1.Assessment of process parameters influencing the enhanced production of prodigiosin from Serratia marcescens and evaluation of its antimicrobial,antioxidant and dyeing potentials
Chandni Gulani ; Sourav Bhattacharya ; Arijit Das
Malaysian Journal of Microbiology 2012;8(2):116-122
Aims: Prodigiosin is a bright red pigment produced by certain strains of Serratia marcescens, characterized by a
common pyrrolylpyrromethane skeleton. This pigment is found to possess antibacterial, antifungal, immunosuppressive and antiproliferative activity. The present study aimed at designing process parameters for the enhanced production of this pigment.
Methodology and Results: Peptone glycerol broth was selected as the best synthetic medium. The effects of various media components and process parameters like carbon and nitrogen sources, temperature, pH, incubation period and other supplements were investigated. Maximal amount of prodigiosin was produced at temperature 25 °C, pH 7.0 and incubation period of 48 h. Supplementation of media with maltose and peptone yielded maximal amount of prodigiosin. Incorporation of minimal amount of supplements like silica gel, iron salts, inorganic phosphate also showed promising results. Chromatographic separations suggested that prodigiosin is made up of three different fractions (purple, orange and red). Further investigation of antimicrobial properties of prodigiosin revealed that it is a potent inhibitor against gram
positive bacteria like Staphylococcus aureus and Bacillus cereus and fungal pathogens like Candida albicans, C.
parapsilosis and Cryptococcus sp. This antimicrobial potency remained stable under a wide range of temperature and pH. The antioxidant capacity of prodigiosin was found to be 22.05 Bg ascorbic acid equivalents/ml of extract. When applied to textiles, prodigiosin resisted the action of acid, alkali and detergent.
Conclusion, Significance and Impact of study: Besides combating gram positive bacterial pathogens and some
pathogenic yeasts, prodigiosin with strong dyeing and antioxidant activity may find broad applications in textile and therapeutic industries.
2.Enhancement of protease production by Pseudomonas aeruginosa isolated from dairy effluent sludge and determination of its fibrinolytic potential
Raj Amrita ; Khess Nancy ; Pujari Namrata ; Bhattacharya Sourav ; Das Arijit ; Rajan Sundara Subbaramiah
Asian Pacific Journal of Tropical Biomedicine 2012;(z3):1845-1851
Objective: The present study aimed at isolating proteolytic bacteria from dairy effluent sludge, designing the process parameters for the enhanced production of protease and determination of its fibrinolytic potential. Methods: The dairy sludge was processed according to the microbiological criteria for the isolation of proteolytic bacteria. All the isolates were screened for their protease production ability and the isolate showing highest proteolysis was selected for further studies. Effects of various media components and process parameters like carbon and nitrogen supplementation, temperature, pH and incubation period were investigated. Partial purification of the protease was done using ammonium sulphate fractionation, following which its molecular weight and fibrinolytic activity were determined. Results: Based on the biochemical studies, the selected isolate was identified as Pseudomonas aeruginosa. The highest protease yield was obtained with maltose and yeast extract as supplements. The optimum pH, temperature and incubation period for protease production by the isolate was found to be 7.0, 37℃ and 48 h respectively. The partially purified enzyme preparation showed a single protein band in sodium dodecyl sulphate polyacrylamide gel electrophoresis, revealing the apparent molecular weight of the enzyme to be 35 kDa. The efficient removal of the blood stain emphasized its fibrinolytic potential. Conclusions: From the present study it is envisaged that cultural parameters significantly affect the protease production. Based upon the fibrinolytic activity, this protease may find broad applications in detergent and pharmaceutical industries.