Growth kinetics of Escherichia coli with galactose and several other sugars in carbon-limited chemostat culture

1999 ◽  
Vol 46 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Urs Lendenmann ◽  
Mario Snozzi ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Steady State ◽  
Specific Growth Rate ◽  
Growth Kinetics ◽  
Specific Growth ◽  
Chemostat Culture ◽  
Monod Model ◽  
E Coli ◽  
Kinetics Of

Kinetic models for microbial growth describe the specific growth rate (μ) as a function of the concentration of the growth-limiting nutrient (s) and a set of parameters. A typical example is the model proposed by Monod, where μ is related to s using substrate affinity (Ks) and the maximum specific growth rate (μmax). The preferred method to determine such parameters is to grow microorganisms in continuous culture and to measure the concentration of the growth-limiting substrate as a function of the dilution rate. However, owing to the lack of analytical methods to quantify sugars in the microgram per litre range, it has not been possible to investigate the growth kinetics of Escherichia coli in chemostat culture. Using an HPLC method able to determine steady-state concentrations of reducing sugars, we previously have shown that the Monod model adequately describes glucose-limited growth of E. coli ML30. This has not been confirmed for any other sugar. Therefore, we carried out a similar study with galactose and found steady-state concentrations between 18 and 840 μg·L-1 for dilution rates between 0.2 and 0.8·h-1, respectively. With these data the parameters of several models giving the specific growth rate as a function of the substrate concentration were estimated by nonlinear parameter estimation, and subsequently, the models were evaluated statistically. From all equations tested, the Monod model described the data best. The parameters for galactose utilisation were μmax = 0.75·h-1 and Ks = 67 μg·L-1. The results indicated that accurate Ks values can be estimated from a limited set of steady-state data when employing μmax measured during balanced growth in batch culture. This simplified procedure was applied for maltose, ribose, and fructose. For growth of E. coli with these sugars, μmax and Ks were for maltose 0.87·h-1, 100 μg·L-1; for ribose 0.57·h-1, 132 μg·L-1, and for fructose 0.70·h-1, 125 μg·L-1. Key words: monod model, continuous culture, galactose, glucose, fructose, maltose, ribose.

Specific growth rate and not cell density controls the general stress response in Escherichia coli

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1637-1648 ◽  
Author(s):  
Julian Ihssen ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Stress Response ◽  
Specific Growth Rate ◽  
Cell Density ◽  
Specific Growth ◽  
Batch Cultures ◽  
General Stress Response ◽  
E Coli ◽  
Density Effects

In batch cultures of Escherichia coli, the intracellular concentration of the general stress response sigma factor RpoS typically increases during the transition from the exponential to the stationary growth phase. However, because this transition is accompanied by complex physico-chemical and biological changes, which signals predominantly elicit this induction is still the subject of debate. Careful design of the growth environment in chemostat and batch cultures allowed the separate study of individual factors affecting RpoS. Specific growth rate, and not cell density or the nature of the growth-limiting nutrient, controlled RpoS expression and RpoS-dependent hydroperoxidase activity. Furthermore, it was demonstrated that the standard E. coli minimal medium A (MMA) is not suitable for high-cell-density cultivation because it lacks trace elements. Previously reported cell-density effects in chemostat cultures of E. coli can be explained by a hidden, secondary nutrient limitation, which points to the importance of medium design and appropriate experimental set-up for studying cell-density effects.

scholarly journals Growth Kinetics of Hyphomicrobium and Thiobacillus spp. in Mixed Cultures Degrading Dimethyl Sulfide and Methanol

2010 ◽  
Vol 76 (16) ◽  
pp. 5423-5431 ◽  
Author(s):  
Alexander C. Hayes ◽  
Steven N. Liss ◽  
D. Grant Allen
Keyword(s):  
Growth Rate ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Specific Growth Rate ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Dimethyl Sulfide ◽  
Specific Growth ◽  
Rrna Gene ◽  
Kinetics Of

