Utilization of Fish Scales for Microbe-mediated Gelatin Extraction: A New Biotechnology and Microbiology Avenue

Waste materials are of major concern around the globe. This study aimed to utilize the scales of fish (Labeo rohita) in microbe-mediated gelatin extraction. Three bacterial isolates were isolated from the fish scales and one bacterial isolate FSW3 showing maximum gelatin yield (61.4 %) was subjected to further analysis. The bacterial culture FSW3 (identified as Staphylococcus spp.) with enhanced production of extracted gelatin was set for physiochemical testing, FTIR analysis, UV-Vis spectroscopy, and stereomicroscopic analysis. The extracted gelatin was successfully utilized in various applications including plant growth promotion under salt stress, anti-adhesion films, firmness of yogurt, biodegradable plastic, and anti-microbial food coatings. Results showed that 0.01 mM gelatin promoted plant growth promotion under salt stress. FSW3 extracted gelatin decreased the 2-fold biofilm-forming ability of E. coli, when exposed to the gelatin-based anti-adhesion films coated on a glass slide and polystyrene sheet. The gelatin showed promising findings as anti-microbial food coatings for tomatoes preservation after 21 days and helpful in the firmness of yogurt. Another advantage of gelatin was casting it into biodegradable plastic. The current study provides a promising approach for fish scales microbe-mediated gelatin extraction and uses it to explore new avenues in biotechnology and microbiology.