scholarly journals Biodegradation of 5-(Hydroxymethyl)-furfural and Furan Derivatives

Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1283 ◽  
Author(s):  
María Isabel Igeño ◽  
Rubén Sánchez-Clemente ◽  
Ana G. Población ◽  
M. Isabel Guijo ◽  
Faustino Merchán ◽  
...  
Keyword(s):  
Furan Ring ◽  
Degradation Products ◽  
Chemical Compounds ◽  
Aldehyde Group ◽  
Bacterial Strains ◽  
Fermentation Inhibitors ◽  
Furan Derivatives ◽  
Hydroxymethyl Furfural ◽  
Common Thread ◽  
Lignocellulose Hydrolysates

Furfural and 5-hydroxymethylfurfural (HMF) are degradation products of lignocellulose during pretreatment operations. Furfural compounds are a group of chemical compounds whose common thread is an aldehyde group attached to a furan ring, and they constitute a problem for the development of second-generation biofuels because they act as fermentation inhibitors of the lignocellulose hydrolysates. Up to date, very few bacteria have been described to be able to eliminate them. The objective of this work was to isolate and characterize bacterial strains able to use, as the sole carbon source, 5-(hydroxymethyl)-furfural (HMF) and furan derivatives.

scholarly journals Identification of the major fermentation inhibitors of recombinant 2G yeasts in diverse lignocellulose hydrolysates

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gert Vanmarcke ◽  
Mekonnen M. Demeke ◽  
Maria R. Foulquié-Moreno ◽  
Johan M. Thevelein
Keyword(s):  
Second Generation ◽  
Industrial Process ◽  
Superior Performance ◽  
Fermentation Inhibitors ◽  
Inhibitor Tolerance ◽  
Xylose Consumption ◽  
Process Economics ◽  
Partial Inhibition ◽  
Second Generation Bioethanol ◽  
Lignocellulose Hydrolysates

Abstract Background Presence of inhibitory chemicals in lignocellulose hydrolysates is a major hurdle for production of second-generation bioethanol. Especially cheaper pre-treatment methods that ensure an economical viable production process generate high levels of these inhibitory chemicals. The effect of several of these inhibitors has been extensively studied with non-xylose-fermenting laboratory strains, in synthetic media, and usually as single inhibitors, or with inhibitor concentrations much higher than those found in lignocellulose hydrolysates. However, the relevance of individual inhibitors in inhibitor-rich lignocellulose hydrolysates has remained unclear. Results The relative importance for inhibition of ethanol fermentation by two industrial second-generation yeast strains in five lignocellulose hydrolysates, from bagasse, corn cobs and spruce, has now been investigated by spiking higher concentrations of each compound in a concentration range relevant for industrial hydrolysates. The strongest inhibition was observed with industrially relevant concentrations of furfural causing partial inhibition of both D-glucose and D-xylose consumption. Addition of 3 or 6 g/L furfural strongly reduced the ethanol titer obtained with strain MD4 in all hydrolysates evaluated, in a range of 34 to 51% and of 77 to 86%, respectively. This was followed by 5-hydroxymethylfurfural, acetic acid and formic acid, for which in general, industrially relevant concentrations caused partial inhibition of D-xylose fermentation. On the other hand, spiking with levulinic acid, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid or vanillin caused little inhibition compared to unspiked hydrolysate. The further evolved MD4 strain generally showed superior performance compared to the previously developed strain GSE16-T18. Conclusion The results highlight the importance of individual inhibitor evaluation in a medium containing a genuine mix of inhibitors as well as the ethanol that is produced by the fermentation. They also highlight the potential of increasing yeast inhibitor tolerance for improving industrial process economics.

scholarly journals Role of Elicitors in Inducing Resistance in Plants against Pathogen Infection: A Review

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Meenakshi Thakur ◽  
Baldev Singh Sohal
Keyword(s):  
Disease Control ◽  
Degradation Products ◽  
Chemical Compounds ◽  
Plant Diseases ◽  
Natural Phenomenon ◽  
Agricultural Practice ◽  
Plant Invaders ◽  
Acid Methyl ◽  
Causative Agents

