Kinetic Growth Model Research Articles

Study of the kinetics of austenite grain growth by dynamic Ti-rich and Nb-rich carbonitride dissolution in HSLA steel: In-situ observation and modeling

The effect of carbonitrides on the growth of austenite grains in high-strength low-alloy (HSLA) steel was investigated through microstructure analysis and high-resolution dilatometry. The austenite grain growth at various temperatures was measured in situ using high temperature laser scanning confocal microscopy. Two kinds of precipitates with different morphologies containing large amounts of Ti and Nb were observed in the austenitized samples at different temperatures. The smaller Nb-rich spherical carbonitrides dissolved at the higher temperature, while the lager Ti-rich rectangular carbonitrides have a higher thermal stability and can pin at the austenite grain boundary. This study reveals that the dissolution of Nb in austenite causes the rapid growth of austenite grains and slows down the ferrite phase transition, which is beneficial to the formation of bainite. A kinetic model of austenite growth considering the dynamic dissolution of different types of carbonitrides is proposed. The results of the model show the same overall trend as the experimental results, and the individual differences can be explained. The proposed model can be used to predict the austenite grain size during the austenitizing process of HSLA steel and can reflect the austenite grain change throughout the process more continuously.

Kinetic modeling of microbial growth, enzyme activity, and gene deletions: An integrated model of β-glucosidase function in Cellvibrio japonicus.

Understanding the complex growth and metabolic dynamics in microorganisms requires advanced kinetic models containing both metabolic reactions and enzymatic regulation to predict phenotypic behaviors under different conditions and perturbations. Most current kinetic models lack gene expression dynamics and are separately calibrated to distinct media, which consequently makes them unable to account for genetic perturbations or multiple substrates. This challenge limits our ability to gain a comprehensive understanding of microbial processes towards advanced metabolic optimizations that are desired for many biotechnology applications. Here, we present an integrated computational and experimental approach for the development and optimization of mechanistic kinetic models for microbial growth and metabolic and enzymatic dynamics. Our approach integrates growth dynamics, gene expression, protein secretion, and gene-deletion phenotypes. We applied this methodology to build a dynamic model of the growth kinetics in batch culture of the bacterium Cellvibrio japonicus grown using either cellobiose or glucose media. The model parameters were inferred from an experimental data set using an evolutionary computation method. The resulting model was able to explain the growth dynamics of C. japonicus using either cellobiose or glucose media and was also able to accurately predict the metabolite concentrations in the wild-type strain as well as in β-glucosidase gene deletion mutant strains. We validated the model by correctly predicting the non-diauxic growth and metabolite consumptions of the wild-type strain in a mixed medium containing both cellobiose and glucose, made further predictions of mutant strains growth phenotypes when using cellobiose and glucose media, and demonstrated the utility of the model for designing industrially-useful strains. Importantly, the model is able to explain the role of the different β-glucosidases and their behavior under genetic perturbations. This integrated approach can be extended to other metabolic pathways to produce mechanistic models for the comprehensive understanding of enzymatic functions in multiple substrates.

Influence of elevated CO2 concentrations on growth, nutrient removal, and CO2 biofixation using Chlorella kessleri cultivation

In this study, the ability of microalgae Chlorella kessleri to remove nutrients, biofix CO2, and generate valuable biomass was investigated. For this purpose, CO2 at different concentrations was added to the synthetic tertiary municipal wastewater for cultivating C. kessleri in batch photobioreactors. The concentration of biomass increases gradually during the cultivation period for the tested CO2 concentrations of 2%, 6%, and 10%, except 0% CO2. The highest biomass concentration found was 607 mg/L, and the highest biomass productivity is 46 mg/L/day, at a CO2 concentration of 2%. Monod growth kinetic model based on a single substrate factor was used, and the experimental findings agree well with the predictions by the model for all feed concentrations except 0% CO2. Biofixation of CO2 depends on the optimal CO2 concentration supplied to the culture. The maximum biofixation rate of CO2 achieved at 2% CO2 is 83.88 mg/L/day. The maximum removal of total nitrogen of 99% was achieved for both 2% and 10% CO2, while the total nitrogen removal is negligible by microalgae cultured with air without CO2 enrichment, which confirms the beneficial effect of CO2 on the removal of nutrients from wastewater media. These findings indicate the possibility of nutrient removal from tertiary municipal wastewater using microalgae C. kessleri along with CO2 biofixation.

