Introduction: The current need of the food industry is to develop a safe packaging system that maintains the quality of food and prevents its spoilage. Food safety techniques improvised using functional nanoparticles minimize the chances of spoilage by maintaining moisture stability, mechanical strength, and durability and ensuring product safety. In the present study, we synthesized silver nanoparticles using purified bacteriocins obtained from probiotics. Bacteriocin-synthesized AgNPs are eco-friendly and secure packaging solutions that can be utilized in the packaging industry for the storage of food products.Methods: Crude, partially purified and purified bacteriocin was obtained from three potential probiotic isolates, i.e., Lactobacillus pentosus S6 (KU92122), Lactobacillus crustorum F11 (KT865221) and Lactobacillus spicheri G2 (JX481912). The antimicrobial efficacy of bacteriocin was tested against two food-borne spoilage-causing pathogens, i.e., Bacillus cereus and Staphylococcus aureus. The purified bacteriocin obtained was used for the synthesis of AgNPs. The synthesized AgNPs were characterized using UV-vis spectroscopy, TEM, and SEM techniques. The AgNPs were used for coating cellulose paper. The coated paper was characterized using SEM and was used for the storage of tomato fruit.Results and discussion: The purified bacteriocin obtained was used for the synthesis of AgNPs. The formation of AgNPs was confirmed by using UV-vis spectroscopy, which showed maximum absorption at 450 nm. Furthermore, we confirm shape and morphology by using Scanning Electron Microscopy (SEM). Transmission Electron Microscopy (TEM) analysis showed the mean size of synthesized AgNPs in the range of 5–20 nm. Bacteriocin-synthesized AgNPs were then used for the coating of cellulose paper with the main motive to avoid spoilage and enhance the shelf stability of tomato fruit during storage. SEM analysis confirmed the coating of AgNPs in the cellulose paper. The enhanced antimicrobial efficacy of different treatments coated paper was observed against B. cereus and S. aureus. Out of all, F11 AgNPs coated paper showed maximum inhibition of 24 mm for S. aureus and 22 mm for B. cereus. The coated paper from three different bacteriocin-synthesized AgNPs, along with silver nitrate (AgNO₃) coated and uncoated paper, was used for the storage of tomato fruit for a period of 10 days at room temperature. Changes during storage were determined by analyzing morphological and color changes. Compared to AgNO₃ coated and uncoated paper, tomato fruit preserved in F11 AgNPs coated paper maintained and held its appearance and firmness, thereby confirming their effectiveness in the preservation of tomatoes.

The present work focusses on development of a safe, inexpensive, and more accessible source for biosynthesis of silver nanoparticles. Four different in-house probiotic isolates, i.e., Lactobacillus pentosus S6, Lactobacillus plantarum F22, Lactobacillus crustorum F11, and Lactobacillus paraplantarum KM1 isolated from different food sources, were used in the current study to check their ability to synthesize silver nanoparticles. All the probiotic-synthesized silver nanoparticles show maximum surface plasmon resonance (SPR) at a peak of 450 nm, which confirms the formation of silver nanoparticles. Scanning electron microscopy (SEM) analysis identified the shape and distribution of silver nanoparticles. Transmission electron microscopy (TEM) revealed the average size of synthesized nanoparticles in the range of 10–50 nm, with the smallest size of 5 nm for silver nanoparticles synthesized by L. crustorum F11. Further, Fourier-transform infrared spectroscopy (FTIR) detected the presence of different functional groups responsible for reduction of silver ion to form silver nanoparticles. The antimicrobial activity of these AgNPs was also found to be effective against different bacterial and fungal pathogens, viz., antibiotic-resistant Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Pythium aphanidermatum, Fusarium oxysporum, and Phytopthora parasitica. However, L. crustorum F11–synthesized AgNP showed maximum inhibition against all the bacterial and fungal pathogens, with highest against S. aureus (20 ± 0.61 mm) and F. oxysporum (23 ± 0.37). Findings from this study provide a durable and eco-friendly method for the biosynthesis of silver nanoparticles, having strong antimicrobial activity against different multidrug-resistant microorganisms. Graphical abstract

Response to Letter in regards to A Response to: Quality Improvement in Delirium Health Literacy in Older Adult Patients and Their Caregivers Attending a Geriatric Clinic [Letter]

The topic of the review article is unique and interesting, however there are certain limitation which the authors should be considered to make it better. 1. why did the author focused only on copper nanoparticles, what is the unique property associat...