scholarly journals A Comparison ofNannochloropsis salinaGrowth Performance in Two Outdoor Pond Designs: Conventional Raceways versus the ARID Pond with Superior Temperature Management

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Braden Crowe ◽  
Said Attalah ◽  
Shweta Agrawal ◽  
Peter Waller ◽  
Randy Ryan ◽  
...  
Keyword(s):  
Culture System ◽  
Light Exposure ◽  
Fatty Acid Content ◽  
Integrated Design ◽  
Climatic Conditions ◽  
Temperature Management ◽  
Nannochloropsis Salina ◽  
Batch Cultures ◽  
Cell Densities ◽  
Pond Design

The present study examines how climatic conditions and pond design affect the growth performance of microalgae. From January to April of 2011, outdoor batch cultures ofNannochloropsis salinawere grown in three replicate 780 L conventional raceways, as well as in an experimental 7500 L algae raceway integrated design (ARID) pond. The ARID culture system utilizes a series of 8–20 cm deep basins and a 1.5 m deep canal to enhance light exposure and mitigate temperature variations and extremes. The ARID culture reached the stationary phase 27 days earlier than the conventional raceways, which can be attributed to its superior temperature management and shallower basins. On a night when the air temperature dropped to −9°C, the water temperature was 18°C higher in the ARID pond than in the conventional raceways. Lipid and fatty acid content ranged from 16 to 25% and from 5 to15%, respectively, as a percentage of AFDW. Palmitic, palmitoleic, and eicosapentaenoic acids comprised the majority of fatty acids. While the ARID culture system achieved nearly double the volumetric productivity relative to the conventional raceways (0.023 versus 0.013 g L−1day−1), areal biomass productivities were of similar magnitude in both pond systems (3.47 versus 3.34 g m−2day−1), suggesting that the ARID pond design has to be further optimized, most likely by increasing the culture depth or operating at higher cell densities while maintaining adequate mixing.

scholarly journals Metabolic, Physiological, and Transcriptomics Analysis of Batch Cultures of the Green Microalga Chlamydomonas Grown on Different Acetate Concentrations

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1367 ◽  
Author(s):  
Bogaert ◽  
Perez ◽  
Rumin ◽  
Giltay ◽  
Carone ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Biomass Yield ◽  
Fatty Acid Content ◽  
Biological Significance ◽  
Exponential Phase ◽  
Low Light ◽  
Batch Mode ◽  
Batch Cultures ◽  
Green Microalga ◽  
Transcriptomics Data

Acetate can be efficiently metabolized by the green microalga Chlamydomonas reinhardtii. The regular concentration is 17 mM, although higher concentrations are reported to increase starch and fatty acid content. To understand the responses to higher acetate concentrations, Chlamydomonas cells were cultivated in batch mode in the light at 17, 31, 44, and 57 mM acetate. Metabolic analyses show that cells grown at 57 mM acetate possess increased contents of all components analyzed (starch, chlorophylls, fatty acids, and proteins), with a three-fold increased volumetric biomass yield compared to cells cultivated at 17 mM acetate at the entry of stationary phase. Physiological analyses highlight the importance of photosynthesis for the low-acetate and exponential-phase samples. The stationary phase is reached when acetate is depleted, except for the cells grown at 57 mM acetate, which still divide until ammonium exhaustion. Surprisal analysis of the transcriptomics data supports the biological significance of our experiments. This allows the establishment of a model for acetate assimilation, its transcriptional regulation and the identification of candidates for genetic engineering of this metabolic pathway. Altogether, our analyses suggest that growing at high-acetate concentrations could increase biomass productivities in low-light and CO2-limiting air-bubbled medium for biotechnology.

scholarly journals Modelling of a hybrid culture system with a stationary layer of liquid perfluorochemical applied as oxygen carrier

2016 ◽  
Vol 37 (1) ◽  
pp. 149-158
Author(s):  
Maciej Pilarek ◽  
Katarzyna Dąbkowska
Keyword(s):  
Mass Transfer ◽  
Aqueous Phase ◽  
Culture System ◽  
Oxygen Carrier ◽  
Published Data ◽  
Monod Kinetics ◽  
Batch Cultures ◽  
Whole Process ◽  
Hybrid Culture ◽  
Stationary Layer

Abstract A mathematical model of a hybrid culture system supported with a stationary layer of liquid perfluorochemical (PFC) as a source of O2 for cells which grow in the aqueous phase of culture medium has been developed and discussed. The two-substrate Monod kinetics without inhibition effects, i.e. the Tsao-Hanson equation, has been assumed to characterise the biomass growth. The Damköhler number which relates the growth rate to the mass transfer effects has been used to appraise the regime (i.e. diffusion-limited or kinetics) of the whole process. The proposed model predicted accurately previously published data on the submerged batch cultures of Nicotiana tabacum BY-2 heterotrophic cells performed in a culture system supported with a stationary layer of hydrophobic perfluorodecalin as a liquid O2 carrier. Estimated values of the parameters of the model showed that the process proceeded in the kinetics regime and the growth kinetics, not the effects of the mass transfer between aqueous phase and liquid PFC, had essential influence on the growth of biomass.

