Adaptastat—a new method for optimising of bacterial growth conditions in continuous culture: Interactive substrate limitation based on dissolved oxygen measurement

2006 ◽  
Vol 64 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Katrin Tomson ◽  
Jill Barber ◽  
Kalju Vanatalu
Keyword(s):  
Dissolved Oxygen ◽  
Continuous Culture ◽  
Bacterial Growth ◽  
Growth Conditions ◽  
New Method ◽  
Substrate Limitation ◽  
Oxygen Measurement

Growth Conditions of a Thermophilic Geobacillus sp. as an Enhanced Oil Recovery Material

2012 ◽  
Vol 496 ◽  
pp. 457-460
Author(s):  
Xiang Ping Kong
Keyword(s):  
Enhanced Oil Recovery ◽  
Bacterial Growth ◽  
Oil Recovery ◽  
Nitrogen Sources ◽  
Growth Conditions ◽  
Good Growth ◽  
Strictly Aerobic ◽  
Aerobic Bacterium ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

The growth conditions of a Geobacillus sp. were investigated by single-factor experiments. The strain was strictly aerobic bacterium, and could grow on hydrocarbons as the sole carbon source. The optimum carbon and nitrogen sources were 3.0% sucrose and 0.20% KNO3, respectively. The range of temperature, salinity and pH for the bacterial growth was 35-70 °C, 0-10% NaCl and 5.5-9.5, and good growth was obtained at 35-65 °C, 0.5-8% NaCl and 6.0-9.0, respectively. Particularly, the optimum temperature for the bacterial growth was between 50 °C and 60 °C. The strain had wide adaptability to the extreme conditions, and may be potentially applied to microbial enhanced oil recovery and oil-waste bioremediation technology.

scholarly journals The Influence of Optic and Polarographic Dissolved Oxygen Sensors Estimating the Volumetric Oxygen Mass Transfer Coefficient (KLa)

2016 ◽  
Vol 10 (8) ◽  
pp. 142 ◽  
Author(s):  
Gustavo Andrés Baquero-Rodríguez ◽  
Jaime A. Lara-Borrero
Keyword(s):  
Mass Transfer ◽  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Oxygen Transfer ◽  
Airflow Rate ◽  
Oxygen Probe ◽  
Aeration System ◽  
Oxygen Measurement

Aeration is usually the most energy intensive part of the wastewater treatment process. Optimizing the aeration system is essential for reducing energy costs. Field tests oriented to estimate parameters related to oxygen transfer are a common approach to compare aeration systems. The aim of this research is to assess the effect of dissolved oxygen probe lag on oxygen transfer parameter estimation. Experimental procedures regarding to process automation and control were applied to quantify dissolved oxygen probe lag. We have measured oxygen transfer in clean water, under a wide range of conditions (airflow rate, diffuser characteristics and diffuser density), with optic and polarographic sensors for dissolved oxygen measurement. The oxygen transfer was measured as per ASCE Standard procedures. Nonparametric statistical tests were used to compare the estimated volumetric mass transfer coefficient KLa with different sensors. According to the results, there is not significant influence of the probe lag (also known as time constant) or probe characteristics on the parameters used to assess oxygen transfer efficiency. This fact has great relevance in common practice of aerobic process for wastewater treatment because dissolved oxygen monitoring is used as an input for decision making related to the energy optimization in the aeration system. Findings from these tests contradict previous studies which claim that lag time in polarographic sensors for the dissolved oxygen measurement can bias estimate KLa.

scholarly journals Bacterial growth laws reflect the evolutionary importance of energy efficiency

2014 ◽  
Vol 112 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Arijit Maitra ◽  
Ken A. Dill
Keyword(s):  
Energy Efficiency ◽  
Bacterial Growth ◽  
Growth Conditions ◽  
High Energy ◽  
Fast Growth ◽  
Growth Speed ◽  
Energy Costs ◽  
Extensive Literature ◽  
E Coli ◽  
Growth Laws

We are interested in the balance of energy and protein synthesis in bacterial growth. How has evolution optimized this balance? We describe an analytical model that leverages extensive literature data on growth laws to infer the underlying fitness landscape and to draw inferences about what evolution has optimized inEscherichia coli. IsE. colioptimized for growth speed, energy efficiency, or some other property? Experimental data show that at its replication speed limit,E. coliproduces about four mass equivalents of nonribosomal proteins for every mass equivalent of ribosomes. This ratio can be explained if the cell’s fitness function is the the energy efficiency of cells under fast growth conditions, indicating a tradeoff between the high energy costs of ribosomes under fast growth and the high energy costs of turning over nonribosomal proteins under slow growth. This model gives insight into some of the complex nonlinear relationships between energy utilization and ribosomal and nonribosomal production as a function of cell growth conditions.

Dissolved oxygen measurement with an improved amperometric cell

1986 ◽  
Vol 190 ◽  
pp. 275-279 ◽  
Author(s):  
Th.W. Rejda ◽  
J.D.N. Bunschoten ◽  
G.A.J. Kalis
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Measurement

scholarly journals Investment in secreted enzymes during nutrient-limited growth is utility dependent

2017 ◽  
Vol 114 (37) ◽  
pp. E7796-E7802 ◽  
Author(s):  
Brent Cezairliyan ◽  
Frederick M. Ausubel
Keyword(s):  
Bacterial Growth ◽  
Pathogenic Bacteria ◽  
Quantitative Relationship ◽  
Growth Conditions ◽  
Limited Growth ◽  
Protein Substrate ◽  
Regulatory Strategy ◽  
Rate Of Increase ◽  
Secreted Proteases ◽  
Secreted Enzymes

Pathogenic bacteria secrete toxins and degradative enzymes that facilitate their growth by liberating nutrients from the environment. To understand bacterial growth under nutrient-limited conditions, we studied resource allocation between cellular and secreted components by the pathogenic bacteriumPseudomonas aeruginosaduring growth on a protein substrate that requires extracellular digestion by secreted proteases. We identified a quantitative relationship between the rate of increase of cellular biomass under nutrient-limiting growth conditions and the rate of increase in investment in secreted proteases. Production of secreted proteases is stimulated by secreted signals that convey information about the utility of secreted proteins during nutrient-limited growth. Growth modeling using this relationship recapitulated the observed kinetics of bacterial growth on a protein substrate. The proposed regulatory strategy suggests a rationale for quorum-sensing–dependent stimulation of the production of secreted enzymes whereby investment in secreted enzymes occurs in proportion to the utility they confer. Our model provides a framework that can be applied toward understanding bacterial growth in many environments where growth rate is limited by the availability of nutrients.

Sign in / Sign up

Export Citation Format

Share Document