The effect of various initial caffeine concentrations on growth and caffeine demethylase production by Pseudomonas sp. was studied in bioreactor. At initial concentration of 6.5 g l-1 caffeine, Pseudomonas sp. showed a maximum specific growth rate of 0.2 h-1, maximum degradation rate of 1.1 g h-1, and caffeine demethylase activity of 18,762 U g CDW-1 (CDW: cell dry weight). Caffeine degradation rate was 25 times higher in bioreactor than in shake flask. For the first time, we show highest degradation of 75 g caffeine (initial concentration 20 g l-1) in 120 h, suggesting that the tested strain has potential for successful bioprocess for caffeine degradation. Growth kinetics showed substrate inhibition phenomenon. Various substrate inhibition models were fitted to the kinetic data, amongst which the double-exponential (R 2 = 0.94), Luong (R 2 = 0.92), and Yano and Koga 2 (R 2 = 0.94) models were found to be the best. The Luedeking-Piret model showed that caffeine demethylase production kinetics was growth related. This is the first report on production of high levels of caffeine demethylase in batch bioreactor with faster degradation rate and high tolerance to caffeine, hence clearly suggesting that Pseudomonas sp. used in this study is a potential biocatalyst for industrial decaffeination. © 2010 Society for Industrial Microbiology.

Sathyanarayana Naidu Gummadi

Department Of Biotechnology

Caffeine

CAFFEINE DEMETHYLASE

methyltransferase

unclassified drug

article

bacterial growth

Bioreactor

degradation kinetics

enzyme activity

enzyme synthesis

growth rate

Kinetics

nonhuman

Pseudomonas

Bioreactors

CYTOCHROME P-450 CYP1A2

Fermentation

Pseudomonas sp.

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Industrial Microbiology and Biotechnology

Caffeine, a purine alkaloid is a constituent of widely consumed beverages. The scientific evidence which has proved the harm of this alkaloid has paved the way for innumerable research in the area of caffeine degradation. In addition to this, the fact that the by-products of the coffee and tea industry pollute the environment has called for the need of decaffeinating coffee and tea industry's by-products. Though physical and chemical methods for decaffeination are available, the lack of specificity for removal of caffeine in these techniques and their non-eco-friendly nature has opened the area of microbial and enzymatic degradation of caffeine. Another important application of microbial caffeine degradation apart from its advantages like specificity, eco-friendliness and cost-effectiveness is the fact that this process will enable the production of industrially and medically useful components of the caffeine degradation pathway like theobromine and theophylline. This is a comprehensive review which mainly focuses on caffeine degradation, large-scale degradation of the same and its applications in the industrial world. © 2011 Springer-Verlag.

Applied Microbiology and Biotechnology

Physiology, biochemistry and possible applications of microbial caffeine degradation

The growth of Pseudomonas sp. was studied in fed-batch process with an aim to improve the caffeine degradation rate and caffeine demethylase activity. The effects of varying initial caffeine concentrations in the batch mode, increase in the number of feeds, varying feed flow rates, and added nutrients to the feed on the fed-batch process were investigated. A maximum caffeine degradation rate of 0.82 g/L h and maximum caffeine demethylase activity of 2.6 U/mg were achieved using manual intermittent pulse feeds of caffeine with substrate concentration as feedback parameter for the fed batch started with an initial caffeine concentration of 3 g/L. A slight increase in the caffeine degradation rate (0.85 g/L h) and caffeine demethylase activity (3.4 U/mg) was observed when the additional nutrients were added along with caffeine in the feed. This is the first report showing complete degradation of large magnitudes of caffeine amounting to 237 g in 75 h. These results show that the fed-batch conditions achieved in this study using Pseudomonas sp. facilitate the development of a sustainable bioprocess to degrade the high concentrations of caffeine in industrial effluents. © 2011 Springer-Verlag.

