Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 24
Filter
1.
Chinese Journal of Biotechnology ; (12): 2104-2112, 2020.
Article in Chinese | WPRIM | ID: wpr-878470

ABSTRACT

Shikimic acid is an intermediate metabolite in the synthesis of aromatic amino acids in Escherichia coli and a synthetic precursor of Tamiflu. The biosynthesis of shikimic acid requires blocking the downstream shikimic acid consuming pathway that leads to inefficient production and cell growth inhibition. In this study, a dynamic molecular switch was constructed by using growth phase-dependent promoters and degrons. This dynamic molecular switch was used to uncouple cell growth from shikimic acid synthesis, resulting in the production of 14.33 g/L shikimic acid after 72 h fermentation. These results show that the dynamic molecular switch could redirect the carbon flux by regulating the abundance of target enzymes, for better production.


Subject(s)
Escherichia coli/genetics , Escherichia coli Proteins/genetics , Industrial Microbiology/methods , Metabolic Engineering , Shikimic Acid/metabolism
2.
Acta cir. bras ; 33(8): 673-683, Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-949378

ABSTRACT

Abstract Purpose: To evaluate the efficacy of the cellulosic exopolysaccharide membrane (CEM) as a urethral reinforcement for urethrovesical anastomosis. Methods: Twenty eight rabbits were submitted to urethrovesical anastomosis with or without CEM reinforcement. The animals were divided into 4 groups: C7, CEM7, C14 and CEM14: (C= only anastomosis or CEM = anastomosis + CEM), evaluated after 7 weeks, and 14 weeks. The biointegration and biocompatibility of CEM were evaluated according to stenosis, fistula, urethral wall thickness, urethral epithelium, rate of inflammation and vascularization. Results: Between the two experimental groups, the difference in the number of stenosis or urinary fistula was not statistically significant. The morphometric analysis revealed preservation of urethral lumen, well adhered CEM without extrusion, a controlled inflammatory process and implant vascularization. The urothelium height remained constant over time after CEM reinforcement and the membrane wall was thicker, statistically, after 14 weeks. Conclusion: The absence of extrusion, stenosis or urinary fistula after 14 weeks of urethrovesical anastomosis demonstrates cellulosic exopolysaccharide membrane biocompatibility and biointegration with tendency to a thicker wall.


Subject(s)
Animals , Male , Rabbits , Urethra/surgery , Biocompatible Materials/therapeutic use , Urinary Bladder/surgery , Cellulose/therapeutic use , Polysaccharides, Bacterial/therapeutic use , Time Factors , Urethra/pathology , Urinary Bladder/pathology , Industrial Microbiology/methods , Materials Testing , Anastomosis, Surgical , Cellulose/biosynthesis , Reproducibility of Results , Treatment Outcome , Translational Medical Research , Neovascularization, Pathologic
3.
Braz. j. microbiol ; 49(supl.1): 140-150, 2018. tab, graf
Article in English | LILACS | ID: biblio-974343

ABSTRACT

Abstract Ethanol production from sweet sorghum juice (SSJ) using the thermotolerant Saccharomyces cerevisiae strain DBKKUY-53 immobilized in an alginate-loofah matrix (ALM) was successfully developed. As found in this study, an ALM with dimensions of 20 × 20 × 5 mm3 is effective for cell immobilization due to its compact structure and long-term stability. The ALM-immobilized cell system exhibited greater ethanol production efficiency than the freely suspended cell system. By using a central composite design (CCD), the optimum conditions for ethanol production from SSJ by ALM-immobilized cells were determined. The maximum ethanol concentration and volumetric ethanol productivity obtained using ALM-immobilized cells under the optimal conditions were 97.54 g/L and 1.36 g/L h, respectively. The use of the ALM-immobilized cells was successful for at least six consecutive batches (360 h) without any loss of ethanol production efficiency, suggesting their potential application in industrial ethanol production.


