查找使用阿拉丁产品的科研文献

Bioactive Secondary Metabolites Produced by the Hadal Actinomycete Streptomyces sp. SY1414 Isolated from the Mariana Trench-derived Sediment

Zhang Di,Feng Yao,Li Huifang,Zhang Zhizhen

Background: Accumulated investigations have demonstrated that the Mariana Trench is enriched in microorganisms. However, the diversity of structures and bioactivities of the secondary metabolites produced by the Mariana Trench-associated microorganisms is poorly known, which needs to be intensively investigated. Objective: This study aimed to investigate the bioactive secondary metabolites produced by a Mariana Trench-derived actinomycete Streptomyces sp. SY1414 that was cultured in BY medium, which was chosen from four different media based on the diversity of secondary metabolites. Methods: A combination of different column chromatographs and HPLC was applied for the separation and purification of the secondary metabolites. The structures of the isolated compounds were determined mainly based on their NMR data, optical rotation values, and the comparison with the reference data, and the Sulforhodamine B (SRB) method was used to evaluate their anti-glioma activities. Results: Four different types of compounds were isolated from the large culture of strain Streptomyces sp. SY1414 in BY medium, including a benzoquinoline alkaloid, actinophenanthroline C (1), a benzamide, (2E,4E)-5-(3-hydroxyphenyl)-penta-2,4-dienamide (2), a cyclopeptide, valinomycin (3), and four macrolides of bafilomycin D (4), bafilomycin A2 (5), bafilomycin W (6), and C(19), C(21)- O-methyl-bafilomycin A1 (7). Actinophenanthroline C (1), bafilomycin D (4), bafilomycin A2 (5), and bafilomycin W (6) displayed significant anti-glioma activities with IC50 values ranging from 1.62 to 8.20 μM for U87MG cells and 2.45 to 3.89 μM for U251. The anti-gliomas of actinophenanthroline C (1) was reported for the first time. Conclusion: The hadal actinomycete Streptomyces sp. SY1414 in BY medium produced four different types of secondary metabolites with significant anti-glioma activity, which enriched the diversity of structures and bioactivities of the Mariana Trench-associated natural products.

Expanding the Chemical Diversity of Secondary Metabolites Produced by Two Marine-Derived Enterocin- and Wailupemycin-Producing Streptomyces Strains

Kunyu Xia,Jiaxu Shang,Jiwen Sun,Weiming Zhu,Peng Fu

To expand the chemical diversity of secondary metabolites produced by two marine-derived enterocin- and wailupemycin-producing Streptomyces strains, OUCMDZ-3434 and OUCMDZ-2599, precursor feeding and solid fermentation strategies were used. Two new compounds, wailupemycins Q (1) and R (2), were isolated from the extracts of liquid and solid fermentation of OUCMDZ-3434. Furthermore, during the fermentation of OUCMDZ-3434, p-fluorobenzoic acid was added as the key biosynthetic precursor, which resulted in the isolation of eight new fluorinated enterocin and wailupemycin derivatives (3–10) and 10 previously reported analogues (11–20). From the solid fermentation extract of OUCMDZ-2599, a new sulfur-containing compound thiotetromycin B (21) and its known analogue thiotetromycin (22) were identified. Moreover, the solid fermentation strategy effectively activated the biosynthesis of siderophores (23–25) of strain OUCMDZ-2599. Compound 3 showed moderate antibacterial activity against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus subsp. aureus with MIC values of 4 μg/mL. Compounds 23–25 were significantly capable of binding Fe(III).

“Toolbox” construction of an extremophilic nitrile hydratase from Streptomyces thermoautotrophicus for the promising industrial production of various amides

Junling Guo,Julia Berdychowska,Qianpeng Lai,Yiwei Meng,Zhongyi Cheng,Lukasz Peplowski,Zhemin Zhou

Nitrile hydratase (NHase; EC 4.2.1.84) is widely used to synthesize the corresponding amides from nitriles, which is the most successful green biocatalyst. However, the limited acceptability of substrates and instability under harsh reaction conditions have hindered its widespread industrial application. Here, a gene encoding an extremophilic NHase from Streptomyces thermoautotrophicus ( S.t NHase) was successfully overexpressed in Escherichia coli . The enzyme exhibited excellent thermostability, retaining >50 % of residual activity after heat treatment at 65 °C for 252 min. To further improve the catalytic performance of S.t NHase, semi-rational engineering of its substrate access tunnel was performed. A mutant βL48D showed a specific activity of 566.18 ± 18.86 U/mg towards 3-cyanopyridine, which was 7.7 times higher than its parent enzyme (73.80 ± 5.76 U/mg). Molecular dynamics simulation showed that the introduction of aspartic acid into βLeu48 resulted in a larger and more frequent opening of the substrate access tunnel entrance. On this basis, a “toolbox” containing various mutants on the substrate access tunnel was further established, whose catalytic activity towards various nitrile substrates was extensively improved, showing great potential for efficient synthesis of multiple high-value amides.