scholarly journals Lactate Control Enhances Growth Advantage in Fed-batch Cultures of Metabolically Engineered CHO Cells with Reduced Novel Growth-inhibitory Compound Formation

2021 ◽  
Author(s):  
Quentin Bethune ◽  
Cameron Harrington ◽  
Bhanu Mulukutla
Keyword(s):  
Amino Acid ◽  
Cho Cells ◽  
Fed Batch ◽  
Compound Formation ◽  
Knock Out ◽  
Batch Cultures ◽  
Growth Inhibitory ◽  
Inhibitory Compound ◽  
Cell Densities ◽  
Produce Amino Acid

CHO cells have been recently shown to produce amino acid catabolism derived byproducts, which accumulate in fed-batch cultures to growth-inhibitory levels. Residual amino acid limitation or genetic engineering strategies have been successfully employed to suppress production of these novel growth inhibitory metabolic byproducts. However, the growth advantage attained due to suppression of these metabolic byproducts in fed-batch cultures is more pronounced when lactate accumulation is also controlled. BCAT1 knock-out (KO) CHO cells, which produce negligible levels of the metabolic byproducts isovalerate, isobutyrate and 2-methylbutyrate, grow to significantly higher peak cell densities in fed-batch cultures with lactate control (HiPDOG) as compared to cultures without lactate control. Henceforth, strategies involving novel metabolic byproduct control should preferably include lactate control to more easily assess the enhanced cell growth and productivities attainable.

scholarly journals Bagatzi ECondHotel: Condominio/Hotel Ecológico

REVISTARQUIS ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Kevin Rojas Varela
Keyword(s):  
Energy Expenditure ◽  
Integrated Design ◽  
Sun Exposure ◽  
Climatic Conditions ◽  
Architecture Design ◽  
Maximum Comfort ◽  
High Standards

PresentaciónEste condominio/hotel fue proyectado bajo altos estándares de arquitectura bioclimática, diseñado para lograr un máximo confort con el mínimo gasto energético, aprovechando las condiciones climáticas del entorno mediante la transformación pasiva de elementos externos -viento, agua y vegetación-, en confort interno. Sumado a un diseño integral, que comprende desde la zonificación en función de vientos, soleamiento y topografía, hasta el diseño de fachadas y dispositivos para el manejo de condiciones climáticas dadas en el sitio. PresentationThis condo / hotel was designed under high standards of bioclimatic architecture design to achieve maximum comfort with the lowest energy expenditure, taking advantage of the climatic conditions of the environment by transforming passive external elements -wind, water and vegetation- to produce internal comfort. In addition to an integrated design, it considers zoning based on wind, sun exposure and topography as well as the design of facades and devices to control climatic conditions given on the site.

scholarly journals A plug-and-play system for enzyme production at commercially viable levels in fed-batch cultures of Escherichia coli BL21 (DE3)

2018 ◽  
Author(s):  
Sujata Vijay Sohoni ◽  
Paras Harendra Kundalia ◽  
Adarsh G. Shetty ◽  
Avinash Vellore Sunder ◽  
Raghavendra P. Gaikaiwari ◽  
...  
Keyword(s):  
Enzyme Production ◽  
Formate Dehydrogenase ◽  
Defined Medium ◽  
Fed Batch ◽  
Batch Cultures ◽  
E Coli ◽  
Induction Strategy ◽  
Cell Densities ◽  
Minimal Modification ◽  
Nutrient Feeding

AbstractCommercial exploitation of enzymes in biotransformation necessitates a robust method for enzyme production that yields high enzyme titer. Nitrilases are a family of hydrolases that can transform nitriles to enantiopure carboxylic acids, which are important pharmaceutical intermediates. Here, we report a fed-batch method that uses a defined medium and involves growth under carbon limiting conditions using DO-stat feeding approach combined with an optimized post-induction strategy, yielding high cell densities and maximum levels of active and soluble enzyme. This strategy affords strict control of nutrient feeding and growth rates, and ensures sustained protein synthesis over a longer period. The method was optimized for highest titer of nitrilase reported so far (247 kU/l) using recombinant E. coli expressing the Alcaligenes sp. ECU0401 nitrilase. The fed-batch protocol presented here can also be employed as template to produce a wide variety of enzymes with minimal modification, as demonstrated for alcohol dehydrogenase and formate dehydrogenase.

scholarly journals Mapping the Fundamental Niches of Two Freshwater Microalgae,Chlorella vulgaris(Trebouxiophyceae) andPeridinium cinctum(Dinophyceae), in 5-Dimensional Ion Space

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Terence J. Evens ◽  
Randall P. Niedz
Keyword(s):  
Growth Rate ◽  
Experimental Design ◽  
Chlorella Vulgaris ◽  
Growth Rates ◽  
Ion Concentration ◽  
Freshwater Microalgae ◽  
Batch Cultures ◽  
Fundamental Niche ◽  
Maximum Cell ◽  
Cell Densities

