chromatography investigated the disintegrated sludge and confirmed that the deflaker was able to destroy the flocs releasing polymeric substances that are typically found outside of cells. When long disintegration times were applied (⩾10 min or ⩾9000 kJ kg −1 TS of specific energy) smaller molecular size materials were released to the liquid phase, which are considered to be found inside the cells indicating cell lysis.

Moderate Ferulate and Diferulate Levels Do Not Impede Maize Cell Wall Degradation by Human Intestinal Microbiota

The degradation of plant fiber by human gut microbiota could be restricted by xylan substitution and cross-linking by ferulate and diferulates, for example, by hindering the association of enzymes such as xylanases with their substrates. To test the influence of feruloylation on cell wall degradability by human intestinal microbiota, nonlignified primary cell walls from maize cell suspensions, containing various degrees of ferulate substitution and diferulate cross-linking, were incubated in nylon bags in vitro with human fecal microbiota. Degradation rates were determined gravimetrically, and the cell walls were analyzed for carbohydrates, ferulate monomers, dehydrodiferulates, dehydrotriferulates, and other minor phenolic constituents. Shifting cell wall concentrations of total ferulates from 1.5 to 15.8 mg/g and those of diferulates from 0.8 to 2.6 mg/g did not alter the release of carbohydrates or the overall degradation of cell walls. After 24 h of fermentation, the degradation of xylans and pectins exceeded 90%, whereas cellulose remained undegraded. The results indicate that low to moderate levels of ferulates and diferulates do not interfere with hydrolysis of nonlignified cell walls by human gut microbiota.

Degradation of extracellular matrix and its components by hypobromous acid

EPO (eosinophil peroxidase) and MPO (myeloperoxidase) are highly basic haem enzymes that can catalyse the production of HOBr (hypobromous acid). They are released extracellularly by activated leucocytes and their binding to the polyanionic glycosa-minoglycan components of extracellular matrix (proteoglycans and hyaluronan) may localize the production of HOBr to these materials. It is shown in the present paper that the reaction of HOBr with glycosaminoglycans (heparan sulfate, heparin, chondroitin sulfate and hyaluronan) generates polymer-derived N-bromo derivatives (bromamines, dibromamines, N-bromosulfon-amides and bromamides). Decomposition of these species, which can occur spontaneously and/or via one-electron reduction by low-valent transition metal ions (Cu+ and Fe2+), results in polymer fragmentation and modification. One-electron reduction of the N-bromo derivatives generates radicals that have been detected by EPR spin trapping. The species detected are consistent with metal ion-dependent polymer fragmentation and modification being initiated by the formation of nitrogen-centred (aminyl, N-bromoaminyl, sulfonamidyl and amidyl) radicals. Previous studies have shown that the reaction of HOBr with proteins generates N-bromo derivatives and results in fragmentation of the polypeptide backbone. The reaction of HOBr with extracellular matrix synthesized by smooth muscle cells in vitro induces the release of carbohydrate and protein components in a time-dependent manner, which is consistent with fragmentation of these materials via the formation of N-bromo derivatives. The degradation of extracellular matrix glycosaminoglycans and proteins by HOBr may contribute to tissue damage associated with inflammatory diseases such as asthma.

Enzymatic Hydrolysis of Flavonoids and Pectic Oligosaccharides from Bergamot (Citrus bergamia Risso) Peel

Pectinolytic and cellulolytic enzymes (Pectinase 62L, Pectinase 690L, and Cellulase CO13P) were used to evaluate the solubilization of carbohydrates and low molecular weight flavonoids from bergamot peel, a major byproduct of the essential oil industry. The enzymes were characterized for main-chain and side-chain polysaccharide hydrolyzing activities and also against pure samples of various flavonoids previously identified in bergamot peel to determine various glycosidase activities. The addition of Pectinase 62L or 690L alone, or the combination of Pectinase 62L and Cellulase CO13P, was capable of solubilizing between 70 and 80% of the bergamot peel, and up to 90% of the flavonoid glycosides present were cleaved to their aglycones. Cellulase CO13P alone solubilized 62% of the peel but had no deglycosylating effect on the flavonoid glycosides. Over a 24-h time course, a rapid release of cell wall carbohydrates was observed after treatment with Pectinase 62L, with a concurrent gradual hydrolysis of the flavonoid glycosides. Size-exclusion chromatography of the solubilized extract showed that after 24-h incubation, the majority of the solubilized carbohydrates were present as monosaccharides with a smaller proportion of oligosaccharides.

