scholarly journals Diversity of Myxobacteria—We Only See the Tip of the Iceberg

2018 ◽  
Vol 6 (3) ◽  
pp. 84 ◽  
Author(s):  
Kathrin Mohr
Keyword(s):  
New Species ◽  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Rich Source ◽  
Cytostatic Activity ◽  
Bioactive Metabolites ◽  
Plate Count ◽  
Bacillus Species ◽  
Bioactive Secondary Metabolites ◽  
New Antibiotics

The discovery of new antibiotics is mandatory with regard to the increasing number of resistant pathogens. One approach is the search for new antibiotic producers in nature. Among actinomycetes, Bacillus species, and fungi, myxobacteria have been a rich source for bioactive secondary metabolites for decades. To date, about 600 substances could be described, many of them with antibacterial, antifungal, or cytostatic activity. But, recent cultivation-independent studies on marine, terrestrial, or uncommon habitats unequivocally demonstrate that the number of uncultured myxobacteria is much higher than would be expected from the number of cultivated strains. Although several highly promising myxobacterial taxa have been identified recently, this so-called Great Plate Count Anomaly must be overcome to get broader access to new secondary metabolite producers. In the last years it turned out that especially new species, genera, and families of myxobacteria are promising sources for new bioactive metabolites. Therefore, the cultivation of the hitherto uncultivable ones is our biggest challenge.

scholarly journals Bioactive Secondary Metabolites of the Genus Diaporthe and Anamorph Phomopsis from Terrestrial and Marine Habitats and Endophytes: 2010–2019

2021 ◽  
Vol 9 (2) ◽  
pp. 217
Author(s):  
Tang-Chang Xu ◽  
Yi-Han Lu ◽  
Jun-Fei Wang ◽  
Zhi-Qiang Song ◽  
Ya-Ge Hou ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Small Molecules ◽  
Host Plants ◽  
Plant Pathogens ◽  
Bioactive Metabolites ◽  
Drug Candidates ◽  
The Past ◽  
Marine Habitats ◽  
Bioactive Secondary Metabolites ◽  
Unidentified Species

The genus Diaporthe and its anamorph Phomopsis are distributed worldwide in many ecosystems. They are regarded as potential sources for producing diverse bioactive metabolites. Most species are attributed to plant pathogens, non-pathogenic endophytes, or saprobes in terrestrial host plants. They colonize in the early parasitic tissue of plants, provide a variety of nutrients in the cycle of parasitism and saprophytism, and participate in the basic metabolic process of plants. In the past ten years, many studies have been focused on the discovery of new species and biological secondary metabolites from this genus. In this review, we summarize a total of 335 bioactive secondary metabolites isolated from 26 known species and various unidentified species of Diaporthe and Phomopsis during 2010–2019. Overall, there are 106 bioactive compounds derived from Diaporthe and 246 from Phomopsis, while 17 compounds are found in both of them. They are classified into polyketides, terpenoids, steroids, macrolides, ten-membered lactones, alkaloids, flavonoids, and fatty acids. Polyketides constitute the main chemical population, accounting for 64%. Meanwhile, their bioactivities mainly involve cytotoxic, antifungal, antibacterial, antiviral, antioxidant, anti-inflammatory, anti-algae, phytotoxic, and enzyme inhibitory activities. Diaporthe and Phomopsis exhibit their potent talents in the discovery of small molecules for drug candidates.

scholarly journals Genomic and Metabolomic Analysis of Antarctic Bacteria Revealed Culture and Elicitation Conditions for the Production of Antimicrobial Compounds

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 673
Author(s):  
Kattia Núñez-Montero ◽  
Damián Quezada-Solís ◽  
Zeinab G. Khalil ◽  
Robert J. Capon ◽  
Fernando D. Andreote ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Culture Media ◽  
Genome Mining ◽  
Gene Clusters ◽  
Culture Conditions ◽  
Bioactive Metabolites ◽  
Bacterial Strains ◽  
Antarctic Bacteria ◽  
New Antibiotics

Concern about finding new antibiotics against drug-resistant pathogens is increasing every year. Antarctic bacteria have been proposed as an unexplored source of bioactive metabolites; however, most biosynthetic gene clusters (BGCs) producing secondary metabolites remain silent under common culture conditions. Our work aimed to characterize elicitation conditions for the production of antibacterial secondary metabolites from 34 Antarctic bacterial strains based on MS/MS metabolomics and genome mining approaches. Bacterial strains were cultivated under different nutrient and elicitation conditions, including the addition of lipopolysaccharide (LPS), sodium nitroprusside (SNP), and coculture. Metabolomes were obtained by HPLC-QTOF-MS/MS and analyzed through molecular networking. Antibacterial activity was determined, and seven strains were selected for genome sequencing and analysis. Biosynthesis pathways were activated by all the elicitation treatments, which varies among strains and dependents of culture media. Increased antibacterial activity was observed for a few strains and addition of LPS was related with inhibition of Gram-negative pathogens. Antibiotic BGCs were found for all selected strains and the expressions of putative actinomycin, carotenoids, and bacillibactin were characterized by comparison of genomic and metabolomic data. This work established the use of promising new elicitors for bioprospection of Antarctic bacteria and highlights the importance of new “-omics” comparative approaches for drug discovery.