Improving the synthetic efficiency of single-wall carbon nanotube forests using a gas-analysis-designed mixed carbon feedstock

A high efficiency, mixed gas carbon feedstock was designed by gas analysis of ethylene-based single-wall carbon nanotube (SWCNT) chemical vapor deposition. Gas analysis identified acetylene and 1,3-butadiene as the primary contributors to CNT growth based on the observed correlation between the decrease in respective concentrations and the CNT growth rate. In addition, a semi-empirical chemical kinetics growth model was developed which further verified that the experimentally observed decrease of acetylene and 1,3-butadiene were due to their contribution to the synthesis reaction. Using these results, we designed a mixed carbon feedstock of acetylene and 1,3-butadiene at a ratio of 2:5 which efficiently grew high purity and selectivity SWCNTs at a high growth efficiency, four-times that of pure ethylene and two-times that of pure acetylene. The combination of acetylene and 1,3-butadiene proved synergetic due to the inherent differences in reactivity and hydrogen content through “carbon scavenging” by the hydrogen byproducts. As a result, unlike single-source carbon feedstocks, the total carbon feedstock concentration could be increased, which resulted in increasing yields without saturating the catalysts. Our results demonstrate the complementary roles of carbon feedstocks in developing high efficiency synthesis, which is important for the advancement of the synthesis of long and clean CNTs.

Utilization of Comprehensive Mathematical Modelling to Evaluate the Growth Kinetics of Pseudomonas putida LY1 on Phenol

Kinetic equations, which explain the behaviour of a microbe or an enzyme towards a specific substrate, are key to understanding many phenomena in biotechnological processes. They facilitate the mathematical prediction of growth parameters essential for the identification of key growth control parameters. We remodelled Banerjee and Ghoshal's published research (Banerjee and Ghoshal 2010) using some more kinetic growth models, such as Monod, Teissier, Andrews and Noack, Hinshelwood, Moser, Aiba, Webb (Edward), Yano and Koga, Han and Levenspiel and Luong used statistical methods such as Root Mean Square (RMSE), Adjusted Coefficient of Determination ( R2), corrected Akaike Information Criterion (AICc), Bias Factor, Accuracy Factor to determine the accuracy of the fitted model. The best model was Haldane with the true value of max determined as the value where the gradient for the slope is zero was 0.115 h-1 at 51 mg/L phenol. The results indicate that the exhaustive use of mathematical models on available published results could gleam new optimal models that can provide new knowledge on the way toxic substance inhibits growth rate in microbes.

Biodegradation and Kinetic Analysis of Acetaminophen with Co-culture of Bacterial Strains Isolated from Sewage Wastewater.

Acetaminophen (paracetamol, APAP) is one of the fastest growing pharmaceutical pollutants in the environment and has been classified under among the emerging organic pollutants (EOPs). The increasing concentration of it in our environment is not only harmful to the ecosystem, but also to the humans as well. In this study, the microscopy, biochemical test and 16S rRNA sequencing the characterization of APAP as the sole degrading stains viz. Staphylococcus sciuri strain DPP1 (MN744326), Bacillus subtilis strain DPP3 (MN744327), Bacillus paralicheniformis strain DKP1 (MN744324), Enterococcus faecium strain DKP2 (MN744325) and DDP2 (MT705211) were performed. Haldane's growth kinetic model was used to identify specific growth rate and observed for DPP1 (485mg/L), DPP3 (593mg/L), DKP1 (477mg/L), DKP2 (702mg/L) and DDP2 (685mg/L). The maximum specific growth rate was reported for the stains viz. DPP1, DPP3, DKP1, DKP2, and DDP2, was in order of 0.076, 0.223, 0.259, 0.179, and 0.141, respectively. The Box-Behnken Design (BBD) was used to identify the effect of physical parameters on degradation using mathematical modeling. The analysis of variance (ANOVA) showed that the strains DPP1, DPP3, DKP1, DKP2, and DDP2 had significant F-value and regression coefficient (R2) value of 0.01%, 0.06%, 0.37%, and 0.18%, respectively. The co-culture of the five strains has utilized 1200mg/L of APAP within 70h while individual strains took 10days. The intermediate metabolites like 4-aminophenol, benzamide, (R)-2-methylpentanoic acid, methylene-3-vinyl cyclohexane, and 1,5-hexadiene were identified by GC-MS. The degradation metabolic pathway was predicted by the intermediates by GC-MS, and PathPred based analysis.

