1,843 research outputs found
BIODEGRADING BIOFILMS ON INNOVATIVE BIOPOLYMERIC SUPPORTS
No full textABSTRACT
Water bioremediation is traditionally carried out using ‘ free ’ bacterial cells, however, in recent years, utilization of ‘immobilized’ bacterial cells on adsorbing matrices, has gained attention as a promising technique due to biotechnological and economic benefits (Sonawane et al., 2022). Bacterial biofilms show greater resilience, survival and degradative activity for longer periods than cells in the planktonic state (Alessandrello et al., 2017); moreover immobilization reduces bioremediation costs, eliminate cell dilution and dispersion in the environment (Bayat et al., 2015). Possible applications of immobilized biodegrading bacteria require long-term survival and maintenance of biodegrading performances. In this study, combinations of polylactic acid (PLA) and polycaprolactone (PCL) biodegradable membrane carriers hosting selected HC-biodegrading marine and soil bacterial biofilms were tested after different incubation periods and their survival was monitored over time, simulating storage effects.
Results
Soil hydrocarbon (HC) degrading actinobacteria and marine hydrocarbonoclastic bacteria were immobilized on absorbent biodegradable biopolymeric polylactic acid (PLA) and polycaprolactone (PCL) membranes (Scaffaro et al., 2017, Catania et al., 2020). Combinations of HC-degrading bacteria and biopolymers were obtained and tested on hexadecane. After 5, 10 and 15 days incubation, the capacity of adhesion and proliferation of bacterial cells into the biopolymers was verified by scanning electron microscopy (SEM); PLA and PCL nanofibers were covered by bacterial cells already after 5 days incubation; Total biomass (estimated as total dsDNA) extracted from biofilms confirmed the colonization up to 15 days incubation. Viable plate counts showed that survival of the bacterial strains was high for the entire experimental period. HC biodegradation ability of biofilms was assessed by high resolution GC-FID analysis, after extraction of total residual HC from the liquid medium and from biopolymers, incubated for different times. HC degradation was observed during the whole experiment and resulted higher in respect to the free-living bacterial cultures. Survival tests of bacterial biofilms adsorbed on biopolymers for up to 30 days are in progress.
Conclusions
The synergistic exploitation of the high absorbent capacity of biodegradable nanofiber membranes and the catabolic capacity of HC-degrading bacteria allow to obtain biodegrading biofilms endowed with higher removal capacity of hexadecane in respect to free-living bacterial cultures. The survival and biodegrading performances of the biofilm-carrier systems is maintained after 30 days incubation. A green, low-cost, biodegradable and reusable bioremediation tool is obtained without negative impacts on the environment.
References:
Alessandrello, M. J., Tomás, M. S. J., Raimondo, E. E., Vullo, D. L. and Ferrero, M. A. “Petroleum oil removal by immobilized bacterial cells on polyurethane foam under different temperature conditions”, Marine pollution bulletin, 122(1-2), 156-160 (2017).
Bayat, Z., Hassanshahian, M. and Cappello, S. “Immobilization of microbes for bioremediation of crude oil polluted environments: a mini review”, The open microbiology journal, 9, 48 (2015).
Catania, V., Lopresti, F., Cappello, S., Scaffaro, R. and Quatrini, P. “Innovative, ecofriendly biosorbent-biodegrading biofilms for bioremediation of oil-contaminated water”, New Biotechnology, 58, 25-31 (2020).
Scaffaro, R., Lopresti, F., Catania, V., Santisi, S., Cappello, S., Botta, L. and Quatrini, P. “Polycaprolactone-based scaffold for oil-selective sorption and improvement of bacteria activity for bioremediation of polluted water: Porous PCL system obtained by leaching melt mixed PCL/PEG/NaCl composites: Oil uptake performance and bioremediation efficiency”, European Polymer Journal, 91, 260-273 (2017).
Sonawane, J. M., Rai, A. K., Sharma, M., Tripathi, M. and Prasad, R. “Microbial biofilms: Recent advances and progress in environmental bioremediation”, Science of The Total Environment, 153843 (2022).
Catania, V., Santisi, S., Signa, G., Vizzini, S., Mazzola, A., Cappello, S., ... & Quatrini, P. (2015). Intrinsic bioremediation potential of a chronically polluted marine coastal area. Marine Pollution Bulletin, 99(1-2), 138-149.
Lo Piccolo, L., De Pasquale, C., Fodale, R., Puglia, A. M., & Quatrini, P. (2011). Involvement of an alkane hydroxylase system of Gordonia sp. strain SoCg in degradation of solid n-alkanes. Applied and environmental microbiology, 77(4), 1204-1213.
