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A Polyketide compounds purified from marine heterotrophic B. amyloliquefaciens MTCC 12,716 (MB6). Images of disc diffusion assay of the polyketide compounds (B) macrocyclic lactone (3) and (C) elansolid type polyketide (5) against MRSA with chloramphenicol disc as standard. The clear zones around the disc (6 mm) indicated the antibacterial activity. Antagonistic activity was recorded as the inhibition zone diameter determined as a space of ≥ 1 mm between the circular area (= disc diameter)
Source publication
During the previous decade, genome-built researches on marine heterotrophic microorganisms displayed the chemical heterogeneity of natural product resources coupled with the efficacies of harnessing the genetic divergence in various strains. Herein, we describe the whole genome data of heterotrophic Bacillus amyloliquefaciens MB6 (MTCC 12,716), iso...
Citations
... Twenty-five macrolides belonging to different classes have been isolated from marine macroalgae Bacillota, including derivatives of macrolactin (1, 2, 13-21) [73,91], bacvalactone (3)(4)(5), elansolid (6)(7)(8) [95][96][97], difficidin (9)(10)(11)(12) [101], and macrobrevin (22)(23)(24)(25) [102]. Compounds 1 and 2 are 24-membered macrolactins isolated from B. subtilis of a brown alga, Anthophycus longifolius [89,91]. ...
... Other compounds with appreciable antibacterial activity are 7 and 34. At an MIC value of 0.38 µg/mL, compound 7, a product of B. amyloliquefaciens isolated from a red alga, Hypnea valentiae, was active against MRSA and Vibrio haemolyticus [96,97], similar to 34, produced by B. velezensis of Laurencia papillosa [103]. Worthy of mention is 40 (MIC value: 0.78 µg/mL), another active compound from B. amyloliquefaciens of Hypnea valentiae, with a broad spectrum activity against pathogenic bacteria [98]. ...
The shift from the terrestrial to the marine environment to discover natural products has given rise to novel bioactive compounds, some of which have been approved for human medicine. However, the ocean, which makes up nearly three-quarters of the Earth’s surface, contains macro- and microorganisms whose natural products are yet to be explored. Among these underexplored marine organisms are macroalgae and their symbiotic microbes, such as Bacillota, a phylum of mostly Gram-positive bacteria previously known as Firmicutes. Macroalgae-associated Bacillota often produce chemical compounds that protect them and their hosts from competitive and harmful rivals. Here, we summarised the natural products made by macroalgae-associated Bacillota and their pharmacological properties. We discovered that these Bacillota are efficient producers of novel biologically active molecules. However, only a few macroalgae had been investigated for chemical constituents of their Bacillota: nine brown, five red and one green algae. Thus, Bacillota, especially from the marine habitat, should be investigated for potential pharmaceutical leads. Moreover, additional diverse biological assays for the isolated molecules of macroalgae Bacillota should be implemented to expand their bioactivity profiles, as only antibacterial properties were tested for most compounds.
Since the report of the antibiotic with anticancer properties, scientists have been focusing to isolate and characterize novel anti-microbial natural products possessing anticancer activities. The current study describes the production of seaweed-associated heterotrophic Bacillus altitudinis MTCC13046 with potential anticancer properties. The bacterium was screened for its capacity to diminish the cell proliferation of the human hepatocellular adenocarcinoma (HepG2) cell line, without upsetting the normal cells. The bacterial extract showed anticancer properties in a dose-reactive form against HepG2 (IC50, half maximal inhibitory concentration ~ 29.5 µg/ml) on tetrazolium bromide analysis with less significant cytotoxicity on common fibroblast (HDF) cells (IC50 ~ 77 µg/ml). The potential antioxidant ability of the organic extract of B. altitudinis MTCC13046 (IC90 133 µg/ml) could corroborate its capacity to attenuate the pathophysiology leading to carcinogenesis. The results of the apoptosis assay showed that the crude extracts of B. altitudinis maintained 68% viability in normal cells compared to 11% in the cancer cells (IC50 76.9 µg/ml). According to the findings, B. altitudinis MTCC13046 could be used to develop prospective anticancer agents.
Graphical abstract
Natural products (NPs) and their derivatives are a major contributor to modern medicine. Historically, microorganisms such as bacteria and fungi have been instrumental in generating drugs and lead compounds because of the ease of culturing and genetically manipulating them. However, the ever-increasing demand for novel drugs highlights the need to bioprospect previously unexplored taxa for their biosynthetic potential. Next-generation sequencing technologies have expanded the range of organisms that can be explored for their biosynthetic content, as these technologies can provide a glimpse of an organism’s entire biosynthetic landscape, without the need for cultivation. The entirety of biosynthetic genes can be compared to the genes of known function to identify the gene clusters potentially coding for novel products. In this study, we mine the genomes of nine lichen-forming fungal species of the genus Umbilicaria for biosynthetic genes, and categorize the biosynthetic gene clusters (BGCs) as “associated product structurally known” or “associated product putatively novel”. Although lichen-forming fungi have been suggested to be a rich source of NPs, it is not known how their biosynthetic diversity compares to that of bacteria and non-lichenized fungi. We found that 25%–30% of biosynthetic genes are divergent as compared to the global database of BGCs, which comprises 1,200,000 characterized biosynthetic genes from plants, bacteria, and fungi. Out of 217 BGCs, 43 were highly divergant suggesting that they potentially encode structurally and functionally novel NPs. Clusters encoding the putatively novel metabolic diversity comprise polyketide synthases (30), non-ribosomal peptide synthetases (12), and terpenes (1). Our study emphasizes the utility of genomic data in bioprospecting microorganisms for their biosynthetic potential and in advancing the industrial application of unexplored taxa. We highlight the untapped structural metabolic diversity encoded in the lichenized fungal genomes. To the best of our knowledge, this is the first investigation identifying genes coding for NPs with potentially novel properties in lichenized fungi.
The ever-increasing demand for novel drugs highlights the need for bioprospecting unexplored taxa for their biosynthetic potential. Lichen-forming fungi (LFF) are a rich source of natural products but their implementation in pharmaceutical industry is limited, mostly because the genes corresponding to a majority of their natural products is unknown. Furthermore, it is not known to what extent these genes encode structurally novel molecules. Advance in next-generation sequencing technologies has expanded the range of organisms that could be exploited for their biosynthetic potential. In this study, we mine the genomes of nine lichen-forming fungal species of the genus Umbilicaria for biosynthetic genes, and categorize the BGCs as associated product structurally known, and associated product putatively novel. We found that about 25-30% of the biosynthetic genes are divergent when compared to the global database of BGCs comprising of 1,200,000 characterized biosynthetic genes from planta, bacteria and fungi. Out of 217 total BGCs, 43 were only distantly related to known BGCs, suggesting they encode structurally and functionally unknown natural products. Clusters encoding the putatively novel metabolic diversity comprise PKSs (30), NRPSs (12) and terpenes (1). Our study emphasizes the utility of genomic data in bioprospecting microorganisms for their biosynthetic potential and in advancing the industrial application of unexplored taxa. We highlight the untapped structural metabolic diversity encoded in the lichenized fungal genomes. To the best of our knowledge, this is the first investigation identifying genes coding for NPs with potentially novel therapeutic properties in LFF.
