The impact of a supervised strength and aerobic training program on muscular strength and aerobic capacity in individuals with type 2 diabetes

An intervention in the clinical management of individuals with type 2 diabetes is strength and aerobic training. Limited research has been conducted that investigates the effect of a supervised strength and aerobic training program on muscular strength and aerobic capacity in people with type 2 diabetes. The purpose of this 1-group repeated-measures-designed study was to investigate the impact of a supervised strength and aerobic training program on muscular strength and aerobic capacity in subjects with type 2 diabetes. Thirteen subjects with type 2 diabetes completed the training program. Subjects met the American Diabetes Association diagnostic criteria for type 2 diabetes. For each subject, muscular strength (estimated 1 repetition maximum) and aerobic capacity (estimated maximal oxygen uptake) were measured before and after a supervised strength and aerobic training program as well as during a 6-week follow-up. Repeated-measures analysis of variance was used to compare muscular strength and aerobic capacity between pretesting, posttesting, and follow-up testing periods. Significant improvements in muscular strength (p < 0.01) and aerobic capacity (p < 0.01) were found during posttesting and follow-up testing, as compared to pretesting measures. Yet a significant loss in muscular strength (p < 0.01) and no significant change in aerobic capacity (p > 0.05) were found during follow-up testing, as compared to posttesting measures. This study indicates that a supervised strength and aerobic training program can significantly improve muscular strength and aerobic capacity in people with type 2 diabetes. Yet improvements in muscular strength due to training will not be maintained if individuals with type 2 diabetes do not adhere to a continuous training program. In addition, aerobic capacity can be improved with training, but aerobic capacity will not continue to improve if people with type 2 diabetes are not compliant with a continuous training program.     

Stoichiometric analysis of dissolved organic carbon flux into storage and growth in aerobic granules culture

This study attempted to address a fundamental question of whether metabolic behaviors of aerobic granules are different from their counterparts, such as activated sludge and biofilms. A series of respirometric experiments were carried out using mature aerobic granules with mean sizes of 0.75–3.4 mm. Results suggested that metabolism of aerobic granules comprised three consecutive phases: (i) conversion of external dissolved organic carbon to a poly-β-hydroxybutyrate-like substance; (ii) growth of aerobic granules on the stored poly-β-hydroxybutyrate-like substance derived from phase I, and (iii) subsequent endogenous metabolism of aerobic granules. The stoichiometric analysis revealed that the conversion yields of external dissolved organic carbon to the poly-β-hydroxybutyrate-like substance, the growth yields of biomass on storage, and the overall growth yields of biomass on external dissolved organic carbon were not significantly correlated to the sizes of aerobic granules, i.e., the metabolism of aerobic granules would be size independent. The conversion coefficients and growth rates of aerobic granules were found to be comparable with those reported in the activated sludge and biofilms cultures, indicating that there would not be significant difference in the metabolisms of aerobic granules over activated sludge and biofilms. This information will be useful for modeling and designing aerobic granular sludge processes.     

Fit women are not able to use the whole aerobic capacity during aerobic dance

Edvardsen, E, Ingjer, F, and B?, K. Fit women are not able to use the whole aerobic capacity during aerobic dance. J Strength Cond Res 25(12): 3479-3485, 2011-This study compared the aerobic capacity during maximal aerobic dance and treadmill running in fit women. Thirteen well-trained female aerobic dance instructors aged 30 ± 8.17 years (mean ± SD) exercised to exhaustion by running on a treadmill for measurement of maximal oxygen uptake (VO(2)max) and peak heart rate (HRpeak). Additionally, all subjects performed aerobic dancing until exhaustion after a choreographed videotaped routine trying to reach the same HRpeak as during maximal running. The p value for statistical significance between running and aerobic dance was set to ≤0.05. The results (mean ± SD) showed a lower VO(2)max in aerobic dance (52.2 ± 4.02 ml·kg·min) compared with treadmill running (55.9 ± 5.03 ml·kg·min) (p = 0.0003). Further, the mean ± SD HRpeak was 182 ± 9.15 b·min in aerobic dance and 192 ± 9.62 b·min in treadmill running, giving no difference in oxygen pulse between the 2 exercise forms (p = 0.32). There was no difference in peak ventilation (aerobic dance: 108 ± 10.81 L·min vs. running: 113 ± 11.49 L·min). In conclusion, aerobic dance does not seem to be able to use the whole aerobic capacity as in running. For well endurance-trained women, this may result in a lower total workload at maximal intensities. Aerobic dance may therefore not be as suitable as running during maximal intensities in well-trained females.     