Subject(s)
Saccharomyces cerevisiae/metabolism , Industrial Microbiology/methods , Sorghum/microbiology , Ethanol/metabolism , Saccharomyces cerevisiae/chemistry , Cells, Immobilized/metabolism , Cells, Immobilized/chemistry , Sorghum/metabolism , Sorghum/chemistry , Ethanol/analysis , Alginates/chemistry , Fermentation
4.
Braz. j. microbiol ; 49(supl.1): 185-192, 2018. tab, graf
Article in English | LILACS | ID: biblio-974316

ABSTRACT

Abstract Biosurfactants have many advantages over synthetic surfactants but have higher production costs. Identifying microorganisms with high production capacities for these molecules and optimizing their growth conditions can reduce cost. The present work aimed to isolate and identify a fungus with high biosurfactant production capacity, optimize its growth conditions in a low cost culture medium, and characterize the chemical structure of the biosurfactant molecule. The fungal strain UFSM-BAS-01 was isolated from soil contaminated with hydrocarbons and identified as Fusarium fujikuroi. To optimize biosurfactant production, a Plackett-Burman design and a central composite rotational design were used. The variables evaluated were pH, incubation period, temperature, agitation and amount of inoculum in a liquid medium containing glucose. The partial structure of the biosurfactant molecule was identified by nuclear magnetic resonance spectrometry. F. fujikuroi reduced surface tension from 72 to 20 mN m−1 under the optimized conditions of pH 5.0, 37 °C and 7 days of incubation with 190 rpm agitation. The partial identification of the structure of the biosurfactant demonstrated the presence of an α,β-trehalose. The present study is the first report of the biosynthesis of this compound by F. fujikuroi, suggesting that the biosurfactant produced belongs to the class of trehalolipids.


Subject(s)
Surface-Active Agents/metabolism , Trehalose/metabolism , Industrial Microbiology/methods , Fusarium/metabolism , Surface-Active Agents/chemistry , Temperature , Culture Media/metabolism , Fermentation , Fusarium/growth & development , Fusarium/chemistry , Hydrogen-Ion Concentration
5.
Braz. j. microbiol ; 49(supl.1): 151-159, 2018. tab, graf
Article in English | LILACS | ID: biblio-974324

ABSTRACT

Abstract To reduce the cost of obtaining bacterial cellulose, acidic by-products of the alcohol and dairy industries were used without any pretreatment or addition of other nitrogen sources. Studies have shown that the greatest accumulation of bacterial cellulose (6.19 g/L) occurs on wheat thin stillage for 3 days of cultivation under dynamic conditions, which is almost 3 times higher than on standard Hestrin and Schramm medium (2.14 g/L). The use of whey as a nutrient medium makes it possible to obtain 5.45 g/L bacterial cellulose under similar conditions of cultivation. It is established that the pH of the medium during the growth of Gluconacetobacter sucrofermentans B-11267 depends on the feedstock used and its initial value. By culturing the bacterium on thin stillage and whey, there is a decrease in the acidity of the waste. It is shown that the infrared spectra of bacterial cellulose obtained in a variety of environments have a similar character, but we found differences in the micromorphology and crystallinity of the resulting biopolymer.


Subject(s)
Waste Products/analysis , Industrial Microbiology/methods , Cellulose/biosynthesis , Gluconacetobacter/metabolism , Waste Products/economics , Triticum/metabolism , Triticum/microbiology , Industrial Microbiology/economics , Food Industry , Culture Media/economics , Culture Media/metabolism , Gluconacetobacter/growth & development , Ethanol/metabolism
6.
Braz. j. microbiol ; 48(3): 427-441, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889130

ABSTRACT

Abstract The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R2) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30 °C, 6% (v/v), inoculum size and 150 rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications.


