Gordonia (nocardia) amarae foaming due to biosurfactant production

2002 ◽  
Vol 46 (1-2) ◽  
pp. 519-524 ◽  
Author(s):  
K.R. Pagilla ◽  
A. Sood ◽  
H. Kim
Keyword(s):  
Surface Tension ◽  
Carbon Source ◽  
Stationary Phase ◽  
Activated Sludge ◽  
Sole Carbon Source ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Biomass Concentration ◽  
Culture Broth ◽  
Biosurfactant Production

Gordonia amarae, a filamentous actinomycete, commonly found in foaming activated sludge wastewater treatment plants was investigated for its biosurfactant production capability. Soluble acetate and sparingly soluble hexadecane were used as carbon sources for G. amarae growth and biosurfactant production in laboratory scale batch reactors. The lowest surface tension (critical micelle concentration, CMC) of the cell-free culture broth was 55 dynes/cm when 1,900 mg/L acetate was used as the sole carbon source. The lowest surface tension was less than 40 dynes/cm when either 1% (v/v) hexadecane or a mixture of 1% (v/v) hexadecane and 0.5% (w/v) acetate was used as the carbon source. The maximum biomass concentration (the stationary phase) was achieved after 4 days when acetate was used along with hexadecane, whereas it took about 8 days to achieve the stationary phase with hexadecane alone. The maximum biosurfactant production was 3 × CMC with hexadecane as the sole carbon source, and it was 5 × CMC with the mixture of hexadecane and acetate. Longer term growth studies (∼ 35 days of culture growth) indicated that G. amarae produces biosurfactant in order to solubilize hexadecane, and that adding acetate improves its biosurfactant production by providing readily degradable substrate for initial biomass growth. This research confirms that the foaming problems in activated sludge containing G. amarae in the activated sludge are due to the biosurfactant production by G. amarae when hydrophobic substrates such as hexadecane are present.

Biosurfactant Production By A New Pseudomonas Putida Strain

2002 ◽  
Vol 57 (3-4) ◽  
pp. 356-360 ◽  
Author(s):  
Borjana K. Tuleva ◽  
George R. Ivanov ◽  
Nelly E. Christova
Keyword(s):  
Surface Tension ◽  
Carbon Source ◽  
Pseudomonas Putida ◽  
Sole Carbon Source ◽  
Biosurfactant Production ◽  
Emulsifying Activity ◽  
Pseudomonas Spp ◽  
Poorly Soluble ◽  
Surface Active

Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by the newly isolated and promising strain Pseudomonas putida 21BN. The biosurfactants were identified as rhamnolipids, the amphiphilic surface-active glycolipids usually secreted by Pseudomonas spp. Their production was observed when the strain was grown on soluble substrates, such as glucose or on poorly soluble substrates, such as hexadecane, reaching values of 1.2 g l-1. When grown on hexadecane as the sole carbon source the biosurfactant lowered the surface tension of the medium to 29 mN m-1 and formed stable and compact emulsions with emulsifying activity of 69%

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.

scholarly journals Bioproduction of succinic acid from xylose by engineered Yarrowia lipolytica without pH control

2020 ◽  
Author(s):  
Ashish Prabhu ◽  
Rodrigo Ledesma- Amaro ◽  
Carol Sze Ki Lin ◽  
Frederic Coulon ◽  
Vijay kumar Thakur ◽  
...  
Keyword(s):  
Cell Growth ◽  
Carbon Source ◽  
Succinic Acid ◽  
Yarrowia Lipolytica ◽  
Recombinant Strain ◽  
Sole Carbon Source ◽  
Substrate Inhibition ◽  
Biomass Concentration ◽  
Value Added ◽  
Green Economy