GROWTH, CARBOHYDRATE PRODUCTIVITY AND GROWTH KINETIC STUDY OF Halochlorella rubescens CULTIVATED UNDER CO2-RICH CONDITIONS

This study was parametrically established to investigate the effect of different initial pH cultivation medium from pH 4.00 to pH 10.00 and CO2 concentration from 0.04% to 25% (v/v) on the growth and carbohydrate content of Halochlorella rubescens. Changes in biochemical compositions were also analysed using Fourier-transform infrared spectroscopy (FTIR). The maximum concentration of biomass and the productivity carbohydrate were 0.49 ± 0.01 g/L and 22.42 ± 0.03 mg/L.d respectively, when pH 10.00 and 5% (v/v) CO2 concentration were used for cultivation. The FTIR analysis revealed obvious changes in the chemical functional groups for the1200-900 cm-1, 1655 cm-1 and 2850 cm-1 bands, which represent carbohydrate, protein and lipid in microalgal biomass under different cultivation conditions. At the completion of this study, two kinetic growth models, Logistic and Gompertz were evaluated for microalgae growth at elevated condition. The kinetic model analysis for Halochlorella rubescens growth at high CO2 condition fit well with the Gompertz equation with R2 value of 0.9977. The data acquired from this research was helpful for predicting the growth characteristics of microalgae in a CO2-rich medium and could act as an essential platform for the production of chemicals and biofuels

Mechanistic investigation in Co-biodegradation of phenanthrene and pyrene by Candida tropicalis MTCC 184

Polycyclic aromatic hydrocarbons like phenanthrene and pyrene are found ubiquitously in terrestrial and aquatic ecosystems. This study has attempted to investigate mechanistic features of simultaneous degradation of phenanthrene and pyrene by the yeast Candida tropicalis. Batch experiments comprising various combinations of initial phenanthrene and pyrene concentrations have been analyzed vis-à-vis kinetic model for cell growth that takes into account self- and cross-inhibition of both substrates. The values of interaction parameters of inhibition revealed strong competitive cross-inhibition between two substrates, due to which biomass yield with dual substrates was reduced significantly. Inhibition induced by pyrene on cell growth was higher than phenanthrene. GC-MS analysis of intermediate metabolites revealed two parallel pathways, first triggered by intracellular cytochrome P450 monooxygenase enzyme, and second initiated by dioxygenase enzymes. The former pathway yielded sulfate conjugate and dihydrodiols, while the latter resulted in acids and aldehydes that enters the TCA cycle.

Ti-in-quartz: Evaluating the role of kinetics in high temperature crystal growth experiments

We present results from 25 hydrothermal quartz growth experiments, all conducted at 800 °C and 1 kbar but with varying starting materials and run times, to address discrepancies between calibrations of the titanium-in-quartz (TitaniQ) thermobarometer. In our experiments, a gold capsule is loaded with silica glass, water, and either rutile or anatase as the TiO2 source. In most experiments, there is also a large quartz seed crystal contained in an open inner capsule. The use of rutile versus anatase has a significant influence on the (re)crystallization pathways of the SiO2 and TiO2 components. When rutile is used, quartz overgrowths have abundant open cavities and complex zonations. The rutile does not completely dissolve because rutile is the stable TiO2 polymorph, and yet, new rutile forms at the quartz seed-overgrowth interface and on the outer surface of quartz crystals. This suggests crystallization of quartz near Ωrut ∼ 1, but wide-ranging Ti concentrations and zonations in quartz are indicative of kinetic effects. When powdered anatase is used, the quartz overgrowths look markedly different, lacking the open cavities and instead exhibiting step edges and terraces. The Ti concentrations in quartz from these experiments are also wide-ranging but reach larger values.Our results span the range of previous calibrations and indicate that Ti concentrations in quartz are sensitive to the TiO2/SiO2 ratio of the fluid as opposed to the absolute concentration (or activity) of dissolved TiO2. We present a kinetic model for quartz and rutile growth from a fluid where the input parameters are the initial degrees of supersaturation with respect to quartz and rutile, the total reactive surface area, and rate constants that link the degree of supersaturation to net precipitation rates. The model can explain many of the salient features of our experimental results, as well as those from previous studies, but requires that the rate constant multiplied by the reactive surface area for rutile is less than that of quartz, and that rutile solubility depends on the SiO2 concentration of the fluid, as documented in the recent literature. Complete quartz-rutile equilibrium may not have been established in any of the experimental studies, but low-pressure experiments with slowly grown quartz seem to be more reliable than extrapolations from high-pressure experiments for thermobarometry of shallow natural systems.

