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.

Sathyanarayana Naidu Gummadi

Department Of Biotechnology

Biodegradation

Optimization

Sodium compounds

Soils

CAFFEINE DEGRADATION

Central composite design

MEDIUM OPTIMIZATION

PLACKETT-BURMAN DESIGN

Organic compounds

Caffeine

article

nonhuman

priority journal

Pseudomonas

Response surface method

Soil analysis

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

Biochemical Engineering Journal

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

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.

Journal of Industrial Microbiology and Biotechnology

Kinetics of growth and caffeine demethylase production of Pseudomonas sp. in bioreactor

Previously, we isolated caffeine degrading Pseudomonas strain from soil of coffee plantation area, which could utilize caffeine as sole carbon and nitrogen source and could tolerate caffeine up to 20 g/L. In this study, caffeine degradation by immobilized cells of this strain was investigated. Various matrices were considered and agar-agar was chosen based on degradation rate (0.08 g/(L h)), bead stability and reusability. Further, immobilization parameters, viz., bead size (mm), agar-agar concentration % (w/v) and cell concentration (g/L) were optimized using central composite design. The optimal conditions of cell concentration, agar-agar concentration and bead size were 7.8 g/L, 5% (w/v) and 6.2 mm. Under optimal conditions, caffeine degradation rate was found to 0.15 g/(L h), which closely agrees with the model predicted values. This is the first report on caffeine degradation at high concentrations (10 g/L) by immobilized cells of Pseudomonas sp. Immobilization efficiency was 80%. Damköhler number is very much higher than 1, suggesting that mass transfer is the rate limiting process. © 2008 Elsevier B.V. All rights reserved.

Enhanced degradation of caffeine by immobilized cells of Pseudomonas sp. in agar-agar matrix using statistical approach

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

A bacterial strain capable of utilizing caffeine as the sole source of carbon and nitrogen has been isolated from soil of coffee plantation area and deposited at National Collection of Industrial Microorganisms as Pseudomonas sp. based on biochemical studies. In this study, the isolate showed close resemblance to Pseudomonas putida strain T-57 based on 16S rRNA analysis. The ability of Pseudomonas sp. to degrade caffeine was studied by growing the isolate in caffeine medium with 1.2, 5, 7.5 and 10 g L -1 of initial concentration of caffeine. It was observed that the isolate could efficiently degrade caffeine at an initial concentration of 5 g L -1 within 48 h. It could also bring about 59.9 and 21.5% degradation of caffeine in 96 h when the initial concentration of caffeine in the medium was 7.5 and 10 g L -1, respectively. Analysis of the metabolites formed during the course of time showed that degradation followed a demethylation pathway with 3, 7-dimethylxanthine as the first major product of degradation. Furthermore, a 12 kb plasmid was isolated and the involvement of this plasmid in caffeine degradation was indicated by growth of transformed E. eoli DH5a strain. This strain can therefore prove to be a very good candidate for the biotreatment of residues of coffee and tea processing plants and also a potential strain for the development of improved methods of decaffeination. © 2010 Academic Journals Inc.

Fulltext

Research Journal of Microbiology

Biodegradation of caffeine by Pseudomonas sp. NCIM 5235

Several microorganisms isolated from soil were tested for their ability to utilize caffeine as the sole carbon and nitrogen source. The isolate identified as Pseudomonas sp. GSC 1182 showed 80% degradation of caffeine in 48 h when caffeine was used as the sole carbon and nitrogen source. In the presence of sucrose (5 g/l), 100% degradation of caffeine was achieved within 36-40 h. The degradation rate was also found to increase when fructose, lactose and galactose were used as carbon source. The isolate showed decreased level (< 10%) of caffeine degradation in the presence of glucose. At an initial pH of 6.0, the complete degradation of caffeine was attained in 24 h. The addition of urea and ammonium sulfate as external nitrogen source decreased the caffeine degradation to 35% and 70% respectively. © 2006 Elsevier B.V. All rights reserved.

International Journal of Food Microbiology

A preliminary study of caffeine degradation by Pseudomonas sp. GSC 1182

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.

Process Biochemistry

Kinetics of cell growth and caffeine utilization by Pseudomonas sp. GSC 1182

Caffeine is a purine alkaloid and is a major constituent of coffee, tea and other beverages. It acts as a central nervous system stimulant and also has negative withdrawal effects. Decaffeinated beverages are being used to overcome its negative effects. Decaffeination is done by different methods like solvent, water and super critical fluid extraction. These methods apart from being non-specific are expensive and involve the usage of toxic organic solvents. Development of a process involving an enzymatic (specific) degradation of caffeine to non-toxic compound is necessary to solve the problems of chemical extraction of caffeine in food products as well as treating the caffeine containing waste products. The different microbial and enzymatic methods of caffeine removal are discussed in this review. The literature revealed that major caffeine degrading strains belong to Pseudomonas and Aspergillus. Though the enzymes involved in degradation of caffeine by microorganisms are known, in vitro enzymatic studies for caffeine degradation is not yet reported. © 2005 Elsevier Inc. All rights reserved.

Journal	Biochemical Engineering Journal
ISSN	1369703X
Open Access	No