Extraction of chitosan and its oligomers from shrimp shell waste, their characterization and antimicrobial effect.
OBJECTIVE
The present study was performed to utilize the shrimp shell waste for chitin and chitosan production, characterization by Fourier transform infrared (FT-IR) technique and to evaluate the antimicrobial effects of chitosan oligomers produced by depolymerization of chitosan by nitrous acid.


METHODS
Chitosan was extracted from the shrimp shell waste by the chemical method and characterized by FT-IR. Chitooligomers were produced by depolymerising chitosan using nitrous acid, and the chitooligomers were tested for antimicrobial effect against four gut pathogenic organisms, i.e.,Enterobacter aerogen(National Collection of Dairy Culture [NCDC] 106),Enterococcus faecalis(NCDC 119),Escherichia coli(NCDC 134), andStaphylococcus aureus(NCDC 109) by well diffusion method using Muller-Hinton agar. A pure culture of pathogenic organisms was collected from NCDC, ICAR-National Dairy Research Institute, Karnal.


RESULTS
Extracted chitosan characterized by FT-IR and chitooligomers demonstrated antimicrobial effect against four gut pathogenic organisms used in this study. Zone of inhibitions (mm) were observed inE. faecalis(13±0.20),E. coli(11.5±0.4),S. aureus(10.7±0.2), andE. aerogen(10.7±0.3).E. faecalisshowed larger inhibition zone as compared to all other organisms and inhibitions zones ofE. aerogenandS. aureuswere comparable to each other.


CONCLUSIONS
Shrimp waste can be utilized for chitosan production, and the chitooligomers can be used as feed additive for gut health enhancement and have potential to replace antibiotics from the feed. Along with value addition pollutant load could be reduced by waste utilization.
Department of Animal Nutrition, ICAR-National Dairy Research Institute, Karnal, Haryana, India.
Tarun Kumar
TK
Varun
Department of Animal Nutrition, ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Bengaluru, Karnataka, India.
Swaraj
S
Senani
Department of Animal Nutrition, ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Bengaluru, Karnataka, India.
Natasha
N
Jayapal
Department of Animal Nutrition, ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Bengaluru, Karnataka, India.
Jayaram
J
Chikkerur
Department of Animal Nutrition, ICAR-National Institute of Animal Nutrition and Physiology, Adugodi, Bengaluru, Karnataka, India.
Sohini
S
Roy
ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India.
Vijay Bhasker
VB
Tekulapally
Department of Animal Nutrition, ICAR-National Dairy Research Institute, Karnal, Haryana, India.
Mayank
M
Gautam
ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India.
Narender
N
Kumar
Fourier transform infrared; chitin; chitooligomers; chitosan; shrimp waste