Enhanced Triacylglycerol Metabolism Contributes to Efficient Oil Utilization and High-Level Production of Salinomycin in Streptomyces albus ZD11

Han Li,Jiaxiu Wei,Jianxin Dong,Yudong Li,Yongquan Li,Yinghu Chen,Wenjun Guan

Streptomyces is well known for biosynthesis of secondary metabolites with diverse bioactivities. Although oils have been employed as carbon sources to produce polyketide antibiotics for several industrial Streptomyces strains, the intrinsic correlation between oil utilization and high production of antibiotics still remains unclear. In this study, we investigated the correlation between oil metabolism and salinomycin biosynthesis in Streptomyces albus ZD11, which employs soybean oil as the main carbon source. Comparative genomic analysis revealed the enrichment of genes related to triacylglycerol (TAG) metabolism in S. albus ZD11. Transcriptomic profiling further confirmed the enhancement of TAG metabolism and acyl coenzyme A biosynthesis in S. albus ZD11. Multiple secreted lipases, which catalyze TAG hydrolysis, were seen to be working in a synergistic and complementary manner in aiding the efficient and stable hydrolyzation of TAGs. Together, our results suggest that enhanced TAG hydrolysis and fatty acid degradation contribute to the high efficiency of oil utilization in S. albus ZD11 in order to provide abundant carbon precursors for cell growth and salinomycin biosynthesis.IMPORTANCE In order to obtain high-level production of antibiotics, oils have been used as the main carbon source for some Streptomyces strains. Based on multiomics analysis, this study provides insight into the relationship between triacylglycerol (TAG) metabolism and antibiotic biosynthesis in S. albus ZD11, an oil-preferring industrial Streptomyces strain. Our investigation into TAG hydrolysis yielded further evidence that this strain utilizes complicated strategies enabling an efficient TAG metabolism. In addition, a novel secreted lipase was identified that exhibited highly hydrolytic activity for medium- and long-chain TAGs. Our findings represent a good start toward clarifying the complicated relationship between TAG catabolism and high-level antibiotic production in the industrial strains.

Biochemical characterization of two β-N-acetylglucosaminidases from Streptomyces violascens for efficient production of N-acetyl-d-glucosamine

Jing Li,Kunpeng Gao,Francesco Secundo,Xiangzhao Mao

Chitin, one of the most abundant renewable biopolymers on Earth, is commercially available from crustacean wastes. One critical step in converting chitin to high-value products is its degradation by chitinolytic enzymes to N -acetyl- d -glucosamine (GlcNAc), which plays a significant role in functional food and pharmaceutical industries. Here, we cloned and biochemically characterized two novel β - N -acetylglucosaminidases named SvNag2557 (family-84) and SvNag4755 (family-3) from Streptomyces violascens ATCC 27968. Both SvNag2557 and SvNag4755 exhibited strict substrate specificity toward N -acetyl chitooligosaccharides with GlcNAc as the sole product. Thus, a one-pot production for pure GlcNAc from chitin by an enzyme cocktail reaction was further developed. Under the co-action of an endo-type chitinase SaChiA4 and SvNag2557 (mass ratio 1:2), the final conversion rates of colloidal chitin and ionic liquid pretreated chitin to GlcNAc were 80.2% and 73.8% with GlcNAc purities of 99.7% and 96.8%, respectively.

Efficient production of ε-poly-l-lysine using cassava starch and fish meal by Streptomyces albulus FQC-24

Yi Zhang,Jing Bai,Chenqi Wu,Yue Wang,Xin Ju,Xin Qi,Liangzhi Li,Lilian Ji,Jiaolong Fu

ε-Poly-l-lysine (ε-PL) is used as a natural food preservative which consists of l-lysine units connected. However, due to the expensive culture medium, the production cost of ε-PL remains high. In this study, cheap raw materials cassava starch (CS) and fish meal (FM) were employed by S. albulus FQC-24 for ε-PL production. In the single factor experiment, the maximum ε-PL production reached 0.97 g/L at 60 g/L CS and 15 g/L FM. The results of screening experiments by Plackett–Burman design showed that three main components affecting ε-PL production were CS, FM, and (NH4)2SO4. And the standardized effects of CS, FM, and (NH4)2SO4 were 0.13, −0.22, and −0.2, respectively. The optimum fermentation medium developed by response surface methodology for ε-PL production contained (g/L) CS, 67.56; FM, 14.70 and (NH4)2SO4, 5.41. Under the optimum conditions, the ε-PL production was achieved 1.30 g/L, with 34.02% higher than that before optimization. Moreover, ε-PL productions of batch and fed-batch fermentation in a 7-L fermentor were improved to 2.13 and 17.17 g/L respectively, which increased by 0.64 and 12.2 times compared with the shake flask culture. The results indicated that FM and CS are promising substrates for the efficient production of ε-PL.

