scholarly journals The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Christianah O. Ogunmola ◽  
Olusimbo O. Aboaba
Keyword(s):  
Carbon Sources ◽  
Pseudomonas Stutzeri ◽  
Diesel Oil ◽  
Alcaligenes Faecalis ◽  
Aviation Fuel ◽  
Gas Chromatography Mass Spectrometry ◽  
Food Spoilage ◽  
Animal Products ◽  
Emulsification Index ◽  
Bacillus Laterosporus

Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC). The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk) and plant products (vegetable salad, water leaf (Talinium triangulare), boiled rice, tomatoes and pumpkin leaf (Teifairia occidentalis).They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides, Bacillus laterosporus, Bacillus laterosporus, Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources.  The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14%) as well as vegetable oil (16.91-28.12%) based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

scholarly journals An Efficient Biosurfactant by Pseudomonas stutzeri Z12 Isolated from an Extreme Environment for Remediation of Soil Contaminated with Hydrocarbons

2020 ◽  
Vol 34 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Sudabeh Pourfadakari ◽  
Sahand Jorfi ◽  
Shokooh Ghafari
Keyword(s):  
Critical Micelle Concentration ◽  
Contact Time ◽  
Chemical Structure ◽  
Pseudomonas Stutzeri ◽  
Extreme Environment ◽  
Diesel Oil ◽  
Oily Sludge ◽  
Operating Parameters ◽  
Emulsification Index ◽  
Remediation Of Soil

Capability of a biosurfactant produced by Pseudomonas stutzeri Z12 for the removal of hydrocarbons from oily sludge contaminated soil was investigated. The effect of operating parameters, including pH, critical micelle concentration (CMC), salinity, and contact time were studied. The chemical structure of produced biosurfactant was characterized using FTIR and LC-MS-MS analysis, which revealed that the extracted biosurfactant was a combination of both mono- and di-rhamnolipid congeners. The main three congeners RhaC12:1C10 (529.9 m z–1), RhaC12C10 (531 m z–1), and RhaC10C10 (503.2 m z–1)<br /> were associated to mono-rhamnolipid, while five congeners, RhaRhaC10C8 (621.2 m z–1), RhaRhaC12C12 (707.7), RhaRhaC10C12 (677.1), RhaRhaC10C12:1 (675.3 m z–1), and RhaRhaC10C1 (649.5 m z–1) were associated to di-rhamnolipid structures. The critical micelle concentration (CMC) was 80 mg L–1, and emulsification index (E24) values for n-hexadecane, n-hexane, kerosene, diesel oil, xylene, and crude oil were 62.1, 57.6, 54.4, 41.5, 46.9, and 30.2 %, respectively.

scholarly journals Factorial Design to Optimize Biosurfactant Production byYarrowia lipolytica

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Gizele Cardoso Fontes ◽  
Priscilla Filomena Fonseca Amaral ◽  
Marcio Nele ◽  
Maria Alice Zarur Coelho
Keyword(s):  
Surface Tension ◽  
Factorial Design ◽  
Ammonium Sulfate ◽  
Yeast Extract ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Biosurfactant Production ◽  
Standard Process ◽  
Emulsification Index ◽  
Full Factorial

In order to improve biosurfactant production byYarrowia lipolyticaIMUFRJ 50682, a factorial design was carried out. A24full factorial design was used to investigate the effects of nitrogen sources (urea, ammonium sulfate, yeast extract, and peptone) on maximum variation of surface tension (ΔST) and emulsification index (EI). The best results (67.7% of EI and 20.9 mNm−1ofΔST) were obtained in a medium composed of 10 g 1−1of ammonium sulfate and 0.5 g 1−1of yeast extract. Then, the effects of carbon sources (glycerol, hexadecane, olive oil, and glucose) were evaluated. The most favorable medium for biosurfactant production was composed of both glucose (4% w/v) and glycerol (2% w/v), which provided an EI of 81.3% and aΔST of 19.5 mN m−1. The experimental design optimization enhancedΔEI by 110.7% andΔST by 108.1% in relation to the standard process.