Abstract Background Xylose is a most prevalent sugar available in hemicellulose fraction of lignocellulosic biomass (LCB) and of great interest for the green economy. Unfortunately, most of the cell factories cannot inherently metabolize xylose as sole carbon source. Yarrowia lipolytica is a non-conventional yeast to produce industrially important metabolites, and it is able to metabolize a large variety of substrates including both hydrophilic and hydrophobic carbon sources. However, Y. lipolytica lacks effective metabolic pathway for xylose uptake and only scarce information is available on utilization of xylose. For the economically feasible of LCB-based biorefineries, effective utilization of both pentose and hexose sugars is obligatory. Results In the present study, succinic acid (SA) production from xylose by Y. lipolytica was examined. To this end, Y. lipolytica PSA02004 strain was engineered by overexpressing pentose pathway cassette comprising of xylose reductase ( XR ), xylitol dehydrogenase ( XDH ) and xylulose kinase ( XK ) gene. The recombinant strain exhibited a robust growth on xylose as sole carbon source and accumulated SA (3.8 g/L) with a yield of 0.19 g/g in shake flask studies. Substrate inhibition studies revealed a marked negative impact on cell growth and product formation above 60 g/L xylose concentration. The modelling based on inhibition kinetics revealed that Aiba model showed better fit with experimental data, which resulted the correlation coefficient (R 2 ) of 0.82 and inhibition constant (K I ) 88.9 g/L. The batch cultivation of recombinant strain in bioreactor resulted in a maximum biomass concentration of 7.3 g/L and SA titer of 11.2 g/L with the yield of 0.18 g/g. Similar results in term of cell growth and SA production were obtained with xylose-rich hydrolysate derived from sugarcane bagasse. The fed-batch fermentation yielded biomass concentration of 11.8 g/L (OD 600 : 56.1) and SA titer of 22.3 g/L with a gradual decrease in pH below 4.0. Acetic acid was obtained as a main byproduct in all the fermentations. Conclusion The recombinant strain displayed potential bioconversion of xylose to succinic acid. Further this study provided a new insight on conversion of LCB into value-added products. To the best of our knowledge, this is the first study on SA production by Y. lipolytica using xylose as a sole carbon source.

scholarly journals Comparative metabolomics of Phialemonium curvatum as an omnipotent fungus cultivated on crude palm oil versus glucose

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Arief Izzairy Zamani ◽  
Susann Barig ◽  
Sarah Ibrahim ◽  
Hirzun Mohd. Yusof ◽  
Julia Ibrahim ◽  
...  
Keyword(s):  
Carbon Source ◽  
Organic Acids ◽  
Vegetable Oil ◽  
Carbon Metabolism ◽  
Sole Carbon Source ◽  
Carbon Sources ◽  
Tca Cycle ◽  
Central Carbon Metabolism ◽  
Targeted Metabolomics ◽  
Central Carbon

Abstract Background Sugars and triglycerides are common carbon sources for microorganisms. Nonetheless, a systematic comparative interpretation of metabolic changes upon vegetable oil or glucose as sole carbon source is still lacking. Selected fungi that can grow in acidic mineral salt media (MSM) with vegetable oil had been identified recently. Hence, this study aimed to investigate the overall metabolite changes of an omnipotent fungus and to reveal changes at central carbon metabolism corresponding to both carbon sources. Results Targeted and non-targeted metabolomics for both polar and semi-polar metabolites of Phialemonium curvatum AWO2 (DSM 23903) cultivated in MSM with palm oil (MSM-P) or glucose (MSM-G) as carbon sources were obtained. Targeted metabolomics on central carbon metabolism of tricarboxylic acid (TCA) cycle and glyoxylate cycle were analysed using LC–MS/MS-TripleQ and GC–MS, while untargeted metabolite profiling was performed using LC–MS/MS-QTOF followed by multivariate analysis. Targeted metabolomics analysis showed that glyoxylate pathway and TCA cycle were recruited at central carbon metabolism for triglyceride and glucose catabolism, respectively. Significant differences in organic acids concentration of about 4- to 8-fold were observed for citric acid, succinic acid, malic acid, and oxaloacetic acid. Correlation of organic acids concentration and key enzymes involved in the central carbon metabolism was further determined by enzymatic assays. On the other hand, the untargeted profiling revealed seven metabolites undergoing significant changes between MSM-P and MSM-G cultures. Conclusions Overall, this study has provided insights on the understanding on the effect of triglycerides and sugar as carbon source in fungi global metabolic pathway, which might become important for future optimization of carbon flux engineering in fungi to improve organic acids production when vegetable oil is applied as the sole carbon source.