Kinetics of crude oil degradation by an indigenous mixed culture isolated from palm oil mill effluent

Objectives: To investigate the microbial growth kinetics and degradation of crude oil (CO) by mixed cultures isolated from palm oil mill effluent (POME). Methods/Statistical analysis: The scanning electron microscope was employed to examine the surface morphology of POME and the CO contaminated soil. Microbial count using the total viable count (TVC), mold, and coliform counts were investigated at different levels of CO contamination. Findings: The TVCs at 20, 40, and 60 mg/L of CO were 7.3x107 CFU/g, 6.8x106 CFU/g and 7.2 x 106 CFU/g, respectively. The concentration of the CO was utilized at 20 mg/L indicating that this concentration did not inhibit microbial growth. Based on the correlation coefficient (R2) values obtained for the four growth kinetic models, the Haldane model with R2 of 0.97 gave the best fit. Application/Improvements: Finally, the one way ANOVA and Tukey\'s honest significant difference (HSD) indicated the statistically significant effect (P< 0.05) of the initial CO concentration on microbial growth. Keywords: Kinetics; Degradation; Mixed culture; Crude oil; Palm oil mill effluent

Predictive model of growth kinetics for Staphylococcus aureus in raw beef under various packaging systems

This study describes a model of the growth kinetics for S. aureus in raw beef under wrapped packaging (WP), modified atmosphere packaging (MAP), vacuum packaging (VP), and vacuum skin packaging (VSP). Beef samples were inoculated with S. aureus and stored at 10, 15, 20, and 25 °C. VP and VSP showed lower maximum bacteria counts and higher lag time than WP and MAP at all temperatures. At 10 °C, S. aureus in VP and VSP decreased to about 2.5 Log CFU/g. Two primary models (modified Gompertz model and reparameterized Gompertz survival model) were used in the study. The secondary models were described using a polynomial equation and the Davey model. The bias factor (Bf), accuracy factor (Af), and root mean square error (RMSE) of the secondary models were 0.91–1.09, 1.00–1.13, and 0.00–0.68, respectively. The predictive models for kinetics of S. aureus in various packaged raw beef could help to predict the fate of S. aureus more accurately.

Callus growth kinetics and accumulation of secondary metabolites of Bletilla striataRchb.f. using a callus suspension culture.

Bletilla striata is an endangered traditional Chinese medicinal plant with multiple uses and a slow regeneration rate of its germplasm resources. To evaluate the callus growth kinetics and accumulation of secondary metabolites (SMs), a callus suspension culture was proven to be a valuable approach for acquiring high yields of medicinal compounds. An effective callus suspension culture for obtaining B. striata callus growth and its SMs was achieved with the in vitro induction of calluses from B. striata seeds. The callus growth kinetics and accumulation of SMs were analyzed using a mathematical model. The resulting callus growth kinetic model revealed that the growth curves of B. striata suspension-cultured calluses were sigmoidal, indicating changes in the growth of the suspension-cultured calluses. Improved Murashige and Skoog callus growth medium was the most favorable medium for B. striata callus formation, with the highest callus growth occurring during the stationary phase of the cultivation period. Callus growth acceleration started after 7 days and thereafter gradually decreased until day 24 of the cultivation period and reached its highest at day 36 period in both the dry weight and fresh weight analyses. The coelonin concentration peaked during the exponential growth stage and decreased afterward during the stationary stage of the callus suspension culture. The maximum content of coelonin (approximately 0.3323 mg/g callus dry weight) was observed on the 18th day of the cultivation cycle, while dactylorhin A and militarine reached the highest concentrations at day 24, and p-hydroxybenzyl alcohol at day 39. This investigation also laid a foundation for a multimathematical model to better describe the accumulation variation of SMs. The production of SMs showed great specificity during callus growth and development. This research provided a well-organized way to increase the accumulation and production of SMs during the scaled-up biosynthesis of calluses in B. striata callus suspension cultures.

Kinetic model of two-monomer polymerization.

We propose a kinetic gelation model of polymer growth with two monomeric types that have distinct functionalities (reaction sites), and can polymerize using different reaction types. The heterotypic aggregation of two monomer types is modeled using a moment generating function approach by tracking the temporal evolution of a closed system of moment equations up until gelation. We investigate several scenarios of polymerization with two distinct monomers that differ in the types of reactions that can occur. We determine numerical and analytical conditions for finite time blow-up (the emergence of an oligomer of infinite size) that depend on initial conditions, reaction rates, and number of reaction sites per monomer.