Effects of a fungicide, an insecticide, and a biopesticide on Tolypothrix scytonemoides

Lower concentrations of Bavistin supported good growth of Tolypothrix scytonemoides with maximum protein and pigment contents. The rates of photosynthetic oxygen evolution declined in cells grown in the pesticide-amended medium but rates of respiratory oxygen consumption were enhanced in cells grown in lower concentrations of Monocrotophos and Nimbicidin. Activities of nitrogenase and glutamine synthetase were affected in all the pesticide treatments but nitrogenase activity was enhanced in the presence of Bavistin. Release of ammonia and carbohydrates was enhanced in cells grown in pesticide-amended medium except for cells grown in medium containing Bavistin where the release of carbohydrates was reduced. New polypeptides of ∼280, 152, and 25 kDa (in 250 ppm Bavistin), ∼58 and 28 kDa (in 0.3 and 0.2–0.4 ppm Monocrotophos, respectively) and ∼31, 28, and 26 kDa (in 0.5 and 1.0 ppm Nimbicidin) were detected in the treated cells.

Effects of several common chemical fertilizers on Tolypothrix scytonemoides (Gardner) Geitler

Good growth of Tolypothrix scytonemoides (Gardner) Geitler was observed in low concentrations of NPK fertilizer, single superphosphate, and urea. Protein content decreased in cells grown in higher concentrations of tested tested chemical fertilizers. Phycobilin pigment contents were enhanced in cells grown in medium amended with NPK fertilizer but were lower in cells grown in 15 and 20 mg·L−1 of single superphosphate and 10, 15, and 20 mg·L−1 of urea. The rates of photosynthetic oxygen evolution and respiratory oxygen consumption were enhanced in cells grown in medium amended with all different concentrations of NPK fertilizer and low concentrations of single superphosphate. Nitrogenase activity was completely inhibited by 20 mg·L−1 NPK fertilizer and 15 mg·L−1 urea but it remained unaffected with the addition of single superphosphate. On one hand, glutamine synthetase activity decreased gradually in a dose-dependent manner in cells grown in NPK fertilizer and urea-amended medium, on the other hand, the cells grown in 10 mg·L−1 single superphosphate exhibited the highest glutamine synthetase activity. Greatest exogenous carbohydrate release was observed in cells grown in 15 mg·L−1 urea.

Polymeric and free sugars released by three phytoplanktonic species from a freshwater tropical eutrophic reservoir

Several studies have focused on the release of carbohydrates by phytoplankton because of the ecological significance of such compounds. This process increases the supply of carbon to the heterotrophic community, enhancing the phytoplankton/bacteria associations. In this article, we report investigations on the carbohydrate release, both polymeric and free sugars, in axenic batch cultures of three tropical freshwater phytoplanktonic species from different taxonomic positions: Cyptomonas tetrapyremidosa (Cryptophyceae), Stattrastrum orbiculare (Zygnematophyceae) and Thalassiosira sp. (Bacillariophy-ceae). The total carbohydrate release rate was increased in the stationary growth phase in all the species under study. Most of the carbohydrates released by the three species were present in the polymeric form, although both polymeric and free carbohydrates could supply carbon enough to support bactenoplanktonic populations, according to rates of consumption found on literature. The composition of the carbohydrate differed significantly from one spews to another, indicating that carbohydrate release might be a species-specific process. We also observed that the contributions of some components from polymeric sugars, such as fucose, rhamnose and arabmose increased with the advancing age of the cultures.