ABSTRACT The growth kinetics of Hyphomicrobium spp. and Thiobacillus spp. on dimethyl sulfide (DMS) and methanol (in the case of Hyphomicrobium spp.) in an enrichment culture created from a biofilter cotreating DMS and methanol were studied. Specific growth rates of 0.099 h−1 and 0.11 h−1 were determined for Hyphomicrobium spp. and Thiobacillus spp., respectively, growing on DMS at pH 7. These specific growth rates are double the highest maximum specific growth rate for bacterial growth on DMS reported to date in the literature. When the pH of the medium was decreased from pH 7 to pH 5, the specific growth rate of Hyphomicrobium spp. decreased by 85%, with a near 100-fold decline in the yield of Hyphomicrobium 16S rRNA gene copies in the mixed culture. Through the same pH shift, the specific growth rate and 16S rRNA gene yield of Thiobacillus spp. remained similar. When methanol was used as a substrate, the specific growth rate of Hyphomicrobium spp. declined much less over the same pH range (up to 30%) while the yield of 16S rRNA gene copies declined by only 50%. Switching from an NH4 +-N-based source to a NO3 −-N-based source resulted in the same trends for the specific growth rate of these microorganisms with respect to pH. This suggests that pH has far more impact on the growth kinetics of these microorganisms than the nitrogen source. The results of these mixed-culture batch experiments indicate that the increased DMS removal rates observed in previous studies of biofilters cotreating DMS and methanol are due to the proliferation of DMS-degrading Hyphomicrobium spp. on methanol at pH levels not conducive to high growth rates on DMS alone.

Proteome reallocation in Escherichia coli with increasing specific growth rate

2015 ◽  
Vol 11 (4) ◽  
pp. 1184-1193 ◽  
Author(s):  
Karl Peebo ◽  
Kaspar Valgepea ◽  
Andres Maser ◽  
Ranno Nahku ◽  
Kaarel Adamberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Protein Expression ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Rich Medium ◽  
Metabolic Processes ◽  
E Coli ◽  
Fast Growing

Allocation of protein expression costs between metabolic processes in slow and fast growingE. coliin defined rich medium.

scholarly journals Specific Growth Rate Determines the Sensitivity of Escherichia coli to Thermal, UVA, and Solar Disinfection

2006 ◽  
Vol 72 (4) ◽  
pp. 2586-2593 ◽  
Author(s):  
Michael Berney ◽  
Hans-Ulrich Weilenmann ◽  
Julian Ihssen ◽  
Claudio Bassin ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
E Coli ◽  
Mild Heat ◽  
Uva Light ◽  
Specific Growth Rates ◽  
Slow Growing

ABSTRACT Knowledge about the sensitivity of the test organism is essential for the evaluation of any disinfection method. In this work we show that sensitivity of Escherichia coli MG1655 to three physical stresses (mild heat, UVA light, and sunlight) that are relevant in the disinfection of drinking water with solar radiation is determined by the specific growth rate of the culture. Batch- and chemostat-cultivated cells from cultures with similar specific growth rates showed similar stress sensitivities. Generally, fast-growing cells were more sensitive to the stresses than slow-growing cells. For example, slow-growing chemostat-cultivated cells (D = 0.08 h−1) and stationary-phase bacteria from batch culture that were exposed to mild heat had very similar T 90 (time until 90% of the population is inactivated) values (T 90, chemostat = 2.66 h; T 90, batch = 2.62 h), whereas T 90 for cells growing at a μ of 0.9 h−1 was 0.2 h. We present evidence that the stress sensitivity of E. coli is correlated with the intracellular level of the alternative sigma factor RpoS. This is also supported by the fact that E. coli rpoS mutant cells were more stress sensitive than the parent strain by factors of 4.9 (mild heat), 5.3 (UVA light), and 4.1 (sunlight). Furthermore, modeling of inactivation curves with GInaFiT revealed that the shape of inactivation curves changed depending on the specific growth rate. Inactivation curves of cells from fast-growing cultures (μ = 1.0 h−1) that were irradiated with UVA light showed a tailing effect, while for slow-growing cultures (μ = 0.3 h−1), inactivation curves with shoulders were obtained. Our findings emphasize the need for accurate reporting of specific growth rates and detailed culture conditions in disinfection studies to allow comparison of data from different studies and laboratories and sound interpretation of the data obtained.

scholarly journals AKTIVITAS INULINASE OLEH Pichia manshurica DAN FUSAN F4 PADA FERMENTASI BATCH DENGAN UMBI DAHLIA (Dahlia sp) SEBAGAI SUBSTRAT