Effect of Glucopon 215 on cell surface properties of Pseudomonas stutzeri and diesel oil biodegradation

2015 ◽  
Vol 104 ◽  
pp. 129-135 ◽  
Author(s):  
Ewa Kaczorek ◽  
Wojciech Smułek ◽  
Agnieszka Zgoła-Grześkowiak ◽  
Katarzyna Bielicka-Daszkiewicz ◽  
Andrzej Olszanowski
Keyword(s):  
Cell Surface ◽  
Surface Properties ◽  
Pseudomonas Stutzeri ◽  
Diesel Oil ◽  
Cell Surface Properties ◽  
Oil Biodegradation

scholarly journals Biodesulfurization of Naphthothiophene and Benzothiophene through Selective Cleavage of Carbon-Sulfur Bonds by Rhodococcus sp. Strain WU-K2R

2002 ◽  
Vol 68 (8) ◽  
pp. 3867-3872 ◽  
Author(s):  
Kohtaro Kirimura ◽  
Toshiki Furuya ◽  
Rika Sato ◽  
Yoshitaka Ishii ◽  
Kuniki Kino ◽  
...  
Keyword(s):  
Sole Source ◽  
Diesel Oil ◽  
The Other ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Structural Isomer ◽  
Degradation Pathways ◽  
Spectrometry Analysis ◽  
Specific Degradation ◽  
Rhodococcus Sp

ABSTRACT Naphtho[2,1-b]thiophene (NTH) is an asymmetric structural isomer of dibenzothiophene (DBT), and in addition to DBT derivatives, NTH derivatives can also be detected in diesel oil following hydrodesulfurization treatment. Rhodococcus sp. strain WU-K2R was newly isolated from soil for its ability to grow in a medium with NTH as the sole source of sulfur, and growing cells of WU-K2R degraded 0.27 mM NTH within 7 days. WU-K2R could also grow in the medium with NTH sulfone, benzothiophene (BTH), 3-methyl-BTH, or 5-methyl-BTH as the sole source of sulfur but could not utilize DBT, DBT sulfone, or 4,6-dimethyl-DBT. On the other hand, WU-K2R did not utilize NTH or BTH as the sole source of carbon. By gas chromatography-mass spectrometry analysis, desulfurized NTH metabolites were identified as NTH sulfone, 2′-hydroxynaphthylethene, and naphtho[2,1-b]furan. Moreover, since desulfurized BTH metabolites were identified as BTH sulfone, benzo[c][1,2]oxathiin S-oxide, benzo[c][1,2]oxathiin S,S-dioxide, o-hydroxystyrene, 2-(2′-hydroxyphenyl)ethan-1-al, and benzofuran, it was concluded that WU-K2R desulfurized NTH and BTH through the sulfur-specific degradation pathways with the selective cleavage of carbon-sulfur bonds. Therefore, Rhodococcus sp. strain WU-K2R, which could preferentially desulfurize asymmetric heterocyclic sulfur compounds such as NTH and BTH through the sulfur-specific degradation pathways, is a unique desulfurizing biocatalyst showing properties different from those of DBT-desulfurizing bacteria.

68 Flux analysis of aerobic glycolysis in bovine blastocysts and CT1 cells

2019 ◽  
Vol 31 (1) ◽  
pp. 159
Author(s):  
J. Chung ◽  
R. Clifford ◽  
G. Sriram ◽  
C. Keefer
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Metabolic Flux ◽  
Aerobic Glycolysis ◽  
Carbon Sources ◽  
Pentose Phosphate ◽  
Gas Chromatography Mass Spectrometry ◽  
Flux Analysis ◽  
Metabolic Modelling ◽  
Chromatography Mass Spectrometry

