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1.
Protease producing Streptomyces sp. A6 was isolated from intertidal zone of the coast of Diu (Gujarat, India). Plackett–Burman method was applied to identify important factors (shrimp waste, FeCl3, ZnSO4 and pH) influencing protease production by Streptomyces sp. A6. Further optimization was done by response surface methodology using central composite design. The concentrations of medium components for higher protease production as optimized using the above approach were (g l?1): Shrimp waste, 14; FeCl3, 0.035; ZnSO4, 0.065 and pH, 8.0. This statistical optimization approach led to production of 129.02 ± 2.03 U ml?1 of protease which was 4.96 fold higher compared to that obtained using the unoptimized medium. The protease production was scaled to 3 l in a 5-l bench fermenter using optimized medium which further increased the production by 63.4%. Deproteinization and chitin recovery obtained at the end of fermentation was 85.12 ± 4.7 and 70.58 ± 1.33%, respectively. The present study is the first report on statistical optimization of medium components for production of protease by Streptomyces species using cheaper raw material such as shrimp waste. The study also explored the possibility Streptomyces sp. A6 for reclamation of shrimp wastes.  相似文献   

2.
A potential glycolipid biosurfactant producer Streptomyces sp. MAB36 was isolated from marine sediment samples. Medium composition and culture conditions for the glycolipid biosurfactant production by Streptomyces sp. MAB36 were optimized, using two statistical methods: Plackett–Burman design was applied to find out the key ingredients and conditions for the best yield of glycolipid biosurfactant production and central composite design was used to optimize the concentration of the four significant variables, starch, casein, crude oil and incubation time. Fructose and yeast extract were the best carbon and nitrogen sources for the production of the glycolipid biosurfactant. Biochemical characterizations including FTIR and MS studies suggested the glycolipid nature of the biosurfactant. The isolated glycolipid biosurfactant reduced the surface tension of water from 73.2 to 32.4 mN/m. The purified glycolipid biosurfactant showed critical micelle concentrations of 36 mg/l. The glycolipid biosurfactant was effective at very low concentrations over a wide range of temperature, pH, and NaCl concentration. The purified glycolipid biosurfactant showed strong antimicrobial activity. Thus, the strain Streptomyces sp. MAB36 has proved to be a potential source of glycolipid biosurfactant that could be used for the bioremediation processes in the marine environment.  相似文献   

3.
《Biologicals》2014,42(6):305-311
Due to the emergence of severe infectious diseases and thriving antibiotic resistance, there is a need to explore microbial-derived bioactive secondary metabolites from unexplored regions. Present study deals with a mangrove estuary derived strain of Streptomyces sp. with potent antimicrobial activity against various pathogens, including methicillin resistant Staphylococcus aureus. Bioactive compound was effective even at low MIC level, damages the membrane of methicillin resistant S. aureus and causes cell death, however it has no cytotoxic effect on H9C2 cells. 16S rRNA shared 99.5% sequence similarity to Streptomyces longispororuber. Optimum biomass and antimicrobial compound production were observed in production medium supplemented with 1.0% maltose and 0.5% yeast extract. The active compound purified from the chloroform extract of the cell-free supernatant was studied by FT-IR, 1H NMR, 13C NMR and LC ESI-MS and identified as aromatic polyketide. β-ketosynthase (KS) domain of the Streptomyces strain revealed 93.2% sequence similarity to the benzoisochromanequinone, an actinorhodin biosynthetic gene cluster of Streptomyces coelicolor A3(2). However, the region synthesizing the secondary metabolite produced by the S. longispororuber was not related to the KS domain of the strain, due to the phenomenon of horizontal gene transfer over the period of evolutionary process, thus generating metabolic compound diversity.  相似文献   