Subject(s)
Aspergillus niger/metabolism , beta-Fructofuranosidase/biosynthesis , Glycoside Hydrolases/biosynthesis , Industrial Microbiology/methods , Aspergillus niger/enzymology , Aspergillus niger/genetics , Aspergillus niger/growth & development , beta-Fructofuranosidase/genetics , Bioreactors/microbiology , Culture Media/chemistry , Culture Media/metabolism , Fermentation , Glycoside Hydrolases/genetics , Temperature
7.
Braz. j. microbiol ; 48(3): 403-409, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889142

ABSTRACT

Abstract Very high gravity (VHG) technology was employed on industrial scale to produce ethanol from molasses (fermented) as well as by-products formation estimation. The effect of different Brix° (32, 36 and 40) air-flow rates (0.00, 0.20, 0.40, and 0.60 vvm) was studied on ethanol production. The maximum ethanol production was recorded to be 12.2% (v/v) at 40 Brix° with 0.2 vvm air-flow rate. At optimum level aeration and 40 Brix° VHG, the residual sugar level was recorded in the range of 12.5-18.5 g/L, whereas the viable cell count remained constant up to 50 h of fermentation and dry matter production increased with fermentation time. Both water and steam consumption reduced significantly under optimum conditions of Brix° and aeration rate with compromising the ethanol production. Results revealed VHG with continuous air flow is viable technique to reduce the ethanol production cost form molasses at commercial scale.


Subject(s)
Chick Embryo , Ethanol/metabolism , Industrial Microbiology/methods , Molasses/microbiology , Saccharomyces cerevisiae/metabolism , Fermentation , Hypergravity , Industrial Microbiology/instrumentation , Molasses/analysis , Molasses/economics , Saccharomyces cerevisiae/genetics
8.
Braz. j. microbiol ; 48(3): 410-418, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889127

ABSTRACT

Abstract Chaetoglobosin A is an antibacterial compound produced by Chaetomium globosum, with potential application as a biopesticide and cancer treatment drug. The aim of this study was to evaluate the feasibility of utilizing cornstalks to produce chaetoglobosin A by C. globosum W7 in solid-batch fermentation and to determine an optimal method for purification of the products. The output of chaetoglobosin A from the cornstalks was 0.34 mg/g, and its content in the crude extract was 4.80%. Purification conditions were optimized to increase the content of chaetoglobosin A in the crude extract, including the extract solvent, temperature, and pH value. The optimum process conditions were found to be acetone as the extractant, under room temperature, and at a pH value of 13. Under these conditions, a production process of the antifungal chaetoglobosin A was established, and the content reached 19.17%. Through further verification, cornstalks could replace crops for the production of chaetoglobosin A using this new production process. Moreover, the purified products showed great inhibition against Rhizoctonia solani, with chaetoglobosin A confirmed as the main effective constituent (IC50 = 3.88 µg/mL). Collectively, these results demonstrate the feasibility of using cornstalks to synthesize chaetoglobosin A and that the production process established in this study was effective.


Subject(s)
Industrial Microbiology/methods , Callosities/microbiology , Chaetomium/metabolism , Indole Alkaloids/metabolism , Antifungal Agents/metabolism , Waste Products/analysis , Industrial Microbiology/instrumentation , Callosities/metabolism , Molecular Structure , Plant Stems/metabolism , Plant Stems/microbiology , Indole Alkaloids/isolation & purification , Indole Alkaloids/chemistry , Antifungal Agents/isolation & purification , Antifungal Agents/chemistry
9.
Braz. j. microbiol ; 48(3): 419-426, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-889135

ABSTRACT

Abstract Antibodies and antibody fragments are nowadays among the most important biotechnological products, and Pichia pastoris is one of the most important vectors to produce them as well as other recombinant proteins. The conditions to effectively cultivate a P. pastoris strain previously genetically modified to produce the single-chain variable fragment anti low density lipoprotein (-) under the control of the alcohol oxidase promoter have been investigated in this study. In particular, it was evaluated if, and eventually how, the carbon source (glucose or glycerol) used in the preculture preceding cryopreservation in 20% glycerol influences both cell and antibody fragment productions either in flasks or in bioreactor. Although in flasks the volumetric productivity of the antibody fragment secreted by cells precultured, cryopreserved and reactivated in glycerol was 42.9% higher compared with cells precultured in glucose, the use of glycerol in bioreactor led to a remarkable shortening of the lag phase, thereby increasing it by no less than thrice compared to flasks. These results are quite promising in comparison with those reported in the literature for possible future industrial applications of this cultivation, taking into account that the overall process time was reduced by around 8 h.