New Bioactive Secondary Metabolites from Bornean Red Alga, Laurencia similis (Ceramiales)

2013 ◽  
Vol 8 (3) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Takashi Kamada ◽  
Charles Santhanaraju Vairappan
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Red Alga ◽  
Algal Population ◽  
Cytotoxic Effects ◽  
Antibiotic Resistant ◽  
Good Antibacterial Activity ◽  
Bioactive Secondary Metabolites ◽  
Red Algal

A Bornean red algal population of Laurencia simlis Nam et Saito was analyzed for its secondary metabolite composition. Seven compounds were identified: ent -1(10)-aristolen-9β-ol (1), (+)-aristolone (2), axinysone B (3), 9-aristolen-1α-ol (4), 2,3,5,6-tetrabromoindole (5), 1-methyl-2,3,5,6-tetrabromoindole (6), and 1-methyl-2,3,5-tribromoindole (7). Compound 1 was identified as a new optical isomer of 1(10)-aristolen-9β-ol. Compounds 1, 4 and 5 exhibited good antibacterial activity against antibiotic resistant clinical bacteria and cytotoxic effects against selected cancer cell lines.

scholarly journals Comparative Analyses of Cytochrome P450s and Those Associated with Secondary Metabolism in Bacillus Species

2018 ◽  
Vol 19 (11) ◽  
pp. 3623 ◽  
Author(s):  
Bongumusa Mthethwa ◽  
Wanping Chen ◽  
Mathula Ngwenya ◽  
Abidemi Kappo ◽  
Puleng Syed ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
In Silico Analysis ◽  
Gene Clusters ◽  
Bacillus Species ◽  
Cytochrome P450 Monooxygenases ◽  
Enzymatic Reactions ◽  
P450 Monooxygenases ◽  
Stereo Selectivity

Cytochrome P450 monooxygenases (CYPs/P450s) are among the most catalytically-diverse enzymes, capable of performing enzymatic reactions with chemo-, regio-, and stereo-selectivity. Our understanding of P450s’ role in secondary metabolite biosynthesis is becoming broader. Among bacteria, Bacillus species are known to produce secondary metabolites, and recent studies have revealed the presence of secondary metabolite biosynthetic gene clusters (BGCs) in these species. However, a comprehensive comparative analysis of P450s and P450s involved in the synthesis of secondary metabolites in Bacillus species has not been reported. This study intends to address these two research gaps. In silico analysis of P450s in 128 Bacillus species revealed the presence of 507 P450s that can be grouped into 13 P450 families and 28 subfamilies. No P450 family was found to be conserved in Bacillus species. Bacillus species were found to have lower numbers of P450s, P450 families and subfamilies, and a lower P450 diversity percentage compared to mycobacterial species. This study revealed that a large number of P450s (112 P450s) are part of different secondary metabolite BGCs, and also identified an association between a specific P450 family and secondary metabolite BGCs in Bacillus species. This study opened new vistas for further characterization of secondary metabolite BGCs, especially P450s in Bacillus species.

Bioactive secondary metabolites produced by microorganisms associated with plants

Biologia ◽  
2007 ◽  
Vol 62 (3) ◽  
Author(s):  
Silvia Firáková ◽  
Mária Šturdíková ◽  
Marta Múčková
Keyword(s):  
Secondary Metabolites ◽  
Host Plants ◽  
Biological Activities ◽  
Bioactive Metabolites ◽  
Intercellular Spaces ◽  
Biotechnological Production ◽  
Bioactive Substances ◽  
The Past ◽  
Endophytic Microorganisms ◽  
Bioactive Secondary Metabolites

AbstractIn the past few decades groups of scientists have focused their study on relatively new microorganisms called endophytes. By definition these microorganisms, mostly fungi and bacteria, colonise the intercellular spaces of the plant tissues. The mutual relationship between endophytic microorganisms and their host plants, taxanomy and ecology of endophytes are being studied. Some of these microorganisms produce bioactive secondary metabolites that may be involved in a host-endophyte relationship. Recently, many endophytic bioactive metabolites, known as well as new substances, possesing a wide variety of biological activities as antibiotic, antitumor, antiinflammatory, antioxidant, etc. have been identified. The microorganisms such as endophytes may be very interesting for biotechnological production of bioactive substances as medicinally important agents. Therefore the aim of this review is to briefly characterize endophytes and summarize the structuraly different bioactive secondary metabolites produced by endophytic microorganisms as well as microbial sources of these metabolites and their host plants.

