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Indian Journal of Microbiology Dec 2022Degradation of nitriles by mixed biofilms of nitrile-hydrolyzing bacteria 2 and gt 1 grown on basalt and carbon carriers, in a submerged packed-bed reactor was...
UNLABELLED
Degradation of nitriles by mixed biofilms of nitrile-hydrolyzing bacteria 2 and gt 1 grown on basalt and carbon carriers, in a submerged packed-bed reactor was studied. It was shown the formation of a massive mixed biofilm of 2 and gt 1 and the effective removal of nitriles and products of their degradation from the reaction medium. After the accumulation of carboxylic acid and some of the unprocessed substrate, the system adapts to 600-1000 h of biofilter operation, which is expressed in a decrease in the content of substrate and reaction products in the medium. The rate of acetonitrile and acrylonitrile utilization was 0.072-0.086 and 0.039-0.215 g/h, respectively, and acrylonitrile utilization with maximum rate was realized by a mixed biofilm on carbon fibers. Biofilms grown on mixed fibers in a "sandwich"-type reactor had the best characteristics for the transformation of aceto- and acrylonitrile (removal capacity of 99.6-99.9%, nitrile utilization rate of 0.080-0.095 g/h). Biofilms grown on basalt fiber with a diameter of 4-12 μm are also well suited for the degradation of acetonitrile (removal capacity of 100%, nitrile utilization rate of 0.086 g/h). The results of metagenomic analysis showed the resistance of 2 and gt 1 mixed biofilms against leaching from a biofilter and to competitive growth in an open system, indicating the advantages of biofilms over homogeneous biomass for wastewater treatment from nitrile compounds. Biofilms of two species of nitrile hydrolyzing bacteria on basalt and carbon fibers effectively purify water from nitriles in a submerged packed-bed reactor.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s12088-022-01030-z.
PubMed: 36458224
DOI: 10.1007/s12088-022-01030-z -
Organic Letters Jun 2023A highly enantioselective formal α-allylic alkylation of acrylonitrile is developed using 4-cyano-3-oxotetrahydrothiophene (c-THT) as a safe and easy-to-handle...
A highly enantioselective formal α-allylic alkylation of acrylonitrile is developed using 4-cyano-3-oxotetrahydrothiophene (c-THT) as a safe and easy-to-handle surrogate of acrylonitrile. This two-step process consists of an Ir(I)/(,olefin)-catalyzed branched-selective allylic alkylation using easily accessible branched -allylic alcohols as the allylic electrophile followed by retro-Dieckmann/retro-Michael fragmentation and is shown to be applicable for the enantioselective synthesis of α-allylic acrylates as well as α-allylic acrolein.
Topics: Allyl Compounds; Iridium; Acrylonitrile; Stereoisomerism; Catalysis; Alkylation
PubMed: 37311003
DOI: 10.1021/acs.orglett.3c01552 -
Cells Jan 2022(1) Background: Three-dimensional (3D) collagen I-based skin models are commonly used in drug development and substance testing but have major drawbacks such as...