Subject(s)
Pichia/metabolism , Industrial Microbiology/methods , Carbon/metabolism , Single-Chain Antibodies/biosynthesis , Antibodies/metabolism , Pichia/growth & development , Pichia/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Culture Media/metabolism , Culture Media/chemistry , Single-Chain Antibodies/genetics , Fermentation , Glycerol/metabolism , Lipoproteins, LDL/immunology , Antibodies/genetics
10.
Braz. j. microbiol ; 47(2): 461-467, Apr.-June 2016. tab, graf
Article in English | LILACS | ID: lil-780837

ABSTRACT

Abstract A Plackett–Burman Factorial Design of 16 experiments was conducted to assess the influence of nine factors on the production of lipases by filamentous fungi. The factors investigated were bran type (used as the main carbon source), nitrogen source, nitrogen source concentration, inducer, inducer concentration, fungal strain (Aspergillus niger or Aspergillus flavus were selected as good lipase producers via submerged fermentation), pH and agitation. The concentration of the yeast extract and soybean oil and the pH had a significant effect (p < 0.05) on lipase production and were consecutively studied through a Full Factorial Design 23, with the concentration of yeast extract and pH being significant (p < 0.05). These variables were optimized using a central composite design, obtaining maximum lipolytic activities with the use of 45 g/L of yeast extract and pH 7.15. The statistical model showed a 94.12% correlation with the experimental data.


Subject(s)
Aspergillus flavus/metabolism , Aspergillus niger/metabolism , Industrial Microbiology/methods , Fungal Proteins/biosynthesis , Lipase/biosynthesis , Carbon/metabolism , Culture Media/metabolism , Culture Media/chemistry , Fermentation , Nitrogen/metabolism
11.
Indian J Exp Biol ; 2014 Nov; 52(11): 1025-1035
Article in English | IMSEAR | ID: sea-153782

ABSTRACT

After cellulose, chitin is the second most abundant organic and renewable polysaccharide in nature. This polymer is degraded by enzymes called chitinases which are a part of the glycoside hydrolase family. Chitinases have many important biophysiological functions and immense potential applications especially in control of phytopathogens, production of chito-oligosaccharides with numerous uses and in treatment and degradation of chitinous biowaste. At present many microbial sources are being explored and tapped for chitinase production which includes potential fungal cultures. With advancement in molecular biology and gene cloning techniques, research on fungal chitinases have made fast progress. The present review focuses on recent advances in fungal chitinases, containing a short introduction to types of chitinases, their fermentative production, purification and characterization and molecular cloning and expression.


Subject(s)
Chitin/metabolism , Chitinases/classification , Chitinases/genetics , Chitinases/isolation & purification , Chitinases/metabolism , Cloning, Molecular , Fermentation , Fungal Proteins/genetics , Fungal Proteins/isolation & purification , Fungal Proteins/metabolism , Fungi/enzymology , Fungi/growth & development , Industrial Microbiology/methods , Mycology/methods
12.
Braz. j. microbiol ; 44(4): 1043-1048, Oct.-Dec. 2013. ilus
Article in English | LILACS | ID: lil-705251

ABSTRACT

Since the 1970s, the establishment and development of the biotech industry has improved exponentially, allowing the commercial production of biopharmaceutical proteins. Nowadays, new recombinant protein production is considered a multibillion-dollar market, in which about 25% of commercial pharmaceuticals are biopharmaceuticals. But to achieve a competitive production process is not an easy task. Any production process has to be highly productive, efficient and economic. Despite that the perfect host is still not discovered, several research groups have chosen Pichia pastoris as expression system for the production of their protein because of its many features. The attempt of this review is to embrace several research lines that have adopted Pichia pastoris as their expression system to produce a protein on an industrial scale in the health care industry.