Embryo quality and maternal recognition are crucial for successful initiation of bovine pregnancy. Previous studies have proposed that better quality embryos use aerobic glycolysis to meet a high demand for biomass components. While hexoses are the principal carbon sources that provide energy to glycolysis, little is known about partitioning of hexoses into metabolic pathways or alteration of partitioning when different hexoses are simultaneously available. Specific metabolic utilisation of 13C-labelled substrates can be quantified by gas chromatography-mass spectrometry, an excellent noninvasive approach for studying cellular metabolism. To assess hexose flux through central metabolism, bovine blastocysts and CT1 cells (a bovine trophectoderm cell line) were cultured in SOF-based media supplemented with combinations of 50% uniformly labelled (U) and 50% naturally abundant (NA) glucose (Glc) or fructose (Fru) (U−13C Glc+NA Glc, U−13C Fru+NA Fru, U−13C Glc+NA Fru, and U−13C Fru+NA Glc), such that total hexose concentration was 1.5mM. Metabolites in spent media from 24-h cultures of single or 5 blastocysts (40-μL drops; 5% CO2, 5% O2, 90% N2) and 1-, 2-, 3-, 6-, 8-, and 24-h incubations of CT1 cells (150 μL; ~3×104 cells per well; 5% CO2, 95% air) were extracted with a MeOH-CHCl3 reagent, derivatized, and analysed by gas chromatography-mass spectrometry. Measurement of mass isotopomer distributions of metabolites, chiefly pyruvate, lactate, and amino acids, followed by correction for natural abundances and metabolic modelling, revealed several insights. For instance, five Day 7 or Day 8 blastocysts (Day 0=fertilization) supplied with U−13C Glc+NA Fru displayed 13C enrichments of 80.3%±1.4% for pyruvate and 71.6%±2.8% for lactate, whereas when supplied with U−13C Fru+NA Glc, they displayed lower 13C enrichments of 5.7%±2.4% for pyruvate and 2.8%±0.4% lactate (mean±standard deviation, n=3 to 4). Metabolic modelling revealed that when Glc and Fru are simultaneously available, the blastocysts used 2.5±0.2 moles of Fru per 100 moles of Glc used. Furthermore, 13C enrichment of pyruvate was 42.0±0.6% when U−13C Glc+NA Glc was supplied and 37.8±2.7% when U−13C Fru+NA Fru was supplied. Lactate enrichments followed a similar trend. This indicates that, individually, Glc and Fru were utilised majorly through aerobic glycolysis with some involvement of the pentose phosphate pathway. Alanine was negligibly labelled in all of the experiments, suggesting either a low TCA flux or that alanine is diluted by extra- or intracellular amino or fatty acids. Single blastocysts and CT1 cells showed a similar labelling pattern when hexoses were available. Following Glc depletion at 8h in CT1 cultures, the 13C enrichments of alanine and citrate in the media increased, suggesting a sharp alteration of metabolic state. These findings demonstrate that metabolic flux can be comprehensively analysed for single bovine blastocysts and CT1 cell metabolism models that of the blastocyst. This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2015-67015-23237 from the USDA National Institute of Food and Agriculture.

Comparative activity of trovafloxacin, alone and in combination with other agents, against gram-negative nonfermentative rods.

1997 ◽  
Vol 41 (7) ◽  
pp. 1475-1481 ◽  
Author(s):  
M A Visalli ◽  
S Bajaksouzian ◽  
M R Jacobs ◽  
P C Appelbaum
Keyword(s):  
Burkholderia Cepacia ◽  
Inhibitory Concentration ◽  
Pseudomonas Stutzeri ◽  
Alcaligenes Faecalis ◽  
Gram Negative ◽  
Agar Dilution ◽  
Flavobacterium Odoratum ◽  
Time Kill ◽  
Synergy Testing ◽  
Comparative Activity