Characterization of aerobic granules by microbial density at different COD loading rates

Aerobic granules were cultivated under temporal alternating aerobic and anoxic conditions without the presence of a carrier material in a sequencing batch reactor (SBR) with a high column height/column diameter ratio. The reactor was operated for 6h per cycle (aerobic: 4.75 h, anoxic: 1.25 h). To determine a new parameter for the definition of aerobic granules, a protocol of 4,6-diamidino-2-phenylindole hydrochloride staining and fluorescence image processing was developed. The d(tm) analysis showed that the increase in the chemical oxygen demand (COD) loading rate promoted no more growth of the aerobic granules. It was inconsistent with the results of the analysis of the sludge volume index (SVI) value but matched well with the results of the COD and nitrogen removal of the SBR and the particle size distribution by LS-PSA. The optimum COD loading rate for aerobic granulation in the SBR was 2.52 kg/m(3)d. When d(tm) was correlated with the biomass concentration and the SVI value during the period of granule formation, d(tm) could be used as a more sensitive and accurate parameter for classifying aerobic granules and optimizing the operational conditions for aerobic granulation processes.     

The therapeutic effect of aerobic exercise with resistance training in elderly men with type 2 diabetes mellitus

Objective: This study was conducted to examine the effects of aerobic exercise alone and aerobic exercise with resistance training on the quality of life in men over the age of 55 years with type 2 diabetes mellitus. Methods: A total of 54 participants were divided into the following three groups so that there were no significant differences in blood chemistry or physical ability indexes among the three groups: control, aerobic exercise, and aerobic exercise with resistance training. The latter two groups exercised for 24 weeks, while the control group performed no exercise. Blood chemistry levels and measures of physical ability in each group members were examined one day before and one day after the exercise regimens. Results: Compared with those before the study, blood glucose, glycated hemoglobin, triglycerides, cholesterol, and low-density lipoprotein levels as well as vital capacity, reaction time, sit-and-reach ability, and balancing while standing on one leg with closed eyes were significantly improved in the aerobic exercise only group(P 0.05). All these measures as well as high-density lipoprotein levels and grip, back, and leg strength were significantly improved in the combined aerobic and resistance training group(P 0.05). By contrast, no significant differences before and after the experiment were found in any measure for the control group(P 0.05). Conclusion: Although both aerobic exercise and aerobic exercise combined with resistance training for 24 weeks effectively improved the quality of life in patients with type 2 diabetes, the effect of the combined training was better than that of aerobic exercise alone. These results suggest that resistance training may be safely added to the rehabilitation training regimen of patients with type 2 diabetes mellitus.     

Treatment of raw and ozonated oil sands process-affected water under decoupled denitrifying anoxic and nitrifying aerobic conditions: a comparative study

Batch experiments were performed to evaluate biodegradation of raw and ozonated oil sands process-affected water (OSPW) under denitrifying anoxic and nitrifying aerobic conditions for 33 days. The results showed both the anoxic and aerobic conditions are effective in degrading OSPW classical and oxidized naphthenic acids (NAs) with the aerobic conditions demonstrating higher removal efficiency. The reactors under nitrifying aerobic condition reduced the total classical NAs of raw OSPW by 69.1 %, with better efficiency for species of higher hydrophobicity. Compared with conventional aerobic reactor, nitrifying aerobic condition substantially shortened the NA degradation half-life to 16 days. The mild-dose ozonation remarkably accelerated the subsequent aerobic biodegradation of classical NAs within the first 14 days, especially for those with long carbon chains. Moreover, the ozone pretreatment enhanced the biological removal of OSPW classical NAs by leaving a considerably lower final residual concentration of 10.4 mg/L under anoxic conditions, and 5.7 mg/L under aerobic conditions. The combination of ozonation and nitrifying aerobic biodegradation removed total classical NAs by 76.5 % and total oxy-NAs (O3–O6) by 23.6 %. 454 Pyrosequencing revealed that microbial species capable of degrading recalcitrant hydrocarbons were dominant in all reactors. The most abundant genus in the raw and ozonated anoxic reactors was Thauera (~56 % in the raw OSPW anoxic reactor, and ~65 % in the ozonated OSPW anoxic reactor); whereas Rhodanobacter (~40 %) and Pseudomonas (~40 %) dominated the raw and ozonated aerobic reactors, respectively. Therefore, the combination of mild-dose ozone pretreatment and subsequent biological process could be a competent choice for OSPW treatment.     