(1) Background: Three-dimensional (3D) collagen I-based skin models are commonly used in drug development and substance testing but have major drawbacks such as batch-to-batch variations and ethical concerns. Recently, synthetic nanofibrous scaffolds created by electrospinning have received increasing interest as potential alternatives due to their morphological similarities to native collagen fibrils in size and orientation. The overall objective of this proof-of-concept study was to demonstrate the suitability of two synthetic polymers in creating electrospun scaffolds for 3D skin cell models. (2) Methods: Electrospun nanofiber mats were produced with (i) poly(acrylonitrile-co-methyl acrylate) (P(AN-MA)) and (ii) a blend of pullulan (Pul), poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) (Pul/PVA/PAA) and characterized by scanning electron microscopy (SEM) and diffuse reflectance infrared Fourier transform (DRIFT) spectra. Primary skin fibroblasts and keratinocytes were seeded onto the nanofiber mats and analyzed for phenotypic characteristics (phalloidin staining), viability (Presto Blue HS assay), proliferation (Ki-67 staining), distribution (H/E staining), responsiveness to biological stimuli (qPCR), and formation of skin-like structures (H/E staining). (3) Results: P(AN-MA) mats were more loosely packed than the Pul/PVA/PAA mats, concomitant with larger fiber diameter (340 nm ± 120 nm vs. 250 nm ± 120 nm, < 0.0001). After sterilization and exposure to cell culture media for 28 days, P(AN-MA) mats showed significant adsorption of fetal calf serum (FCS) from the media into the fibers (DRIFT spectra) and increased fiber diameter (590 nm ± 290 nm, < 0.0001). Skin fibroblasts were viable over time on both nanofiber mats, but suitable cell infiltration only occurred in the P(AN-MA) nanofiber mats. On P(AN-MA) mats, fibroblasts showed their characteristic spindle-like shape, produced a dermis-like structure, and responded well to TGFβ stimulation, with a significant increase in the mRNA expression of , , and (all < 0.05). Primary keratinocytes seeded on top of the dermis equivalent proliferated and formed a stratified epidermis-like structure. (4) Conclusion: P(AN-MA) and Pul/PVA/PAA are both biocompatible materials suitable for nanofiber mat production. P(AN-MA) mats hold greater potential as future 3D skin models due to enhanced cell compatibility (i.e., adsorption of FCS proteins), cell infiltration (i.e., increased pore size due to swelling behavior), and cell phenotype preservation. Thus, our proof-of-concept study shows an easy and robust process of producing electrospun scaffolds for 3D skin cell models made of P(AN-MA) nanofibers without the need for bioactive molecule attachments.
Topics: Acrylonitrile; Collagen; Glucans; Nanofibers; Tissue Engineering; Tissue Scaffolds
PubMed: 35159255
DOI: 10.3390/cells11030445 -
The Journal of Physical Chemistry. A Jun 2023Dissociative electron attachment (DEA) of acrylonitrile (CHCN) is investigated theoretically for two dominant anions CN and CN for the electron impact energy range of...
Dissociative electron attachment (DEA) of acrylonitrile (CHCN) is investigated theoretically for two dominant anions CN and CN for the electron impact energy range of 0-20 eV. The present low-energy DEA calculations are performed using the UK molecular R-matrix code using Quantemol-N. We have performed static exchange polarization (SEP) calculations by employing a cc-pVTZ basis set. Furthermore, present DEA cross-sections along with the appearance potential find good agreement with the three measurements reported many decades ago by Sugiura et al. [ , 14(4), 187-200], Tsuda et al. [ , 46 (8), 2273-2277] and Heni and Illenberger [ , 73 (1-2), 127-144]. The molecule acrylonitrile and the anions are important for understanding interstellar chemistry, and it is the maiden theoretical attempt to compute a DEA cross-section for this molecule.
PubMed: 37200052
DOI: 10.1021/acs.jpca.3c01712 -
Chemistry (Weinheim An Der Bergstrasse,... Sep 2022The direct hydrodimerization of acrylates and acrylonitrile offers a general streamlined access to industrially important intermediates to nylon 6,6. However, a...
The direct hydrodimerization of acrylates and acrylonitrile offers a general streamlined access to industrially important intermediates to nylon 6,6. However, a practical catalytic method for this process has thus far underdeveloped owing to the challenges in regioselectivity and environmental compatibility of applied reagents. Here, we report a cobalt-catalyzed tail-to-tail hydrodimerization of activated alkenes driven by a visible-light photoredox catalysis at ambient temperature, which is applicable to both adipates and adiponitrile synthesis from potentially renewable feedstocks. This protocol utilizes half equivalent of hantzsch ester as a recyclable two-electron and two-proton donor with the assistance of catalytic amount of base as a proton shuttle, and has been shown to be highly regioselective and efficient for hydrodimerizing various activated alkenes to 1,4-difunctionalized butane derivatives.
