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Ferda Mavituna - One of the best experts on this subject based on the ideXlab platform.
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In Search of the E. coli Compounds that Change the Antibiotic Production Pattern of Streptomyces coelicolor During Inter-species Interaction.
Enzyme and microbial technology, 2016Co-Authors: Ferda Mavituna, Khalid Jaber Kadhum LutiAbstract:The aim of this work was to investigate the interaction between E.coli and Streptomyces coelicolor A3 (2) for the increased Production of undecylprodigiosin and identify the E. coli actives mediating this inter-species interaction. The antibiotics of interest were the red-pigmented undecylprodigiosin and blue-pigmented actinorhodin. Pure cultures of S. coelicolor in a defined medium produced higher concentrations of actinorhodin compared to those of undecylprodigiosin. The latter however, is more important due to its immunosuppressive and antitumor properties. As a strategy to increase undecylprodigiosin Production, we added separately, live cells and heat-killed cells of E. coli C600, and the cell-free supernatant of E. coli culture to S. coelicolor cultures in shake flasks. The interaction with live cells of E. coli altered the antibiotic Production Pattern and undecylprodigiosin Production was enhanced by 3.5-fold compared to the pure cultures of S. coelicolor and actinorhodin decreased by 15-fold. The heat-killed cells of E. coli however, had no effect on antibiotic Production. In all cases, growth and glucose consumption of S. coelicolor remained almost the same as those observed in the pure culture indicating that the changes in antibiotic Production were not due to nutritional stress. Results with cell-free supernatant of E. coli culture indicated that the interaction between S. coelicolor and E. coli was mediated via diffusible molecule(s). Using a set of extraction procedures and agar-well diffusion bioassays, we isolated and preliminarily identified a class of compounds. For the preliminary verification, we added the compound which was the common chemical structural moiety in this class of compounds to the pure S. coelicolor cultures. We observed similar effects on antibiotic Production as with the live E. coli cells and their supernatant indicating that this class of compounds secreted by E. coli indeed could act as actives during interspecies interaction and increase the Production of undecylprodigiosin.
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Elicitation of Streptomyces coelicolor with E. coli in a bioreactor enhances undecylprodigiosin Production
Biochemical Engineering Journal, 2011Co-Authors: Khalid Jaber Kadhum Luti, Ferda MavitunaAbstract:Abstract Elicitation mimics the inter-species interactions in nature resulting in complex metabolic responses in interacting microorganisms. In pure culture systems in industry and laboratory, most of these metabolic pathways are not active. We therefore, investigated for the first time in a bioreactor, the effect of introducing a live culture of another species to the Streptomyces coelicolor cultures that produce antibiotics such as undecylprodigiosin and actinorhodin. Recently, undecylprodigiosin has also been attributed with antitumor activities. Pure cultures of S. coelicolor produced higher concentrations of actinorhodin compared with undecylprodigiosin in a defined medium in a 2 L bioreactor. Elicitation by live cells of Escherichia coli altered this Production Pattern such that undecylprodigiosin Production was enhanced and actinorhodin repressed. E. coli elicitor with a concentration of 1 × 10 7 cells mL −1 was added at 2.5% (v/v) so that it did not overtake the growth of S. coelicolor . Since the timing of elicitation is also important, we tested E. coli addition at the beginning, on the second and the fourth day of the start of S. coelicolor cultivation. Day zero elicitation gave the maximum enhancement of undecylprodigiosin Production which was 3.5 mg L −1 compared with 0.58 mg L −1 in the pure culture.
Khalid Jaber Kadhum Luti - One of the best experts on this subject based on the ideXlab platform.
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In Search of the E. coli Compounds that Change the Antibiotic Production Pattern of Streptomyces coelicolor During Inter-species Interaction.