Sexual dimorphism in primate aerobic capacity: a phylogenetic test

Male intrasexual competition should favour increased male physical prowess. This should in turn result in greater aerobic capacity in males than in females (i.e. sexual dimorphism) and a correlation between sexual dimorphism in aerobic capacity and the strength of sexual selection among species. However, physiological scaling laws predict that aerobic capacity should be lower per unit body mass in larger than in smaller animals, potentially reducing or reversing the sex difference and its association with measures of sexual selection. We used measures of haematocrit and red blood cell (RBC) counts from 45 species of primates to test four predictions related to sexual selection and body mass: (i) on average, males should have higher aerobic capacity than females, (ii) aerobic capacity should be higher in adult than juvenile males, (iii) aerobic capacity should increase with increasing sexual selection, but also that (iv) measures of aerobic capacity should co‐vary negatively with body mass. For the first two predictions, we used a phylogenetic paired t‐test developed for this study. We found support for predictions (i) and (ii). For prediction (iii), however, we found a negative correlation between the degree of sexual selection and aerobic capacity, which was opposite to our prediction. Prediction (iv) was generally supported. We also investigated whether substrate use, basal metabolic rate and agility influenced physiological measures of oxygen transport, but we found only weak evidence for a correlation between RBC count and agility.     

Molar Growth Yields as Evidence for Oxidative Phosphorylation in Streptococcus faecalis Strain 10C1

During the aerobic growth of Streptococcus faecalis strain 10C1, with limiting levels of glucose as the substrate, a molar growth yield (Y) of 58.2 g (dry weight) per mole of glucose was obtained. Under these conditions of growth, glucose was dissimilated primarily to acetate and CO(2). The incorporation of (14)C-glucose into cell material was no greater under aerobic conditions than during anaerobic growth. Assuming an adenosine triphosphate coefficient of 10.5, the aerobic Y cannot be explained solely on the basis of substrate phosphorylation and would appear to substantiate previous enzymatic evidence for oxidative phosphorylation in this cytochromeless species. With mannitol as the substrate, an aerobic Y of 64.6 was obtained. Extracts of mannitol-grown cells contained a nicotinamide adenine dinucleotide (NAD)-linked mannitol-1-phosphate (M-1-P) dehydrogenase. The difference in aerobic Y values with mannitol and glucose as substrates would indicate that the in vivo P/O ratio from the oxidation of reduced NAD generated by the oxidation of M-1-P approximates 0.6. The Y values with pyruvate and glycerol as substrates under aerobic conditions were 15.5 and 24.7, respectively.     

Biodegradability of extracellular polymeric substances produced by aerobic granules

This study investigated the biodegradability of extracellular polymeric substances (EPS) produced by aerobic granules. Aerobic granules were precultivated with synthetic wastewater in a lab-scale sequencing batch reactor. EPS were extracted from aerobic granules and were then fed as the sole carbon source to their own producers. Results showed that about 50% of EPS produced by aerobic granules could be utilized by their producers under aerobic starvation condition. The average biodegradation rate of the granule EPS in terms of chemical oxygen demand was five times slower than that of acetate, but 50 times faster than that of nonbiodegradable EPS produced by aerobic granules. The nonbiodegradable EPS was mainly found on the outer shell of aerobic granule. EPS produced by aerobic granules basically comprised two major components, i.e., biodegradable and nonbiodegradable EPS. The biodegradable EPS could serve as a useful energy source to sustain the growth of aerobic granules under starvation. This study provides experimental evidence that part of the EPS produced by aerobic granules would be biodegradable, but only nonbiodegradable EPS would play a crucial role in maintaining the structural integrity of aerobic granule.     