Topics: Acrylates; Acrylonitrile; Adipates; Alkenes; Butanes; Catalysis; Cobalt; Esters; Molecular Structure; Nitriles; Protons
PubMed: 35766153
DOI: 10.1002/chem.202201442 -
Critical Reviews in Toxicology Feb 2023Acrylonitrile (ACN) is a known rodent and possible human carcinogen. There have also been concerns as to it causing adverse reproductive health effects. Numerous... (Review)
Review
Acrylonitrile (ACN) is a known rodent and possible human carcinogen. There have also been concerns as to it causing adverse reproductive health effects. Numerous genotoxicity studies at the somatic level in a variety of test systems have demonstrated ACN's mutagenicity; its potential to induce mutations in germ cells has also been evaluated. ACN is metabolized to reactive intermediates capable of forming adducts with macromolecules including DNA, a necessary first step in establishing a direct mutagenic mode of action (MOA) for its carcinogenicity. The mutagenicity of ACN has been well demonstrated, however, numerous studies have found no evidence for the capacity of ACN to induce direct DNA lesions that initiate the mutagenic process. Although ACN and its oxidative metabolite (2-cyanoethylene oxide or CNEO) have been shown to bind with isolated DNA and associated proteins, usually under non-physiological conditions, studies in mammalian cells or have provided little specification as to an ACN-DNA reaction. Only one early study in rats has shown an ACN/CNEO DNA adduct in liver, a non-target tissue for its carcinogenicity in the rat. By contrast, numerous studies have shown that ACN can act indirectly to induce at least one DNA adduct by forming reactive oxygen species (ROS) but it has not been definitively shown that the resulting DNA damage is causative for the induction of mutations. Genotoxicity studies for ACN in somatic and germinal cells are summarized and critically reviewed. Significant data gaps have been identified for bringing together the massive data base that provides the basis of ACN's current genotoxicity profile.
Topics: Rats; Humans; Animals; Mutagens; DNA Adducts; Acrylonitrile; Mutagenicity Tests; DNA Damage; DNA; Mammals
PubMed: 37278976
DOI: 10.1080/10408444.2023.2179912 -
Journal of Environmental Management Jul 2024The newly discovered ClO• and BrO• contribute to pollutant degradation in advanced oxidation processes, while acrylamide (AM) and acrylonitrile (ACN) are always the...
The newly discovered ClO• and BrO• contribute to pollutant degradation in advanced oxidation processes, while acrylamide (AM) and acrylonitrile (ACN) are always the focus of scientists concerned due to their continuous production and highly toxic effects. Moreover, various particles with a graphene-like structure are the companions of AM/ACN in dry/wet sedimentation or aqueous phase existence, which play an important role in heterogeneous oxidation. Thus, this work focuses on the reaction mechanism and environmental effect of AM/ACN with ClO•/BrO•/HO• in the water environment under the influence of graphene (GP). The results show that although the reactivity sequence of AM and ACN takes the order of with HO• > with BrO• > with ClO•, the easiest channel always occurs at the same C-position of the two reactants. The reaction rate constants (k) of AM with three radicals are 2 times larger than that with ACN, and amide groups have a better ability to activate CC bonds than cyanide groups. The existence of GP can accelerate the target reaction, and the k increased by 9-13 orders of magnitude. The toxicity assessment results show that the toxic effect of most products is lower than that of parent compounds, but the environmental risk of products from ClO•/BrO•-adducts is higher than those from HO•-adducts. The oxidative degradation process based on ClO• and BrO• deserves special attention, and the catalytic effect of GP and its derivatives on the oxidation process is non-negligible.
Topics: Acrylonitrile; Acrylamide; Graphite; Oxidation-Reduction; Water Pollutants, Chemical; Models, Theoretical; Hydroxyl Radical
PubMed: 38878582
DOI: 10.1016/j.jenvman.2024.121473 -
Journal of Applied Microbiology Mar 2022The efficiency of acrylamide production was examined with immobilized cells of Rhodococcus rhodochrous (RS-6) containing NHase.
AIMS
The efficiency of acrylamide production was examined with immobilized cells of Rhodococcus rhodochrous (RS-6) containing NHase.