REAKTOR ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 187 ◽  
Author(s):  
Wijanarka Wijanarka ◽  
Endang Sutariningsih Soetarto ◽  
Kumala Dewi ◽  
Ari Indrianto
Keyword(s):  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Lag Phase ◽  
Growth Media ◽  
A Value ◽  
Inulinase Activity ◽  
Pichia Manshurica ◽  
Microbial Strains ◽  
Kinetics Of

ACTIVITY OF INULINASE OF Pichia Manshuria AND FUSAN F4 ON BATCH FERMENTATION UDING DAHLIA TUBER (Dahlia sp) AS A SUBSTRATE. A dahlia tuber is one of the common inulin rich crops. Inulin is formed by units of fructans, which are polymers of D-fructose. Inulinases (EC 3.2.1.7) catalyze the hydrolysis of inulin, producing fructooligosaccharides (FOS), inulooligosaccharides (IOS), pulullan, acetone, butanol and sorbitol, therefore dahlia tubers are used as growth media. The inulin hydrolyzing activity has been reported from various microbial strains Pichia manshurica and Fusan F4 which is the result of fusion protoplast. The objective of this study was to determine the activity of inulinase Pichia manshurica and Fusan F4 on the substrate dahlia tubers. Fusan F4 to increase inulinase activity compared with Pichia manshurica and to investigate the kinetics of specific growth rate (μ) and time double (g) from of Pichia manshurica and Fusan F4. The results showed that the exponential phase occurs at 0-12 hour without a lag phase. P. manshurica has a specific growth rate (μ) of 0.18/hour with time double (g) 3.90 hours and the inulinase enzyme activity of 0.56 IU, while for Fusan F4 consecutive has a value μ of 0.20/hour, g of 3.49 hours and the activity of 0.69 IU. The conclusion of this research is to improve Fusan F4 inulinase activity and the ability has to be better than the Pichia manshurica.Umbi dahlia merupakan salah satu umbi yang mengandung inulin. Inulin merupakan polimer fruktan yang dapat dipecah oleh enzim inulinase (E.C. 3.2.1.7) menjadi fruktosa. Fruktosa merupakan bahan baku dasar untuk pembuatan FOS, IOS, pulullan, aseton dan sorbitol, oleh karena itu umbi dahlia digunakan sebagai media pertumbuhan. Enzim inulinase ini secara indigenous dimiliki oleh Pichia manshurica dan Fusan F4 yang merupakan hasil fusi protoplas.Tujuan  penelitian ini adalah  untuk mengetahui aktivitas inulinase Pichia manshurica dan Fusan F4 pada substrat umbi dahlia, Fusan F4 mampu meningkatkan aktivitas inulinase dibandingkan dengan Pichia manshurica serta untuk mengetahui kinetika kecepatan pertumbuhan specifik (µ) dan waktu generasi (g) Pichia manshurica dan Fusan F4. Hasil penelitian menunjukkan bahwa fase  eksponensial terjadi pada jam ke-0 sampai jam ke-12 tanpa diikuti fase lag, Pichia manshurica mempunyai kecepatan pertumbuhan specific (µ)  sebesar 0,18/jam dengan waktu generasi (g) 3,90 jam dan aktivitas enzim inulinase yang dihasilkan sebesar 0,56 IU, sedangkan untuk fusan F4 secara berturut-turut mempunyai nilai µ sebesar 0,20/jam, g sebesar 3,49 jam dan aktivitas sebesar 0,69 IU. Kesimpulan dari penelitian ini adalah Fusan F4 mampu meningkatkan aktivitas inulinase dan mempunyai kemampuan lebih baik dibanding dengan Pichia manshurica.

Effect of specific growth rate on the production of a recombinant nuclease by Escherichia coli

2003 ◽  
Vol 14 (2) ◽  
pp. 101-107 ◽  
Author(s):  
Li-Chun Cheng ◽  
Lien-I Hor ◽  
Jau-Yann Wu ◽  
Teh-Liang Chen
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth

Influence of specific growth rate over the secretory expression of recombinant potato carboxypeptidase inhibitor in fed-batch cultures of Escherichia coli

2010 ◽  
Vol 45 (8) ◽  
pp. 1334-1341 ◽  
Author(s):  
Juan-Miguel Puertas ◽  
Jordi Ruiz ◽  
Mónica Rodríguez de la Vega ◽  
Julia Lorenzo ◽  
Glòria Caminal ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Fed Batch ◽  
Secretory Expression ◽  
Batch Cultures ◽  
Carboxypeptidase Inhibitor

