Search results for "Bacterial growth"
showing 10 items of 76 documents
Ús del programa Berkeley Madonna per al desenvolupament de models en la docència en Enginyeria Química
2014
La modelització és un procediment metodològic fonamental per a resoldre problemes en enginyeria. Consisteix en representar el problema d'una forma adequada, de manera que s'aconsegueixi una substitució del sistema real per altre més adequat que permeti el tractament formal. És per això que el seu aprenentatge és molt important en l'estudi de l'Enginyeria Química i s'emmarca en les competències contingudes en el mòdul de tecnologia específica, Química Industrial (Ordre CIN/351/2009). En el present treball, es proposa l'ús del programa informàtic Berkeley Madonna per a l'estudi de la modelització del creixement bacterià sobre un o diversos substrats en l'assignatura Processos Biotecnològics d…
Comparison of the antibacterial effect of uroepithelial cells from healthy donors and children with asymptomatic bacteriuria
1985
Bacterial attachment to uroepithelial cells (UEC) and the effect of UEC on bacterial growth was investigated in 15 healthy persons and 12 patients suffering from asymptomatic bacteriuria (ABU) with recurrent urinary tract infections (UTI). Desquamated UEC and mannose-resistant Escherichia coli were co-cultivated for up to 90 min. While no difference in bacterial adherence was observed between healthy controls and patients, 33.4% of the bacteria attached to normal UEC were found to be dead under microscopic evaluation (acridine orange staining), whereas no killing effect could be observed in patients' UEC 5 min after the onset of incubation. This phenomenon was confirmed by investigating the…
Fumigation of Brazil nuts with allyl isothiocyanate to inhibit the growth of Aspergillus parasiticus and aflatoxin production
2017
Abstract BACKGROUND Brazil produces approximately 40 000 tons of Brazil nuts annually, which is commonly contaminated with fungi and mycotoxins. Gaseous allyl isothiocyanate (AITC) was used to inhibit the growth of Aspergillus parasiticus and its production of aflatoxins (AFs) in Brazil nuts. RESULTS Nuts were inoculated with 104 spores g−1 of A. parasiticus and placed in airtight glass jars with controlled relative humidity (RH = 95 or 85%). Samples were treated with 0, 0.5, 1.0 or 2.5 µL L−1 of gaseous AITC and analyzed after 30 days to determine the fungal population and AFs content. Samples were also submitted to sensory evaluation. AITC at 2.5 µL L−1 could completely inhibit the fungal…
Rapid antibiotic susceptibility testing on blood cultures using MALDI-TOF MS
2018
International audience; Antibiotic resistance is a major public health problem requiring the early optimization of antibiotic prescriptions. Matrix-Assisted Laser Desorption Ionization-Time Of Flight Mass Spectrometry (MALDI-TOF MS) has been shown to accurately identify bacteria from positive blood culture. Here, we developed a rapid detection of Escherichia coli resistance to amoxicillin (AMX) and cefotaxime (CTX) from positive blood culture based on MALDI-TOF MS. Potential sparing of broad-spectrum antibiotics was also evaluated. We tested 103 E. coli-positive blood cultures. Blood cultures were subculture 1-hour in antibiotic-free rich liquid media before further incubation with and with…
Towards a microbial thermoelectric cell.
2013
Microbial growth is an exothermic process. Biotechnological industries produce large amounts of heat, usually considered an undesirable by-product. In this work, we report the construction and characterization of the first microbial thermoelectric cell (MTC), in which the metabolic heat produced by a thermally insulated microbial culture is partially converted into electricity through a thermoelectric device optimized for low ΔT values. A temperature of 41°C and net electric voltage of around 250–600 mV was achieved with 1.7 L baker’s yeast culture. This is the first time microbial metabolic energy has been converted into electricity with an ad hoc thermoelectric device. These results might…
Biologically labile photoproducts from riverine non-labile dissolved organic carbon in the coastal waters
2015
In order to assess the production of biologically labile photoproducts (BLPs) from non-labile riverine dissolved organic carbon (DOC), we collected water samples from ten major rivers, removed labile DOC and mixed the residual non-labile DOC with artificial seawater for microbial and photochemical experiments. Bacteria grew on non-labile DOC with a growth efficiency of 11.5% (mean; range from 3.6 to 15.3%). Simulated solar radiation transformed a part of non-labile DOC into BLPs, which stimulated bacterial respiration and production, but did not change bacterial growth efficiency (BGE) compared to the non-irradiated dark controls. In the irradiated water samples, the amount of BLPs stimulat…
Synthetic small molecules as anti-biofilm agents in the struggle against antibiotic resistance
2018
Abstract Biofilm formation significantly contributes to microbial survival in hostile environments and it is currently considered a key virulence factor for pathogens responsible for serious chronic infections. In the last decade many efforts have been made to identify new agents able to modulate bacterial biofilm life cycle, and many compounds have shown interesting activities in inhibiting biofilm formation or in dispersing pre-formed biofilms. However, only a few of these compounds were tested using in vivo models for their clinical significance. Contrary to conventional antibiotics, most of the anti-biofilm compounds act as anti-virulence agents as they do not affect bacterial growth. I…
Effects of Ultrasound-Assisted Extraction and Solvent on the Phenolic Profile, Bacterial Growth, and Anti-Inflammatory/Antioxidant Activities of Medi…
2020
© 2020 by the authors.
Marine organisms as source of bioactive molecules applied in restoration projects
2015
Abstract In recent decades research in the conservation and restoration field has provided sustainable alternatives to traditional procedures for cleaning or controlling the microbial colonization of works of art. In the present study, for the first time novel bioactive molecules extracted from marine invertebrate organisms (Anthozoa) were tested instead of chemical compounds for removing protein layers or as a biocide for controlling fungal or bacterial colonization. In particular, Bioactive Molecules with Protease activity (BMP), acting in a temperature range of 4- 30°C, were tested for the hydrolysis of protein layers on laboratory specimens. The cleaning protocol provides a selective pr…
Application of propidium monoazide-qPCR to evaluate the ultrasonic inactivation of Escherichia coli O157:H7 in fresh-cut vegetable wash water.
2012
The efficacy of sanitizing technologies in produce or in vegetable wash water is generally evaluated by plate count in selective media. This procedure is time consuming and can lead to misinterpretations because environmental conditions and sanitizing processes may affect bacterial growth or culturable capability. Thus, the aim of this study was to determine the applicability of a propidium monoazide real-time PCR (PMA-qPCR) method to monitor the inactivation by ultrasound treatment of foodborne bacteria in fresh-cut vegetable wash water. To this aim, lettuce wash water was artificially inoculated with Escherichia coli O157:H7 (10⁶ CFU/mL) and treated by means of a continuous ultrasonic irr…