4.
The strain Lactobacillus plantarum DM5 was isolated from fermented beverage Marcha of Sikkim and explored for its antagonistic activity against food-borne pathogens. The cell-free supernatant of L. plantarum DM5 showed antibacterial activity of 6,400 AU/mL in MRS medium (pH 6.0) against the indicator strain Staphylococcus aureus. MRS medium supplemented with 15 g/L of maltose at 37 °C under static condition yielded highest antimicrobial activity (6,400 AU/mL) with 3 % increase in specific activity when compared to 20 g/L glucose. The antimicrobial compound was heat stable (60 min at 100 °C) and was active over a wide pH range. It showed bactericidal effect on S. aureus and Listeria monocytogenes by causing 96 and 98 % of cell lysis, respectively. The cell morphology of the treated S. aureus and L. monocytogenes was completely deformed as revealed by scanning electron microscopy, suggesting the high potential of L. plantarum DM5 as natural preservatives in food industry. The antimicrobial compound was purified by 80 % ammonium sulphate precipitation and showed antimicrobial activity of 12,800 AU/mL with 19-fold purification and a molecular mass of 15.2 kDa, indicating the proteinaceous nature of the compound.  相似文献   

5.
The exploration of novel therapeutic agents and other bioactive secondary metabolite from Streptomyces species, for possible agricultural farming, pharmaceutical and industrialized applications, has been, and still is, essential. The existing studies were aimed with biologically potential Streptomyces species and its antagonistic activity against dreadful microorganisms. Totally, morphological three different actinomycetes were selected from the fertile agricultural lands. Among the three, the isolate SA4 exhibited significant antimicrobial and anti-nematicidal activity towards selected microbial pathogens such as E Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis, Proteus vulgaris, Shigella flexineri, Candida albicans, and Fusarium sp. The prospective strain SA4 was identified as Streptomyces cuspidosporus. The isolate SA4 optimized for secondary metabolites production with International Streptomyces project 4 (ISP 4) medium, pH 7.0 at 37 °C for 14 days. Gas Chromatography-Mass spectrometry (GCMS) analysis of strain SA4 bioactive extract publicized the existence of 1,2-Benzenedicarboxylic acid, bis(2-Methylpropyl) ester compound and occupied by high peak area and its possessed significant biological properties.  相似文献   

6.
Marine sponges and other sessile macro-organisms were collected at a shallow water hydrothermal site in Eyjafjörður, Iceland. Bacteria were isolated from the organisms using selective media for actinomycetes, and the isolates were screened for antimicrobial activity. A total of 111 isolates revealed antimicrobial activity displaying different antimicrobial patterns which indicates production of various compounds. Known test strains were grown in the presence of ethyl acetate extracts from one selected isolate, and a clear growth inhibition of Staphylococcus aureus was observed down to 0.1 % extract concentration in the medium. Identification of isolates shows different species of Actinobacteria with Streptomyces sp. playing the largest role, but also members of Bacilli, Alphaproteobacteria and Gammaproteobacteria. Sponges have an excellent record regarding production of bioactive compounds, often involving microbial symbionts. At the hydrothermal vents, however, the majority of active isolates originated from other invertebrates such as sea anemones or algae. The results indicate that antimicrobial assays involving isolates in full growth can detect activity not visible by other methods. The macro-organisms inhabiting the Eyjafjörður hydrothermal vent area host diverse microbial species in the phylum Actinobacteria with antimicrobial activity, and the compounds responsible for the activity will be subject to further research.  相似文献   

