Rapid identification of potential drought tolerance genes from Solanum tuberosum by using a yeast functional screening method

Identification of major stress tolerance genes of a crop plant is important for the rapid development of its stress-tolerant cultivar. Here, we used a yeast functional screen method to identify potential drought-tolerance genes from a potato plant. A cDNA expression library was constructed from hyperosmotic stressed potato plants. The yeast transformants expressing different cDNAs were selected for their ability to survive in hyperosmotic stress conditions. The relative tolerances of the selected yeast transformants to multiple abiotic stresses were also studied. Specific potato cDNAs expressed in the tolerant yeast transformants were identified. Sixty-nine genes were found capable of enhancing hyperosmotic stress tolerance of yeast. Based on the relative tolerance data generated, 12 genes were selected, which could be most effective in imparting higher drought tolerance to potato with better survival in salt and high-temperature stresses. Orthologues of few genes identified here are previously known to increase osmotic stress tolerance of yeast and plants; however, specific studies are needed to confirm their role in the osmotic stress tolerance of potato.     

Anti-biofouling property of vanillin on Aeromonas hydrophila initial biofilm on various membrane surfaces

Biofouling is a serious problem on filter membranes of water purification systems due to formation of bacterial biofilms, which can be detrimental to the membrane performance. Biofouling occurs on membrane surface and therefore greatly influences the physical and chemical aspects of the surface. Several membranes including microfiltration, ultrafiltration, and reverse osmosis (RO) membranes were used to learn about the anti-biofouling properties of vanillin affecting the membrane performances. Vanillin has been recognized as a potential quorum quenching compound for Aeromonas hydrophila biofilms. The initial attachment and dynamics of biofilm growth were monitored using scanning electron microscopy and confocal laser scanning microscopy. Biofilm quantities were measured using a plate count method and total protein determinations. Vanillin addition was effective in the prevention of biofilm formation on the tested membrane surfaces. Among the membranes, RO membranes made with cellulose acetate showed the most substantial reduction of biofilm formation by addition of vanillin. The biofilm reduction was confirmed by the results of surface coverage, biomass and protein accumulation. The HPLC spectrum of the spent culture with vanillin addition showed that vanillin may interfere with quorum sensing molecules and thus prevent the formation of the biofilms.     

Vanillin,a potential agent to prevent biofouling of reverse osmosis membrane

Reverse osmosis (RO) membrane systems are widely used in water purification plants. Reduction in plant performance due to biofilm formation over the membrane is an inherent problem. As quorum sensing (QS) mechanisms of microorganisms have been reported to be involved in the formation of biofilm, ways are sought for quorum quenching (QQ) and thereby prevention of biofilm formation. In this study using a chemostat culture run for seven days in a CDC reactor it was found that a natural QQ compound, vanillin considerably suppressed bacterial biofilm formation on RO membrane. There was 97% reduction in biofilm surface coverage, when grown in the presence of vanillin. Similarly, the average thickness, total biomass and the total protein content of the biofilm that formed in the presence of vanillin were significantly less than that of the control. However vanillin had no effect on 1-day old pre-formed biofilm.