scholarly journals Lysobacter enzymogenes Uses Two Distinct Cell-Cell Signaling Systems for Differential Regulation of Secondary-Metabolite Biosynthesis and Colony Morphology

2013 ◽  
Vol 79 (21) ◽  
pp. 6604-6616 ◽  
Author(s):  
Guoliang Qian ◽  
Yulan Wang ◽  
Yiru Liu ◽  
Feifei Xu ◽  
Ya-Wen He ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Cell Signaling ◽  
Secondary Metabolite ◽  
Colony Morphology ◽  
Content Type ◽  
Signaling Systems ◽  
Lysobacter Enzymogenes ◽  
Bioactive Secondary Metabolites ◽  
Secondary Metabolite Biosynthesis ◽  
First Time

ABSTRACTLysobacter enzymogenesis a ubiquitous environmental bacterium that is emerging as a potentially novel biological control agent and a new source of bioactive secondary metabolites, such as the heat-stable antifungal factor (HSAF) and photoprotective polyene pigments. Thus far, the regulatory mechanism(s) for biosynthesis of these bioactive secondary metabolites remains largely unknown inL. enzymogenes. In the present study, the diffusible signal factor (DSF) and diffusible factor (DF)-mediated cell-cell signaling systems were identified for the first time fromL. enzymogenes. The results show that both Rpf/DSF and DF signaling systems played critical roles in modulating HSAF biosynthesis inL. enzymogenes. Rpf/DSF signaling and DF signaling played negative and positive effects in polyene pigment production, respectively, with DF playing a more important role in regulating this phenotype. Interestingly, only Rpf/DSF, but not the DF signaling system, regulated colony morphology ofL. enzymgenes. Both Rpf/DSF and DF signaling systems were involved in the modulation of expression of genes with diverse functions inL. enzymogenes, and their own regulons exhibited only a few loci that were regulated by both systems. These findings unveil for the first time new roles of the Rpf/DSF and DF signaling systems in secondary metabolite biosynthesis ofL. enzymogenes.

scholarly journals More P450s Are Involved in Secondary Metabolite Biosynthesis in Streptomyces Compared to Bacillus, Cyanobacteria, and Mycobacterium

2020 ◽  
Vol 21 (13) ◽  
pp. 4814
Author(s):  
Fanele Cabangile Mnguni ◽  
Tiara Padayachee ◽  
Wanping Chen ◽  
Dominik Gront ◽  
Jae-Hyuk Yu ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Gene Clusters ◽  
Bacillus Species ◽  
Cytochrome P450 Monooxygenases ◽  
Streptomyces Species ◽  
P450 Monooxygenases ◽  
Cyanobacterial Species ◽  
Metabolite Synthesis

Unraveling the role of cytochrome P450 monooxygenases (CYPs/P450s), heme-thiolate proteins present in living and non-living entities, in secondary metabolite synthesis is gaining momentum. In this direction, in this study, we analyzed the genomes of 203 Streptomyces species for P450s and unraveled their association with secondary metabolism. Our analyses revealed the presence of 5460 P450s, grouped into 253 families and 698 subfamilies. The CYP107 family was found to be conserved and highly populated in Streptomyces and Bacillus species, indicating its key role in the synthesis of secondary metabolites. Streptomyces species had a higher number of P450s than Bacillus and cyanobacterial species. The average number of secondary metabolite biosynthetic gene clusters (BGCs) and the number of P450s located in BGCs were higher in Streptomyces species than in Bacillus, mycobacterial, and cyanobacterial species, corroborating the superior capacity of Streptomyces species for generating diverse secondary metabolites. Functional analysis via data mining confirmed that many Streptomyces P450s are involved in the biosynthesis of secondary metabolites. This study was the first of its kind to conduct a comparative analysis of P450s in such a large number (203) of Streptomyces species, revealing the P450s’ association with secondary metabolite synthesis in Streptomyces species. Future studies should include the selection of Streptomyces species with a higher number of P450s and BGCs and explore the biotechnological value of secondary metabolites they produce.

scholarly journals INFLUENCE OF PHYSICO-CHEMICAL PARAMETERS ON SECONDARY METABOLITE PRODUCTION BY MARINE FUNGI

2017 ◽  
pp. 112-118
Author(s):  
Anuhya G. ◽  
Jyostna V. ◽  
Aswani Kumar Yvv ◽  
Bodaiah B. ◽  
Sudhakar P.
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Secondary Metabolites ◽  
Secondary Metabolite ◽  
Inhibitory Concentration ◽  
Marine Fungi ◽  
Mineral Salts ◽  
Potato Dextrose Broth ◽  
Physico Chemical ◽  
Bioactive Secondary Metabolites