Sebatian Metoksiaromatik Sebagai Substrat Pertumbuhan dan Pengaruh Enzim Demetilase dalam Acetobacterium Woodii DSM 1030

2012 ◽  
Author(s):  
Mohd. Sahaid Hj. Kalil ◽  
Muhammad Zaki ◽  
Wan Mohtar Wan Yusoff ◽  
Mohammad Ramlan Mohd. Salleh
Keyword(s):  
Growth Rate ◽  
Steady State ◽  
Sole Carbon Source ◽  
Specific Growth ◽  
Chemostat Culture ◽  
Carbon Sources ◽  
Syringic Acid ◽  
Organic Substrate ◽  
Acetobacterium Woodii ◽  
Vanilic Acid

Penyelidikan ini bertujuan untuk menyaring substrat organik bagi untuk penghasilan sel–sel A. woodii teraruh demetilase. Pertumbuhan A. woodii dilakukan dalam medium “Balch” yang mengandungi sumber karbon berbeza dalam keadaan anaerobik. Sebanyak sebelas substrat telah diuji iaitu anisol, 2– dan 3–metoksifenol, asid vanilik, asid siringik, asid 2,3,4–, 2,4,5– dan 3,4,5–trimetoksi benzoik, 2,3,4–, 2,4,5– dan 3,4,5–trimetoksi benzil alkohol. 2–metoksifenol merupakan substrat terbaik untuk pertumbuhan A. woodii pada kadar pertumbuhan spesifik 0.14 j–1. Penghasilan sel–sel teraruh demetilase dilakukan dalam kultur kemostat pada kadar pencairan (D) 0.0j–1. Sel-sel pada keadaan mantap dituai dalam keadaan anaerobik dan dipekatkan sebelum digunakan. Pertumbuhan A. woodii didapati maksimum dengan menggunakan kepekatan 0.62 g/L 2–metoksifenol sebagai sumber karbon tunggal. Tindak balas penyahmetilan oleh sel–sel A. woodii meningkat sebanyak 78% apabila 2–metoksifenol sebanyak 0.31 g/L ditambah dalam medium yang mengandungi fruktosa (1% w/v) semasa kultur kemostat. Kata kunci: tindak balas penyahmetilan; demetilase; sel-sel tertuai; metosiaromatik, Acetobacteriumwoodii The objective of this project was to screen organic substrate suitable for the growth of A. woodii, and as for the production of demethylase. A. woodii was grown in “Balch” medium containing different carbon sources. Eleven substrates were tested including anisole, 2– and 3–methoxyphenol, vanilic acid, syringic acid, 2,3,4–, 2,4,5– and 3,4,5–trimethoxy benzoic acid and 2,3,4–, 2,4,5– and 3,4,5–trimethoxy benzyl alcohol. It was found that 2–methoxyphenol was the best substrate with a specific growth rate of 0.14 h–1. The production of demethylase induced cells was carried out in a chemostat culture at a dilution rate (D) of 0.08 h–1. Cells were harvested at steady state of growth and concentrated before use. Optimal concentration of 2–methoxvphenol as the sole carbon source was 0.62 g/L. Demethylation reaction of 0.31 g/L 2–methoxyphenol by induced culture increases 78% relative to the chemostat culture containing only fructose. Key words: Demethylation reaction; demethylase; harvested cells; methoxyaromatic; Acetobacteriumwoodii

Evolution of Escherichia coli During Growth in a Constant Environment

Genetics ◽  
1987 ◽  
Vol 116 (3) ◽  
pp. 349-358
Author(s):  
Robert B Helling ◽  
Christopher N Vargas ◽  
Julian Adams
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Specific Growth Rate ◽  
Continuous Culture ◽  
Specific Growth ◽  
Maximum Specific Growth Rate ◽  
Constant Environment ◽  
Single Clone ◽  
Mixed Populations

ABSTRACT Populations of Escherichia coli, initiated with a single clone and maintained for long periods in glucose-limited continuous culture, developed extensive polymorphisms. In one population, examined after 765 generations, two majority and two minority types were identified. Stable mixed populations were reestablished from the isolated strains. Factors involved in the development of this polymorphism included differences in the maximum specific growth rate and in the transport of glucose, and excretion of metabolites by some clones which were utilized by minority clones.

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