Enzyme and microbial technology, 2016Co-Authors: Ferda Mavituna, Khalid Jaber Kadhum LutiAbstract:The aim of this work was to investigate the interaction between E.coli and Streptomyces coelicolor A3 (2) for the increased Production of undecylprodigiosin and identify the E. coli actives mediating this inter-species interaction. The antibiotics of interest were the red-pigmented undecylprodigiosin and blue-pigmented actinorhodin. Pure cultures of S. coelicolor in a defined medium produced higher concentrations of actinorhodin compared to those of undecylprodigiosin. The latter however, is more important due to its immunosuppressive and antitumor properties. As a strategy to increase undecylprodigiosin Production, we added separately, live cells and heat-killed cells of E. coli C600, and the cell-free supernatant of E. coli culture to S. coelicolor cultures in shake flasks. The interaction with live cells of E. coli altered the antibiotic Production Pattern and undecylprodigiosin Production was enhanced by 3.5-fold compared to the pure cultures of S. coelicolor and actinorhodin decreased by 15-fold. The heat-killed cells of E. coli however, had no effect on antibiotic Production. In all cases, growth and glucose consumption of S. coelicolor remained almost the same as those observed in the pure culture indicating that the changes in antibiotic Production were not due to nutritional stress. Results with cell-free supernatant of E. coli culture indicated that the interaction between S. coelicolor and E. coli was mediated via diffusible molecule(s). Using a set of extraction procedures and agar-well diffusion bioassays, we isolated and preliminarily identified a class of compounds. For the preliminary verification, we added the compound which was the common chemical structural moiety in this class of compounds to the pure S. coelicolor cultures. We observed similar effects on antibiotic Production as with the live E. coli cells and their supernatant indicating that this class of compounds secreted by E. coli indeed could act as actives during interspecies interaction and increase the Production of undecylprodigiosin.
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Elicitation of Streptomyces coelicolor with E. coli in a bioreactor enhances undecylprodigiosin Production
Biochemical Engineering Journal, 2011Co-Authors: Khalid Jaber Kadhum Luti, Ferda MavitunaAbstract:Abstract Elicitation mimics the inter-species interactions in nature resulting in complex metabolic responses in interacting microorganisms. In pure culture systems in industry and laboratory, most of these metabolic pathways are not active. We therefore, investigated for the first time in a bioreactor, the effect of introducing a live culture of another species to the Streptomyces coelicolor cultures that produce antibiotics such as undecylprodigiosin and actinorhodin. Recently, undecylprodigiosin has also been attributed with antitumor activities. Pure cultures of S. coelicolor produced higher concentrations of actinorhodin compared with undecylprodigiosin in a defined medium in a 2 L bioreactor. Elicitation by live cells of Escherichia coli altered this Production Pattern such that undecylprodigiosin Production was enhanced and actinorhodin repressed. E. coli elicitor with a concentration of 1 × 10 7 cells mL −1 was added at 2.5% (v/v) so that it did not overtake the growth of S. coelicolor . Since the timing of elicitation is also important, we tested E. coli addition at the beginning, on the second and the fourth day of the start of S. coelicolor cultivation. Day zero elicitation gave the maximum enhancement of undecylprodigiosin Production which was 3.5 mg L −1 compared with 0.58 mg L −1 in the pure culture.
Ruixue Tang - One of the best experts on this subject based on the ideXlab platform.
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Experimental Investigation on Injection and Production Pattern in Fractured-Vuggy Carbonate Reservoirs
Energies, 2020Co-Authors: Ruixue TangAbstract:To constitute and adjust the injection and Production Pattern in fractured-vuggy reservoirs, we extracted twelve fractured-cave structures, fabricated them into physical models with acrylic plates, and performed experiments via these models. The results show that utilizing oil/water gravity segregation sufficiently and forming valid flow channels should be emphasized. Preferentially exploiting the reservoir body containing intermediate-scaled or large-scaled caves, arranging injection wells in fractures or small-scaled caves while placing Production wells in large-scaled caves, and separately putting injection wells and Production wells in low/high parts of an intermediate-scaled or large-scaled cave, were found to benefit oil/water gravity segregation and thus gain a better water flooding effect in these experiments. Experiments with combined models also figured out that, after adjusting the injection and Production Pattern, the valid flow channel newly formed must pass through caves containing enough residual oil to improve the water flooding effect and could be obtained by shutting down the old Production well while adding a new Production well, adding a new Production well, or switching the Production well into an injection well while adding a new Production well. In the actual field, adjusting the well location and altering the flow channel were proposed to conduct together. This study may provide references on the Production management of analogous reservoirs.
M Fondevila - One of the best experts on this subject based on the ideXlab platform.