The fundamental niche defined by five ions,NO3 −,PO4 3−, K+, Na+, andCl−, was mapped forChlorella vulgaris(Trebouxiophyceae) andPeridinium cinctum(Dinophyceae) growth rates and maximum cell densities in batch cultures. A five dimensional ion-mixture experimental design was projected across a total ion concentration gradient of 1 to 30 mM to delineate the ion-based, “potential” niche space, defined as the entiren-dimensional hypervolume demarcated by the feasible ranges of the independent factors under consideration. The growth rate-based, fundamental niche volumes overlapped for ca. 94% of the ion mixtures, although the regions of maximal growth rates and cell densities were different for each alga. BothC. vulgarisandP. cinctumexhibited similar positive responses to cations and negative responses to anions. It was determined that total ion concentration for these five ions, from 1 to 30 mM, did not directly affect either growth rate or maximal cell density for either alga, although it did play an interactive role with several ions. This study is the first that we are aware of to attempt the mapping of a multivariate, ion-based, fundamental niche volume. The implications of the experimental design utilized and the potential utility of this type of approach are discussed.

scholarly journals Displacement of Escherichia coli O157:H7 from Rumen Medium Containing Prebiotic Sugars

2002 ◽  
Vol 68 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Albane de Vaux ◽  
Mark Morrison ◽  
Robert W. Hutkins
Keyword(s):  
Escherichia Coli ◽  
Culture System ◽  
Rumen Fluid ◽  
Enteric Bacteria ◽  
Fermentation Medium ◽  
Escherichia Coli O157 ◽  
Anaerobic Culture ◽  
Fluid Medium ◽  
E Coli ◽  
Cell Densities

ABSTRACT A fed-batch, anaerobic culture system was developed to assess the behavior of Escherichia coli O157:H7 in a rumen-like environment. Fermentation medium consisted of either 50% (vol/vol) raw or sterile rumen fluid and 50% phosphate buffer. Additional rumen fluid was added twice per day, and samples were removed three times per day to simulate the exiting of digesta and microbes from the rumen environment under typical feeding regimens. With both types of medium, anaerobic and enteric bacteria reached 1010 and 104 cells/ml, respectively, and were maintained at these levels for at least 5 days. When a rifampin-resistant strain of E. coli O157:H7 was inoculated into medium containing raw rumen fluid, growth did not occur. In contrast, when this strain was added to sterile rumen fluid medium, cell densities increased from 106 to 109 CFU/ml within 24 h. Most strains of E. coli O157:H7 are unable to ferment sorbitol; therefore, we assessed whether the addition of sorbitol as the only added carbohydrate could be used to competitively exclude E. coli O157:H7 from the culture system. When inoculated into raw rumen broth containing 3 g of sorbitol per liter, E. coli O157:H7 was displaced within 72 h. The addition of other competitive sugars, such as l-arabinose, trehalose, and rhamnose, to rumen medium gave similar results. However, whenever E. coli O157:H7 was grown in sterile rumen broth containing sorbitol, sorbitol-positive mutants appeared. These results suggest that a robust population of commensal ruminal microflora is required to invoke competitive exclusion of E. coli O157:H7 by the addition of “nonfermentable” sugars and that this approach may be effective as a preharvest strategy for reducing carriage of E. coli O157:H7 in the rumen.

scholarly journals Environmental safety of the steppe zone cities within the development of the technique of a «green framework» belt formation

2019 ◽  
Vol 135 ◽  
pp. 03021
Author(s):  
Natalia Yudina ◽  
Ekaterina Lysova ◽  
Oksana Paramonova ◽  
Natalia Samarskaya
Keyword(s):  
Urban Areas ◽  
Design Method ◽  
Integrated Design ◽  
Steppe Zone ◽  
Environmental Safety ◽  
Climatic Conditions ◽  
Actual Problem ◽  
Green Belt ◽  
Situation Specificity ◽  
The City

The article is devoted to solving the actual problem of creating a comfortable urban environment in the climatic conditions of the southern cities of Russia. The environmental safety of urban areas in the steppe zone can be ensured by forming belts of the «green belt» of the city, based on the use of specific functions of green spaces. The aim of the work was development of an integrated design method for the «green belt» of the city on the example of the territory of Rostov region, based on the analysis of the urban ecological situation, specificity of the regional range of perennial vegetation with the selection of plants that have environmental tolerance to man-made territory. The proposed technique can be used for other physiographic zones of the territory of the Russian Federation on the basis of selection and ranking of environmental and city-forming criteria for designing the «green belt».

Beech Leaf Colonization by the Endophyte Apiognomonia errabunda Dramatically Depends on Light Exposure and Climatic Conditions

Plant Biology ◽  
2005 ◽  
Vol 7 (6) ◽  
pp. 659-669 ◽  
Author(s):  
G. Bahnweg ◽  
W. Heller ◽  
S. Stich ◽  
C. Knappe ◽  
G. Betz ◽  
...  
Keyword(s):  
Light Exposure ◽  
Climatic Conditions
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