## 3 Bioactive Compounds from Marine Actinomycetes
### Isolation and Maintenance of Cultivable Actinobacteria for Bioflecultural Production  
Actinomycetes usually exist in mixed bacterial consortium in soil, water, marine sediments, and sponges [47; 48]. For the sake of eliminating non-sportulating bacteria from samples, each sample is usually subjected to pre-heat treatment at 60 \({}^{\circ}\)C for 15 min. Afterwards, the samples are thoroughly shaken in sterile medium, vortexed for 2 to 5 min, and are serially diluted (10\({}^{-4}\) and 10\({}^{-6}\)) before plating on selective media for the isolation of actinobacteria. The selective isolation media generally employed includes: M1 Agar [49], ISP2 and NaST21 Cx Agar [50], R2A Agar [51], and Marine Agar (MA) 2216 [52]. The media are usually supplemented with penicillin (100 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\)) or nalidixic acid (25 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\)), and cycloheximide (100 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\)) or potassium dichromate (50 \(\mathrm{\SIUnitSymbolMicro mL^{-1}}\)) to purposely inhibit the growth of other bacteria and fungi respectively. Bacterial colonies that show resemblance to actinobacteria under light microscope are then purified several times on respective media. For isolation and purification purposes, colonies are individually streaked out onto any isolation media of choice, prepared with sea water and eventually transferred on new plates until pure cultures  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Compound** & **Species** & **Other Biological Activity** & **References** \\ \hline \multicolumn{3}{c}{**Antibacterial activity**} \\ \hline Abyssomicins & _Verrucosispora_ sp. & – & [27] \\ \hline Bonactin & _Streptomyces_ sp. & Antifungal & [28] \\ \hline Chloro-dihydroquino & _Streptomyces_ sp. & Anticancer & [29] \\ \hline Diazepinomicin & _Micromosoma_ sp. & Anticancer; anti-inflammatory & [30] \\ \hline Frigocyclinone & _Streptomyces griseus_ & – & [31] \\ \hline Essramycin & _Streptomyces_ sp. & – & [32] \\ \hline Lynamicins & _Marinispora_ sp. & – & [33] \\ \hline Marinopyrroles & _Streptomyces_ sp. & Cytotoxic & [34] \\ \hline Caboxamycin & _Streptomyces_ sp. & Cytotoxic & [35] \\ \hline Himalomycins & _Streptomyces_ sp. & – & [36] \\ \hline Chandrananamycin & _Actinomadura_ sp. & Antialgal; antibacterial & [37] \\ \hline N-(2-hydroxyethylphenyl)-2- & _Nocardia dassonvillei_ & Anticancer & [38] \\ \hline \multicolumn{3}{c}{**Anticancer activity**} \\ \hline Salinosporamide A & _Salinispora tropica_ & – & [39] \\ \hline Caprolactones & _Streptomyces_ sp. & – & [40] \\ \hline
3, 6-Disubstituted indoles & _Streptomyces_ sp. & – & [41] \\ \hline IB-00208 & _Actinomadura_ sp. & – & [42] \\ \hline \multicolumn{3}{c}{**Antitumor activity**} \\ \hline Chinikomycins & _Streptomyces_ sp. & – & [43] \\ \hline Glycicapyrroles & _Streptomyces_ sp. & – & [35] \\ \hline Mechercharmycin A & _Thermoactinomyées_ sp & – & [44] \\ \hline Aureoverticillactam &
\begin{tabular}{c} _Streptomyces_ \\ _autorecorticillatus_ \\ \end{tabular} & – & [45] \\ \hline Arenicolides & _Salinispora arenicola_ & – & [46] \\ \hline Chalomycin & _Streptomyces_ sp. & – & [9] \\ \hline \hline \end{tabular}
\end{table}
Table 2: Some secondary metabolites produced by marine actinobacteria.  
are obtained. Isolated bacteria are usually stored at \(-20\) and \(-80\)\({}^{\circ}\)C, in 20% glycerol and isolation medium for maintenance.