CHINESE SCIENCE BULLETIN
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2013
·Vol. 58
·期 26
·3266-3273
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IF 1.319
Wu Qiong,Bai LinQuan,Liu WeiCheng,Li YingYing,Lu CaiGe,Li YaQian,Lin ZhenYa,Wang Meng,Xue ChunSheng,Chen Jie
Streptomyces lydicus A01 resists many plant pathogens (including Fusarium spp.) by producing the antifungal agent natamycin, which binds to the ergosterol of fungal cell membranes and inhibits the growth of pathogens. Trichoderma harzianum CECT2413 is a widely-distributed soil fungus that antagonizes several plant fungal pathogens (including Fusarium spp.) by producing chitinase and degrading chitin, a major component of the fungal cell wall. This study attempted to enhance the biocontrol effect of S. lydicus A01 on Fusarium spp. by transforming the chitinase gene of Trichoderma . Chitinase and natamycin could act synergistically on both the cell walls and cell membranes of pathogens. The 33-kD chitinase-encoding gene ( chit33 ) was cloned and conjugal-transformed from T. harzianum CECT2413 to S. lydicus A01, and then confirmed via polymerase chain reaction (PCR) assays. Subsequent analyses using the 3,5-dinitrosalicylic acid (DNS) method and ultraviolet spectrophotometry showed that compared with its wild type strain (WT), the S. lydicus A01 conjugal transformant (CT) with chit33 gene exhibited substantially higher chitinase activity and natamycin production. The resistance of S. lydicus A01- chit33 CT and WT to four Fusaria in crops and vegetables was tested via the cup-plate method. Compared with the WT, the conjugal transformant of S. lydicus A01 with chit33 gene from T. harzianum CECT2413 showed greatly increased biocontrol effect on fusarium disease. This study would be beneficial to the development of high-quality antifungal bio-agents for agricultural applications via the synergy between the previously non-existent and pre-existing functions achieved through heterogeneous gene transformation.
研究领域:
微生物学
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植物病理学
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分子生物学
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DOI
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Frontiers in Bioengineering and Biotechnology
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2021
·
IF 5.89
Wu Jiequn,Chen Danqing,Wu Jinrong,Chu Xiaohe,Yang Yongmei,Fang Lina,Zhang Wei
Daptomycin, which is produced by Streptomyces roseosporus, has been characterized as a novel cyclic lipopeptide antibiotic that is effective against Gram-positive bacteria. The biosynthesis of daptomycin is regulated by various factors. In the present study, we demonstrated that the cyclic AMP receptor protein (Crp) plays an important role in producing daptomycin in the S. roseosporus industrial strain. We found that daptomycin production from the crp deletion strain decreased drastically, whereas production from the crp overexpression strain increased by 22.1%. Transcriptome and qPCR analyses showed that some genes related to the daptomycin biosynthetic gene cluster (dpt) and the pleiotropic regulator (adpA) were significantly upregulated. RNA-seq also shows Crp to be a multifunctional regulator that modulates primary metabolism and enhances precursor flux to secondary metabolite biosynthesis. These results provide guidance for the development and improvement of potential natural products.
研究领域:
微生物学
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分子生物学
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药学
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DOI
PubMed
高影响因子
POSTHARVEST BIOLOGY AND TECHNOLOGY
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2025
·
IF 6.8
Ke Xing,Si Yang,Jing Tao,Sun-Yan Liang,Su-Yun Kong,Sheng Qin
Gray mold disease caused by Botrytis cinerea severely compromises postharvest strawberry quality. As an eco-friendly alternative to chemical fungicides, biological control agents based on microbial volatile organic compounds (VOCs) have emerged as promising candidates. This study developed a VOC-producing fumigant derived from wheat grain-cultured Streptomyces setonii WY228 to control gray mold in postharvest strawberries. Key parameters influencing the fumigant’s antifungal activity, including inoculation volume, culture temperature, incubation time, moisture content and dosage of wheat grains, were systematically optimized to establish a preparation strategy. Storage at 4 °C with vacuum maintained 70 % B. cinerea inhibition with sustained viability of fumigant for 90 d. Application of the fumigant at 26.7 g L −1 suppressed gray mold in postharvest strawberries. The firmness, ascorbic acid content, titratable acidity, and superoxide dismutase activity of fumigated strawberries were 42 %, 54 %, 24 %, and 160 % higher than those of the positive control group, respectively. Four main compounds in VOCs were identified as methyl 2-furoate, 2-methylbutyric acid, 4-methylpentanoic acid, and cyclopentanone, and exhibited antifungal activity and gray mold suppression in strawberries. The wheat grain solid fumigant prepared by S. setonii WY228 demonstrates potential as a biological control agent for gray mold suppression in postharvest strawberries.
