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This study was conducted to extract essential oil from an edible seaweed, Undaria pinnatifida, and determine its chemical constituents, antibacterial and antioxidant potential. Gas chromatography and mass spectroscopy analysis of the U. pinnatifida essential oil (UPEO) revealed 26 volatile compounds comprising a total of 97.03%. Fatty acids such as tetradecanoic acid (31.32%) and hexadecanoic acid (22.39%) were present in the highest amount, followed by 3-hexen-1-ol (5.67%), erythritol (4.73%), 4-imidazolidinone (4.40%) and (9Z)-hexadec-9-enoic acid (4.37%). UPEO displayed potent antibacterial activity (9.5-11.0 mm inhibition zone), an MIC of 12.5-25.0 mg/mL and an MBC of 25.0 mg/mL. UPEO also exhibited strong hydroxyl radical scavenging (IC50 85.54 µg/mL), reducing power (IC0.5 178.82 µg/mL) and superoxide radical scavenging (IC50 260.89 µg/mL) potential. Taken together, these results indicate that UPEO could be an economical and safe resource for natural antioxidant and antibacterial compounds that can be utilized in food processing, cosmetics and pharmaceutical sectors. Practical Applications Seaweeds are a rich source of natural bioactive compounds with various medicinal properties. The essential oils extracted from an edible seaweed, U. pinnatifida, could serve as an alternative source of natural antioxidant compounds with the potential for use as food additives and in food preservation and cosmetics. Use of this compound could minimize the use of synthetic antioxidant compounds that trigger health hazards. Furthermore, the bioactive compounds present in the UPEO could serve as a source of natural antibiotics against both Gram positive and Gram negative pathogenic bacteria. [ABSTRACT FROM AUTHOR]

In this study, the utility of the combined application of Benzo-(1,2,3)-thidiazole-7-carbothioic acid S-methyl ester (BTH), a systemic acquired resistance (SAR) inducer, and the plant growth-promoting rhizobacteria (PGPR),Bacillus subtilisstrain B4 (B4), was investigated for the suppression of soft rot disease caused by Pectobacterium carotovorum SCC1 (SCC1) in tobacco seedlings. Soft rot disease was completely suppressed in tobacco with combined application of B4 strain and 0.1 mM BTH when compared to individual application upon pathogen challenge. In addition, the population of bacterial cells of B4 strain was found to be greater when cultured in growth media in the presence of BTH, compared to the growth of B4 strain in the absence of BTH. Spectrophotometer analysis revealed that there was an increased broad range of compounds in the culture filtrate of B4 strain when grown with BTH, compared to the culture filtrate of B4 strain alone. The combined application of B4 strain and 0.1 mM BTH induced the increased expression of PR1a::GUS on tobacco and elicited systemic resistance against SCC1 when compared to individual application. However, there was low expression of PR1a::GUS in the water-treated control. Hence, the integrated use of BTH and B4 strain might be one of the strategies for biological control of soft rot disease through induced systemic resistance (ISR) in tobacco plants. [ABSTRACT FROM AUTHOR]

Although cadusafos, an aliphatic organophosphorus (OP) insecticide, is not approved by the European commission, it is used in several countries and sometimes detected as a residue in soils and agricultural products. In this study, two cadusafos-degrading Sphingobium sp. strains, K22212 and Cam5-1, were isolated and characterized for use as detoxifying agents of the insecticide. Both strains degraded 100 mg L −1 of cadusafos in mineral medium within 12 h through a common metabolite, which was supposed to be dimerized thiophosphates based on its molecular weight. Degradation of cadusafos increased cell growth for Cam5-1 but not for K22212. K2212 and Cam5-1 degraded cadusafos in soil (15 mg kg −1 dry soil) within 5 and 2 days, respectively. Both strains also degraded ethoprophos, phenthoate and phorate but not chlorpyrifos and diazinon, indicating that they are specialized for degradation of OP insecticides with at least one single bond connecting phosphorus and sulfur atoms (P S bond). For both strains, the degradation rate was the largest for ethoprophos, followed by cadusafos, phenthoate, and phorate. Our results indicate that these bacterial strains are effective degraders of OP insecticides with P S bonds, and in particular, Cam5-1 is more promising for removal of the OP insecticides in soils. [ABSTRACT FROM AUTHOR]