Cliona varians-Derived Actinomycetes as Bioresources of Photoprotection-Related Bioactive End-Products

Abstract

Sunscreen and sunblock are crucial skincare products to prevent photoaging and photocarcinogenesis through the addition of chemical filters to absorb or block ultraviolet (UV) radiation. However, several sunscreen and sunblock ingredients, mostly UV filters, have been associated with human and environmental safety concerns. Therefore, the exploration and discovery of promising novel sources of efficient and safer compounds with photoprotection-related activities are currently required. Marine invertebrates, particularly their associated microbiota, are promising providers of specialized metabolites with valuable biotechnological applications. Nevertheless, despite Actinobacteria members being a well-known source of bioactive metabolites, their photoprotective potential has been poorly explored so far. Hence, a set of methanolic extracts obtained from Cliona varians-derived actinomycetes was screened regarding their antioxidant and UV-absorbing capacities (i.e., photoprotection-related activities). The active extract-producing strains were identified and classified within genera Streptomyces, Micrococcus, Gordonia, and Promicromonospora. This is the first report of the isolation of these microorganisms from C. varians (an ecologically important Caribbean coral reef-boring sponge). The in vitro cytotoxicity on dermal fibroblasts of oxybenzone and the selected active extracts revealed that oxybenzone exerted a cytotoxic effect, whereas no cytotoxic effect of test extracts was observed. Accordingly, the most active (SPFi > 5, radical scavenging > 50%) and nontoxic (cell viability > 75%) extracts were obtained from Streptomyces strains. Finally, LC-MS-based characterization suggested a broad chemical space within the test strains and agreed with the reported streptomycetes’ chemodiversity. The respective metabolite profiling exposed a strain-specific metabolite occurrence, leading to the recognition of potential hits. These findings suggest that marine Streptomyces produce photoprotectants ought to be further explored in skincare applications.

Optimized carotenoid production and antioxidant capacity of Gordonia hongkongensis

“…Gordonia hongkongensis strain EUFUS-Z928 was isolated from the octocoral Eunicea fusca (Marine environment of Santa Marta Bay, Colombia), as described in a previous study. 21 This strain was selected for its presence of orange intracellular pigment production and antioxidant activity without cytotoxic activity against human primary dermal fibroblast (HDFa, ATCC® PCS-201-012™, Primary Dermal Fibroblast; Normal, Human, Adult) as described by Sanchez-Suarez et al 22 The actinobacterium of interest was reactivated in the growth medium (Zobell agar) (composition g/L: yeast extract (Oxoid LP0021); 1.25; Peptone (PanReac CAS: 91079-40-2), 3.75; NaCl (Honeywell Cat. 31434), 18; MgCl 2 (PanReac CAS: 7791-18-6), 2.0; KCl (PanReac CAS: 740-61), 0.525; CaCl 2 (PanReac CAS: 10043-52-4), 0.075; pH, 7.4 ± 0.2) in agar), 23 and incubated for seven days at 30 °C (Friocell, USA).…”

The response of aquatic ecosystems to the interactive effects of stratospheric ozone depletion, UV radiation, and climate change

“…5.2 . Among the various compounds, there is a particular interest in mycosporine-glycine [ 180 ], palythine [ 181 ], palythene [ 182 ], shinorine [ 183 ], porphyra-334 [ 184 ], and scytonemin as UV filters for sunscreen [ 185 ], skin care [ 186 ], and cosmetic formulations [ 187 , 188 ] due to their availability, stability, and antioxidant properties. Genetic engineering of bacteria to overproduce MAAs is also considered a cost-efficient form of production [ 183 ].…”