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BIORESOURCE TECHNOLOGY
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2021
·
IF 9.642
Cheng Wang,Xi Chen,Yingying Jiang,Na Li,Ping Zhu,Hong Xu
Facile and green fabrication of reduced graphene oxide on loofah sponge (rGOLS) carrier was applied for cell immobilization of ε-Poly- l -lysine (ε-PL) production. Due to surface properties including large specific surface area, high polarity, and low interaction energy, rGOLS-1 was employed as the optimum rGOLS to enhance immobilization of Streptomyces albulus . Compared with raw LS, batch experiments showed rGOLS-1 facilitated superior cell vitality for ε-PL production due to the presence of reduced graphene oxide. In the sequential fed-batch cultivation of Streptomyces albulus using rGOLS-1 with an aerobic plant fibrous-bed bioreactor (rGOLS-1-AFPB), the maximum ε-PL concentration and productivity reached to 39.2 ± 0.63 g/L and 0.48 g/L/h. The cells immobilized in rGOLS-1 with high vitality and ε-PL production efficiency were reused six times over a period of 624 h. This research afforded an effective approach to enhance the fermentation performance of immobilized cells with the design of an advanced immobilization carrier.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
·
IF 5.279
Rongkang Hu,Ruiguo Cui,Qingyun Tang,Dongming Lan,Fanghua Wang,Yonghua Wang
The mechanism of active site loops of Streptomyces phospholipase D (PLD) binding to the lipid–water interface for catalytic reactions still remains elusive. A flexible loop (residues 376–382) in the active site of Streptomyces klenkii PLD (SkPLD) is conserved within PLDs in most of the Streptomyces species. The residue Ser380 was found to be essential for the enzyme’s adsorption to the interface and its substrate recognition. The S380V mutant showed a 4.8 times higher catalytic efficiency and nearly seven times higher adsorption equilibrium coefficient compared to the wild-type SkPLD. The monolayer film technique has confirmed that the substitution of Ser380 with valine in the loop exhibited positive interaction between the enzyme and PCs with different acyl chain lengths. The results of the interfacial binding properties indicated that the S380V mutant might display suitable phosphatidylserine synthesis activity. The present study will be helpful to explain the role of residue 380 in the active site loops of Streptomyces PLD.
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Junwei Huang,Zilin Zhu,Ruomu Chen,Dandan Pan,Qing X. Li,Xiangwei Wu
Ibuprofen, a widely used nonsteroidal anti-inflammatory drug, contaminates agricultural products and potentially threatens human health due to its frequent detection and poor biodegradability. Microbial metabolism dominates the elimination of residual ibuprofen in the environment. In mineral salt medium at pH 6 with 5 mM glucose, Streptomyces sp. D218 transformed ibuprofen concentrations ranging from 0.05 to 0.40 mM in 24 h. The optimal temperature, pH, and initial OD600 nm for ibuprofen transformation by strain D218 were 25–37 °C, 5.0–6.0, and 1.0–1.5, respectively. Strain D218 could simultaneously transform ibuprofen into the intermediates 2-hydroxyibuprofen and ibuprofen amide (IBUA). The two intermediates were further metabolized to 2-hydroxyibuprofen amide (2HIBUA), thus relieving the growth inhibition of ibuprofen in Scenedesmus obliquus. This is the first complete pathway reported for the detoxification of ibuprofen transformation by a Gram-positive strain. These findings further our understanding of the microbial catabolism of the IBU.
