Isolation and Identification of Algicidal Compound from Streptomyces and Algicidal Mechanism to Microcystis aeruginosa

Abstract

The biological control of cyanobacterial harmful algal blooms (cyanoHABs) is important to promote human health, environmental protection, and economic growth. Active algicidal compounds and algicidal mechanisms should be identified and investigated to control cyanoHABs. In this study, the algicidal actinobacterium Streptomyces sp. L74 was isolated from the soil of a nearby pond which located in the center lake of Guanghzou Higher Education Mega Center. Results showed that the algicidal activities of cyanoHABs are mainly achieved via an indirect attack by producing algicidal compounds. All active algicidal compounds are hydrophilic substances that are heat and pH stable. In the present study, an active compound (B3) was isolated and purified by high-performance liquid chromatography and identified as a type of triterpenoid saponin (2-hydroxy-12-oleanene-3, 28-O-D-glucopyranosyl) with a molecular formula of C42H70O13 as determined by infrared spectrometry, electrospray ionization mass spectrometry, and nuclear magnetic resonance. Active algicidal compounds from Streptomyces sp. L74 were shown to disrupt the antioxidant systems of Microcystis aeruginosa cells.

Microbial communities reflect temporal changes in cyanobacterial composition in a shallow ephemeral freshwater lake

“…The sudden collapse in the D. circinale population strongly implicates an external biological effector, such as viral lysis or bacterial predation, neither of which was addressed at length within the scope this study. In this regard, numerous studies have demonstrated biotic mechanisms for the rapid dispersal of cyanobacteria from surface waters that may explain this observation, including phage-induced lysis (Proctor and Fuhrman, 1990;Williamson et al, 2002;Matteson et al, 2011;Steffen et al, 2015), bacteria-induced lysis (Rashidan and Bird, 2001), grazing by protists (Ger et al, 2014), algicidal compounds (Luo et al, 2013; and cyanobacterial programmed cell death (Franklin, 2014).…”

Exploring the potential of algae/bacteria interactions

“…On the other hand, bacterial quorum-sensing molecules (e.g., acyl homoserine lactones) have been reported to interfere with the germination and growth of Ulva zoospores, a macroalga causing biofouling of artificial constructs [25]. In addition, different taxa of bacteria, for example, Shewanella [26], Streptomyces [27], and Bacillus [28], are known to produce algicidal metabolites. These studies have manifested complex signaling interactions in phycospheres, which we expect to exploit for controlling algae and/or bacteria in the context of biotechnology.…”

The first evidence of deinoxanthin from Deinococcus sp. Y35 with strong algicidal effect on the toxic dinoflagellate Alexandrium tamarense

“…Therefore, biological agents, including plants [19], protozoan [20], viruses [21] and bacteria [22,23] are considered as effective and biosecure ways to mitigate HABs, and the relationship between bacteria and algae has received particular interest in recent years [24][25][26]. Some bacteria supply cobalamin for algal growth [27], and get nutrients from algae, other bacteria compete with algae for nutrients [28], and some bacteria even produce secondary metabolites with a diverse range of algicidal activities to inhibit or kill algal cells [29]. Therefore, we need to isolate the bacteria with algicidal effect on specific algae, in order to achieve the purpose of effectively solving the problems of HABs.…”