METHODS AND RESULTS
Different entrapment matrices such as agar, alginate and polyacrylamide were used. Various immobilization parameters like agar concentration, cell concentration and reaction conditions affecting the bioconversion process using suitable matrices were determined. The cells immobilized with agar matrix were found to be most effective for acrylonitrile conversion. The bioconversion was more efficient in beads prepared with 2% agar and 5% (v/v) cell concentration. The entire conversion of acrylonitrile to acrylamide with agar entrapped cells was achieved in 120 min at 15°C. The agar entrapped R. rhodochrous (RS-6) cells exhibited 8% (w/v) tolerance to acrylonitrile and 35% tolerance to acrylamide. The immobilized cells also retained 50% of its conversion ability up to seven cycles. The laboratory-scale (1 L) production resulted in 466 g L accumulation of acrylamide in 16 h.
CONCLUSIONS
The cells immobilized in agar showed better stability and biocatalytic properties and increased reusability potential.
SIGNIFICANCE AND IMPACT OF THE STUDY
The agar-immobilized Rhodococcus rhodochrous (RS-6) cells showed enhanced tolerance for both the substrate and product and is economical for the large-scale production of acrylamide.
Topics: Acrylamide; Acrylonitrile; Agar; Cells, Immobilized; Rhodococcus
PubMed: 34564923
DOI: 10.1111/jam.15303 -
Organic & Biomolecular Chemistry Oct 2022An iodine-mediated radical cyclization of 1,6-enynones with sulphonyl hydrazides using -butyl hydroperoxide (TBHP) as the oxidant has been developed for the synthesis of...
An iodine-mediated radical cyclization of 1,6-enynones with sulphonyl hydrazides using -butyl hydroperoxide (TBHP) as the oxidant has been developed for the synthesis of iodo-sulphonylated-succinimide derivatives. The notable advantages of the developed method are metal-free conditions, broad functional group tolerance, column chromatography-free purification, high stereoselectivity ( isomer), shorter reaction times, and the cascade construction of three new bonds (C-S, C-I, and C-C). The synthetic application of the iodo-functionality has been extended to the Heck coupling reaction with acrylonitrile and to the Suzuki coupling reaction with benzene boronic acid.
Topics: tert-Butylhydroperoxide; Succinimides; Acrylonitrile; Benzene; Molecular Structure; Iodine; Metals; Oxidants; Boronic Acids
PubMed: 36178240
DOI: 10.1039/d2ob01277d -
Journal of Environmental Management Nov 2023E-waste comprising plastics causes serious ecological problems due to low degradability, but it is capable of producing a high amount of energy by thermochemical...
E-waste comprising plastics causes serious ecological problems due to low degradability, but it is capable of producing a high amount of energy by thermochemical conversion. Therefore, the current study focuses on generating clean syngas through plasma gasification of acrylonitrile butadiene styrene (ABS) based computer keyboard plastic waste (CKPW) using CO as a gasifying agent. The effect of feed rate, gas flow rate and plasma power on the syngas composition was studied. In addition, a comprehensive investigation of energy, exergy, economic and environmental analyses along with characterization of the obtained products was conducted to evaluate the performance of the system. Based on the experimental results, the optimum process parameters for producing syngas possessing a higher calorific value (15.80 MJ/m) with a higher percentage of H (30.16 vol%) and CO (46.09 vol%) were estimated. The optimum feed flow rates of solid fuel and CO gas and torch power were estimated as 40 g/10 min, 0.5 lpm and 1.12 kW, respectively. At these conditions, the system could achieve a maximum energy and exergy efficiency of 46.06% and 44.34%, respectively, while the levelized cost of syngas (LCOS) was estimated as 25.45 INR/kWh, including the social cost. Likewise, the lower values of the estimated global warming potential (370.19 gCO/h) illustrate the better sustainability of the process. The obtained oil with the estimated LHV of 39.13 MJ/kg could be an alternative fuel for diesel and the residue containing a higher proportion of TiO has medical applications upon further enrichment. The reaction mechanism of ABS conversion to syngas under plasma gasification conditions is proposed.
Topics: Refuse Disposal; Gases; Carbon Dioxide; Acrylonitrile; Butadienes; Plastics; Styrenes
PubMed: 37517092
DOI: 10.1016/j.jenvman.2023.118655