An atypical two-component system, AtcR/AtcK, simultaneously regulates the biosynthesis of multiple secondary metabolites in Streptomyces bingchenggensis

Yu-Si Yan,Li-Sha Zou,He-Geng Wei,Meng-Yao Yang,Yun-Qi Yang,Xiao-Fang Li,Hai-Yang Xia

Biodegradation of phthalate acid esters and whole-genome analysis of a novel Streptomyces sp. FZ201 isolated from natural habitats

Nai-Xian Feng,Da-Wei Li,Fei Zhang,Hui Bin,Yi-Tong Huang,Lei Xiang,Bai-Lin Liu,Quan-Ying Cai,Yan-Wen Li,De-Lin Xu,Yunchang Xie,Ce-Hui Mo

Di-n-butyl phthalate (DBP) is one of the most extensively used phthalic acid esters (PAEs) and is considered to be an emerging, globally concerning pollutant. The genus Streptomyces holds promise as a degrader of various organic pollutants, but PAE biodegradation mechanisms by Streptomyces species remain unsolved. In this study, a novel PAE-degrading Streptomyces sp. FZ201 isolated from natural habitats efficiently degraded various PAEs. FZ201 had strong resilience against DBP and exhibited immediate degradation, with kinetics adhering to a first-order model. The comprehensive biodegradation of DBP involves de-esterification, β -oxidation, trans-esterification, and aromatic ring cleavage. FZ201 contains numerous catabolic genes that potentially facilitate PAE biodegradation. The DBP metabolic pathway was reconstructed by genome annotation and intermediate identification. Streptomyces species have an open pangenome with substantial genome expansion events during the evolutionary process, enabling extensive genetic diversity and highly plastic genomes within the Streptomyces genus. FZ201 had a diverse array of highly expressed genes associated with the degradation of PAEs, potentially contributing significantly to its adaptive advantage and efficiency of PAE degradation. Thus, FZ201 is a promising candidate for remediating highly PAE-contaminated environments. These findings enhance our preliminary understanding of the molecular mechanisms employed by Streptomyces for the removal of PAEs.

Actinomycin X2, an Antimicrobial Depsipeptide from Marine-Derived Streptomyces cyaneofuscatus Applied as a Good Natural Dye for Silk Fabric

Wei Chen,Kaixiong Ye,Xiaoji Zhu,Huihui Zhang,Ranran Si,Jianing Chen,Zijun Chen,Kaili Song,Zhicheng Yu,Bingnan Han

Actinomycins as clinical medicine have been extensively studied, while few investigations were conducted to discover the feasibility of actinomycins as antimicrobial natural dye contributing to the medical value of the functional fabrics. This study was focused on the application of actinomycin X2 (Ac.X2), a peptide pigment cultured from marine-derivedStreptomyces cyaneofuscatus, in the dyeing and finishing of silk fabric. The dyeing potential of Ac.X2 with silk vs. cotton fabrics was assessed. As a result, the silk fabric exhibited greater uptake and color fastness with Ac.X2. Through Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses, some changes of chemical property for the dyed fabric and Ac.X2 were studied. The silk fabric dyed with Ac.X2 exhibited good UV protection ability. The antibacterial properties of dyed and finished silk were also evaluated, which exhibited over 90% antibacterial activity even after 20 washing cycles. In addition, the brine shrimp assay was conducted to evaluate the general toxicity of the tested fabric, and the results indicated that the dyed silk fabrics had a good biological safety property.

Identification and genomic analyses of a novel actinobacterium Streptomyces shaowuensis sp. nov. with biocontrol potential for rice bacterial blight

He Ya-Wen,Law Jodi Woan-Fei,Azad Sepideh Mazhari,Hu Wen-Da,Song Kai,Chua Kah-Ooi,Jiang Lian,Jin Yu,Lee Learn-Han,Zhou Lian