Subject(s)
Humans , Biotechnology/methods , Health Care Sector , Industrial Microbiology/methods , Organisms, Genetically Modified , Pichia/genetics , Pichia/metabolism , Technology, Pharmaceutical/methods
13.
Indian J Exp Biol ; 2013 Apr; 51(4): 336-342
Article in English | IMSEAR | ID: sea-147599

ABSTRACT

Proteases are shown to have greener mode of application in leather processing for dehairing of goat skins and cow hides. Production of protease by submerged fermentation with potent activity is reported using a new isolate P. aeruginosa MTCC 10501. The production parameters were optimized by statistical methods such as Plackett-Burman and response surface methodology. The optimized production medium contained (g/L); tryptone, 2.5; yeast extract, 3.0; skim milk 30.0; dextrose 1.0; inoculum concentration 4%: initial pH 6.0; incubation temperature 30 °C and optimum production at 48 h with protease activity of 7.6 U/mL. The protease had the following characteristics: pH optima, 9.0; temperature optima 50 °C; pH stability between 5.0-10.0 and temperature stability between 10-40 °C. The protease was observed to have high potential for dehairing of goat skins in the pre- tanning process comparable to that of the chemical process as evidenced by histology. The method offers cleaner processing using enzyme only instead of toxic chemicals in the pre-tanning process of leather manufacture.


Subject(s)
Animals , Bacterial Proteins/biosynthesis , Culture Media , Endopeptidases/biosynthesis , Goats , Hydrogen-Ion Concentration , Industrial Microbiology/methods , Industry , Models, Statistical , Peptones/chemistry , Pressure , Pseudomonas aeruginosa/metabolism , Tanning , Temperature , Yeasts/chemistry
14.
Braz. j. microbiol ; 44(2): 523-528, 2013. graf
Article in English | LILACS | ID: lil-688565

ABSTRACT

The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum) were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control.


Subject(s)
Bacteria/metabolism , Copper/metabolism , Industrial Microbiology/methods , Microbial Consortia
15.
Braz. j. microbiol ; 44(2): 351-356, 2013.
Article in English | LILACS | ID: lil-688566

ABSTRACT

The innovation in industrial process with impact in the efficient production is the major challenge for actual industry. A high numerous of enzymes are utilized in at different level of process; the search for new alternatives with better characteristic has become a field of study of great interest, the recombinant protein achievement in a different host system is an alternative widely assessed for production of this. The microorganism Pichia pastoris has been used like a successful expression system in diverse areas, improved the yield and extraction-recovery of the product expressed. The reported of diverse authors in the production of enzymes with different application in industry is varied, in this review the different industry areas and the characteristic of the enzymes produced are detailed.


Subject(s)
Genetic Vectors , Industrial Microbiology/methods , Pichia/genetics , Pichia/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism
16.
Rev. argent. microbiol ; 44(2): 105-112, jun. 2012. graf, tab
Article in Spanish | LILACS | ID: lil-657620

ABSTRACT

The aim of this work was to evaluate the potential of grape stalks, an agroindustrial waste, for growth and lignocellulolytic enzyme production via solid-state fermentation, using the following three white rot fungi: Trametes trogii, Stereum hirsutum and Coriolus antarcticus. The decolorization of several dyes by the above mentioned cultures was also investigated. Similar values of dry weight loss of the substrate were measured after 60 days (33-43 %). C. antarcticus produced the highest laccase and Mn-peroxldase activities (33.0 and 1.6 U/g dry solid). The maximum endoglucanase production was measured in S. hirsutum cultures (10.4 U/g), while the endoxylanase peak corresponded to T. trogii (14.6 U/g). The C. antarcticus/grape stalk system seems potentially competitive in bioremediation of textile processing effluents, attaining percentages of decolorization of 93, 86, 82, 82, 77, and 58 % for indigo carmine, malachite green, azure B, remazol brilliant blue R, crystal violet and xylidine, respectively, in 5 h.


