Secondary Metabolites of an of <i>Streptomyces griseorubens</i> Isolate Are Predominantly Pyrrole- and Linoleic-acid like Compounds

Abstract

IntroductionActinomycetes are bona fide producers of new antibiotic agents 1 . Most of the commercialised antibiotics have been discovered from Actinomycetes by screening natural soil and water habitats 2 5 . A wide taxonomic range of Actinomycetes also has the ability to produce many other secondary metabolites with biological activities including anticancer, antiviral, and immunosuppressant 6 10 . Despite the increase in resistance to commonly used antibiotics, new antimicrobial agents are being constantly searched from novel Actinomycetes isolates 11,12 .Many new types of Actinomycetes have been characterised and named, and their secondary metabolites have been extracted using various techniques 4,13 .Most Actinomycetes are free-living organisms that are widely distributed in nature. They are found in both aquatic and terrestrial habitats. The survival rate of these bacteria in unsuitable environmental conditions is high 14 .Actinomycetes are grouped phylogenetically as Grampositive bacteria with high guanine and cytosine content in their genome. They provide approximately 75 of the current bioactive compounds. Species of Streptomyces alone produce two-thirds of naturally occurring antibiotics worldwide 15 .

Volatile Nitrogenous Compounds from Bacteria: Source of Novel Bioactive Compounds

“…[27,28] The large size and high boiling point of pyrrolopyrazines, compared to other compounds, make them less susceptible to volatilizing when subject to the temperatures used in the headspace (in Solid Phase Micro Extraction (SPME), for example), thus also making this class more prominent for liquid-liquid extraction (LLE). [26,[29][30][31][32][33][34] Approximately 34 articles describing pyrrolo-pyrazines from bacterial isolates were found in the scientific database (Table 1). However, not many described the purification and identification methods for nitrogenous compounds or their biological activity.…”

“…Antioxidant Antibacterial (MRSA) [30] Halobacillus kuroshimensis (ND) Antibiofilm [45] Streptomyces (mangrove soil) Antioxidant [46] Bacillus sp. (marine sponge) Antioxidant and antimicrobial [20,39] Vibrio sp.…”

“…and Bacillus sp. (ND) Algicidal [24,37] Bacillus subtilis and Achromobacter kerstersii (sea and rizhosphere soil) Antifungal [30,47] Streptomyces (mangrove soil) Antioxidant [48,49] -dione, hexahydro,3-(2-methyl propyl) Staphylococcus sp. (Deep Sea sediments and marine sponges)…”

“…Antimicrobial and anticancer [38,50] Brevibacillus brevis (ND) Anticancer [37] Pseudomonas putida (ND) ND [51] Bacillus sp. and Achromobacter kerstersii (ND) Antifungal [15,30] Nocardiopsis sp. and Bacillus cereus (ND) Antibacterial [40,52] Streptomyces sp.…”

“…Brevibacillus brevis (soil) Antifungal [17,54] Streptomyces sp. (soil) Antifungal and antibacterial [17,54] Cladosporium sp., and Streptomyces griseorubens (mangrove) Antibacterial [30,55] Streptomyces antioxidans (ND) Neuroprotective and antioxidant [56] -hexahydro-3-(phenylmethyl) and hexahydro-3-(2-methylpropyl)-…”