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Edna M. Sabido Chuckcris P. Tenebro Dana Joanne Von L. Trono Carmela Vannette B. Vicera Sheeny Fane L. Leonida Jose Jeffrey Wayne B. Maybay Rikka Reyes-Salarda Diana S. Amago Angelica Marie V. Aguadera May C. Octaviano Jonel P. Saludes Doralyn S. Dalisay 《Marine drugs》2021,19(8)
Marine sediments host diverse actinomycetes that serve as a source of new natural products to combat infectious diseases and cancer. Here, we report the biodiversity, bioactivities against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) and ovarian cancer, and metabolites variation among culturable actinomycetes isolated from the marine sediments of Visayan Sea, Philippines. We identified 15 Streptomyces species based on a 16S rRNA gene sequence analysis. The crude extracts of 10 Streptomyces species have inhibited the growth of ESKAPE pathogens with minimum inhibitory concentration (MIC) values ranging from 0.312 mg/mL to 20 mg/mL depending on the strain and pathogens targeted. Additionally, ten crude extracts have antiproliferative activity against A2780 human ovarian carcinoma at 2 mg/mL. To highlight, we observed that four phylogenetically identical Streptomyces albogriseolus strains demonstrated variation in antibiotic and anticancer activities. These strains harbored type I and II polyketide synthase (PKS) and non-ribosomal synthetase (NRPS) genes in their genomes, implying that their bioactivity is independent of the polymerase chain reaction (PCR)-detected bio-synthetic gene clusters (BGCs) in this study. Metabolite profiling revealed that the taxonomically identical strains produced core and strain-specific metabolites. Thus, the chemical diversity among these strains influences the variation observed in their biological activities. This study expanded our knowledge on the potential of marine-derived Streptomyces residing from the unexplored regions of the Visayan Sea as a source of small molecules against ESKAPE pathogens and cancer. It also highlights that Streptomyces species strains produce unique strain-specific secondary metabolites; thus, offering new chemical space for natural product discovery. 相似文献
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Early performance of two dipterocarp species Anisoptera marginata and Shorea parvifolia, and a long-living pioneer species Peronema canescens (Verbenaceae) planted in artificial gaps (size 260 m2) and surrounding untreated stands was studied in a fast-growing plantation of Acacia mangium on an Imperata cylindrica grassland site in South Kalimantan, Indonesia. Forty seedlings of each species were planted at one-meter intervals in lines across each of the five gaps, starting and ending under closed stand. Survival, height and diameter (d0.05) increments were measured, and the effect of gap opening on the composition and abundance of understorey vegetation (grass, shrub and native tree seedlings and saplings) was studied. 19 months after planting, average survival rates were 97% for A. marginata, 94% for P. canescens and 71% for S. parvifolia, with no statistical differences between gap and closed stand. Substantial mortality and damage of dipterocarps were caused by wild boars; minor damage by dieback (for S. parvifolia) and insect pests (for A. marginata). Early growth was clearly influenced by distance from gap centre and light conditions; the growth of seedlings was greater the nearer the seedlings were situated to centre and the higher the level of daily photosynthetic photon flux density (PPFD) was. Gap opening increased the growth of shrub species Chromolaena odorata, but not that of Imperata grass. It also increased the density and height growth of saplings of native pioneer and secondary tree species. Seedling density increased both in closed stand and actual gaps, but was higher inside gaps.Results indicate good prospects for diversifying the composition of fast-growing forest plantations on severely degraded former forest lands and integrating slow-growing valuable species in plantation programs. Both in-depth ecophysiological studies on species-specific growth requirements, and practical oriented research on silvicultural options and economics need further studies. 相似文献
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Rikka Reyes Annabelle del Norte‐Campos Nathaniel C. Aasco Sheila Mae S. Santander‐de Leon 《Aquaculture Research》2020,51(8):3129-3138
Biofouling poses low productivity and high maintenance in aquaculture. This study simulated the nets of fish cages to investigate biofouling composition and development as influenced by net colour, immersion period and environmental conditions. Yellow and green net panels were immersed for 60 days and sampled at 7, 15, 30, 45 and 60 days. Results revealed that biofouling composition was dominated by Bryozoan Bugula sp. (31%–38% cover), tanaids Tanaidae (64–146 individuals.100 cm‐2) and nematodes Linhomoeidae and Oncholaimidae (142–189 individuals.100 cm‐2). Biofouling development was observed in succession patterns of harpacticoid–nematode–amphipod–tanaid in yellow nets and amphipod–nematode in green nets. Water velocity within the cages significantly and positively influenced the total cover, biomass and the densities of amphipods, bivalves, polychaetes, fish eggs and bryozoans. Polychaetes, gastropods, fish eggs and macroalgae were present in green nets and absent in yellow nets at 7 days. Uniformity of biofouling assemblage in both net colours was observed beyond 7 days which may be largely explained by brown biofilm formation. The result of the study revealed the dynamics of biofouling in a marine fish farm and provides vital information for developing strategies in biofouling management to lessen its impacts. 相似文献
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