Abstract WP291: Stochastic Methods Can Resolve the Dilemma of Emergency Stroke Transport

Introduction: Drip and Ship (DNS) and Mothership (MS) are well-known emergency transport strategies in acute stroke care, but the criteria for choosing between the two is widely debated. Existing models define time-dependent outcomes but cannot resolve this debate with statistical significance because the independent variables are deterministic. We propose a novel stochastic framework that quantifies statistical significance between DNS and MS in a network of primary and comprehensive stroke centers. Methods: We represented the physiology of ischemic core growth as a stochastic first-order differential equation, enabling infarct volume at time of reperfusion to be calculated and mapped to 90-day mRS. Using Texas as a case study, we configured the state’s stroke network within 15,811 geographic blocks as defined by census data. For each block, we ran Monte Carlo simulations to generate Beta distributions of large- and small-vessel infarct volumes, which were then translated into cumulative distribution functions of mRS. A two-sample Kolmogorov-Smirnov test for significance, and Cohen’s d effect size statistic for practical significance were computed between each DNS and MS pair. Stable effect sizes were assured by sampling &gt; 5,000 total infarct volumes for each block. All model parameters were established from large cohort studies or trials. Results: Of the 13,113 blocks where the primary stroke center is the closest hospital from origin, DNS produces significantly better stroke outcomes than MS in 79.0% (0.3% SEM; P &lt; 0.05; 0.2 &lt; d &lt; 0.5). For the subset of patients with large-vessel strokes, MS produces significantly better outcomes in 44.6% of blocks (1.3% SEM; P &lt; 0.05; 0.4 &lt; d &lt; 0.85). Conclusion: Stochastic methods enable the use of clinically relevant metrics for comparative significance of DNS and MS in a geographic region. This formalism, which has not been incorporated in previous models, can be further generalized beyond stochastic infarct volumes if sufficiently large datasets become available. For example, the kinetic growth model can integrate the statistical distributions of times (pre-hospital and hospital) leading up to intervention, and patient attributes that affect outcomes, such as the degree of collateral flow and comorbidities.

A Multiscale Approach for Gas Hydrates Considering Structure, Agglomeration, and Transportability under Multiphase Flow Conditions: II. Growth Kinetic Model

A Multiscale Approach for Gas Hydrates Considering Structure, Agglomeration, and Transportability under Multiphase Flow Conditions: II. Growth Kinetic Model

Kinetics of cooperative CO2 adsorption in diamine-appended variants of the metal-organic framework Mg2(dobpdc).

Carbon capture and sequestration is a key element of global initiatives to minimize anthropogenic greenhouse gas emissions. Although many investigations of new candidate CO2 capture materials focus on equilibrium adsorption properties, it is also critical to consider adsorption/desorption kinetics when evaluating adsorbent performance. Diamine-appended variants of the metal–organic framework Mg2(dobpdc) (dobpdc4− = 4,4′-dioxidobiphenyl-3,3′-dicarboxylate) are promising materials for CO2 capture because of their cooperative chemisorption mechanism and associated step-shaped equilibrium isotherms, which enable large working capacities to be accessed with small temperature swings. However, the adsorption/desorption kinetics of these unique materials remain understudied. More generally, despite the necessity of kinetics characterization to advance adsorbents toward commercial separations, detailed kinetic studies of metal–organic framework-based gas separations remain rare. Here, we systematically investigate the CO2 adsorption kinetics of diamine-appended Mg2(dobpdc) variants using a thermogravimetric analysis (TGA) assay. In particular, we examine the effects of diamine structure, temperature, and partial pressure on CO2 adsorption and desorption kinetics. Importantly, most diamine-appended Mg2(dobpdc) variants exhibit an induction period prior to reaching the maximum rate of CO2 adsorption, which we attribute to their unique cooperative chemisorption mechanism. In addition, these materials exhibit inverse Arrhenius behavior, displaying faster adsorption kinetics and shorter induction periods at lower temperatures. Using the Avrami model for nucleation and growth kinetics, we determine rate constants for CO2 adsorption and quantitatively compare rate constants among different diamine-appended variants. Overall, these results provide guidelines for optimizing adsorbent design to facilitate CO2 capture from diverse target streams and highlight kinetic phenomena relevant for other materials in which cooperative chemisorption mechanisms are operative.

