A new alkaloid paenidigyamycin A (1) was obtained from the novel Ghanaian Paenibacillus sp. isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Ghana. Compound 1 was isolated on HPLC at tR = 37.0 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against L. major, 1 (IC50 0.75 µM) was just as effective as amphotericin B (IC50 0.31 µM). Against L. donovani, 1 (IC50 7.02 µM) was twenty-two times less active than amphotericin B (IC50 0.32 µM), reinforcing the unique effectiveness of 1 against L. major. For T. brucei brucei, 1 (IC50 0.78 µM) was ten times more active than the laboratory standard Coptis japonica (IC50 8.20 µM). The IC50 of 9.08 µM for 1 against P. falciparum 3d7 compared to artesunate (IC50 36 nM) was not strong, but this result suggests the possibility of using the paenidigyamycin scaffold for the development of potent antimalarial drugs. Against cercariae, 1 showed high anticercaricidal activity compared to artesunate. The minimal lethal concentration (MLC) and minimal effective concentration (MEC) of the compound were 25 and 6.25 µM, respectively, while artesunate was needed in higher quantities to produce such results. However, 1 (IC50 > 100 µM) was not active against T. mobilensis.

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Through the use of genomes that have undergone millions of years of evolution, marine are known to have adapted to rapidly changing environmental pressures. The result is a huge chemical and biological diversity among marine. It is gradually becoming a known fact that, marine have the capability to produce nanoparticles which have reasonable sizes and structures with possible applications in biotechnology and pharmacology. sp. BRS2A-AR2 was isolated from the aerial roots of the mangrove plant . The was demonstrated for the first time ever to produce AuNPs with sizes that range between 5 and 55 nm. The highest level absorbance of the biosynthesized AuNPs was typical for actinobacterial strains (2.881 at 545 nm). The polydispersity index was measured as 0.207 in DLS and the zeta potential was negatively charged (- 28.3 mV). Significant vibration stretches were seen at 3314, 2358, 1635 and 667 cm in FT-IR spectra. This demonstrated the possible use of small aliphatic compounds containing -COOH, -OH, -Cl and -NH functional groups in the stabilization of the AuNPs. The effect of the biosynthesized AuNPs on HUVEC and HeLA cell lines was measured at 48 h. IC values were determined at 3500 µg/ml concentration for HUVEC and HeLA cell lines at 45.25 and 53.41% respectively.

The Ghanaian Paenibacillus sp. DE2SH (GenBank Accession Number: MH091697) is a prolific producer of potent antiparasitic alkaloids. Further detailed study of the culture broth of this strain produced the compound Paenidigyamycin G (1), which is a derivative of the known antiparasitic compound Paenidigyamycin A (2). Compound (1) was isolated on HPLC at tR ≈ 37.5 min and its structure determined by IR, UV, MS, 1D, and 2D-NMR data. Compound 1 produced weak to moderate antileishmanial and antitrypanosomal activity when tested against Leishmania donovani (Laveran and Mesnil) Ross (D10) and Trypanosoma brucei subsp. brucei strain GUTat 3.1 with IC50 = 115.41 and 28.75 μM, respectively. This result is interesting since the parent compound 2 is known to possess consistent and potent antiparasitic activity. However, 1 displayed a promising selectivity profile towards T. brucei subsp. brucei due to its relatively low toxicity against normal mouse macrophages RAW 264.7 cells (SI = 8.70). Given that compound 1 is also the main metabolite found in the hexane fraction of all extracts produced by Paenibacillus sp. DE2SH when it is co-cultured with other bacteria strains, it must possess some unique biological functions which should make it an excellent candidate for further biological activity screening in other bioassays.

Ethyl acetate extracts from 70 strains of marine-derived fungi, isolated from sponges, were screened against four fish pathogenic bacteria. Sixteen of the fungal isolates exhibited antibacterial activity against at least one pathogen. All the strains showed antibacterial activity against Vagococcus salmoninarum. Three isolates showed strong inhibition against all test pathogens and they may therefore be remarkable as a broadspectrum antimicrobial. Nine isolates showed antibacterial activity against Lactococcus garvieae, six were against Vibrio anguillarum, and four isolates inhibited the growth of Yersinia ruckeri. Co-culture of the fungus with the mix of the pathogen bacteria led to the induction of bioactivity in two isolates. Aspergillus iizukae produced strong and broadspectrum antibacterial activity against pathogens with minimum inhibitory concentrations of 0.8-406 mg mL À1 . The screening results confirmed the sponge associated fungi as a source of environmentally friendly antimicrobials that may contribute the sustainable development of aquaculture. In addition, co-culture technique is a promising strategy to increase antimicrobial activity that can stimulate the production of novel compounds, and increases the antimicrobial activities of marine derived fungi.