~ 135 ~ International Journal of Herbal Medicine 2018; 6(2): 135-140 E-ISSN: 2321-2187 P-ISSN: 2394-0514 IJHM 2018; 6(2): 135-140 Received: 20-01-2018 Accepted: 21-02-2018 Nilam Chavda Government Science College, K. K. Shastri Educational Campus, Khokhara Road, Maninagar (E), Ahmedabad, Gujarat, India Bhupesh Yagnik Government Science College, K. K. Shastri Educational Campus, Khokhara Road, Maninagar (E), Ahmedabad, Gujarat, India Neelam Amit Kungwani Government Science College, K. K. Shastri Educational Campus, Khokhara Road, Maninagar (E), Ahmedabad, Gujarat, India Correspondence Neelam Amit Kungwani Government Science College, K. K. Shastri Educational Campus, Khokhara Road, Maninagar (E), Ahmedabad, Gujarat, India Effect of Indian spices on lasR mutant of Pseudomonas aeruginosa PAO1 biofilm Nilam Chavda, Bhupesh Yagnik and Neelam Amit Kungwani Abstract The study was undertaken to analyse the impact of bark of cinnamon (Cinnamomum zeylanicum), seeds of mustard (Brassica nigra) and nutmeg fruit (Myristica fragrans) on the biofilm by lasR mutant of Pseudomonas aeruginosa PAO1. The analysis of the phytoextracts showed that the test culture is inhibited to varying degrees by different phytoextracts. Aqueous and methanolic extracts were prepared and its phenolic content and antioxidant properties were assessed. The effect of the extract was further studied for the biofilm formation by the lasR mutant. Different phytoextract cause varying degree of structural changes in biofilm architecture of wild type and lasR mutant. The finding indicates involvement of lasR during biofilm development in presence any antimicrobial compound of plant origin. Keywords: Antimicrobial, antioxidant, biofilm, phenolic, quorum sensing 1. Introduction Spices are the dried part of a plant used for seasoning and flavouring a recipe and include various seeds, roots, fruits, barks, and vegetables. Their main use is to add colour and flavour to food as well as to help in remain preserved and good to eat. Apart from these uses, they also find application in control of various microorganisms. The antimicrobial activity has been reported since very long and is still a topic of interest amount the researchers [1-5] . The antimicrobial activity of spices varies with; spice variety, phytochemical, organism and its occurrence level and processing conditions and storage [6, 7] . The alternates to chemical preservatives are being searched for food preservation so as to partially or completely replace the chemical preservatives [8, 9] . Consumers prefer foods free or with lower chemical preservatives because of the toxicity they possess [10] . Thus, plants with antimicrobial activity can be an alternate to these preservatives in food. Food contamination by microorganisms is mainly mediated by biofilm formation. Biofilms are formed by several pathogenic bacterial species e.g. of human pathogens forming biofilms in natural aquatic environments include Pseudomonas aeruginosa, Vibrio cholera and certain species of nontuberculous mycobacteria [11] . Most oligotrophic bacteria in environment grow in biofilms rather than as single planktonic cells as biofilms provides a protective degree of homeostasis and stability in changing environment, are structured, specialised communities of adherent microorganisms encased in a complex extra polymeric substance (EPS) matrix [12] . Therefore, biofilm formation represents a facile microbial survival strategy where microorganisms [13] . Biofilm formation is a result of bacterial cell to cell communication called quorum sensing (QS). It allows cells to communicate and share information about the cell density and gene expression adjustment accordingly. The biofilm formation and bio fouling are the result QS molecules produced by the microorganisms in their natural environments. For instance, in P. aeruginosa lasI/lasR and rhlI/rhlR are QS genes regulating many features including biofilm development [14] . Thus, interfering with the quorum sensing mechanism of the bacteria could be useful to control the biofilm growth and thus, prevent the food spoilage. The attachment of different bacteria with subsequent development of biofilms on food surface can lead food spoilage or transmission of diseases [15-17] . The most common foodborne biofilm producers belong to the genera Pseudomonas, Listeria, Enterobacter, Flavobacterium, Alcaligenes, Staphylococcus and Bacillus [18, 19] . The aim of present study is to evaluate the effect of phytochemicals extracted from spices used in food preservation on the lasR mutant of Pseudomonas aeruginosa PAO1 biofilm.