Turk. J. Fish.& Aquat. Sci. 22(12), TRJFAS21768 https://doi.org/10.4194/TRJFAS21768 Published by Central Fisheries Research Institute (SUMAE) Trabzon, Türkiye R E S E A R C H P A P E R Utilization of Fish Scales for Microbe-mediated Gelatin Extraction: A New Biotechnology and Microbiology Avenue Rabia Anwar Rao 1 , Aisha Waheed Qurashi 1 , Iram Liaqat 2, * , Mawra Gohar 1 , Urooj Zafar 3 , Muhammad Amjad Khan 5 , Saraj Bahadur 4, * 1 Lahore Garrison University, Department of Biology, Sector C phase 6 DHA Lahore, Pakistan. 2 Government College University, Department of Zoology, Microbiology Lab, Lahore, Pakistan. 3 Univeristy of Karachi, Department of Microbiology, Karachi, Pakistan. 4 College of Forestry Hainan University Haikou, 570228, China. 5 Hainan University Haikou, College of Ecology and Environment, 570228, China. Article History Received 24 April 2022 Accepted 03 August 2022 First Online 05 August 2022 Corresponding Author Tel.: +923417824964 +8613111981002 E-mail: iramliaq@hotmail.com sirajbahadur14@gmail.com Keywords Anti-adhesion Anti-microbial coatings BBacterial isolates Biodegradable plastic Salt stress scales Abstract 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. Pseudomonas sp.) 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 0.012 mM gelatin promoted plant growth promotion under salt stress. FSW3 extracted gelatin decreased the 2 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 microbe-mediated gelatin extraction and uses it to explore new avenues in biotechnology and microbiology. Introduction Fish products are an important source of protein containing 15 – 20 % of protein (Fagbenro et al., 2005; Usman et al., 2022). Different methods are developed to convert the wastes into useful products. In the fish industry, almost 50 % or more materials (containing gelatin) are not used as food and are responsible for creating almost 32 million tons of waste (Arvanitoyannis et al., 2008). Gelatin is hydrolyzed form of a protein and obtained by hydrolysis of collagen present in fish skin waste and a source of protein (Shankar et al., 2016; Ali pal et al., 2020). Main objective of present study is to highlight the significance of indigenous microbes involved in the extraction of gelatin from waste material like aquaculture and fish farming industry as a promising approach for gelatin provision. Religious or ethical sentiments of diverse communities and some historical diseases of cows (Wangtueai & Noomhorm, 2009) led to the possible offering of this approach. Gelatin is present in different parts of animals and contains few amino acids. The denaturation/melting temperature of gelatin gel is above 30 o C whereas the gelatin denaturation temperature is above 40 o C (Hayashi & Oh, 1983). Gelatin contains many residues of How to cite Rao, R.A., Qurashi, A.W., Liaqat, I., Gohar, M., Zafar, U., Khan, M.A., Bahadur, S. (2022). Utilization of Fish Scales for Microbe-mediated Gelatin Extraction: A New Biotechnology and Microbiology Avenue. Turkish Journal of Fisheries and Aquatic Sciences, 22(12), TRJFAS21768. https://doi.org/10.4194/TRJFAS21768