Disease control is largely based on the use of fungicides, bactericides, and insecticides—chemical compounds toxic to plant invaders, causative agents, or vectors of plant diseases. However, the hazardous effect of these chemicals or their degradation products on the environment and human health strongly necessitates the search for new, harmless means of disease control. There must be some natural phenomenon of induced resistance to protect plants from disease. Elicitors are compounds, which activate chemical defense in plants. Various biosynthetic pathways are activated in treated plants depending on the compound used. Commonly tested chemical elicitors are salicylic acid, methyl salicylate, benzothiadiazole, benzoic acid, chitosan, and so forth which affect production of phenolic compounds and activation of various defense-related enzymes in plants. Their introduction into agricultural practice could minimize the scope of chemical control, thus contributing to the development of sustainable agriculture. This paper chiefly highlights the uses of elicitors aiming to draw sufficient attention of researchers to the frontier research needed in this context.

scholarly journals Biodegradation of two organic UV-Filters by single bacteria strains

2021 ◽  
Author(s):  
Florentina Laura Chiriac ◽  
Catalina Stoica ◽  
Iuiana Paun ◽  
Florinela Pirvu ◽  
Toma Galaon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Emerging Contaminants ◽  
Degradation Products ◽  
Aquatic Organisms ◽  
Uv Filters ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Biodegradation Process ◽  
Salmonella Thyphimurium ◽  
Organic Uv Filters

Abstract Organic UV-filters, including 4-hydroxybenzophenone (4-HBP) and 2,4-dihydroxybenzophenone (BP-1), are persistent emerging contaminants whose presence in the environment poses a threat to aquatic organisms due to their endocrine disruptor’s properties. For this reason, finding suitable technological processes for their safety and efficient removal from the environment represent a priority for the scientific community. To the author’s knowledge, until now, there are no studies reporting the biodegradation of 4-HBP and BP-1 by a single bacteria strain. In this paper, there were tested the 4-HBP and BP-1 biodegradation potential of two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Salmonella typhimurium and Serratia rubidae). The 4-HPB biodegradation process was observed only in the presence of Gram-negative bacterial strains. Thus, the biodegradation rates of 4-HBP reached up to 12.7% after 24h of incubation in presence of Salmonella thyphimurium and up to 24.0% after 24h of incubation with Serratia rubidae. Staphylococcus aureus was able to biodegrade 26.7% of BP-1, while Salmonella thiphymurium was able to biodegrade 14.7% of BP-1 after 24h of incubation. Their biodegradation products generated during the 4-HBP biodegradation process by Serratia rubidae were analyzed through LC-MS/MS analysis. The (bio)degradation products were benzophenone and a multi-hydroxylated derivative of 4-HBP and the degradation pathways were proposed. The data obtained in this study gave important information regarding the 4-HBP and BP-1 potential biodegradation by single bacterial strains.

Characterization of enzyme-resistant xylooligosaccharides extracted from hardwood chips by pre-hydrolysis and further depolymerized by enzymatic treatment

Holzforschung ◽  
2020 ◽  
Vol 74 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Valentin Guigon ◽  
Christine Chirat ◽  
Laure Fort ◽  
Dominique Lachenal
Keyword(s):  
Degradation Products ◽  
Laser Desorption ◽  
Enzymatic Treatment ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Hydroxymethyl Furfural ◽  
Desorption Ionization ◽  
Matrix Assisted Laser ◽  
Matrix Assisted Laser Desorption