Bacterial leaf blight (BLB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most severe bacterial diseases in rice. The current BLB-prevention strategy depends on chemical antimicrobials. The biological control methods have gained considerable attention. Among them, Streptomyces are particularly promising candidates due to their ability to produce diverse natural antimicrobial and plant-growth-promoting metabolites. In this study, we isolated a Streptomyces strain HSW2009 from the rice rhizosphere. This strain displayed significant antagonistic activity against Xoo. The antagonistic metabolite was extracted and purified from the HSW2009 culture. High-performance liquid chromatography-mass chromatography and nuclear magnetic resonance analyses revealed that the active compound is Piericidin A1, a member of the piericidin family metabolites containing a 4-pyridinol core linked with a methylated polyketide side chain. Piericidin A1 was shown to protect rice from Xoo infection in the microclimate chamber. The strain HSW2009 produced pale yellow aerial mycelia on the agar plate of the International Streptomyces Project-2 medium. Its cellular morphology conformed to that typically observed in the genus Streptomyces . Phylogenetic analysis of 16S rRNA gene sequences showed that HSW2009 was closely related to Streptomyces zagrosensis , S. youssoufiensis , and S. varsoviensis . HSW2009 displayed a unique DNA profile in BOX-PCR fingerprinting analysis and had a genome size of 8,806,972 bp, with a 72.83% G + C content. Average nucleotide identity analysis and digital DNA–DNA hybridization using the Type Strain Genome Server supported HSW2009 as a novel Streptomyces sp. It was therefore proposed as Streptomyces shaowuensis sp. nov., type strain HSW2009.

Antifungal mechanisms of volatile organic compounds from Streptomyces albidoflavus SC-3 against postharvest kiwifruit rot caused by Botryosphaeria dothidea

Wenzhi Li,Jiling Ma,Youhua Long,Weizhen Wang,Xianhui Yin,Zhuzhu Zhang,Bingce Wang,Lu Yang,Hujun Qin

Botryosphaeria dothidea is one of the primary pathogens responsible for kiwifruit soft rot, leading to significant postharvest economic losses. Streptomyces spp., known for producing abundant volatile organic compounds (VOCs), have emerged as a crucial biological resource for controlling postharvest diseases. This study employed wheat grain cultures of Streptomyces albidoflavus SC-3 to produce VOCs, with the aim of systematically evaluating their antifungal mechanisms against B. dothidea . The VOCs emitted by SC-3 showed remarkable antifungal activity against B. dothidea , effectively inhibiting mycelial growth and suppressing sclerotia germination. Through optimization of culture conditions including inoculation volume, culture temperature, incubation time, and dosage of wheat grains, the antifungal efficacy of VOCs produced by SC-3 was significantly improved. Strain SC-3 VOCs reduced the pathogenicity of B. dothidea in kiwifruit, thereby delaying the progression of fruit soft rot. The VOCs induced abnormal hyphal morphology and compromised cell wall and membrane integrity of B. dothidea . Transcriptomic analysis further revealed that these VOCs primarily function by disrupting energy metabolism, impairing cell membrane integrity, and disturbing redox homeostasis-related metabolic pathways. GC-MS analysis identified three antifungal VOCs, including carvone, 3,5-di-tert-butylphenol, and 3-butylidenephthalide. Carvone exhibited the strongest inhibitory effect with EC 50 value of 0.03 μL mL −1 , suggesting that it serves as the key active compound against B. dothidea . In conclusion, Streptomyces albidoflavus SC-3 VOCs, primarily carvone, effectively control kiwifruit soft rot by inhibiting the pathogen B. dothidea through multiple mechanisms.

Culture medium optimization and active compounds investigation of an anti-quorum sensing marine-derived actinomycete Streptomyces chumphonensis HN2-56

Zongjun Li,Zeren Wu,Jie Mo,Yali Sun,Wei Jiang,Likui Zhang,Kunming Dong,Li Miao

Quorum sensing inhibitors (QSIs) can inhibit the quorum sensing regulated physiological functions of bacteria and might be useful in drug-resistant bacterial infection therapy. The culture medium of a mangrove derived actinobacterium Streptomyces chumphonensis HN2-56, which exhibiting higher anti-quorum sensing activity, was optimized in this study. The results showed that the GS medium was the most favourable medium for the bioactivity of HN2-56 and that the content of soluble starch in the GS medium had a significant impact on the yield of metabolites. By culturing under the optimized condition (soluble starch 40 g/L, KNO3 4 g/L, salinity of 0 and pH 6.5), both metabolites production and anti-quorum sensing activity of HN2-56 against the purple pigment (violacein) production of Chromobacterium violaceum 12472 were significantly increased (41.8% and 177.9%, respectively). Five pure compounds were obtained from the extract of HN2-56 and identified as 2,2-[bis-4-(2,3-dihydroxypropane) phenyl] propane (1), bisphenol A (2), 5-(2-methylphenyl)-4-pentenoic acid (3), 3-methyl-1H-indole-2-carboxylate (4) and dibutyl phthalate (5). Among them, compounds 2 and 3 showed anti-quorum sensing activity against C. violaceum 12472 and anti-biofilm activity against Staphylococcus aureus 43300. These findings indicated that S. chumphonensis HN2-56 should be a promising candidate for QSIs with potential anti-quorum sensing application. Although BPA was detected in the HN2-56 extract, experimental contamination could not be excluded because of the ubiquitous presence of BPA in plasticware and laboratory reagents.