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Molecular Catalysis
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2024
·
IF 3.9
Xiangyu Zheng,Zhe Dou,Wenqiang Xiang,Wen Zhang,Ye Ni,Guochao Xu
N -substituted β-amino esters as an important class of chiral amines, are widely used as building blocks in pharmaceuticals. A novel imine reductase Sv IRED was identified through gene mining from Streptomyces viridochromogenes with high enantioselectivity of > 99 % ee (1 R , 2 S ), 95 % de ( cis:trans ), towards 2-oxocyclohexane-1-carboxylate and cyclopropylamine. Sv IRED exhibited the highest activity at pH 7.0 and 40 °C. A variety of amine donors could be used by Sv IRED and produce chiral N -substituted β-amino esters with different enantioselectivity. Employing methylamine ( i ) and pyrrolidine ( n ) as amine donors, Sv IRED exhibited reversed enantioselectivity of 23 % ee (1 S , 2 R ) and 79 % ee (1 S , 2 R ) respectively. Through alanine scanning, M183 and H244 were identified with remarkable roles in governing enantioselectivity towards i and n . Compared with WT Sv IRED, the enantioselectivity of M183A was inverted to ee value of >99 % (1 R , 2 S ) and de value of >99 % ( cis:trans ) towards i , and the enantioselectivity of H244A was inverted to ee value of 88 % (1 R , 2 S ) and de value of >99 % ( cis:trans ) towards n . Interaction analysis indicated the orientation of ester group was vital for manipulation of enantioselectivity. This study provides novel Imine reductase mutants for enantioselective synthesis of N -substituted β -amino esters with different amine donors.
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ENZYME AND MICROBIAL TECHNOLOGY
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2023
·
IF 3.4
Rui Huang,Chuang Li,Shi-Guang Zhao,Qing-Tao Liu,Yan Liu,Zheng-Lian Xue
In order to excavate microbial epoxide hydrolases (EHs) with desired catalytic properties, a novel EH, Sf EH1, was identified based on the genome annotation of Streptomyces fradiae and sequence alignment analysis with local protein library. The Sf EH1-encoding gene, sfeh 1, was then cloned and over-expressed in soluble form in Escherichia coli /BL21(DE3). The optimal temperature and pH of recombinant Sf EH1 (re Sf EH1) and re Sf EH1-expressing E. coli ( E. coli / sfeh 1) were both determined as 30 ℃ and 7.0, also indicating that the influences of temperature and pH on re Sf EH1′s activities were more obvious than those of E. coli / sfeh 1 whole cells. Subsequently, using E. coli / sfeh 1 as catalyst, its catalytic properties towards thirteen common mono-substituted epoxides were tested, in which E. coli / sfeh 1 had the highest activity of 28.5 U/g dry cells for rac -1,2-epoxyoctane ( rac - 6a ), and ( R )-1,2-pentanediol (( R )- 3b ) (or ( R )-1,2-hexanediol (( R )- 4b )) with up to 92.5% (or 94.1%) ee p was obtained at almost 100% conversion ratio. Regioselectivity coefficients (α S and β R ) displayed in the enantioconvergent hydrolysis of rac - 3a (or rac - 4a ) were calculated to be 98.7% and 93.8% (or 95.2% and 98.9%). Finally, the reason of the high and complementary regioselectivity was confirmed by both kinetic parameter analysis and molecular docking simulations .
研究领域:
生物化学
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微生物学
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生物催化
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酶学
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DOI
PubMed
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
·
IF 5.279
Cong Qiu,Yang Liu,Yangbao Wu,Linguo Zhao,Jianjun Pei
Prenyl groups increase the lipophilicity of flavonoids, endowing them with a special activity, selectivity, and pharmacological properties by prenylation. Herein, a novel prenyltransferase (ShFPT) gene from Streptomyces sp. NT11 was expressed in Escherichia coli, and its biochemical characteristics were determined. ShFPT exhibited high selectivity to prenylate naringenin at C-6 to generate 6-prenylnaringenin. The optimal activity was observed at pH 6.0 and 55 °C. The Kcat and Km for naringenin were 0.0095 s–1 and 0.20 mM, respectively. Several promiscuous kinase and isopentenyl phosphate kinase genes were screened to develop the most efficient dimethylallyl diphosphate (DMAPP) synthesis pathway for 6-prenylnaringenin synthesis in E. coli. The 6-prenylnaringenin production was improved by changing the induction strategies and optimizing the bioconversion conditions. Finally, 6-prenylnaringenin production reached the highest yield of 69.9 mg/L with average productivity of 4.0 mg/L/h after 16 h incubation, which is the highest yield for any prenylated flavonoid reported to date in E. coli. Therefore, this study provides an efficient method for 6-prenylnaringenin production and reveals the DMAPP synthesis pathway.