The impact of ionic mercury on antioxidant defenses in two mercury-sensitive anaerobic bacteria

While the toxicological effects of mercury (Hg) are well studied in mammals, little is known about the mechanisms of toxicity to bacterial cells lacking an Hg resistance (mer) operon. We determined that Shewanella oneidensis MR-1 is more sensitive to ionic mercury [Hg(II)] under aerobic conditions than in fumarate reducing conditions, with minimum inhibitory concentrations of 0.25 and 2 μM respectively. This increased sensitivity in aerobic conditions is not due to increased import, as more Hg is associated with cellular material in fumarate reducing conditions than in aerobic conditions. In fumarate reducing conditions, glutathione may provide protection, as glutathione levels decrease in a dose-dependent manner, but this does not occur in aerobic conditions. Hg(II) does not change the redox state of thioredoxin in MR1 in either fumarate reducing conditions or aerobic conditions, although thioredoxin is oxidized in Geobacter sulfurreducens PCA in response to Hg(II) treatment. However, treatment with 0.5 μM Hg(II) increases lipid peroxidation in aerobic conditions but not in fumarate reducing conditions in MR-1. We conclude that the enhanced sensitivity of MR-1 to Hg(II) in aerobic conditions is not due to differences in intracellular responses, but due to damage at the cell envelope.     

State of the art of aerobic granulation in continuous flow bioreactors

In the wake of the success of aerobic granulation in sequential batch reactors (SBRs) for treating wastewater, attention is beginning to turn to continuous flow applications. This is a necessary step given the advantages of continuous flow treatment processes and the fact that the majority of full-scale wastewater treatment plants across the world are operated with aeration tanks and clarifiers in a continuous flow mode. As in SBRs, applying a selection pressure, based on differences in either settling velocity or the size of the biomass, is essential for successful granulation in continuous flow reactors (CFRs). CFRs employed for aerobic granulation come in multiple configurations, each with their own means of achieving such a selection pressure. Other factors, such as bioaugmentation and hydraulic shear force, also contribute to aerobic granulation to some extent. Besides the formation of aerobic granules, long-term stability of aerobic granules is also a critical issue to be addressed. Inorganic precipitation, special inocula, and various operational optimization strategies have been used to improve granule long-term structural integrity. Accumulated studies reviewed in this work demonstrate that aerobic granulation in CFRs is capable of removing a wide spectrum of contaminants and achieving properties generally comparable to those in SBRs. Despite the notable research progress made toward successful aerobic granulation in lab-scale CFRs, to the best of our knowledge, there are only three full-scale tests of the technique, two being seeded with anammox-supported aerobic granules and the other with conventional aerobic granules; two other process alternatives are currently in development. Application of settling- or size-based selection pressures and feast/famine conditions are especially difficult to implement to these and similar mainstream systems. Future research efforts needs to be focused on the optimization of the granule-to-floc ratio, enhancement of granule activity, improvement of long-term granule stability, and a better understanding of aerobic granulation mechanisms in CFRs, especially in full-scale applications.     

Production of polyhydroxybutyrate by activated sludge performing enhanced biological phosphorus removal

In this study, polyhydroxybutyrate (PHB) – a biodegradable plastics material – was produced by activated sludge performing enhanced biological phosphorus removal (EBPR) in batch experiments under anaerobic, aerobic and anaerobic/aerobic conditions. Under anaerobic conditions, the maximum PHB content of the dry biomass was 28.8% by weight, while under aerobic or anaerobic/aerobic conditions, the maximum PHB content was about 50%. The PHB production rate with respect to the volatile suspended solids (VSS) was: (i) 70 mg/(g VSS) h under aerobic conditions that followed anaerobic conditions, (ii) 156 mg/(g VSS) h under anaerobic condition, and (iii) 200 mg/(g VSS) h under aerobic conditions with energy also supplied from polyphosphate. A side stream, with initially anaerobic conditions for PHB accumulation and phosphorus release, and then aerobic conditions for PHB accumulation, was proposed. In this side stream, biomass with a high PHB content and a high PHB production rate could be both achieved.     

胆道手术患者胆汁的菌群分析

本文对59例胆道手术患者的胆汁标本进行了菌群分析。共检出各类细菌156株,其中厌氧菌70株,以类杆菌最为常见(44株);兼性需氧菌86株,以大肠杆菌最为常见(37株)。胆汁细菌培养阳性率为86.4％(51/59);64.4％(38/59)的标本为厌氧菌与兼性厌氧菌混合污染。22.0％(13/59)的标本中仅分离到兼性需氧菌。提示,胆汁中污染的类杆菌及大肠杆菌是胆道手术后感染的主要原因菌。     

Thermal acclimation is not necessary to maintain a wide thermal breadth of aerobic scope in the common killifish (Fundulus heteroclitus)

