Densification of activated sludge for better settling performances: experimental characterization in batch column and model parameters calibration.

Conventional activated sludge (CAS) and densified sludge obtained using hydro-cyclone selective wasting were compared at a full-scale water resources recovery facility. The densified tested sludge, containing around 30-50% of aerobic granules, showed enhanced settleability with low and stable sludge volume index (SVI) compared to CAS, which suffered recurrent filamentous bulking. Further in-depth batch settling tests were carried out using a 40 cm diameter column fitted with ultrasonic transducers to monitor both sludge blanket height and vertical velocity profiles.

Redox proteomic study of Bacillus cereus thiol proteome during fermentative anaerobic growth.

Background: Bacillus cereus is a notorious foodborne pathogen, which can grow under anoxic conditions. Anoxic growth is supported by endogenous redox metabolism, for which the thiol redox proteome serves as an interface. Here, we studied the cysteine (Cys) proteome dynamics of B.

Comparison of Time Resolved Optical Turbidity Measurements for Water Monitoring to Standard Real-Time Techniques.

Environmental water monitoring requires the estimation of the suspended solids load. In this paper, we compare the concentration range accessible through three different techniques: optical turbidity, acoustic backscattering and the newly in-lab developed time resolved optical turbidity. We focus on their comparison on measurements made in the laboratory on water suspensions of known particles and concentrations.

Adaptation in : From Stress to Disease.

is a food-borne pathogen that causes diarrheal disease in humans. After ingestion, experiences in the human gastro-intestinal tract abiotic physical variables encountered in food, such as acidic pH in the stomach and changing oxygen conditions in the human intestine. responds to environmental changing conditions (stress) by reversibly adjusting its physiology to maximize resource utilization while maintaining structural and genetic integrity by repairing and minimizing damage to cellular infrastructure.

Adaptive responses of Bacillus cereus ATCC14579 cells upon exposure to acid conditions involve ATPase activity to maintain their internal pH.

This study examined the involvement of ATPase activity in the acid tolerance response (ATR) of Bacillus cereus ATCC14579 strain. In the current work, B. cereus cells were grown in anaerobic chemostat culture at external pH (pH ) 7.

Synthesis and biological evaluation of (-)-6-O-desmethylcryptopleurine and analogs.

(-)-Cryptopleurine 1 is one of the most potent anti-proliferative member of the phenanthroquinolizidine class of alkaloids. We report here the synthesis of (-)-6-O-desmethylcryptopleurine (-)-2 and (-)-6-O-desmethyl-(15R)-hydroxycryptopleurine (-)-4 in their enantiomerically enriched form through a convergent synthetic route, where the chirality is introduced by the use of commercially available (R)-methyl piperidine-2-carboxylate hydrochloride 17. Anti-proliferative activities of these compounds were evaluated on a panel of four cancer cell lines, revealing that compounds (-)-2 and (-)-4 are potent cytotoxic compared to cryptopleurine.

Reducing activity, glucose metabolism and acid tolerance response of Bacillus cereus grown at various pH and oxydo-reduction potential levels.

Bacillus cereus is a major foodborne bacterial pathogen able to survive a large number of physical-chemical stresses. B. cereus encounters different pH and redox potential (Eh7) levels during its passage through the gastrointestinal tract.

A new chemically defined medium for the growth and sporulation of Bacillus cereus strains in anaerobiosis.

A new chemically defined liquid medium, MODS, was developed for the aerobic growth and anaerobic growth and sporulation of Bacillus cereus strains. The comparison of sporulation capacity of 18 strains of B. cereus has shown effective growth and spore production in anaerobiosis.

Absence of oxygen affects the capacity to sporulate and the spore properties of Bacillus cereus.

This study was performed to evaluate the effect of anaerobiosis on the formation of Bacillus cereus spores and their resulting properties. For this purpose, an appropriate sporulation medium was developed (MODs). Sporulation of 18 strains from different phylogenetic groups of B.

Amino acids improve acid tolerance and internal pH maintenance in Bacillus cereus ATCC14579 strain.

This study investigated the involvement of glutamate-, arginine- and lysine-dependent systems in the Acid Tolerance Response (ATR) of Bacillus cereus ATCC14579 strain. Cells were grown in a chemostat at external pH (pH(e)) 7.0 and 5.

Fnr mediates carbohydrate-dependent regulation of catabolic and enterotoxin genes in Bacillus cereus F4430/73.