scholarly journals Identification and Ecophysiological Characterization of Epiphytic Protein-Hydrolyzing Saprospiraceae (“Candidatus Epiflobacter” spp.) in Activated Sludge

2008 ◽  
Vol 74 (7) ◽  
pp. 2229-2238 ◽  
Author(s):  
Yun Xia ◽  
Yunhong Kong ◽  
Trine Rolighed Thomsen ◽  
Per Halkjær Nielsen
Keyword(s):  
Activated Sludge ◽  
Industrial Wastewater ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Histochemical Staining ◽  
Filamentous Bacteria ◽  
Biological Phosphorus Removal ◽  
The Family ◽  
Biological Phosphorus

ABSTRACT The identity and ecophysiology of a group of uncultured protein-hydrolyzing epiphytic rods attached to filamentous bacteria in activated sludge from nutrient removal plants were investigated by using the full-cycle rRNA approach combined with microautoradiography and histochemical staining. The epiphytic group consists of three closely related clusters, each containing 11 to 16 clones. The closest related cultured isolate is the type strain Haliscomenobacter hydrossis (ATCC 27775) (<87% similarity) in the family Saprospiraceae of the phylum Bacteroidetes. Oligonucleotide probes at different hierarchical levels were designed for each cluster and used for ecophysiological studies. All three clusters behaved similarly in their physiology and were specialized in protein hydrolysis and used amino acids as energy and carbon sources. They were not involved in denitrification. No storage of polyphosphate and polyhydroxyalkanoates was found. They all colonized probe-defined filamentous bacteria belonging to the phyla Chloroflexi, Proteobacteria, and candidate phylum TM7, with the exception of cluster 1, which did not colonize TM7 filaments. The three epiphytic clusters were all widespread in domestic and industrial wastewater treatment plants with or without biological phosphorus removal, constituting, in total, up to 9% of the bacterial biovolume. A new genus, “Candidatus Epiflobacter,” is proposed for this epiphytic group in activated-sludge treatment plants, where it presumably plays an important role in protein degradation.

Biosurfactant production by Rhodococcus erythropolis grown on glycerol as sole carbon source

1996 ◽  
Vol 131 (1-3) ◽  
pp. 880-886
Author(s):  
Elisa M. P. Ciapina ◽  
Walber C. Melo ◽  
Lidia M. M. Santa Anna ◽  
Alexandre S. Santos ◽  
Denise M. G. Freire ◽  
...  
Keyword(s):  
Carbon Source ◽  
Sole Carbon Source ◽  
Rhodococcus Erythropolis ◽  
Biosurfactant Production

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR

2006 ◽  
Vol 54 (1) ◽  
pp. 39-45 ◽  
Author(s):  
E.L. Carr ◽  
K.L. Eales ◽  
R.J. Seviour
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Mycolic Acid ◽  
Substrate Uptake ◽  
Wastewater Treatment Process ◽  
Pure Cultures ◽  
Gordonia Amarae

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.

scholarly journals Bioproduction of succinic acid from xylose by engineered Yarrowia lipolytica without pH control

2020 ◽  
Author(s):  
Ashish Prabhu ◽  
Rodrigo Ledesma- Amaro ◽  
Carol Sze Ki Lin ◽  
Frederic Coulon ◽  
Vijay kumar Thakur ◽  
...  
Keyword(s):  
Cell Growth ◽  
Carbon Source ◽  
Succinic Acid ◽  
Lignocellulosic Biomass ◽  
Yarrowia Lipolytica ◽  
Recombinant Strain ◽  
Sole Carbon Source ◽  
Biomass Concentration ◽  
Value Added ◽  
Green Economy

