Evaluating factors that influence microbial phenanthrene biodegradation rates by regression with categorical variables

Tang, Yinjie J.; Qi, Lihong; Krieger-Brockett, Barbara

doi:10.1016/j.chemosphere.2004.10.037

Cited by 41 publications

(32 citation statements)

References 60 publications

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“…Table II shows the categories for each ordinal-dependent variable. The relationship between model predicted yield (on a logarithmic scale) and the independent variables (regressors) can be correlated using linear regression (Tang et al, 2005), such that:…”

Section: Model Developmentmentioning

confidence: 99%

Evaluating Factors That Influence Microbial Synthesis Yields by Linear Regression with Numerical and Ordinal Variables

Colletti

Goyal

Varman

et al. 2010

Biotech & Bioengineering

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In the production of chemicals via microbial fermentation, achieving a high yield is one of the most important objectives. We developed a statistical model to analyze influential factors that determine product yield by compiling data obtained from engineered Escherichia coli developed within last 10 years. Using both numerical and ordinal variables (e.g., enzymatic steps, cultivation conditions, and genetic modifications) as input parameters, our model revealed that cultivation modes, nutrient supplementation, and oxygen conditions were the three significant factors for improving product yield. Generally, the model showed that product yield decreases as the number of enzymatic steps in the biosynthesis pathway increases (7-9% loss of yield per enzymatic step). Moreover, overexpression of enzymes or removal of competitive pathways (e.g., knockout) does not necessarily result in an amplification of product yield (P-value>0.1), possibly because of limited capacity in the biosynthesis pathway to accommodate an increase in flux. The model not only provides general guidelines for metabolic engineering and fermentation processes, but also allows a priori estimation and comparison of product yields under designed cultivation conditions.

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Section: Model Developmentmentioning

confidence: 99%

Evaluating Factors That Influence Microbial Synthesis Yields by Linear Regression with Numerical and Ordinal Variables

Colletti

Goyal

Varman

et al. 2010

Biotech & Bioengineering

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“…Stimulation with the addition of nutrients is shown to increase the number and activity of microbial populations, thus enhancing degradation [40,41]. Enhanced biodegradation rate is observed after the addition of nitrate and phosphate in sites when the background nutrients are insufficient [42]. Anaerobic biodegradation of PAHs is possible through both fermentative and respiratory metabolism, provided that suitable terminal electron acceptors (nitrate, sulfate and ferric ion) are present [43,44].…”

Section: Discussionmentioning

confidence: 99%

Effect of Co‐culture and Nutrients Supplementation on Bioremediation of Crude Petroleum Sludge

Devi

Reddy

Juwarkar

et al. 2011

CLEAN Soil Air Water

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Ex-situ bioremediation of real-field crude petroleum sludge was evaluated to elucidate the role of co-culture (bioaugmentation) and external nutrients supplementation (biostimulation) under anaerobic microenvironment. Maximum removal of total petroleum hydrocarbons (TPH) was observed by integrating biostimulation with bioaugmentation (R5, 44.01%) followed by bioaugmentation alone (R4, 34.47%), co-substrate supplemented operations [R6, 23.36%; R3, 16.5%; R2, 9.88%] and control (R1, 4.36%). Aromatics fraction showed higher degradation in all the conditions studied. Fate of six selected polycyclic aromatic hydrocarbons (PAHs) was evaluated during bioremediation. Among these, four ring PAHs compounds showed good degradation by integration of biostimulation with bioaugmentation (R5) while bioaugmentation alone (R4) documented good degradation of three ring PAHs. Lower ring PAHs compounds showed good degradation with the application of biostimulation (R6). Fluorescent in situ hybridization (FISH) detected the presence of known PAHs degrading microorganisms viz., Bacillus, Pseudomonas, Acido bacteria, Sulphur reducing bacteria Firmicutes, etc. Application of biostimulation and bioaugmentation strategies alone or in combinations documented noticeable influence on the degradation of petroleum sludge.

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“…Major factors that have a significant influence on bioremediation process efficiency are presented in the Table 2. Tang et al (2005) suggested that in view of the complex nature of the bioremediation process, especially in the soil matrix, a proper optimization of factors is essential to advance its efficiency. They in turn carried out studies to investigate ways to optimize such factors for enhancing PAH bioremediation efficiency in soil by employing the published degradation data using a multiple linear regression approach.…”

Section: Problems Associated With the Bioremediation Processmentioning

confidence: 99%

“…Some factors will alter the rate of microbial uptake and metabolism (the intrinsic activity of the cell) and other factors change the rate of contaminant transport to the microorganisms (bioavailability) Tang et al 2005). According to Semple and co-workers (2004), bioavailability actually describes two distinct fractions: (i) 'bio-available' (that compound which is interacting with biota at a given moment in time) plus and (ii) 'bioaccessible' (encompasses what is bio-available now plus what is potentially bio-available).…”

Section: Problems Associated With the Bioremediation Processmentioning

confidence: 99%

Bioremediation technologies for treatment of PAH-contaminated soil and strategies to enhance process efficiency

Mohan

Kisa

Ohkuma

et al. 2006

Rev Environ Sci Biotechnol

200

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The complex and diverse structural configurations of polycyclic aromatic hydrocarbons (PAHs), combined with their low bioavailability, hydrophobic nature, strong sorption phenomena, and high persistence in soil makes the design of effective bioremediation methodologies a challenge. The multi-phasic nature of the bioremediation process, restricted mass transfer and non-availability of degrading soil microflora further compound the problem. In this direction, this communication presents a focused review of bioremediation technologies used recently for the treatment of PAH-contaminated soils. The specific roles of important factors affecting bioremediation process efficiency are discussed. Finally some of the recently used strategies to enhance bioremediation process efficiency, including bioaugmentation, biostimulation, rhizoremediation, the use of chemotaxins, the biomimetic catalytic system approach, and integrated techniques, are reviewed.

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Evaluating factors that influence microbial phenanthrene biodegradation rates by regression with categorical variables

Cited by 41 publications

References 60 publications

Evaluating Factors That Influence Microbial Synthesis Yields by Linear Regression with Numerical and Ordinal Variables

Evaluating Factors That Influence Microbial Synthesis Yields by Linear Regression with Numerical and Ordinal Variables

Effect of Co‐culture and Nutrients Supplementation on Bioremediation of Crude Petroleum Sludge

Bioremediation technologies for treatment of PAH-contaminated soil and strategies to enhance process efficiency

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