AbstractXylose-rich solutions were produced by applying water pre-hydrolysis on mixed hardwood chips followed by an enzymatic treatment of the filtrate. The liquid phase obtained after water pre-hydrolysis contained xylose and xylans as the major components as well as other hemicelluloses and monosaccharides, acetic acid, and some degradation products of the monosaccharides [furfural, 5-(hydroxymethyl)furfural]. This hydrolysate underwent a two-step enzymatic treatment successively with endo-1,4-β-xylanase and 1,4-β-xylosidase to specifically depolymerize xylans into xylose without producing monosaccharides from the other oligosaccharides. After this treatment, 20.5% of the xylose units remained as oligomers. Matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) mass spectrometry was applied after each step of the treatment to approach the structure of hemicellulose oligomers, to follow their depolymerization and to understand the reason for the resistance of some of them to enzymatic hydrolysis. It was found that highly acetylated xylans and/or xylans still substituted with 4-O-methylglucuronic groups were particularly resistant to this treatment.

scholarly journals Qualifying the T-2 Toxin-Degrading Properties of Seven Microbes with Zebrafish Embryo Microinjection Method

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 460
Author(s):  
Edina Garai ◽  
Anita Risa ◽  
Emese Varga ◽  
Mátyás Cserháti ◽  
Balázs Kriszt ◽  
...  
Keyword(s):  
Sublethal Effects ◽  
Degradation Products ◽  
Rhodococcus Erythropolis ◽  
Bacterial Strains ◽  
Cell Stage ◽  
Bacterial Metabolites ◽  
Mycotoxin Degradation

T-2 mycotoxin degradation and detoxification efficiency of seven bacterial strains were investigated with zebrafish microinjection method in three steps ((1) determination of mycotoxin toxicity baseline, (2) examination of bacterial metabolites toxicity, (3) identification of degradation products toxicity). Toxicity of T-2 was used as a baseline of toxic effects, bacterial metabolites of strains as control of bacterial toxicity and degradation products of toxin as control of biodegradation were injected into one-cell stage embryos in the same experiment. The results of in vivo tests were checked and supplemented with UHPLC-MS/MS measurement of T-2 concentration of samples. Results showed that the Rhodococcus erythropolis NI1 strain was the only one of the seven tested (R. gordoniae AK38, R. ruber N361, R. coprophilus N774, R. rhodochrous NI2, R. globerulus N58, Gordonia paraffinivorans NZS14), which was appropriated to criteria all aspects (bacterial and degradation metabolites of strains caused lower toxicity effects than T-2, and strains were able to degrade T-2 mycotoxin). Bacterial and degradation metabolites of the NI1 strain caused slight lethal and sublethal effects on zebrafish embryos at 72- and 120-h postinjection. Results demonstrated that the three-step zebrafish microinjection method is well-suited to the determination and classification of different bacterial strains by their mycotoxin degradation and detoxification efficiency.

scholarly journals Identification of biodegradation products of biphenyl and 2,3-dihydroxybiphenyl (2,3-DHB)

2014 ◽  
Vol 7 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Slavomíra Murínová ◽  
Katarína Dercová ◽  
Peter Tarábek ◽  
Peter Tölgyessy
Keyword(s):  
Degradation Products ◽  
Pseudomonas Stutzeri ◽  
Dienoic Acid ◽  
Transformation Rate ◽  
Contaminated Sediment ◽  
Bacterial Strains ◽  
Fission Rate ◽  
Transformation Pathway ◽  
Biphenyl Degradation

Abstract We investigated the degradation of biphenyl and identified main degradation products. Biphenyl and 2,3-dihydroxybiphenyl (2,3-DHB) was added to cultivation media to identify whole collection of degradation products of four bacterial strains isolated from long-term PCB contaminated soil (Alcaligenes xylosoxidans and Pseudomonas stutzeri) and long-term PCB contaminated sediment (Ochrobactrum anthropi and Pseudomonas veronii). Cultivation flasks were processed in different time after inoculation to determine biphenyl fission rate. Alcaligenes xylosoxidans was revealed as the most appropriate strain for bioremediation process with the highest biphenyl transformation rate. Biphenyl degradation led to the formation of benzoic acid. However, as the presence of 2-hydroxy-6-oxo-6-phenylhex-2,4-dienoic acid (HOPDA) was not confirmed, the transformation pathway common for many other bacteria is probably modified.