Loss of aerobic scope at high and low temperatures is a physiological mechanism proposed to limit the thermal performance and tolerance of organisms, a theory known as oxygen- and capacity-limited thermal tolerance (OCLTT). Eurythermal organisms maintain aerobic scope over wide ranges of temperatures, but it is unknown whether acclimation is necessary to maintain this breadth. The objective of this study was to examine changes in aerobic scope in Fundulus heteroclitus, a eurythermal fish, after acclimation and acute exposure to temperatures from 5° to 33°C. The range of temperatures over which aerobic scope was nonzero was similar in acclimated and acutely exposed fish, suggesting that acclimation has modest effects on the thermal breadth of aerobic scope. However, in acclimated fish, there was a clear optimum temperature range for aerobic scope between 25° and 30°C, whereas aerobic scope was relatively constant across the entire temperature range with acute temperature exposure. Therefore, the primary effect of acclimation was to increase aerobic scope between 25° and 30°C, which paradoxically resulted in a narrower temperature range of optimal performance in acclimated fish compared to acutely exposed fish. There was only weak evidence for correlations between the thermal optimum of aerobic scope and the thermal optimum of measures of performance (specific growth rate and gonadosomatic index), and indicators of anaerobic metabolism (lactate accumulation and lactate dehydrogenase activity) only increased at high temperatures. Together these data fit many, but not all, of the predictions made by OCLTT.     

Temperature effects on the aerobic metabolism of glycogen-accumulating organisms

Short-term temperature effects on the aerobic metabolism of glycogen-accumulating organisms (GAO) were investigated within a temperature range from 10 to 40 degrees C. Candidatus Competibacter Phosphatis, known GAO, were the dominant microorganisms in the enriched culture comprising 93 +/- 1% of total bacterial population as indicated by fluorescence in situ hybridization (FISH) analysis. Between 10 and 30 degrees C, the aerobic stoichiometry of GAO was insensitive to temperature changes. Around 30 degrees C, the optimal temperature for most of the aerobic kinetic rates was found. At temperatures higher than 30 degrees C, a decrease on the aerobic stoichiometric yields combined with an increase on the aerobic maintenance requirements were observed. An optimal overall temperature for both anaerobic and aerobic metabolisms of GAO appears to be found around 30 degrees C. Furthermore, within a temperature range (10-30 degrees C) that covers the operating temperature range of most of domestic wastewater treatment systems, GAOs aerobic kinetic rates exhibited a medium degree of dependency on temperature (theta = 1.046-1.090) comparable to that of phosphorus accumulating organisms (PAO). We conclude that GAO do not have metabolic advantages over PAO concerning the effects of temperature on their aerobic metabolism, and competitive advantages are due to anaerobic processes.     

Proteome analysis of aerobic and fermentative metabolism in Rhizobium etli CE3

Rhizobium etli undergoes a transition from an aerobic to a fermentative metabolism during successive subcultures in minimal medium. This metabolic transition does not occur in cells subcultured in rich medium, or in minimal medium containing either biotin or thiamine. In this report, we characterize the aerobic and fermentative metabolism of R. etli using proteome analysis. According to their synthesis patterns in response to aerobic (rich medium, minimal medium with biotin or minimal medium with thiamine) or fermentative (minimal medium without supplements) growth conditions, proteins were assigned to five different classes: (i) proteins produced only in aerobic conditions (e.g., catalase-peroxidase KatG and the E2 component of pyruvate dehydrogenase); (ii) protein produced under both conditions but strongly induced in aerobic metabolism (e.g., malate dehydrogenase and the succinyl-CoA synthetase beta subunit); (iii) proteins that were induced equally under all conditions tested (e.g., AniA, DnaK, and GroEL); (iv) proteins downregulated during aerobic metabolism, and (v) proteins specific to only one of the conditions analyzed. Northern blotting studies of katG expression confirmed the proteome data for this protein. The negative regulation of carbon metabolism proteins observed in fermentative metabolism is consistent with the drastic physiological changes which occur during this process.     