El objetivo de este trabajo fue evaluar el potencial del escobajo, un residuo agroindustrial, como sustrato para el crecimiento y la producción de enzimas lignocelulósicas de tres hongos causantes de pudrición blanca en la madera: Trametes trogii, Stereum hirsutum y Coriolus antarcticus. Para ello se utilizaron técnicas de fermentación en estado sólido. También se ensayó la decoloración de colorantes industriales sobre estos cultivos. La pérdida de peso seco del sustrato fue similar después del día 60 (33-43 %). C. antarcticus produjo las mayores actividades de lacasa y Mn-peroxidasa (33,0 y 1,6 U/g peso seco). La mayor actividad endoglucanasa fue medida en cultivos de S. hirsutum (10,4 U/g), y la mayor actividad endoxilanasa en T. trogii (14,6 U/g). El sistema C. antarcticus/escobap mostró un importante potencial para su aplicación en la biorremediación de efluentes textiles, con porcentajes de decoloración de 93, 86, 82, 82, 77 y 58 % para índigo carmín, verde de malaquita, azure B, azul R brillante de remazol, cristal violeta y xilidina, respectivamente, en 5 h.


Subject(s)
Biodegradation, Environmental , Basidiomycota/growth & development , Cellulase/isolation & purification , Coloring Agents/metabolism , /isolation & purification , Fungal Proteins/isolation & purification , Industrial Waste , Industrial Microbiology/methods , Laccase/isolation & purification , Lignin/metabolism , Peroxidases/isolation & purification , Plant Stems/microbiology , Vitis/microbiology , Argentina , Basidiomycota/enzymology , Cellulase/metabolism , Coloring Agents/classification , Coriolaceae/enzymology , Coriolaceae/growth & development , /metabolism , Fermentation , Fungal Proteins/metabolism , Laccase/metabolism , Peroxidases/metabolism , Trametes/enzymology , Trametes/growth & development
17.
Rev. argent. microbiol ; 44(1): 49-60, mar. 2012. graf, tab
Article in English | LILACS | ID: lil-639718

ABSTRACT

Bioprospección de microorganismos marinos: aplicaciones biotecnológicas y métodos. Los microorganismos ambientales constituyen una reserva prácticamente inagotable de diversidad genética, acumulada durante millones de años de evolución adaptativa a varias presiones selectivas. En particular, la magnitud de la biodiversidad microbiana en hábitats marinos parece crecer al emerger nuevas técnicas para medirla. Como resultado, se han comenzado a utilizar enfoques novedosos y más complejos para la búsqueda de moléculas y actividades de interés biotecnológico en estos ambientes. En este artículo de revisión, nosotros exploramos los diferentes campos de la biotecnología que utilizan microorganismos, los cuales se superponen parcialmente, y describimos los diferentes hábitats marinos que resultan particularmente atractivos para la bioprospección. Además, revisamos los enfoques metodológicos actualmente utilizados para la bioprospección microbiana, desde las técnicas de cultivo tradicionales hasta modernos enfoques metagenómicos, con énfasis en el medio ambiente marino.


Environmental microorganisms constitute an almost inexhaustible reserve of genetic and functional diversity, accumulated during millions of years of adaptive evolution to various selective pressures. In particular, the extent of microbial biodiversity in marine habitats seems to grow larger as new techniques emerge to measure it. This has resulted in novel and more complex approaches for the screening of molecules and activities of biotechnological interest in these environments. In this review, we explore the different partially overlapping biotechnological fields that make use of microorganisms and we describe the different marine habitats that are particularly attractive for bioprospection. In addition, we review the methodological approaches currently used for microbial bioprospection, from the traditional cultivation techniques to state of the art metagenomic approaches, with emphasis in the marine environment.


Subject(s)
Biotechnology/methods , Environmental Microbiology , Marine Biology/methods , Agricultural Inoculants , Argentina , Biocatalysis , Biodiversity , Biotechnology/trends , Drug Discovery , Ecosystem , Industrial Microbiology/methods , Industrial Microbiology/trends , Microbial Consortia , Marine Biology/trends , Metagenomics/methods
18.
Rev. argent. microbiol ; 43(3): 218-225, jun.-set. 2011. graf, tab
Article in English | LILACS | ID: lil-634695