Kinetics of epitaxial formation of nanostructures by Frank–van der Merwe, Volmer–Weber and Stranski–Krastanow growth modes

Nowadays, two-dimensional crystals (2D materials) and structures with quantum dots (0D materials) are considered as one of the most promising materials for electronics and photonics of the next generation. The basic method of synthesis of heterostructures with 2D and 0D structures is their self-induced formation during the molecular beam epitaxy. Three epitaxial growth modes are distinguished: Frank–van der Merwe, Volmer–Weber, and Stranski–Krastanow, that allow one to obtain multi-layered structures with 2D materials, quantum wells and quantum dots. In this work generalized kinetic model of epitaxial growth of nanostructures by all three mechanisms is presented. Comparison of various growth modes is conducted and their peculiarities are pointed out. Ways to control the properties of obtained 2D and 0D nanostructures are proposed with the help of the established model.

A colourimetric method for the measuring of the mass transfer kinetics of carbon dioxide in aqueous media

The measurement of the gas-liquid mass transfer coefficient of carbon dioxide in aqueous media is relevant in the field of phototrophic microorganism culture. Here, we present an approach that allowed the handling of a system composed of seven chemical reactions, in which the transfer process of CO2 was one of them, pursuing the objective of quantifying the rate of dissolution of carbon dioxide in a designed liquid medium. A simple methodology, involving the use of an acid-base indicator, acting as a tracer, was successfully employed. It was established, that starting from a condition distant from its unique equilibrium, through the alteration of the initial pH value of a designed arbitrary state by adding onto it exact amounts of a strong base, the incorporation of CO2, from an air current in contact with the perturbed liquid, occurred in order to restore a new balance. For each experience, achieved under the same operational conditions, it was possible to calculate nearly equal values of kinetic constants which holds information about the behaviour of the system. Collectively the results presented here suggest that this methodology could be adapted to several different systems, enlightening easier ways of incorporating the transfer kinetics of this major carbon source on the existing growth kinetic models of phototrophic microorganisms. At the same time, it highlights the fact that probably the rate-controlling step it is not the transfer reaction of CO2 by itself, as the process of hydration of CO2 is.

Batch and fed-batch fermentation of optically pure D (-) lactic acid from Kodo millet (Paspalum scrobiculatum) bran residue hydrolysate: growth and inhibition kinetic modeling

A low-cost Kodo millet bran residue was utilized as feedstock for the production of D (−) lactic acid (DLA) using Lactobacillus delbrueckii NBRC3202 under anaerobic condition. Data culled from a series of batch fermentation processes with different initial Kodo millet bran residue hydrolysate (KMBRH) and DLA concentrations were used for kinetic model development. Both simulated and experimental data were in good agreement for cell growth, KMBRH utilization, and DLA formation. The values of kinetic constants specific growth rate, (μm = 0.17 h−1); growth (αP = 0.96 g.g−1) and non-growth (βP = 1.19 g.g−1.h−1) associated constant for DLA production and the maximum specific KMBRH utilization rate, (qG, max = 1.18 g.g−1.h−1) were in good agreement with the literature reports. Kinetic analysis elucidated that L. delbrueckii growth was predominantly influenced by KMBRH limitation and highly sensitive to DLA inhibition. Fed-batch fermentation studies demonstrated the existence of substrate and product inhibition paving the scope for process intensification.

Isolation, characterization and growth kinetics of phenol hyper-tolerant bacteria from sewage-fed aquaculture system

Pollution of aquatic resources is increasing day-by-day, and phenolic compounds are common pollutants negatively impacting aquatic biodiversity and production. This study aimed at isolation of phenol hyper-tolerant bacteria from polluted aquaculture resource so that they might be useful in aquaculture systems. Four phenol hyper-tolerant bacterial strains were isolated from sewage fed East Kolkata Wetlands, a Ramsar site. By 16S rDNA sequence, cell morphology and biochemical characteristics the strains PDB2, PDB13, PDB16, and PDB26 were identified as Acinetobacter sp., Acinetobacter junii, Pseudomonas citronellolis, and Bacillus cereus, respectively. Pseudomonas citronellolis strain PDB16, described in this study, is possibly the first report of phenol hyper-tolerant strain in this species. All the four strains degraded 600 mg L−1 phenol within 5 days and expressed catechol 1,2-dioxygenase but lacked catechol 2,3-dioxygenase enzyme suggesting that the bacteria used the ortho-cleavage pathway for phenol degradation. In growth kinetic study Edwards and Aiba model, rather than the most popular Haldane model, gave the best fit indicating behavioral divergence of these strains with those from petroleum contaminated environments. The phenol degrading bacteria isolated from a polluted sewage fed aquaculture system might be useful in degradation and remediation of polluted aquaculture resources as well as inland open waters.