Protective effects of sulforaphane and aerobic exercise on acute alcoholic hepatic injury in mice

ObjectiveThe paper intends to study the protective effects of sulforaphane (SF) on acute alcoholic hepatic injury in mice by intragastric administration of SF, aerobic exercise and the approach of SF integrated with aerobic exercise.Methodology60 NIH mice were randomly divided into 6 groups of equal number according to their body weight and were intragastrically administrated with 50% ethanol. The serum and liver indexes of each group of mice were detected, and the liver was stained with oil red O for pathological examination.ResultsCompared with the model group, the serum TG and the ratio of liver to body weight of the model mice that suffered from acute alcoholic hepatic injury could be significantly decreased in the group that practiced aerobic exercise, the group administered with SF, and the group treated with the approach of SF integrated with aerobic exercise (P < 0.05). The contents of TG and MDA in liver could be significantly decreased (P < 0.05) and SOD activity could be significantly increased (P < 0.05) both in the group administered with SF and the group treated with the approach of SF integrated with aerobic exercise. Serum VLDL (P < 0.05) could also be significantly reduced in the group treated with the approach of SF integrated with aerobic exercise.ConclusionBoth SF and aerobic exercise could alleviate alcohol-induced acute alcoholic hepatic injury in mice possibly thanks to the working mechanism related to antioxidant stress that reduced the harm posed by alcohol on hepatic cells. In addition, the protective effect of SF on acute alcoholic hepatic injury in mice was stronger than that of aerobic exercise, while the approach of SF integrated with aerobic exercise had the strongest protective effect on acute alcoholic hepatic injury in mice.     

Novel halophilic aerobic anoxygenic phototrophs from a Canadian hypersaline spring system

The first enumeration of cultivable obligately aerobic phototrophic bacteria from a terrestrial saline spring was accomplished in the East German Creek system (salinity approximately 6%), near Lake Winnipegosis, Manitoba, Canada. Occurring at densities up to 3.3 x 10(7) CFU/ml of sample, aerobic phototrophs comprised 15-36% of the total cultivable bacterial population in the diatom- and chlorophyte-dominated aerobic microbial mats. Many of the representative strains isolated for phenotypic characterization and phylogenetic analysis possessed <96% 16S rDNA sequence overlap with published species, including an obligately aerobic phototrophic gammaproteobacterium displaying only 92.9% 16S rDNA sequence similarity to Congregibacter litoralis. The springs yielded the most highly halotolerant aerobic anoxygenic phototroph yet recorded, strain EG11, which grew with 26% NaCl.     

Distribution of EPS and cell surface hydrophobicity in aerobic granules

This study described the distribution of extracellular polysaccharides (EPS) and hydrophobicity in aerobic granule as well as the essential role of EPS in maintaining the stable structure of aerobic granules. Aerobic granules showed a heterogeneous structure, which had an outer shell with high biomass density and an inner core having a relatively low biomass density. Results showed that the outer shell of aerobic granule was composed of poorly soluble and noneasily biodegradable EPS, whereas its core part was filled with readily soluble and biodegradable EPS. It was further found that the shell of aerobic granule exhibited a higher hydrophobicity than the core of granule. The insoluble EPS present in the granule shell would play a protective role with respect to the structure stability and integrity of aerobic granules.     

The role of cellular polysaccharides in the formation and stability of aerobic granules

AIMS: This paper attempts to investigate the role of cellular polysaccharides in the formation and stability of aerobic granules. METHODS AND RESULTS: Three column sequential aerobic sludge blanket reactors (R1, R2 and R3) were operated at a superficial air upflow velocity of 0.3 cm s(-1), 1.2 cm s(-1) and 2.4 cm s(-1), respectively. Aerobic granules appeared at cycle 42 in R2 and R3 with a mean size of 0.37 mm in R2 and 0.35 mm in R3, however, aerobic granulation was not observed in R1. After the formation of aerobic granules, the sludge volume index (SVI) decreased to 55 ml g(-1) in R2 and 46 ml g(-1) in R3. Aerobic granulation was concurrent with a sharp increase of cellular polysaccharides normalized to cellular proteins, which increased from 5.7 to 13.0 mg per mg proteins in R2, and 7.5-13.9 mg per mg protein in R3. The content of polysaccharides in aerobic granules was 2-3 times higher than that in the bioflocci cultivated in R1. The disappearance of aerobic granules in R2 was tightly coupled to a drop in cellular polysaccharides. After the reappearance of bioflocci in R2, the content of cellular polysaccharides were found to be restored to the level observed in R1. CONCLUSION: It appears that the production of cellular polysaccharides could be stimulated by hydrodynamic shear force and contributes to the formation and stability of aerobic granules. SIGNIFICANCE AND IMPACT OF THE STUDY: It is expected that this study would provide useful information for better understanding the mechanisms of aerobic granulation.