Quatrini, P., Scaglione, G., De Pasquale, C., Riela, S., & Puglia, A. M. (2008). Isolation of Gram‐positive n‐alkane degraders from a hydrocarbon‐contaminated Mediterranean shoreline. Journal of applied microbiology, 104(1), 251-259
Schermi. Immagini, corpi, condivisioni
No full textIn this book the author investigates the digital image proliferation of our times from an interdisciplinary point of view. Starting from the Visual Culture theoretical frame, Valentina Mignano explores the ways in which we interact with the screen, dealing with the "screen experience" in the first years of the network societ
Synthesis of colloidal Ag nanoparticles with citrate based ionic liquids as reducing and capping agents
No full textThe aim of this paper was to synthesize ionic liquids (ILs) that can play the double role of capping and reducing agents for the fabrication of silver nanoparticles (Ag NPs). A new simple method of synthesis of some ILs that have as counter ion citrate and their application in silver and gold nanoparticles preparation will be presented. AgNPs with a medium diameter of 8 nm, stable for more than 7 months in aqueous solution at room temperature were obtained with trioctyl ammonium citrate (TOM3Citr) at 1:7 molar ratio (AgNO3:TOM3Citr). The stability of these nanoparticles was investigated with UV–vis spectroscopy and the shape and diameter by TEM characterization. The effect of synthesis conditions was also investigated (molar ratio, temperature, pH) as well as the possibility to use the same IL to prepare Au NPs
Non-linear optical response by functionalized gold nanospheres: identifying design principles to maximize the molecular photo-release
No full textInnovative ready to use carrier-bacteria devices for bioremediation of oil contaminated water
No full textBioremediation, that uses microorganisms to remove environmental pollutants, is the best way of restoring
the environment due to its low cost and sustainability. Immobilization of microorganisms capable of
degrading specific contaminants significantly promotes bioremediation processes. An innovative ready to
use bioremediation system to clean up oil-contaminated water was developed immobilizing highly
performant marine and soil HC degrading bacteria, on biodegradable oil-absorbing carriers. Two soil
Actinobacteria (Gordonia sp. SoCg, Nocardia sp. SoB) and two marine Gammaproteobacteria (Alcanivorax
sp. SK2, Oleibacter sp.5), were immobilized on biopolymeric membranes prepared by electrospinning
(polylactic acid, PLA and polycaprolactone, PCL). These carriers are characterized by high uptake capacity,
oil retention, buoyancy, durability, reusability and recoverability of the oil absorbed. The morphology of the
carriers and microbial adhesion and proliferation were evaluated using scanning electron microscopy (SEM).
A high capacity of adhesion and proliferation of bacterial cells was observed on membranes after 5 days. The
bioremediation efficiency of the carrier-bacteria systems was tested on crude oil by GC-FID analysis and
compared whit planktonic cells. The bacterial immobilization on PLA and PCL membranes was a
promoting factor for biodegradation, increasing hydrocarbon removal up to 20%, in respect to planktonic
cells. Biofilm-mediated bioremediation is a versatile tool to be developed for in situ and ex situ
bioremediation of aquatic systems. Several applications can be designed to exploit both the high oil uptake
capacity of the carriers, and the biodegradation potential of autochtonous microrganisms and/or of selected
microorganisms that are immobilized on the carriers before exposure to the contaminated site
Passion fruit-like nano-architectures as biodegradable inorganic theranostics to prevent accumulation in excretory system organs
No full textENTREPRENEURSHIP AND FEMALE ENTREPRENEURSHIP IN MARAMURES COUNTY
No full textInitiating and developing a business involves a considerable risk and a sustained effort in order to defeat the inertia against what is new. The person initiating a business, assuming the responsibility and risk of its development and benefiting from theentrepreneurship, female entrepreneurship, profit, businesses
Endogenously-activated ultrasmall-in-nano therapeutics: Assessment on 3d head and neck squamous cell carcinomas
No full textNegative or positive HPV-associated Head and Neck Squamous Cell Carcinomas (HNSCCs) are high recurrence neoplasms usually resulting in a poor prognosis, mainly due to metastasis formation. Despite the low overall patient survival rate and the severe side effects, the treatment of choice is still cisplatin-based chemotherapy. Here, we report a straightforward protocol for the production of high throughput 3D models of negative or positive HPV-associated HNSCCs, together with their employment in the therapeutic evaluation of gold ultrasmall-in-nano architectures comprising an endogenously-activatable cisplatin prodrug. Beyond enhancing the biosafety of cisplatin, our approach paves the way for the establishment of synergistic co-therapies for HNSCCs based on excretable noble metals. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Neuromuscular Junction Dismantling in Amyotrophic Lateral Sclerosis
No full textNeuromuscular junction assembly and plasticity during embryonic, postnatal, and adult life are tightly regulated by the continuous cross-talk among motor nerve endings, muscle fibers, and glial cells. Altered communications among these components is thought to be responsible for the physiological age-related changes at this synapse and possibly for its destruction in pathological states. Neuromuscular junction dismantling plays a crucial role in the onset of Amyotrophic Lateral Sclerosis (ALS). ALS is characterized by the degeneration and death of motor neurons leading to skeletal muscle denervation, atrophy and, most often, death of the patient within five years from diagnosis. ALS is a non-cell autonomous disease as, besides motor neuron degeneration, glial cells, and possibly muscle fibers, play a role in its onset and progression. Here, we will review the recent literature regarding the mechanisms leading to neuromuscular junction disassembly and muscle denervation focusing on the role of the three players of this peripheral tripartite synapse
The use of initial tocolysis and maintenance tocolysis in preterm birth : guideline-based approach or off-label use - a survey on the current application in Switzerland
No full textAuthor Valentina Schedl, BscMasterarbeit Universität Linz 202
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