Online measurement of dissolved oxygen in shake flask to elucidate its role on caffeine degradation by Pseudomonas sp.

Self-directing optimization for enhanced caffeine degradation in synthetic coffee wastewater using induced cells of Pseudomonas sp.: Bioreactor studies

Abstract: Coffee wastewater poses a serious threat to the environment due to the presence of a large number of toxic compounds which necessitates the importance of developing suitable treatment methodologies. Although there are treatments available to treat the different wastewaters, the presence of caffeine in wastewater interrupts the complete treatment of coffee wastewater. Alternatively, Pseudomonas sp. showed an excellent capacity to withstand coffee wastewater and degrades caffeine completely in shake flask studies. In this study, we scaled up the coffee wastewater treatment to a 1 L in bioreactor and optimized for caffeine degradation using the self-directing optimization technique. Using self-directing optimization maximum degradation rate of 16.73 mg/L.h was obtained at 210 rpm, 1.16 vvm, and 0.383 g/L of initial biomass. A regression model was developed to predict the caffeine degradation rate with oxygen mass transfer coefficient (kLa) and initial biomass concentration. The regression model was solved and the optimal conditions of initial biomass concentration and kLa are 0.23 g/L and 64.26 h−1 respectively. Under those conditions, experiments were performed and maximum degradation rate was 16.9 mg/L.h was obtained, which is in comparison with model prediction (15.2 mg/L.h).

Beverage caffeine intakes in the U.S.

Abstract: Caffeine is one of the most researched food components, with the vast majority of dietary contributions coming from beverage consumption; however, there is little population-level data on caffeine intakes in the US This study estimated the caffeine intakes of the US population using a comprehensive beverage survey, the Kantar Worldpanel Beverage Consumption Panel A nationally representative sample of 37,602 consumers (aged ≥ 2 years) of caffeinated beverages completed 7-day diaries which facilitated the development of a detailed database of caffeine values to assess intakes Results showed that 85% of the US population consumes at least one caffeinated beverage per day The mean (±SE) daily caffeine intake from all beverages was 165±1 mg for all ages combined Caffeine intake was highest in consumers aged 50-64 years (226±2 mg/day) The 90th percentile intake was 380 mg/day for all ages combined Coffee was the primary contributor to caffeine intakes in all age groups Carbonated soft drinks and tea provided a greater percentage of caffeine in the younger (<18 years) age groups The percentage of energy drink consumers across all age groups was low (≤10%) These data provide a current perspective on caffeinated beverage consumption patterns and caffeine intakes in the US population

Theobromine inhibits sensory nerve activation and cough

Abstract: SPECIFIC AIMSCough is a condition that affects the vast majority of people at some point in their lives and is the most common complaint for which medical attention is sought. Currently, no effective treatment exists. The aim of this study was to investigate the utility of a novel antitussive called theobromine, a methylxanthine derivative present in cocoa and chocolate, on cough and airway sensory nerve function in humans.PRINCIPAL FINDINGS1. Theobromine as a potential antitussiveSeveral synthetic antitussives are characterized by the presence of a 1,2,4-oxadiazole ring in their chemical structure. With the renaissance of the methylxanthine theophylline to treat asthma in the 1970s, a series of novel compounds with an oxadiazolylalkyl substituent at the N7 atom on the basic xanthine skeleton was synthesized and investigated as potential antiasthmatic and antitussive agents.With two of these compounds selected for preclinical testing, 3,7-dihydro-3-methyl-7-/(5-methyl-1,2,4-oxadiazol-3yl)methyl/-1H-purine...

Catabolic pathways and biotechnological applications of microbial caffeine degradation

Abstract: Catabolism of caffeine (1,3,7-trimethylxanthine) in microorganisms commences via two possible mechanisms: demethylation and oxidation. Through the demethylation route, the major metabolite formed in fungi is theophylline (1,3-dimethylxanthine), whereas theobromine (3,7-dimethylxanthine) is the major metabolite in bacteria. In certain bacterial species, caffeine has also been oxidized directly to trimethyl uric acid in a single step. The conversion of caffeine to its metabolites is primarily brought about by N-demethylases (such as caffeine demethylase, theobromine demethylase and heteroxanthinedemethylase), caffeine oxidase and xanthine oxidase that are produced by several caffeine-degrading bacterial species such as Pseudomonas putida and species within the genera Alcaligenes, Rhodococcus and Klebsiella. Development of biodecaffeination techniques using these enzymes or using whole cells offers an attractive alternative to the present existing chemical and physical methods removal of caffeine, which are costly, toxic and non-specific to caffeine. This review mainly focuses on the biochemistry of microbial caffeine degradation, presenting recent advances and the potential biotechnological application of caffeine-degrading enzymes.

Novel, Highly Specific N-Demethylases Enable Bacteria To Live on Caffeine and Related Purine Alkaloids

Abstract: The molecular basis for the ability of bacteria to live on caffeine as a sole carbon and nitrogen source is unknown. Pseudomonas putida CBB5, which grows on several purine alkaloids, metabolizes caffeine and related methylxanthines via sequential N-demethylation to xanthine. Metabolism of caffeine by CBB5 was previously attributed to one broad-specificity methylxanthine N-demethylase composed of two subunits, NdmA and NdmB. Here, we report that NdmA and NdmB are actually two independent Rieske nonheme iron monooxygenases with N(1)- and N(3)-specific N-demethylation activity, respectively. Activity for both enzymes is dependent on electron transfer from NADH via a redox-center-dense Rieske reductase, NdmD. NdmD itself is a novel protein with one Rieske [2Fe-2S] cluster, one plant-type [2Fe-2S] cluster, and one flavin mononucleotide (FMN) per enzyme. All ndm genes are located in a 13.2-kb genomic DNA fragment which also contained a formaldehyde dehydrogenase. ndmA, ndmB, and ndmD were cloned as His(6) fusion genes, expressed in Escherichia coli, and purified using a Ni-NTA column. NdmA-His(6) plus His(6)-NdmD catalyzed N(1)-demethylation of caffeine, theophylline, paraxanthine, and 1-methylxanthine to theobromine, 3-methylxanthine, 7-methylxanthine, and xanthine, respectively. NdmB-His(6) plus His(6)-NdmD catalyzed N(3)-demethylation of theobromine, 3-methylxanthine, caffeine, and theophylline to 7-methylxanthine, xanthine, paraxanthine, and 1-methylxanthine, respectively. One formaldehyde was produced from each methyl group removed. Activity of an N(7)-specific N-demethylase, NdmC, has been confirmed biochemically. This is the first report of bacterial N-demethylase genes that enable bacteria to live on caffeine. These genes represent a new class of Rieske oxygenases and have the potential to produce biofuels, animal feed, and pharmaceuticals from coffee and tea waste.

Improvement of tea leaves fermentation with Aspergillus spp. pectinase.

Abstract: The pectinase enzymes isolated from Aspergillus spp., A. indicus, A. flavus and A. niveus were used for fermentation of tea leaves. The enzymes were purified and characterized. The effect of both crude enzyme preparation and purified pectinase enzymes on the improvement of tea leaf fermentation were determined in terms of theaflavin, thearubigin, high polymerized substances, total liquor colour, dry matter content and total soluble solids of the tea produced. The crude enzyme preparations obtained from ethanol precipitation were found to be more effective in improving tea leaf fermentation than the purified pectinase enzymes.