Objective: Our study aimed to characterize and optimize the physico-chemical properties which render the high yield of bioactive secondary metabolites from marine fungi and its antibacterial activity against clinical pathogens.Methods: Bioactive secondary metabolites extracted from marine fungi of Nijampatnam mangroves, Guntur district Andhra Pradesh, India. By using different solvent systems, secondary metabolite was screened for antimicrobial activity against clinical pathogen, Optimization of cultural conditions for maximizing the yield of biomass and compared the yield in different broth media and minimum inhibitory concentration of the optimised compound done for both compounds.Results: fungal extracts GAPS-1 and GAPS-2 was affectively extracted in ethyl acetate. Isolated compound showed antibacterial activity highest zone of inhibition against E. coli and least to Pseudomonas. Maximum yield of the compound was achieved in modified potato dextrose broth (PDB) medium containing 20% w/v Potato 2% w/v Dextrose broth containing1% w/v glucose and sucrose,1% w/v beef extract and ammonium chloride and 0.01 % mineral salts(MGSO4 and MNSO4) at 25 °C and 30 °C and pH 7.0 and 8.0 with 144 h of incubation period. The yield was observed maximum in potato dextrose broth compared to czapek dox broth, sabaraud’s broth and nutrient broth and minimum inhibitory concentration of the optimized compound ranges from 250 μg for gaps-1 and 300 μg for gaps-2.Conclusion: Secondary metabolite yield maximum in potato dextrose broth and its potential anti-bacterial activity needs further investigation for pharmaceutical applications.

scholarly journals Antimicrobial Activities of Lipopeptides and Polyketides of Bacillus velezensis for Agricultural Applications

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4973
Author(s):  
Muhammad Fazle Rabbee ◽  
Kwang-Hyun Baek
Keyword(s):  
Secondary Metabolites ◽  
Gene Clusters ◽  
Bioactive Metabolites ◽  
Bacillus Species ◽  
Biological Applications ◽  
Biosynthetic Gene ◽  
Bacillus Velezensis ◽  
Biosynthetic Gene Clusters ◽  
Chemical Structures ◽  
Plant Disease Management

Since the discovery of penicillin, bacteria are known to be major sources of secondary metabolites that can function as drugs or pesticides. Scientists worldwide attempted to isolate novel compounds from microorganisms; however, only less than 1% of all existing microorganisms have been successfully identified or characterized till now. Despite the limitations and gaps in knowledge, in recent years, many Bacillus velezensis isolates were identified to harbor a large number of biosynthetic gene clusters encoding gene products for the production of secondary metabolites. These chemically diverse bioactive metabolites could serve as a repository for novel drug discovery. More specifically, current projects on whole-genome sequencing of B. velezensis identified a large number of biosynthetic gene clusters that encode enzymes for the synthesis of numerous antimicrobial compounds, including lipopeptides and polyketides; nevertheless, their biological applications are yet to be identified or established. In this review, we discuss the recent research on synthesis of bioactive compounds by B. velezensis and related Bacillus species, their chemical structures, bioactive gene clusters of interest, as well as their biological applications for effective plant disease management.

scholarly journals Actinobacteria Derived from Algerian Ecosystems as a Prominent Source of Antimicrobial Molecules

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 172 ◽  
Author(s):  
Djinni ◽  
Defant ◽  
Kecha ◽  
Mancini
Keyword(s):  
New Species ◽  
Culture Media ◽  
Bioactive Metabolites ◽  
Antitumor Activities ◽  
Natural Sources ◽  
Antifungal Metabolites ◽  
Saharan Soil ◽  
Bioactive Secondary Metabolites ◽  
Antimicrobial Metabolites ◽  
Rare Actinobacteria

Actinobacteria, in particular “rare actinobacteria” isolated from extreme ecosystems, remain the most inexhaustible source of novel antimicrobials, offering a chance to discover new bioactive metabolites. This is the first overview on actinobacteria isolated in Algeria since 2002 to date with the aim to present their potential in producing bioactive secondary metabolites. Twenty-nine new species and one novel genus have been isolated, mainly from the Saharan soil and palm groves, where 37.93% of the most abundant genera belong to Saccharothrix and Actinopolyspora. Several of these strains were found to produce antibiotics and antifungal metabolites, including 17 new molecules among the 50 structures reported, and some of these antibacterial metabolites have shown interesting antitumor activities. A series of approaches used to enhance the production of bioactive compounds is also presented as the manipulation of culture media by both classical methods and modeling designs through statistical strategies and the associations with diverse organisms and strains. Focusing on the Algerian natural sources of antimicrobial metabolites, this work is a representative example of the potential of a closely combined study on biology and chemistry of natural products.

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