An endosymbiotic Pseudomonas sp. (MSI057), which could produce high yields of lipase, was isolated from marine sponge Dendrilla nigra, collected from the peninsular coast of India. Maximum production of enzyme was obtained in minimal medium supplemented with 1% tributyrin. Catabolite repression was observed when the medium was supplemented with readily available carbon sources. The optimum temperature and pH for the enzyme production was 30 degrees C and 9.0, respectively. The enzyme exhibited maximum activity in pH range of 8-9 with an optimum pH 9.0. The activity of purified enzyme was optimum at 37 degrees C and showed 80% activity at 20 degrees C and the enzyme activity decreased dramatically above 50 degrees C. Based on the present findings, the enzyme was characterized as psychrophilic alkaline lipase, which can be developed for industrial applications.

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Spirulina platensis is one of the most potential microalgae explored for antibacterial, antiviral and anticancerous properties. However, its antibiofilm potential has not been studied. Biofilms are of significant interest as they confer resistance towards antimicrobials and host immunity both in diverse group of bacteria. Exploring Spirulina towards the biofilm would give an easy way of treatment against bacterial pathogens. In this milieu, the antibiofilm potentials of organic extracts prepared from S. platensis was revealed. The results clearly showed that methanolic extract of S. platensis at a concentration of 100 ng mL -1 efficiently inhibited the biofilms of Vibrio parahaemolyticus (ATCC17802), Chromobacterium violaceum (ATCC 12742) and Vibrio alginolyticus (ATCC17749) about 90, 89 and 88 % respectively. Significant reduction in cell surface hydrophobicity was documented for Aeromonas hydrophila (MTCC1739), Escherichia coli (MTCC 739) and Staphylococcus aureus (MTCC 96 and 2940). Besides the inhibition of extracellular polymeric substances in A. hydrophila (MTCC1739) and S. aureus (MTCC2940) was about 88 and 71 % respectively. The availability of Spirulina as nutritious food makes it as a foremost contender against bacterial biofilm. The present study reveals the antibiofilm potential of S. platensis against a broad spectrum of both Gram Positive and Gram Negative bacteria. S. platensis effectively inhibited the biofilm of Vibro spp., a major menace in aquaculture industries. Further characterization and purification of the active compounds could be a major remedy against biofilm forming bacteria.