ABSTRACT

The yeast Yarrowia lipolytica accumulates oils and is able to produce extracellular lipases when growing in different carbon sources including glycerol, the principal by-product of the biodiesel industry. In this study, biomass production of a novel mutant strain of Y. lipolytica was statistically optimized by Response Surface Methodology in media containing biodiesel-derived glycerol as main carbon source. This strain exhibited distinctive morphological and fatty acid profile characteristics, and showed an increased extracellular lipase activity. An organic source of nitrogen and the addition of 1.0 g/l olive oil were necessary for significant lipase production. Plackett-Burman and Central Composite Statistical Designs were employed for screening and optimization of fermentation in shaken flasks cultures, and the maximum values obtained were 16.1 g/l for biomass and 12.2 Units/ml for lipase, respectively. Optimized batch bioprocess was thereafter scaled in aerated bioreactors and the values reached for lipase specific activity after 95 % of the glycerol had been consumed, were three-fold higher than those obtained in shaken flasks cultures. A sustainable bioprocess to obtain biomass and extracellular lipase activity was attained by maximizing the use of the by-products of biodiesel industry.


Optimización de la producción de biomasa usando glicerol crudo, de una cepa mutante de Yarrowia lipolytica con actividad incrementada de lipasa. La levadura Yarrowia lipolytica acumula aceites y produce una lipasa extracelular al crecer en diferentes fuentes de carbono, entre ellas el glicerol, principal subproducto de la creciente industria del biodiésel. En el presente trabajo, se optimizó mediante la metodología de superficies de respuesta la producción de biomasa de una nueva cepa mutante de Y. lipolytica, empleando medios con glicerol derivado de la industria del biodiésel como principal fuente de carbono. Esta cepa presentó características morfológicas y perfil de ácidos grasos distintivos, y una mayor actividad de lipasa extracelular. Para obtener una producción significativa de lipasa extracelular, fue necesario el agregado de una fuente orgánica de nitrógeno y de 1 g/l de aceite de oliva. Se utilizaron los diseños estadísticos de Plackett-Burman y central compuesto para la selección y la optimización de las fermentaciones en frascos agitados; los máximos valores de biomasa y de lipasa obtenidos fueron de 16,1 g/l y 12,2 unidades/ml, respectivamente. Luego, el bioproceso en lote optimizado se escaló a biorreactores aireados, y los valores de actividad específica de lipasa alcanzados después de haberse consumido el 95 % del glicerol fueron tres veces más altos que los obtenidos en los cultivos en frascos agitados. En suma, se desarrolló un bioproceso sostenible para la obtención de biomasa y de una actividad de lipasa extracelular, que a la vez maximiza el uso de subproductos de la industria del biodiésel.


Subject(s)
Biomass , Culture Media/pharmacology , Fungal Proteins/genetics , Glycerol/pharmacology , Industrial Microbiology/methods , Lipase/genetics , Mycology/methods , Yarrowia/growth & development , Bioreactors , Biofuels/analysis , Culture Media, Conditioned/chemistry , DNA, Fungal/genetics , DNA, Intergenic/genetics , Fermentation , Fungal Proteins/biosynthesis , Genes, Fungal , Glycerol/isolation & purification , Hyphae/ultrastructure , Lipase/biosynthesis , Yarrowia/enzymology , Yarrowia/genetics , Yarrowia/ultrastructure
19.
Iranian Journal of Environmental Health Science and Engineering. 2011; 8 (3): 207-218
in English | IMEMR | ID: emr-137344

ABSTRACT

In this research, possibility of reducing excess sludge production in wastewater treatment was investigated using a combined anaerobic and aerobic submerged biological filter in a pilot scale. The physical model designed, erected and operated consisted of two pipes of PVC type with 147mm and 237mm diameter used as aerobic and anaerobic filters, respectively. The effective height of porous media in these filters was 70cm. Two filters were connected to eachother in a series form and the resulted system was loaded using synthetic wastewater based on sucrose in the range of 1.91 to 30.61 kg/m[3] for anaerobic filter and 1.133 to 53.017 kg/m[3] for aerobic filter. For similar loadings, the aerobic filter showed efficiency of 1.8 times that of anaerobic filter in removal of soluble COD. Return of 100% flow from the aerobic filter to the anaerobic filter for 30kg/m[3].d of organic loading increased the efficiencies of the anaerobic filter, the aerobic filter and the combined system as 17%, 14% and 15%, respectively and the effect of the return of the flow was more pronounced in smaller hydraulic retention times and larger loadings. 100% return of the flow reduced the yield coefficient for the whole system to 0.037 for 53 kg/m[3] loading which is a suitable value with regard to the scheme and no use of chemical materials such as chlorine and ozone. This coefficient reached a value as small as 0.007 in common loadings [7.5kg/m[3] for 100% return of the flow which is very close to zero. So, this method could be considered as a complete biological treatment with low excess sludge and could be assessed in full scale