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高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2023
·
IF 6.1
Ming Zhao,Xiu-Shan Zhang,Liang-Bin Xiong,Kun Liu,Xiang-Fei Li,Yan Liu,Feng-Qing Wang
Indigoidine, as a kind of natural blue pigment, is widely used in textiles, food, and pharmaceuticals and is mainly synthesized from l-glutamine via a condensation reaction by indigoidine synthetases, most of which originates from Streptomyces species. However, due to the complex metabolic switches of Streptomyces, most of the researchers choose to overexpress indigoidine synthetases in the heterologous host to achieve high-level production of indigoidine. Considering the advantages of low-cost culture medium and simple culture conditions during the large-scale culture of Streptomyces, here, an updated regulation system derived from the Streptomyces self-sustaining system, constructed in our previous study, was established for the highly efficient production of indigoidine in Streptomyces lividans TK24. The updated system was constructed via promoter mining and σhrdB expression optimization, and this system was applied to precisely and continuously regulate the expression of indigoidine synthetase IndC derived from Streptomyces albus J1704. Finally, the engineered strain was cultured with cheap industrial glycerol as a supplementary carbon source, and 14.3 and 46.27 g/L indigoidine could be achieved in a flask and a 4 L fermentor, respectively, reaching the highest level of microbial synthesis of indigoidine. This study will lay a foundation for the industrial application of Streptomyces cell factories to produce indigoidine.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Meng Shi,Demin Kong,Hui Zhang,Deming Rao,Tianlong Zhao,Jing Yang,Zhanzhi Liu,Sheng Chen,Fengshan Zhang,Jing Wu,Lei Wang
Latex clearing protein from Streptomyces sp. strain K30 (Lcp K30 ) is a natural oxidoreductase that can catalyse the cleavage of rubber through dioxygenation. It has significant potential applications in polymer degradation. However, its limited expression in engineered strains restricts its utility. This study aimed to enhance the soluble expression and enzyme activity of Lcp K30 in E. coli BL21 (DE3) by optimizing fermentation conditions and making molecular modifications. The enzyme activity reached 5.05 U·mL −1 by optimizing the induction conditions, adding cofactors, and using chemical chaperones , which was 237.1 % of the initial case. Further enhancements in soluble expression were achieved through site mutations guided by the PROSS server, resulting in 8 out of 13 mutants with increased protein expression , a high positive mutation rate of 61.5 %. Subsequently, combined mutants were created by merging single mutants with enhanced protein expression and enzyme activity. The top three double mutants, G91D/S149A, G91D/A210H, and G91D/H296P, displayed expression levels at 173.3 %, 173.3 %, and 153.3 % of the wild-type Lcp K30 , respectively. These mutants also exhibited enhanced fermentation enzyme activity, reaching 149.5 %, 250.0 %, and 420.2 % compared to the wild-type, along with improved specific activities. This study provides insights for the efficient production of Lcp K30 and a practical foundation for its application.
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PubMed
高影响因子
JOURNAL OF NATURAL PRODUCTS
·
2024
·
IF 3.3
Weihong Wang,Jiaxu Shang,Shupeng Yin,Kunyu Xia,Rui Ma,Weiming Zhu,Peng Fu
Metabolites with high chemical reactivity serve important roles in chemical defenses of organisms. Formaldehyde, as a simple and highly reactive small molecule, can be produced by microorganisms, plants, and animals. Its toxicity is well known, but information about its other biological functions remains scarce. Here, we report that the natural product SEK34b produced by Streptomyces species can react nonenzymatically with formaldehyde in water to yield the methylene-bridged dimer phaeochromycin F. This process can eliminate the toxic substance formaldehyde produced by Staphylococcus aureus. Furthermore, there is a substantial inhibitory impact of phaeochromycin F on S. aureus. We hypothesize that these constitute an integrated system of defense and attack of Streptomyces species against competitors. Our study indicates that formaldehyde can react with vancomycin and tigecycline under mild conditions to generate the derivatives bearing an imidazolidin-4-one moiety, thereby reducing the antibacterial activity of these antibiotics. These data provide a possible chemical interaction mechanism of bacteria involving the nonenzymatic reactions of formaldehyde with highly reactive natural products.
研究领域:
微生物学
·
生物化学
·
药理学
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DOI
PubMed
高影响因子
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