7.
Polysaccharides and ganoderic acids (GAs) are the major bioactive constituents of Ganoderma species. However, the commercialization of their production was limited by low yield in the submerged culture of Ganoderma despite improvement made in recent years. In this work, twelve Ganoderma strains were screened to efficiently produce polysaccharides and GAs, and Ganoderma lucidum 5.26 (GL 5.26) that had been never reported in fermentation process was found to be most efficient among the tested stains. Then, the fermentation medium was optimized for GL 5.26 by statistical method. Firstly, glucose and yeast extract were found to be the optimum carbon source and nitrogen source according to the single-factor tests. Ferric sulfate was found to have significant effect on GL 5.26 biomass production according to the results of Plackett–Burman design. The concentrations of glucose, yeast extract and ferric sulfate were further optimized by response surface methodology. The optimum medium composition was 55 g/L of glucose, 14 g/L of yeast extract, 0.3 g/L of ferric acid, with other medium components unchanged. The optimized medium was testified in the 10-L bioreactor, and the production of biomass, IPS, total GAs and GA-T enhanced by 85, 27, 49 and 93 %, respectively, compared to the initial medium. The fermentation process was scaled up to 300-L bioreactor; it showed good IPS (3.6 g/L) and GAs (670 mg/L) production. The biomass was 23.9 g/L in 300-L bioreactor, which was the highest biomass production in pilot scale. According to this study, the strain GL 5.26 showed good fermentation property by optimizing the medium. It might be a candidate industrial strain by further process optimization and scale-up study.  相似文献   

8.
Tiancimycin (TNM) A, a recently discovered enediyne natural product from Streptomyces sp. CB03234, showed rapid and complete killing of cancer cells and could be used as a payload in antibody drug conjugates. The low yield of TNM A in the wild-type strain promoted us to use ribosome engineering and fermentation optimization for its yield improvement. The Streptomyces sp. CB03234-R-16 mutant strain with a L422P mutation in RpoB, the RNA polymerase β-subunit, was obtained from the rifamycin-resistant screening. After fermentation optimization, the titers of TNM A in Streptomyces sp. CB03234-R-16 reached to 22.5 ± 3.1 mg L?1 in shaking flasks, and 13 ± 1 mg L?1 in 15 L fermentors, which were at least 40-fold higher than that in the wild-type strain (~ 0.3 mg L?1). Quantitative real-time RT-PCR revealed markedly enhanced expression of key genes encoding TNM A biosynthetic enzymes and regulators in Streptomyces sp. CB03234-R-16. Our study should greatly facilitate the future efforts to develop TNM A into a clinical anticancer drug.  相似文献   

9.
Exploration of novel active anti-tumor compounds from marine microbes for pharmaceutical applications has been a continuously hot spot in natural product research. Bacterial growth and metabolites may greatly vary under different culture conditions. In this study, the effects of different culture conditions and medium components on the growth and bioactive metabolites of Serratia proteamacula 657, an anti-tumor bacterium found in our previous study, were investigated. The results showed that lower temperature, weak acidic condition and solid fermentation favored the bacterial growth and the production of active compounds. Four components in the culture medium, NaCl, peptone, yeast extract and MgSO4, were found important to the bacterial growth and active compounds production in medium optimization. Under the optimized condition of solid state fermentation at pH 6.0–7.0, 23–25 °C, with the MgSO4-free medium containing 10.0 g/L peptone, 1.0 g/L yeast extract and 19.45 g/L NaCl, the antitumor activity of S. proteamacula 657 and the yield of crude extracts increased about 15 times and 6 times than the sample obtained in the original liquid fermentation, respectively. The active components in the metabolites of S. proteamacula 657 were identified as a homolog of prodigiosin, a red bacterial pigment, based on the analysis of the NMR and GC–MS. The bacterium S. proteamacula 657, which is adapted to lower temperature, produced prodigiosin-like pigments with highly antitumor activity, suggesting the bacterium is a potential new source for prodigiosin production.  相似文献   