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effect of pelleting and pellet size of a concentrate for intensively reared beef cattle on in vitro fermentation by two different approaches
Animal Feed Science and Technology, 2010Co-Authors: L M A Bertipaglia, M Fondevila, H H Van Laar, C CastrilloAbstract:Abstract Two in vitro experiments were performed to evaluate the effect of concentrate pelleting for intensively reared cattle on rumen microbial fermentation. In Experiment 1, a concentrate was incubated as meal (M) or pelleted to 3.5 (P3.5) and 10 (P10) mm diameter, either in their original form or re-ground to 1 mm particle size (MG, P3.5G and P10G) and their gas Production Pattern was studied. When the concentrate was incubated in its original form, gas produced with M was higher than with P10 at 1 h and from 3 to 6 h of incubation ( P P P P P P
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in vitro microbial fermentation of tropical grasses at an advanced maturity stage
Animal Feed Science and Technology, 2000Co-Authors: J Nogueira C M Filho, M Fondevila, Barrios A Urdaneta, Gonzalez M RonquilloAbstract:Abstract Four tropical grasses ( Cynodon dactylon , Cd , C. plectostachyus , Cp , Brachiaria humidicola , Bh and Pennisetum purpureum , Pp ) harvested in Central Brazil during the dry season at 100-day age were compared in terms of chemical composition and in vitro gas Production Pattern in order to select the most promising species for feeding ruminants during the dry season. Because of its lower proportion of neutral detergent fibre (NDF, 709 g/kg dry matter, DM) and lignin (44 g/kg), and its higher nitrogen (N) content (15.3 g/kg), Pp appears to have the higher nutritive value in such conditions. In contrast, Cp showed a high NDF (843 g/kg) and lignin (115 g/kg) contents, and low N content (8.7 g/kg). Microbial fermentation, estimated by the gas Production Pattern agreed well with chemical composition of the studied species, and ranked them as follows: Pp > Cd ≥ Bh > Cp . The metabolic energy content of grasses was estimated from the volume of gas produced at 24 h and their crude protein content, and were (in MJ/kg DM): Cd , 5.76; Cp , 5.15; Bh , 5.91; Pp , 9.12. In another experiment, Cp , Bh and Pp were chosen to study the bacterial adhesion (estimated by 15 N as microbial marker) and polysaccharidase and s-glucosidase enzymatic activities after in vitro incubation of grasses for 4, 8, 12, 24 and 32 h. The Pattern of microbial adhesion and total enzymatic activities agreed well with the chemical composition and gas Production results. Although P. purpureum promoted a higher adhesion and total cellulolytic activity, bacterial enzymatic activity (per unit of adhered bacteria) showed that populations associated with the grasses do not differ qualitatively in their cellulolytic capability.
Gonzalez M Ronquillo - One of the best experts on this subject based on the ideXlab platform.
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in vitro microbial fermentation of tropical grasses at an advanced maturity stage
Animal Feed Science and Technology, 2000Co-Authors: J Nogueira C M Filho, M Fondevila, Barrios A Urdaneta, Gonzalez M RonquilloAbstract:Abstract Four tropical grasses ( Cynodon dactylon , Cd , C. plectostachyus , Cp , Brachiaria humidicola , Bh and Pennisetum purpureum , Pp ) harvested in Central Brazil during the dry season at 100-day age were compared in terms of chemical composition and in vitro gas Production Pattern in order to select the most promising species for feeding ruminants during the dry season. Because of its lower proportion of neutral detergent fibre (NDF, 709 g/kg dry matter, DM) and lignin (44 g/kg), and its higher nitrogen (N) content (15.3 g/kg), Pp appears to have the higher nutritive value in such conditions. In contrast, Cp showed a high NDF (843 g/kg) and lignin (115 g/kg) contents, and low N content (8.7 g/kg). Microbial fermentation, estimated by the gas Production Pattern agreed well with chemical composition of the studied species, and ranked them as follows: Pp > Cd ≥ Bh > Cp . The metabolic energy content of grasses was estimated from the volume of gas produced at 24 h and their crude protein content, and were (in MJ/kg DM): Cd , 5.76; Cp , 5.15; Bh , 5.91; Pp , 9.12. In another experiment, Cp , Bh and Pp were chosen to study the bacterial adhesion (estimated by 15 N as microbial marker) and polysaccharidase and s-glucosidase enzymatic activities after in vitro incubation of grasses for 4, 8, 12, 24 and 32 h. The Pattern of microbial adhesion and total enzymatic activities agreed well with the chemical composition and gas Production results. Although P. purpureum promoted a higher adhesion and total cellulolytic activity, bacterial enzymatic activity (per unit of adhered bacteria) showed that populations associated with the grasses do not differ qualitatively in their cellulolytic capability.
