Immobilization of lactic acid bacteria and application of bacteriocin for preservation of fruit juices and bacteriocin production

Divya .; J. R. Xavier; Natarajan Gopalan; K. V. Ramana

doi:10.14429/dlsj.2.11361

Divya . Defence Food Research Laboratory, Mysuru
J. R. Xavier Defence Food Research Laboratory, Mysuru
Natarajan Gopalan Defence Food Research Laboratory, Mysuru
K. V. Ramana Defence Food Research Laboratory, Mysuru

DOI: https://doi.org/10.14429/dlsj.2.11361

Keywords: Bacteriocin, Immobilisation, Adsorption, Co-culture

Abstract

Lactic acid bacteria are generally recognized as safe (GRAS) organisms producingbacteriocins that help in inhibiting foodborne pathogens. However, its narrow spectrum activity is a major limitation for food applications. Thus, a combination of different methods were attemptedto broaden the antimicrobial spectrum of bacteriocins produced using lactic acid bacteria. Initially, the antimicrobial activity of bacteriocin from various combinations of mixed lactic acid bacteria and single culture were determined after 56 hours at 35ºC to select the desirable combination with maximum antimicrobial activity. Combination of bacteriocin produced by Lactobacillus plantarum DFR4, Enterococcus faecalis DFR4 and E.Faecalis DFRP1 showed maximumactivity against Listeria monocytogenes with zone of 31.24±0.33 mm in agar disc diffusion assay. The specific activity and purification of bacteriocins produced by these isolates werefound to be highest in gel permeation chromatography whereas, the yield was highest in 80 percent acetone precipitation. The partially purified bacteriocins were further investigated for the effect of pH, enzymes and temperature stability and were found to be thermostableand active at pH range of 3 to 5. Proteolytic enzymes such as protease and papain inactivedthe bacteriocinswhile amylase had no inhibitory effect. The antimicrobial activity of bacteriocin produced from bamboo (Bambusa vulgaris) fibre immobilized Lactobacillus plantarum DFR4 was found to be more (zone size=20.91±0.35 mm) in comparison to free cells (zone size=8.52±0.26 mm) after 24 h of incubation at 37°C. Further, immobilization of Lactobacillus plantarum DFR4, Enterococcus faecalis DFR4 and E. Faecalis DFRP1 using bamboo fibre aided in faster production of bacteriocins in 24 h.Mosambi juice (Citrus limetta) supplemented with bacteriocins (produced from mixed bacterial isolates) had a shelf life of 26 days at 5ºC.

Author Biographies

Divya ., Defence Food Research Laboratory, Mysuru

Ms Divya received her MSc (Applied Genetics) from Garden City College, Bangalore. She is pursuing PhD (Biotechnology) from Food Biotechnology Division, DFRL, Mysuru.

She has contributed towards the experimental planning, data analysis and writing of the manuscript.

J. R. Xavier, Defence Food Research Laboratory, Mysuru

Mrs J.R. Xavier, obtained her MSc (Agricultural Biotechnology)from Tamil Nadu Agricultural University, Coimbatore and persuing her PhD (Biotechnology) from Bharathiar University. Presently working as Scientist ‘C’ at Food Biotechnology Department at DFRL, Mysore and working in the area of biopolymers, biopreservaties, food enzymes and prebiotic foods.

She has contributed towards the experimental planning for identification of isolated bacteria, identified and submitted the 16S rDNA sequences to Genbank, NCBI and contributed in editing and proof reading of the manuscript.

Natarajan Gopalan, Defence Food Research Laboratory, Mysuru

Dr Natarajan Gopalan received his PhD (Zoology) form Jiwaji University, Gwalior and PDF from OUHSC, USA. Presently working as Scientist ‘F’ at DFRL, Mysuru. He is having vast experience in vector borne diseases diagnosis and monitoring, new process preparation of large scale recombinant proteins for therapeutic and diagnosis purposes and novel therapeutic paradigms to inflammation for digestive diseases like colon and pancreatic cancers.

Contribution in the current study, he has conducted scanning electron microscopic studies for the study.

K. V. Ramana, Defence Food Research Laboratory, Mysuru

Dr K.V. Ramana, obtained his PhD (Biotechnology) and presently working as Scientist ‘F’ at Food Biotechnology Department at DFRL, Mysore and working in the are of carried out extensive research in biotechnological aspects of biopolymers such as polyhydroxyalkanotaes, bacterial cellulose and pullulan.

Contribution in the current study, he has conceptualised of the work carried out, interpretation of the data generated and proof reading the manuscript.