Enhanced degradation of caffeine and caffeine demethylase production by Pseudomonas sp. in bioreactors under fed-batch mode

This report presents the substrate inhibitory effect of xanthine (XN) on microbial growth and optimisation of effective parameters to achieve high enzyme activity of xanthine oxidoreductase (XOR) through statistical design. Three efficient isolated strains (Pseudomonas aeruginosa CEBP1 and CEBP2, Pseudomonas sp. CEB1G) were screened for growth kinetic studies. Substrate inhibitory models (eg. Aiba, Edward) could explain the growth kinetics of CEBP1, CEBP2 and CEB1G very well with various initial [XN] (S 0 ), e.g., 0.1–35 g L −1 . Highest XOR activity was obtained at stationary phase when biomass yield was high. Highest catalytic efficiency (k cat /K M ) of XOR was obtained by CEBP1 at optimum specific growth rate of 0.082 h −1 and biomass yield of 0.196 g g −1 at S 0 = 5 g L −1 . The effects of S 0 , pH and temperature were studied by Box-Behnken experimental design to evaluate the interactive effects of the significant variables influencing XOR production by CEBP1. ANOVA with high correlation coefficient (R 2 &gt; 0.99) and lower ‘Prob &gt; F’value (&lt; 0.05) validated the second order polynomial model for the enzyme production. The highest XOR activity of 31.2 KU min −1 mg −1 was achieved by CEBP1 under optimised conditions (35 °C; S 0 =5 g L −1 ; pH = 7.0) as compared to any report in literature. A sevenfold substrate affinity of the enzyme was observed after purification. © 2019, © 2019 Taylor & Francis Group, LLC.

Journal of Environmental Science and Health - Part A Toxic/Hazardous Substances and Environmental Engineering

Modelling of growth kinetics of isolated Pseudomonas sp. and optimisation of parameters for enhancement of xanthine oxidoreductase production by statistical design of experiments

This report presents the substrate inhibitory effect of xanthine (XN) on microbial growth and optimisation of effective parameters to achieve high enzyme activity of xanthine oxidoreductase (XOR) through statistical design. Three efficient isolated strains (Pseudomonas aeruginosa CEBP1 and CEBP2, Pseudomonas sp. CEB1G) were screened for growth kinetic studies. Substrate inhibitory models (eg. Aiba, Edward) could explain the growth kinetics of CEBP1, CEBP2 and CEB1G very well with various initial [XN] (S-0), e.g., 0.1-35 g L-1. Highest XOR activity was obtained at stationary phase when biomass yield was high. Highest catalytic efficiency (k(cat)/K-M) of XOR was obtained by CEBP1 at optimum specific growth rate of 0.082 h(-1) and biomass yield of 0.196 g g(-1) at S-0 = 5 g L-1. The effects of S-0, pH and temperature were studied by Box-Behnken experimental design to evaluate the interactive effects of the significant variables influencing XOR production by CEBP1. ANOVA with high correlation coefficient (R-2 > 0.99) and lower 'Prob > F'value (< 0.05) validated the second order polynomial model for the enzyme production. The highest XOR activity of 31.2 KU min(-1) mg(-1) was achieved by CEBP1 under optimised conditions (35 degrees C; S-0=5 g L-1; pH = 7.0) as compared to any report in literature. A sevenfold substrate affinity of the enzyme was observed after purification.

JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART A-TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING

The effect of pH, aeration rate, and agitation rate on specific productivity of caffeine demethylase from Pseudomonas sp. was studied in a bioreactor. Maximum specific productivity of caffeine demethylase of 2,214 U g cell dry weight-1 h-1 was obtained at 0.27 vvm, 700 rpm, and pH 7.0. Under these conditions, volumetric oxygen transfer coefficient was 74.2 h-1, indicating that caffeine demethylase production by Pseudomonas sp. was highly oxygen-dependent. Different metabolite formation at different agitation and aeration rates can be used as a strategy for recovery of pharmaceutically important metabolites from caffeine by manipulation of conditions in a bacterial culture. This is the first report on production of high levels of caffeine demethylase in bioreactors. © 2009 Society for Industrial Microbiology.

