Development and characterization of chitosan-based antimicrobial films incorporated with streptomycin loaded starch nanoparticles

Nowadays, Chitosan has attained more attention due to its potential applications in food, agriculture and pharmaceutics. The cationic nature of chitosan enhances the film forming capacity of this polymer. However, films made only from chitosan lack water resistance and have reduced mechanical properties. The functional properties of chitosan films can be improved when chitosan films are combined with other film forming materials. The objective of this study was to prepare chitosan based antimicrobial films by the incorporation of streptomycin loaded starch Nanocrystals. Different properties of this film such as swelling nature, moisture content, degradation nature and the antimicrobial activity of modified chitosan films were investigated. Drug releasing efficacy of the film was also studied. The addition of streptomycin loaded Starch nanocrystals in chitosan-gelatin film increased crystallinity of the film, lowered the swelling nature of the film to a controlled manner. Moreover the Modified chitosan based antimicrobial film showed almost 90% of 'Escherichia coli' inhibition and 80% of 'Bacillus subtilis' inhibition and also the film showed a sustained release (60%) of streptomycin for 10 days. Focal point • Benchside Synthesis of streptomycin loaded starch nanoparticles (SS-NPs) using nanoprecipitation method and the development of novel chitosan based antimicrobial film by the incorporation of streptomycin loaded starch nanoparticles using solvent casting technique • Bedside Development of potential multifunctional antimicrobial film for medical, pharmaceutical and food based applications due to its excellent film forming ability, biocompatibility, biodegradability and antimicrobial property • Industry The designed unique antimicrobial film, if finely tuned, can be used both in biomedical fields for developing scaffolds in tissue engineering, wound dressing material, capsule material for sustained drug release and immobilization of enzyme and food industry as packaging material • Government Financial investment and support from government would help to develop new novel translational tools which contribute for better health care and also help to reduces disease burden • RegulatoryStringent regulatory principles limit the clinical trials essential for validation of biomaterials which might have turned in to a highly beneficial multifunctional product such as antimicrobial film potentially useful both in biomedical and food industry

Purification and Characterization of Alkaline Metalloprotease from Bacillus sp. MTCC 9558 and its Application in Bioactive Peptide Production

The present study describes the protease purification from halophilic Bacillus sp. MTCC 9558 by a single step hydrophobic interaction chromatographic using Phenyl-Sepharose CL - 4B column. After the final purification steps, protease was purified to 59.62-fold with a specific activity of 165.75 U/mg protein and overall recovery of 5.89%. The homogeneity of the enzyme preparation was confirmed by procedures such as SDS - PAGE, zymogram analysis and MALDI-TOF techniques. The molecular weight was determined to be 80.7 KDa and casein zymogram analysis of purified protease showed a single band indicating that the protease is active as a monomer. This paper also describes comparison of purified protease with crude in order to determine the effect of impurities or contaminating proteins on its characteristics. The purified protease exhibited improved thermostability and stability in presence of organic solvents in comparison with crude enzyme. The alkaline protease was determined to be halotolerant and Zn2+ activated metalloprotease. The purified protease was characterized to determine its kinetic constants such as Km, Vmax, kcat and kcat/Km values. The purified enzyme exhibited promising characteristics of potential biotechnological interest. In this paper, one of the applications of this protease in protein hydrolysis for bioactive peptide production with emphasis on antibacterial studies is discussed

Scale up of production in a bioreactor of a halotolerant protease from moderately halophilic Bacillus sp. isolated from soil

Studies were conducted on the production of protease by moderately halophilic Bacillus sp. on agro-industrial waste materials. The bacterium could efficiently use many agro wastes as substrates but wheat bran supported maximum enzyme production. To ascertain the performance of the process in shake flasks and lab scale bioreactor, experiments were conducted to analyse protease activity utilizing wheat bran as cost effective substrate. The studies unveiled that pH 7.0, temperature 30°C and static conditions were optimal for enzyme production in flask level fermentation. In scale-up fermentation, at optimal pH and temperature, agitation rate of 50 rpm was best for protease production. The enzymatic nature was studied in 10% SDS gels with BSA (2.5 mg/mL) as substrate and banding pattern was compared with undigested BSA as control. The endoprotease nature and the kinetics of protease activity were confirmed. The enzyme retained 37% of its activity even at 5 M NaCl concentration. The proteolytic activity was also confirmed by casein zymogram analysis. The fermentation medium containing inexpensive substrates, physical conditions and ability of Bacillus sp. to exhibit protease activity on a large scale could collectively be useful for commercial production