scholarly journals Development of a Saccharomyces cerevisiae Strain with Enhanced Resistance to Phenolic Fermentation Inhibitors in Lignocellulose Hydrolysates by Heterologous Expression of Laccase

2001 ◽  
Vol 67 (3) ◽  
pp. 1163-1170 ◽  
Author(s):  
Simona Larsson ◽  
Pierre Cassland ◽  
Leif J. Jönsson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Mass ◽  
Raw Materials ◽  
White Rot ◽  
White Rot Fungus ◽  
Fermentation Inhibitors ◽  
Factors Affecting ◽  
Ethanol Formation ◽  
Active Laccase ◽  
Lignocellulose Hydrolysates

ABSTRACT To improve production of fuel ethanol from renewable raw materials, laccase from the white rot fungus Trametes versicolor was expressed under control of the PGK1 promoter inSaccharomyces cerevisiae to increase its resistance to phenolic inhibitors in lignocellulose hydrolysates. It was found that the laccase activity could be enhanced twofold by simultaneous overexpression of the homologous t-SNARE Sso2p. The factors affecting the level of active laccase obtained, besides the cultivation temperature, included pH and aeration. Laccase-expressing and Sso2p-overexpressing S. cerevisiae was cultivated in the presence of coniferyl aldehyde to examine resistance to lignocellulose-derived phenolic fermentation inhibitors. The laccase-producing transformant had the ability to convert coniferyl aldehyde at a faster rate than a control transformant not expressing laccase, which enabled faster growth and ethanol formation. The laccase-producing transformant was also able to ferment a dilute acid spruce hydrolysate at a faster rate than the control transformant. A decrease in the content of low-molecular-mass aromatic compounds, accompanied by an increase in the content of high-molecular-mass compounds, was observed during fermentation with the laccase-expressing strain, illustrating that laccase was active even at the very low levels of oxygen supplied. Our results demonstrate the importance of phenolic compounds as fermentation inhibitors and the advantage of using laccase-expressing yeast strains for producing ethanol from lignocellulose.

scholarly journals Assessment and antimricrobial modulating activity of the extract of Baccharis cinerea DC. from cariri cearense

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Cleberton Torres Santos ◽  
Luiz Eduardo Oliveira Teotônio ◽  
Ana Paula Leite Nascimento ◽  
Darcio Luiz de Sousa Júnior ◽  
Ítalo Mykaell da Silva Benjamin ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Constituents ◽  
Folk Medicine ◽  
Chemical Compounds ◽  
Therapeutic Effects ◽  
Bacterial Strains ◽  
Microdilution Method ◽  
Ethanol Extracts ◽  
Asteraceae Family

Baccharis cinerea belongs to the Asteraceae family, in Brazil is found in the Northeast and Southeast, occurring in the Caatinga and Mata Atlântica biomes, on the edges of the seasonal forests, board and altitude forests in both regenerating primary and secondary areas. Has proven antimicrobial and antiviral activity and is widely used in folk medicine for its various therapeutic effects and is used as an antiseptic for skin and wound infections, inflammation, diarrhea as well as being used as a purgative. The plants used in the traditional medicine are more and more explored scientifically because they are possible resources of substances with antimicrobial activity in front damage man’s health microorganism. In this context the objective of the study was to investigate the antimicrobial activity, modulator activity of antibiotic and in vitro phytochemical prospection of leaf ethanol extracts. Tests were performed on the bacterial strains of Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 15442) and Escherichia coli (ATCC 10536). The antibacterial activity was analyzed by means determining the Minimum Inhibitory Concentration (MIC). For the evaluation of the modulating activity, the microdilution method of the diluted extract samples with the antibiotic’s amikacin, clindamycin and gentamicin was used. The MIC results were ≥ 1024 μg mL-1 by the bacterial strains. There was a relevance of concentrations in modulation with the antimicrobials tested such as amikacin and gentamicin, there were no discrepancy of clindamycin results in association with the extract. The chemical constituents found were leucoanthocyanidins, flabobenic tannins, flavanones, flavones, flavonoids, xanthones, chalcones, aurones. It is important to note that is necessary to do other studies to evaluate the potential of this species because it has important chemical compounds in reducing antimicrobial resistance.