Abstract Background : Xylose is a most prevalent sugar available in hemicellulose fraction of lignocellulosic biomass (LCB) and of great interest for the green economy. Unfortunately, most of the cell factories cannot inherently metabolize xylose as sole carbon source. Yarrowia lipolytica is a non-conventional yeast to produce industrially important metabolites. The yeast is able to metabolize a large variety of substrates including both hydrophilic and hydrophobic carbon sources. However, Y. lipolytica lacks effective metabolic pathway for xylose uptake and only scarce information is available on utilization of xylose. For the economically feasibility of LCB-based biorefineries, effective utilization of both pentose and hexose sugars is obligatory. Results : In the present study, succinic acid (SA) production from xylose by Y. lipolytica was examined. To this end, Y. lipolytica PSA02004 strain was engineered by overexpressing pentose pathway cassette comprising of xylose reductase ( XR ), xylitol dehydrogenase ( XDH ) and xylulose kinase ( XK ) gene. The recombinant strain exhibited a robust growth on xylose as sole carbon source and produced substantial amount of SA. The inhibition of cell growth and SA formation was observed above 60 g/L xylose concentration. The batch cultivation of recombinant strain in bioreactor resulted in a maximum biomass concentration of 7.3 g/L and SA titer of 11.2 g/L with the yield of 0.19 g/g. Similar results in term of cell growth and SA production were obtained with xylose-rich hydrolysate derived from sugarcane bagasse. The fed-batch fermentation yielded biomass concentration of 11.8 g/L (OD 600 : 56.1) and SA titer of 22.3 g/L with a gradual decrease in pH below 4.0. Acetic acid was obtained as a main byproduct in all the fermentations. Conclusion : The recombinant strain displayed potential for bioconversion of xylose to SA. Further, this study provided a new insight on conversion of lignocellulosic biomass into value-added products. To the best of our knowledge, this is the first study on SA production by Y. lipolytica using xylose as a sole carbon source.

scholarly journals Host engineering for improved valerolactam production in Pseudomonas putida

2019 ◽  
Author(s):  
Mitchell G. Thompson ◽  
Luis E. Valencia ◽  
Jacquelyn M. Blake-Hedges ◽  
Pablo Cruz-Morales ◽  
Alexandria E. Velasquez ◽  
...  
Keyword(s):  
Metabolic Engineering ◽  
Carbon Source ◽  
Pseudomonas Putida ◽  
Aromatic Compounds ◽  
Sole Carbon Source ◽  
Carbon Sources ◽  
Shotgun Proteomics ◽  
Rich Media ◽  
Amide Hydrolase

ABSTRACTPseudomonas putida is a promising bacterial chassis for metabolic engineering given its ability to metabolize a wide array of carbon sources, especially aromatic compounds derived from lignin. However, this omnivorous metabolism can also be a hindrance when it can naturally metabolize products produced from engineered pathways. Herein we show that P. putida is able to use valerolactam as a sole carbon source, as well as degrade caprolactam. Lactams represent important nylon precursors, and are produced in quantities exceeding one million tons per year[1]. To better understand this metabolism we use a combination of Random Barcode Transposon Sequencing (RB-TnSeq) and shotgun proteomics to identify the oplBA locus as the likely responsible amide hydrolase that initiates valerolactam catabolism. Deletion of the oplBA genes prevented P. putida from growing on valerolactam, prevented the degradation of valerolactam in rich media, and dramatically reduced caprolactam degradation under the same conditions. Deletion of oplBA, as well as pathways that compete for precursors L-lysine or 5-aminovalerate, increased the titer of valerolactam from undetectable after 48 hours of production to ~90 mg/L. This work may serve as a template to rapidly eliminate undesirable metabolism in non-model hosts in future metabolic engineering efforts.

Iterative design of a nitrate controller using an external carbon source in an activated sludge process

1998 ◽  
Vol 37 (12) ◽  
pp. 95-102 ◽  
Author(s):  
Pericles R. Barros ◽  
Bengt Carlsson
Keyword(s):  
Carbon Source ◽  
Activated Sludge ◽  
High Performance ◽  
Controller Design ◽  
Wastewater Treatment Plants ◽  
Design Procedure ◽  
Pole Placement ◽  
Activated Sludge Process ◽  
Suggested Approach ◽  
External Carbon Source

More stringent effluent and cost requirements are increasing the need for better control of wastewater treatment plants. In an activated sludge process, the nitrogen removal efficiency may be improved by adding an external carbon source. In this paper, automatic control of the nitrate level by regulating external carbon flow is discussed. More specifically, an iterative tuning procedure for the controller is outlined. Iterative controller design schemes aim at tuning high performance controllers of low complexity using closed loop data. The basic strategy used in this paper is an iterative pole placement controller design procedure. The suggested approach is compared with conventional design in a simulation study.

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