In the first part of this study, agar dilution MICs were used to test the activities of trovafloxacin, ciprofloxacin, ofloxacin, levofloxacin, sparfloxacin, clinafloxacin, ceftazidime, and imipenem against 458 gram-negative nonfermenters. The overall respective MICs at which 50% of isolates are inhibited (MIC50s) and MIC90s were as follows: trovafloxacin, 1.0 and 16.0 microg/ml; ciprofloxacin, 2.0 and 16.0 microg/ml; ofloxacin, 2.0 and 32.0 microg/ml; levofloxacin, 1.0 and 16.0 microg/ml; sparfloxacin, 1.0 and 16.0 microg/ml; clinafloxacin, 0.5 and 4.0 microg/ml; ceftazidime, 8.0 and 128.0 microg/ml; imipenem, 2.0 and 256.0 microg/ml. Clinafloxacin was the most active of all the quinolones tested. The MIC90s of trovafloxacin were < or = 4.0 microg/ml for Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Flavobacterium odoratum, and Chryseobacterium meningosepticum; trovafloxacin MIC90s were < or = 2.0 microg/ml for Moraxella spp., Pseudomonas stutzeri, and Chryseobacterium indologenes-C. gleum. Of the other quinolones tested, the MICs of sparfloxacin and levofloxacin were lower than those of ciprofloxacin and ofloxacin. High ceftazidime MICs (> or = 32.0 microg/ml) were observed for all nonfermentative species tested. Although for the majority of strains tested imipenem MICs were < or = 8.0 microg/ml, high imipenem MICs were observed for many species, especially S. maltophilia, Burkholderia cepacia, F. odoratum, and Chryseobacterium meningosepticum. For Alcaligenes xylosoxidans strains, the MICs of all compounds were generally a few dilutions lower than those for Alcaligenes faecalis-A. odorans. Time-kill studies with five strains revealed that trovafloxacin and all quinolones yielded more rapid time-kill kinetics than ceftazidime and imipenem. Synergy testing by checkerboard titrations of 286 strains with trovafloxacin combined with ceftazidime, amikacin, and imipenem revealed fractional inhibitory concentration (FIC) indices in the range indicating synergism (< or = 0.5) for 81, 41, and 40 strains, respectively, and FIC indices indicating additivity or indifference (> 0.5 to 4.0) for 205, 245, and 246 strains, respectively. No FIC indices indicating antagonism (> 4.0) were observed. Synergy between trovafloxacin and ceftazidime was found for 32 of 36 S. maltophilia strains. Time-kill studies with 20 strains showed that for most strains for which FIC indices were in the range indicating additivity or indifference, FIC indices indicated synergy by the time-kill method. Synergy was particularly noticeable for S. maltophilia strains with combinations of ceftazidime and trovafloxacin.

scholarly journals Substrate-dependent CO2 fixation in heterotrophic bacteria revealed by stable isotope labelling

2020 ◽  
Vol 96 (6) ◽  
Author(s):  
Marina Spona-Friedl ◽  
Alexander Braun ◽  
Claudia Huber ◽  
Wolfgang Eisenreich ◽  
Christian Griebler ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Heterotrophic Bacteria ◽  
Tricarboxylic Acid Cycle ◽  
Carbon Sources ◽  
Organic Substrate ◽  
Gas Chromatography Mass Spectrometry ◽  
Logarithmic Phase ◽  
Natural Environments ◽  
Organic Substrates ◽  
Stable Isotope Labelling

ABSTRACT Virtually all heterotrophs incorporate carbon dioxide by anaplerotic fixation. Little explored, however, is the interdependency of pathways and rates of CO2fixation on the concurrent usage of organic substrate(s). Potentially, this could reveal which substrates out of a pool of dissolved organic carbon are utilised by environmental microorganisms. To explore this possibility, Bacillus subtilis W23 was grown in a minimal medium with normalised amounts of either glucose, lactate or malate as only organic substrates, each together with 1 g/L NaH13CO3. Incorporation of H13CO3− was traced by elemental analysis-isotope ratio mass spectrometry of biomass and gas chromatography-mass spectrometry of protein-derived amino acids. Until the late logarithmic phase, 13C incorporation into the tricarboxylic acid cycle increased with time and occurred via [4–13C]oxaloacetate formed by carboxylation of pyruvate. The levels of 13C incorporation were highest for growth on glucose and lowest on malate. Incorporation of 13C into gluconeogenesis products was mainly detected in the lactate and malate experiment, whereas glucose down-regulated this path. A proof-of-principle study with a natural groundwater community confirmed the ability to determine incorporation from H13CO3− by natural communities leading to specific labelling patterns. This underlines the potential of the labelling approach to characterise carbon sources of heterotrophic microorganisms in their natural environments.