Subject(s)
Biofilms , Sewage/microbiology , Bacteria, Anaerobic/metabolism , Bacteria, Aerobic/metabolism , Efficiency , Biomass , Bioreactors , Industrial Microbiology/methods , Membranes
20.
Rev. argent. microbiol ; 42(4): 298-306, oct.-dic. 2010. ilus, graf, tab
Article in English | LILACS | ID: lil-634669

ABSTRACT

A new optimized semiquantitative yeast killer assay is reported for the first time. The killer activity of 36 yeast isolates belonging to three species, namely, Metschnikowia pulcherrima, Wickerhamomyces anomala and Torulaspora delbrueckii, was tested with a view to potentially using these yeasts as biocontrol agents against the wine spoilage species Pichia guilliermondii and Pichia membranifaciens. The effectiveness of the classical streak-based (qualitative method) and the new semiquantitative techniques was compared. The percentage of yeasts showing killer activity was found to be higher by the semiquantitative technique (60%) than by the qualitative method (45%). In all cases, the addition of 1% NaCl into the medium allowed a better observation of the killer phenomenon. Important differences were observed in the killer capacity of different isolates belonging to a same killer species. The broadest spectrum of action was detected in isolates of W. anomala NPCC 1023 and 1025, and M. pulcherrima NPCC 1009 and 1013. We also brought experimental evidence supporting the importance of the adequate selection of the sensitive isolate to be used in killer evaluation. The new semiquantitative method proposed in this work enables to visualize the relationship between the number of yeasts tested and the growth of the inhibition halo (specific productivity). Hence, this experimental approach could become an interesting tool to be taken into account for killer yeast selection protocols.


En este trabajo se presenta un nuevo ensayo semicuantitativo que optimiza la detección de actividad killer en levaduras. Se evaluó la actividad killer de 36 cepas pertenecientes a las especies Metschnikowia pulcherrima, Wickerhamomyces anomala y Torulaspora delbrueckii, en vista del potencial uso de estas levaduras como agentes de biocontrol frente a las especies contaminantes de vinos Pichia guilliermondii y Pichia membranifaciens. Se comparó la efectividad de la técnica clásica basada en estrías (método cualitativo) con la del nuevo método semicuantitativo. El porcentaje de levaduras que mostraron actividad killer fue más alto cuando se utilizó el método semicuantitativo (60%) que con el método cualitativo (45%). En todos los casos, el agregado de 1% de NaCl en el medio permitió una mejor observación del fenómeno killer. Se observaron importantes diferencias en la capacidad killer de diferentes cepas dentro de la misma especie. Se detectaron dos cepas de W. anomala (NPCC 1023 y 1025) y dos cepas de M. pulcherrima (NPCC 1009 y 1013) con un amplio espectro de acción, ya que fueron capaces de inhibir el desarrollo de las tres levaduras sensibles evaluadas. La evidencia experimental demuestra la importancia de una adecuada selección de la cepa sensible al evaluar la actividad killer. El nuevo método semicuantitativo propuesto en este trabajo permite visualizar la relación entre el número de levaduras sembradas y el halo de inhibición del crecimiento (productividad específica). En conclusión, este método resulta una herramienta interesante para ser tenida en cuenta en los protocolos de selección de levaduras killer.


Subject(s)
Culture Media/pharmacology , Industrial Microbiology/methods , Killer Factors, Yeast/analysis , Microbial Sensitivity Tests/methods , Mycology/methods , Wine/microbiology , Yeasts/isolation & purification , Dose-Response Relationship, Drug , Fermentation , Pest Control, Biological , Salt Tolerance , Sodium Chloride/pharmacology , Yeasts/drug effects , Yeasts/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL