Enhancement of undecylprodigiosin production from marine endophytic recombinant strain Streptomyces sp. ALAA-R20 through low-cost induction strategy

Enhanced Natamycin production in Streptomyces gilvosporeus through phosphate tolerance screening and transcriptome-based analysis of high-yielding mechanisms

BACKGROUND

Natamycin is a natural antibiotic with broad-spectrum antifungal activity, widely used in food preservation, medicine, and biological control. However, the relatively low biosynthetic capacity of producing strains limits further industrialization and broader applications of natamycin. Due to the complexity of cellular metabolism, evolutionary engineering is required for developing strains with enhanced natamycin biosynthetic capacity.

RESULTS

Here, protoplast fusion combined with phosphate tolerance screening was employed for the first time to enhance natamycin production of Streptomyces gilvosporeus. A high-yielding strain, GR-2, was obtained, with natamycin production twice that of the original strain. Transcriptomic analysis revealed that the natamycin biosynthetic gene cluster and several primary metabolic pathways were significantly upregulated in GR-2, likely contributing to its high production performance. Further experiments, including amino acid addition and reverse engineering, confirmed that branched-chain amino acid, nitrogen, and phosphate metabolism play crucial roles in promoting natamycin production. Silencing of the phosphate metabolism transcriptional regulators PhoP and PhoR led to a decreased expression of natamycin biosynthetic genes and significantly reduced natamycin production, highlighting the key role of these regulators in S. gilvosporeus. Based on omics data, co-expression of phoP and phoR in GR-2 resulted in the engineered strain GR2-P3, which exhibited a 25% increase in natamycin production in shake flasks. In a 5 L fermenter, GR2-P3 achieved a natamycin production of 12.2 ± 0.6 g·L⁻¹, the highest yield reported for S. gilvosporeus to date.

CONCLUSIONS

Our findings suggest that the high production performance of GR-2 is primarily due to the upregulation of the natamycin biosynthetic gene cluster and genes related to precursor supply. Increasing the intracellular supply of valine and glutamate significantly enhanced natamycin production. Additionally, the natamycin biosynthetic gene cluster is likely positively regulated by PhoP and PhoR. Our work presents a novel strategy for strain screening and evolution to improve natamycin production and identifies novel molecular targets for metabolic engineering.

Enhanced undecylprodigiosin production using collagen hydrolysate: a cost-effective and high-efficiency synthesis strategy

Undecylprodigiosin (UDP), a desirable pyrrole-based biomaterial, holds significant promise in pharmaceutical and medical applications due to its diverse biological activities. However, its application is usually hampered by low synthesis efficiency and high production costs. Here, we developed a high-efficiency and cost-effective strategy for UDP synthesis using collagen hydrolysate (COH) as a readily available and abundant precursor source in conjunction with Streptomyces sp. SLL-523. COH obviously accelerated the proliferation of Streptomyces sp. SLL-523. Replacing muscle hydrolysate with COH resulted in a 7-fold increase in UDP yield and a 10-fold reduction in fermentation time, indicating that COH significantly enhanced the synthesis efficiency of UDP. Besides, COH remarkably increased the intracellular levels of UDP precursor amino acids (AAs). Whole-genome analysis of Streptomyces sp. SLL-523 revealed the gene clusters responsible for UDP synthesis and COH utilization. COH markedly stimulated the expression of genes involved in the metabolism pathways of energy, transporters, peptides, and AAs, ultimately promoting the UDP synthesis. Significantly, COH efficiently triggered and boosted the expression of key genes in the UDP biosynthesis pathway, including redQ, redM, redN, and redL, leading to highly efficient UDP synthesis. Thus, this innovative approach provides a novel framework for the high-efficiency synthesis of natural pyrrole biomedical materials based on renewable nitrogen-contained biomass.

Evaluation of multidrug resistance in the Gram-negative microbiome of cancer patients and the adverse effects of their metabolites on albino rats and epithelial or fibroblasts cell lines

BACKGROUND

Cancer is a significant global health issue due to its high incidence and mortality rates. In recent years, the relationship between the human microbiota and cancer has garnered attention across various medical fields. This includes research into the microbial communities that influence cancer development, tumor-associated microorganisms, and the interactions between the microbiome and tumor, collectively referred to as the oncobiome.

METHODS

The negative effects of secondary metabolites extracted from selected multidrug-resistant Gram-negative bacteria within the cancer microbiota were evaluated. These effects included carcinogenicity, mutagenicity, hepatotoxicity, nephrotoxicity, and sperm deformities observed in albino rats after one month of oral ingestion of these microbial extracts.

RESULTS

Our findings in the present investigation revealed that among the bacterial community derived from the microbiota, Gram-negative bacteria accounted for 74.87% the total microbiota (146 out of 195) and their spectrum including Escherichia sp. (n = 36, 24.66%) followed by Acinetobacter sp. (n = 34, 23.29%), Stenotrophomonas sp. (n = 29, 19.86%), Pseudomonas sp. (n = 26, 17.81%) and Serratia sp. (n = 21, 14.38%), as the most prevalent pathogens. All isolates derived from the cancer microbiome exhibited multidrug resistance to a large number of conventional therapies. Out of them Serratia sp. Esraa 1, Stenotrophomonas sp. Esraa 2, Acinetobacter sp. Esraa 3, Escherichia sp. Esraa 4 and Pseudomonas sp. Esraa 5 strains showed multidrug resistant profile against all antibiotic classes under study including penicillins, cephalosporins, carbapenems, fluoroquinolones, β-lactamase inhibitors combinations, folate synthesis pathway inhibitors, phosphonic, aminoglycosides, polymyxins, tetracyclines, macrolides, and chloramphenicol antibiotics. The adverse effects of oral ingestion of their metabolites were evaluated in albino rats. They induced pronounced carcinogenesis along with severe raise in the inflammatory cytokines, hepatotoxicity, nephrotoxicity, mutagenicity along with sperm deformities in treated animals. Moreover, all metabolites showed marked cytotoxicity against human normal cell lines; human mammary epithelial (MCF10A), human lung fibroblasts (WI38) and human dermal fibroblasts (HDFs).

CONCLUSION

These bacterial strains isolated from the cancer microbiome may play significant roles in inducing cancer, inflammation, mutagenesis, hepatotoxicity, nephrotoxicity, and sperm abnormalities, along with histopathological changes in the treated animal groups by orally administrated metabolites in compared to the untreated group.

Actinomycete-Derived Pigments: A Path Toward Sustainable Industrial Colorants

Pigment production has a substantial negative impact on the environment, since mining for natural pigments causes ecosystem degradation, while synthetic pigments, derived from petrochemicals, generate toxic by-products that accumulate and persist in aquatic systems due to their resistance to biodegradation. Despite these challenges, pigments remain essential across numerous industries, including the cosmetic, textile, food, automotive, paints and coatings, plastics, and packaging industries. In response to growing consumer demand for sustainable options, there is increasing interest in eco-friendly alternatives, particularly bio-based pigments derived from algae, fungi, and actinomycetes. This shift is largely driven by consumer demand for sustainable options. For bio-pigments, actinomycetes, particularly from the Streptomyces genus, have emerged as a promising green source, aligning with global sustainability goals due to their renewability and biodegradability. Scale-up of production and yield optimization challenges have been circumvented with the aid of biotechnology advancements, including genetic engineering and innovative fermentation and extraction methods, which have enhanced these bio-pigments' viability and cost-competitiveness. Actinomycete-derived pigments have successfully transitioned from laboratory research to commercialization, showcasing their potential as sustainable and eco-friendly alternatives to synthetic dyes. With the global pigment market valued at approximately USD 24.28 billion in 2023, which is projected to reach USD 36.58 billion by 2030, the economic potential for actinomycete pigments is extensive. This review explores the environmental advantages of actinomycete pigments, their role in modern industry, and the regulatory and commercialization challenges they face, highlighting the importance of these pigments as promising solutions to reduce our reliance on conventional toxic pigments. The successful commercialization of actinomycete pigments can drive an industry-wide transition to environmentally responsible alternatives, offering substantial benefits for human health, safety, and environmental sustainability.

Genomic and Untargeted Metabolomic Analysis of Secondary Metabolites in the Streptomyces griseoaurantiacus Strain MH191 Shows Media-Based Dependency for the Production of Bioactive Compounds with Potential Antifungal Activity

Streptomyces species can form beneficial relationships with hosts as endophytes, including the phytopathogen-inhibiting strain, Streptomyces griseoaurantiacusMH191, isolated from wheat plants. Using genomic characterization and untargeted metabolomics, we explored the capacity of strain MH191 to inhibit a range of fungal phytopathogens through the production of secondary metabolites. Complete genome assembly of strain MH191 predicted 24 biosynthetic gene clusters. Secondary metabolite production was assessed following culture on six different media, with the detection of 205 putative compounds. Members of the manumycin family, undecylprodigiosin, and desferrioxamine were identified as the predominant metabolites. Antifungal activity was validated for undecylprodigiosin and manumycin. These compounds were produced from different BGCs, which showed similarity to asukamycin, undecylprodigiosin, and FW0622 gene clusters, respectively. The growth of strain MH191 on different media illustrated the metabolic regulation of these gene clusters and the strain's extended chemical potential, with the asukamycin gene cluster alone, producing a variety of antifungal metabolites. The study highlights the extended chemical capability of strain MH191, which could be exploited as a biological control agent for designing future crop protection solutions.

Blue Biotechnology: Marine Bacteria Bioproducts

The ocean is the habitat of a great number of organisms with different characteristics. Compared to terrestrial microorganisms, marine microorganisms also represent a vast and largely unexplored reservoir of bioactive compounds with diverse industrial applications like terrestrial microorganisms. This review examines the properties and potential applications of products derived from marine microorganisms, including bacteriocins, enzymes, exopolysaccharides, and pigments, juxtaposing them in some cases against their terrestrial counterparts. We discuss the distinct characteristics that set marine-derived products apart, including enhanced stability and unique structural features such as the amount of uronic acid and sulfate groups in exopolysaccharides. Further, we explore the uses of these marine-derived compounds across various industries, ranging from food and pharmaceuticals to cosmetics and biotechnology. This review also presents a broad description of biotechnologically important compounds produced by bacteria isolated from marine environments, some of them with different qualities compared to their terrestrial counterparts.

Antimicrobial Natural Products Derived from Microorganisms Inhabiting the MENA Region

Objective/Background

Natural products (NPs) derived from microorganisms are the basis of a plethora of clinically utilized medications, namely, antimicrobial remedies. Although these secondary metabolites have been extensively explored all over the planet, they remain understudied in the Middle East and North Africa (MENA) region.

Methods

A literature search was conducted to first find NPs that were isolated from environmental fungi and bacteria that inhabit the soils and seawater of the MENA region. Then, purified molecules with biological activity against pathogenic bacteria, biofilms, fungi, and parasites were described in terms of structure, function, and location. Moreover, the methods that could be used to ameliorate the discovery of novel NPs from this region were investigated.

Results

A multitude of antimicrobial molecules from various chemical classes were found to be derived from the environmental microbes of MENA. Although many were rediscovered, some represented novel structural scaffolds for novel families of antimicrobial agents. Additionally, the geographical distribution showed a high number of these NPs were unraveled in a restricted area leaving much of MENA untapped. Furthermore, as relatively traditional and low-efficiency methods were typically used in the discovery process, advanced high-throughput techniques were suggested to enhance this practice at the regional level.

Conclusion

MENA represents a fairly unexploited region where antimicrobial drug discovery could be performed comprehensively through the concomitant exploration of untouched geographical locations and advanced molecular techniques.

Phytochemical Screening, Antifungal, and Anticancer Activities of Medicinal Plants Thymelaea Hirsuta, Urginea Maritima, and Plantago Albicans

Ethyl acetate, ethanol, and acetone extracts of the medicinal plants Thymelaea hirsuta L., Urginea maritima L., and Plantago albicans L. (aerial parts) were evaluated for their phytochemical compositions, antimycotic activity against dermatophytes, and antiproliferative activity against different human cancer cell lines. Among them, the ethanolic extracts showed the highest phytochemical contents along with hyperactivities and were then selected for gas chromatography-mass spectrometry and Fourier-transform infrared spectroscopy analysis. The Fourier-transform infrared spectroscopy analysis confirmed the presence of different characteristic peak values with various functional chemical groups of the active components. However, U. maritima extracts through Fourier-transform infrared spectroscopy analysis showed distinctive peaks related to phenolic, amines, amides, aromatic, alkanes, alkyne, cyclopentanone, conjugated aldehyde, nitro, methoxy, uronic acids, aromatic esters, tertiary alcohol or ester, secondary and primary alcohols, aliphatic ether, sulfoxide, vinylidene, and halo compounds. Many bioactive main compounds with reported biological activities were detected by GC/MS (%) in the ethanolic extract of T. hirsuta, U. maritima, and P. albicans. All studied dermatophytes included a diverse set of virulence factors, including phospholipase, protease, keratinase, hemolysis, and melanoid production, all of which play vital roles in dermatophytic infection. Ethanolic extract of P. albicans inhibited the growth of Trichophyton soudanense totally and Trichophyton erinacei in addition to all Microsporum species. In contrast, the ethanolic extract of Trichophyton hirsuta at concentrations of 25 g/mL totally prevented the growth of all Trichophyton species. EtOH extract of U. maritima completely prevented the growth (100% inhibition) of all dermatophytic strains under study at the lowest concentration of 12.5 μg/mL. Scanning electron microscope analysis revealed considerable morphological modifications and structural alterations in dermatophyte species exposed to ethanolic extract of these plants. The viability of HCT-116, HepG-2, MCF-7, and HeLa cell lines was reduced after treatment with the ethanolic extracts of T. hirsuta, U. maritima, and P. albicans individually with IC50 values (10.0, 9.97, 48.5, and 56.24 μg/mL), (26.98, 25.0, 17.11, and 9.52 μg/mL), and (9.32, 7.46, 12.50, and 16.32 μg/mL), respectively. Our work revealed the significance of these traditional ethnomedical plants as potent sources for biologically active pharmaceuticals with potential applicability for the treatment of fungal and cancer diseases.

Assessment of the phylogenetic analysis and antimicrobial, antiviral, and anticancer activities of marine endophytic Streptomyces species of the soft coral Sarcophyton convolutum

In the present work, the extensive biological activities of marine endophytic Streptomyces strains isolated from marine soft coral Sarcophyton convolutum have been demonstrated. Within fifty-one Streptomyces isolates evaluated for their hydrolytic enzymes and enzyme inhibitors productivities, six isolates showed the hyperactivities. Pharmaceutical metabolites productivities evaluated include enzymes (alkaline protease, L-asparaginase, L-glutaminase, tyrosinase, and L-methioninase) and enzyme inhibitors (inhibitors of α-amylase, hyaluronidase, β-lactamase, α-glucosidase, and β-glucosidase). These isolates were identified based on their morphological, biochemical, and genetic characteristics as Streptomyces sp. MORSY 17, Streptomyces sp. MORSY 22, Streptomyces sp. MORSY 25, Streptomyces sp. MORSY 36, Streptomyces sp. MORSY 45, and Streptomyces sp. MORSY 50. Moreover, in further evaluation, these strains exhibited wide spectrum of antimicrobial (against bacteria and fungi), antiviral (against hepatitis C virus), antibiofilm against biofilm-forming bacteria (methicillin-resistant Staphylococcus aureus and multidrug-resistant Pseudomonas species), and anti-proliferative activities (against liver and colon carcinoma cell lines). The GC-MS analysis of the hyperactive strains MORSY 17 and MORSY 22 revealed the presence of different bioactive agents in the ethyl acetate extract of both strains.