THE SYNTHESIS OF POSSIBLE DEGRADATION PRODUCTS OF METATHEBAINONE. I.

1944 ◽  
Vol 22b (3) ◽  
pp. 56-65 ◽  
Author(s):  
H. L. Holmes ◽  
L. W. Trevoy
Keyword(s):  
Carboxylic Acid ◽  
Ethyl Ester ◽  
Degradation Products ◽  
Aldehyde Group ◽  
Carboxyl Group ◽  
Unsuccessful Attempt ◽  
Naphthoic Acid ◽  
Relationship Of ◽  
The Relationship ◽  
General Method

The method of Crowley and Robinson (5) for the synthesis of 6-methoxy-3,4-dihydro-2-naphthoic acid has been modified to provide an improved and general method for the synthesis of 3,4-dihydro-2-naphthoic acids. The 7-methoxy-3,4-dihydro-2-naphthoic acid and its ethyl ester have been shown to react with butadiene and 2,3-dimethylbutadiene to give 3-methoxy-5,8,9,10,13,14-hexahydrophenanthrene-14-carboxylic acid and its 6,7-dimethyl derivative. The relationship of these hydrophenanthrenes to possible degradation products of morphine and metathebainone has been discussed. An unsuccessful attempt was made to lengthen the C14-chain by converting the carboxyl group to an aldehyde group by the Rosenmund method followed by condensation with malonic acid. The projected conversion failed in the first stage.

scholarly journals Enhanced Cypermethrin Degradation Kinetics and Metabolic Pathway in Bacillus thuringiensis Strain SG4

2020 ◽  
Vol 8 (2) ◽  
pp. 223 ◽  
Author(s):  
Pankaj Bhatt ◽  
Yaohua Huang ◽  
Wenping Zhang ◽  
Anita Sharma ◽  
Shaohua Chen
Keyword(s):  
Bacillus Thuringiensis ◽  
Metabolic Pathway ◽  
Large Scale ◽  
Degradation Products ◽  
Degradation Kinetics ◽  
Active Role ◽  
Minimal Salt Medium ◽  
Bacterial Strains ◽  
Soil Slurry ◽  
Thuringiensis Strain

Cypermethrin is popularly used as an insecticide in households and agricultural fields, resulting in serious environmental contamination. Rapid and effective techniques that minimize or remove insecticidal residues from the environment are urgently required. However, the currently available cypermethrin-degrading bacterial strains are suboptimal. We aimed to characterize the kinetics and metabolic pathway of highly efficient cypermethrin-degrading Bacillus thuringiensis strain SG4. Strain SG4 effectively degraded cypermethrin under different conditions. The maximum degradation was observed at 32 °C, pH 7.0, and a shaking speed of 110 rpm, and about 80% of the initial dose of cypermethrin (50 mg·L−1) was degraded in minimal salt medium within 15 days. SG4 cells immobilized with sodium alginate provided a higher degradation rate (85.0%) and lower half-life (t1/2) of 5.3 days compared to the 52.9 days of the control. Bioaugmentation of cypermethrin-contaminated soil slurry with strain SG4 significantly enhanced its biodegradation (83.3%). Analysis of the degradation products led to identification of nine metabolites of cypermethrin, which revealed that cypermethrin could be degraded first by cleavage of its ester bond, followed by degradation of the benzene ring, and subsequent metabolism. A new degradation pathway for cypermethrin was proposed based on analysis of the metabolites. We investigated the active role of B. thuringiensis strain SG4 in cypermethrin degradation under various conditions that could be applied in large-scale pollutant treatment.

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