scholarly journals Adaptation of Pseudomonas sp. Strain 7-6 to Quaternary Ammonium Compounds and Their Degradation via Dual Pathways

2007 ◽  
Vol 73 (6) ◽  
pp. 1797-1802 ◽  
Author(s):  
Shinji Takenaka ◽  
Takashi Tonoki ◽  
Kazuya Taira ◽  
Shuichiro Murakami ◽  
Kenji Aoki
Keyword(s):  
Lauric Acid ◽  
Quaternary Ammonium ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Continuous Exposure ◽  
Active Sludge ◽  
Spectrometry Analysis ◽  
Ammonium Compounds

ABSTRACT Pseudomonas sp. strain 7-6, isolated from active sludge obtained from a wastewater facility, utilized a quaternary ammonium surfactant, n-dodecyltrimethylammonium chloride (DTAC), as its sole carbon, nitrogen, and energy source. When initially grown in the presence of 10 mM DTAC medium, the isolate was unable to degrade DTAC. The strain was cultivated in gradually increasing concentrations of the surfactant until continuous exposure led to high tolerance and biodegradation of the compound. Based on the identification of five metabolites by gas chromatography-mass spectrometry analysis, two possible pathways for DTAC metabolism were proposed. In pathway 1, DTAC is converted to lauric acid via n-dodecanal with the release of trimethylamine; in pathway 2, DTAC is converted to lauric acid via n-dodecyldimethylamine and then n-dodecanal with the release of dimethylamine. Among the identified metabolites, the strain precultivated on DTAC medium could utilize n-dodecanal and lauric acid as sole carbon sources and trimethylamine and dimethylamine as sole nitrogen sources, but it could not efficiently utilize n-dodecyldimethylamine. These results indicated pathway 1 is the main pathway for the degradation of DTAC.

scholarly journals Genetic Diversity and Horizontal Transfer of Genes Involved in Oxidation of Reduced Phosphorus Compounds by Alcaligenes faecalis WM2072

2005 ◽  
Vol 71 (1) ◽  
pp. 290-296 ◽  
Author(s):  
Marlena M. Wilson ◽  
William W. Metcalf
Keyword(s):  
Pseudomonas Stutzeri ◽  
Alcaligenes Faecalis ◽  
Phosphorus Compounds ◽  
Rrna Gene ◽  
Sequencing Data ◽  
16S Rrna Gene Analysis ◽  
Evolutionary Selection ◽  
Selection For ◽  
Phosphite Dehydrogenase

ABSTRACT Enrichment was performed to isolate organisms that could utilize reduced phosphorus compounds as their sole phosphorus sources. One isolate that grew well with either hypophosphite or phosphite was identified by 16S rRNA gene analysis as a strain of Alcaligenes faecalis. The genes required for oxidation of hypophosphite and phosphite by this organism were identified by using transposon mutagenesis and include homologs of the ptxD and htxA genes of Pseudomonas stutzeri WM88, which encode an NAD-dependent phosphite dehydrogenase (PtxD) and 2-oxoglutarate-dependent hypophosphite dioxygenase (HtxA). This organism also has the htxB, htxC, and htxD genes that comprise an ABC-type transporter, presumably for hypophosphite and phosphite transport. The role of these genes in reduced phosphorus metabolism was confirmed by analyzing the growth of mutants in which these genes were deleted. Sequencing data showed that htxA, htxB, htxC, and htxD are virtually identical to their homologs in P. stutzeri at the DNA level, indicating that horizontal gene transfer occurred. However, A. faecalis ptxD is very different from its P. stutzeri homolog and represents a new ptxD lineage. Therefore, this gene has ancient evolutionary roots in bacteria. These data suggest that there is strong evolutionary selection for the ability of microorganisms to oxidize hypophosphite and phosphite.

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