We had previously demonstrated that Fnr is required for fermentative growth and oxic production of hemolysin BL (Hbl) and non-hemolytic enterotoxin (Nhe) in the food-borne pathogen Bacillus cereus F4430/73. In the present work, the regulatory impact of Fnr on microaerobic growth and enterotoxin production in response to carbohydrates was examined using glucose, fructose, sucrose or a glucose-fructose mixture as carbon and energy sources. Growth parameters, byproduct spectra and transcription levels of catabolic and enterotoxin genes were analyzed in a strain lacking Fnr in comparison to the parental F4430/73 strain.

The redox regulator Fnr is required for fermentative growth and enterotoxin synthesis in Bacillus cereus F4430/73.

Glucose-grown cells of Bacillus cereus respond to anaerobiosis and low extracellular oxidoreduction potentials (ORP), notably by enhancing enterotoxin production. This response involves the ResDE two-component system. We searched the B.

Control of enterotoxin gene expression in Bacillus cereus F4430/73 involves the redox-sensitive ResDE signal transduction system.

In contrast to Bacillus subtilis, the role of the two-component regulatory system ResDE has not yet been investigated in the facultative anaerobe Bacillus cereus. We examined the role of ResDE in the food-borne pathogen B. cereus F4430/73 by constructing resDE and resE mutants.

The acid tolerance response of Bacillus cereus ATCC14579 is dependent on culture pH, growth rate and intracellular pH.

The food pathogen Bacillus cereus is likely to encounter acidic environments (i) in food when organic acids are added for preservation purposes, and (ii) during the stomachal transit of aliments. In order to characterise the acid stress response of B. cereus ATCC14579, cells were grown in chemostat at different pH values (pH(o) from 9.

The production of Bacillus cereus enterotoxins is influenced by carbohydrate and growth rate.

Enterotoxin production is a key factor in Bacillus cereus food poisoning. Herein, the effect of the growth rate (mu) on B. cereus toxin production when grown on sucrose was studied and the Hemolytic BL enterotoxin (HBL) and nonhemolytic enterotoxin (Nhe) production by B.

Discovery of protein-protein binding disruptors using multi-component condensations small molecules.

A series of small molecule compounds interfering with the binding process of VEGF and NRP1 has been identified and further optimized. Full synthetic details as well as SAR are reported which demonstrate that expeditious MCC-based syntheses may lead to valuable molecules addressing challenging targets such as protein-protein interactions. Preliminary functional assay data confirm that these compounds may be further developed toward drug candidates.

Characterization of aerobic and anaerobic vegetative growth of the food-borne pathogen Bacillus cereus F4430/73 strain.

The Gram-positive bacterium Bacillus cereus is a facultative anaerobe that is still poorly characterized metabolically. In this study, the aerobic vegetative growth and anaerobic vegetative growth of the food-borne pathogen B. cereus F4430/73 strain were compared with those of the genome-sequenced ATCC14579 strain using glucose and glycerol as fermentative and nonfermentative carbon sources, respectively.

Activation of camptothecin derivatives by conjugation to triple helix-forming oligonucleotides.

Topoisomerase I (topo I) is a ubiquitous DNA-cleaving enzyme and an important therapeutic target in cancer chemotherapy. Camptothecins (CPTs) reversibly trap topo I in covalent complex with DNA but exhibit limited sequence preference. The utilization of conjugates such as triplex-forming oligonucleotides (TFOs) to target a medicinal agent (like CPT) to a specific genetic sequence and orientation within the DNA has been accomplished successfully.

Anaerobiosis and low specific growth rates enhance hemolysin BL production by Bacillus cereus F4430/73.

Bacillus cereus F4430/73 produced the highest levels of hemolysin BL (HBL) when grown under anaerobiosis in MOD medium. Anaerobic cells grown in a chemostat at low specific growth rate (0.1-0.

PCR performance of the highly thermostable proof-reading B-type DNA polymerase from Pyrococcus abyssi.

DNA polymerase from the archaeon Pyrococcus abyssi strain Orsay was expressed in Escherichia coli. The recombinant DNA polymerase (Pab) was purified to homogeneity by heat treatment followed by 5 steps of chromatography and characterized for PCR applications. Buffer optimization experiments indicated that Pab PCR performance and fidelity parameters were highest in the presence of 20 mM Tris-HCl, pH 9.

Acid tolerance response is low-pH and late-stationary growth phase inducible in Bacillus cereus TZ415.

The acid tolerance of foodborne pathogen Bacillus cereus TZ415 was examined. B. cereus was more tolerant to an acid challenge at pH 4.

Benzoindoloquinolines interact with DNA tetraplexes and inhibit telomerase.

Telomeric G-rich single-stranded DNA can adopt a G-tetraplex structure which has been shown to inhibit telomerase activity. We have examined benzoindoloquinolines derivatives for their ability to stabilize an intramolecular G-quadruplex. The increase in T(m) value of the G-quadruplex was associated with telomerase inhibition in vitro.