Optimization of production of caffeine demethylase by Pseudomonas sp. in a bioreactor

Previously isolated strain of Pseudomonas sp. has the capability of utilizing caffeine as the sole source of carbon and nitrogen and degrading caffeine at higher concentrations (&gt;10 g l-1). In this study, an assay has been developed to study the enzymatic conversion of caffeine to subsequent methylxanthines by cell free extracts of Pseudomonas sp., the activity of which has been stabilized by use of stabilizers in the lysis buffer. Growth of the strain in various methylxanthines and later enzyme assay demonstrated that the enzyme(s) involved in degradation of caffeine and other methylxanthines were inducible in nature. The results also indicated that more than one enzyme are involved in degradation of caffeine to xanthine, which constitute the primary steps in bacterial caffeine catabolism. © 2008 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

Journal of Basic Microbiology

Inducible nature of the enzymes involved in catabolism of caffeine and related methylxanthines

Pseudomonas sp. NCIM 5235 capable of degrading high concentrations of caffeine (&gt;5 g/l) has been previously isolated from the soil of coffee plantation area. The critical medium components viz., KH2PO4, Na2HPO4, caffeine and Fe2+ affecting the rate of caffeine degradation were determined by Plackett-Burman design. These critical parameters were further optimized using response surface methodology. The optimum concentrations of KH2PO4, Na2HPO4, caffeine and Fe2+ were found to be 3.4 g/l, 0.352 g/l, 6.4 g/l and 0.075% (w/v), respectively. Under optimal conditions the caffeine degradation rate was increased to 0.18 g/(l h) from 0.1 g/(l h). Although the approach used for optimization is conventional, the increase in the rate of degradation of caffeine is significant. This is the first report on a strain capable of growing at higher concentrations of caffeine (&gt;5 g/l) at maximum rate of degradation (0.18 g/(l h)). © 2007 Elsevier B.V. All rights reserved.

Biochemical Engineering Journal

Enhanced biodegradation of caffeine by Pseudomonas sp. using response surface methodology

Pseudomonas sp. NCIM 5235 capable of degrading high concentrations of caffeine has been previously isolated from the soil of coffee plantation area. The isolate was capable of degrading 6.4 gL-1 initial concentration of caffeine at a rate of 0.1 g L-1 h-1. In this study, the physical parameters viz., pH, temperature and shaking speed have been optimized using central composite design. The optimum values of pH, temperature and shaking speed were found to be 7.8, 28°C and 190 rpm, respectively. Under optimized condition of pH, temperature and shaking speed, the rate of degradation of caffeine has been enhanced from 0.18 to 0.29 g L-1 h-1 which is 1.6 fold higher than the normal rate. This is the first report on degradation of high concentration of caffeine at higher rates. Under optimal conditions, the strain has also been found to degrade caffeine at 15 g L-1 initial concentration efficiently within 48 h. This makes Pseudomonas sp. NCIM 5235 an attractive candidate for development of biodecaffeination strategies. © Academic Journals Inc., USA.

Fulltext

American Journal of Food Technology

Optimization of physical parameters for biodegradation of caffeine by Pseudomonas sp.: A statistical approach

Caffeine in coffee pulp prevents the utilization of nutrition rich coffee pulp effectively. Microbial methods of caffeine degradation can help in detoxifying the pulp and it prove as a better alternative to the conventional methods of environmental unfriendly solvent extraction process of decaffeination. Previously Pseudomonas sp. GSC 1182 was isolated from the soil samples of coffee cultivation area to degrade caffeine. In this report, the cell growth kinetics of Pseudomonas sp. GSC 1182 at various concentration of caffeine ranging from 0.05 to 20 g/l was studied. The kinetic data showed substrate inhibition kinetics and maximum growth rate was obtained when the isolate was grown in medium containing 2.5 g/l of initial concentration of caffeine. The results also showed that the isolate was able to grow at high concentrations of caffeine (10 g/l). Different substrate inhibition models were fitted to the kinetic data and found the Luong model was best. The model predicted kinetic parameters were in agreement with the experimental findings. The kinetic parameters were: Sm = 20.2 g/l; KS = 0.59 g/l; μm = 0.24 h-1 and n = 2. This is the first detailed report on the cell growth kinetics of microorganism using caffeine as the substrate. © 2005 Elsevier Ltd. All rights reserved.

Journal	Journal of Industrial Microbiology and Biotechnology
ISSN	13675435
Open Access	No