Resistance of a multiple-isolate marine culture to ultraviolet C irradiation: inactivationvsbiofilm formation

Abstract

This study examined the resistance of a multiple-isolate native marine culture to UV-C irradiation, in terms of viability, vitality and the ability to form biofilm. Results of this study showed that even though most of the cells were inactivated both in single-isolate and in multiple-isolate cultures, still the multiple-isolate cultures manages to form biofilms, surprisingly with higher biomass than without irradiation. The significance of the study is in its conclusion that studies on UV-C irradiation of biofilm-forming model micro-organisms are not always applicable to natural multiple-species communities.

Chemical synthesis and antifouling activity of monoterpene–furan hybrid molecules

“…Then, the biological activity of the synthetic hybrids 4a-4i toward the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite was evaluated. All nine hybrids showed higher antifouling activity than geraniol (1), (S)-citronellol (10), or furan 12, combined with low toxicity. These findings indicate that combining two antifouling-active scaffolds, i.e., monoterpene and furan, increases the antifouling activity.…”

“…First, the activity of CuSO 4 was assessed as a positive control, and the obtained values (EC 50 = 0.29 μg mL −1 ; LC 50 = 2.10 μg mL −1 ) were comparable to the reported ones (Table 1). 31 Geraniol (1) and (S)-citronellol (10) showed antifouling activity with EC 50 values of 19.3 and 12.7 μg mL −1 , respectively, without toxicity (LC 50 > 50 μg mL −1 ). The reference furan compound 12 32 displayed an EC 50 value of 21.8 μg mL −1 and no toxicity.…”

“…To install structural variation in the monoterpene moiety of the hybrid molecules, geraniol (1), nerol ( 7), (R)-citronellal (9), and (S)-citronellol (10) were chosen as scaffolds. We first examined the synthesis of geraniol-furan hybrid molecules.…”

“…3 The economic costs of biofouling control in marine industries are substantial. 1,3 Several techniques to prevent biofouling have been developed, including acoustic methods, 4 electrochemical systems, 5 freshwater flushing, 6 laser cleaning, 7 mechanical cleaning, 8 photocatalytic systems, 9 ultraviolet irradiation, 10 and antifouling coatings. 1 a ,11 Among these methods, antifouling coatings are regarded as the most effective, economic, and convenient technique.…”

“…4 , geraniol (1), (S)-citronellol(10), furan 12, and hybrid molecules 4a-4i aCompoundEC 50 (μg mL −1 ) L C 50 (μg mL −1 )a Against the cypris larvae of the barnacle Balanus (Amphibalanus) amphitrite.…”