10.
Twenty-seven endophytic actinomycete strains were isolated from five spontaneous plants well adapted to the poor sandy soil and arid climatic conditions of the Algerian Sahara. Morphological and chemotaxonomical analysis indicated that twenty-two isolates belonged to the Streptomyces genus and the remaining five were non-Streptomyces. All endophytic strains were screened for their ability to produce indole-3-acetic acid (IAA) in vitro on a chemically defined medium. Eighteen strains were able to produce IAA and the maximum production occurred with the Streptomyces sp. PT2 strain. The IAA produced was further extracted, partially purified and confirmed by thin layer chromatography (TLC) analysis. The 16S rDNA sequence analysis and phylogenetic studies indicated that strain PT2 was closely related to Streptomyces enissocaecilis NRRL B 16365T, Streptomyces rochei NBRC 12908T and Streptomyces plicatus NBRC 13071T, with 99.52 % similarity. The production of IAA was affected by cultural conditions such as temperature, pH, incubation period and l-tryptophan concentration. The highest level of IAA production (127 μg/ml) was obtained by cultivating the Streptomyces sp. PT2 strain in yeast extract-tryptone broth supplemented with 5 mg l-tryptophan/ml at pH 7 and incubated on a rotary shaker (200 rpm) at 30 °C for 5 days. Twenty-four-hour treatment of tomato cv. Marmande seeds with the supernatant culture of Streptomyces sp. PT2 that contained the crude IAA showed the maximum effect in promoting seed germination and root elongation.  相似文献   

11.
The current work details the screening of about 100 isolates from various soil samples, from which 1 isolate was finally selected based on the productivity of cholesterol oxidase. Further biochemical identification tests and 16S rRNA gene sequencing identified this isolate as Streptomyces badius. A preliminary culture media optimization was carried out using the initial screening method of Plackett-Burman. Then, a Box-Behnken design was employed to investigate the optimum concentrations of medium components and interactive effects of main variables on cholesterol oxidase production. The regression analysis showed a significant coefficient of determination (R 2) value (91 %), which was in close agreement ensuring a satisfactory adjustment of the proposed model. Maximal enzyme production (2.38 U/mL, i.e., approximately more than 100 % activity in the basal medium) was obtained at: temperature 35 °C; Tween 20 0.1 %; pH 6.5 and yeast extract 0.15 %. This two-stage statistical approach provided rapid identification and integration of key medium parameters for Streptomyces sp., resulting in high cholesterol oxidase production.  相似文献   

12.
In the course of our examination for the alkaloid productivities of Streptomyces strains, Streptomyces sp. NA–15 was found to produce a new alkaloid, pyrindicin, in the culture medium. The strain NA–15 was found to be a variant of Streptomyces griseoflavus and was designated as S. griseoflavus var. pyr indie us nov. var.

After the culture conditions for pyrindicin production were studied, pyrindicin was obtained as its hydrochloride (mp 145°C, decomp.) from the cultured broth. The compound was shown to possess weak antimicrobial and several pharmacological activities. The LD50 of the hydrochloride (ip, in mice) was 87 mg/kg.  相似文献   

13.
Total of 171 alkaliphilic actinomycetes were evaluated for extracellular RNase production and Streptomyces sp. M49-1 was selected for further experiments. Fermentation optimization for RNase production was implemented in two steps using response surface methodology with central composite design. In the first step, the effect of independent fermentation variables including temperature, initial pH and process time were investigated. After identification of carbon and nitrogen sources affecting the production by one variable at a time method, concentrations of glucose and yeast extract and also inoculum size were chosen for the second central composite design. A maximum RNase activity was obtained under optimal conditions of 4.14 % glucose concentration, 4.63 % yeast extract concentration, 6.7 × 106 spores as inoculum size for 50 ml medium, 42.9 °C, 91.2 h process time and medium initial pH 9.0. Optimum activity of the enzyme is achieved at pH 11 and temperature 60 °C. The enzyme is highly stable at pH range 9.0–12.0 and at 90 °C after 2 h. Statistical optimization experiments provide 2.25 fold increases in the activity of alkalotolerant and thermostable RNase and shortened the fermentation time compared to that of unoptimized condition. The members of Streptomyces can be promising qualified RNase producer for pharmaceutical industries.  相似文献   

14.
The bioactive compound, bacoside A, has immense importance for the treatment of memory disorders and Alzheimer’s disease. Due to the growing commercial interest in the herb, Bacopa monnieri, it has been listed as highly endangered species. The present study was aimed at enhancing the production of bacoside A using an alternative technology of plant cell suspension culture. Initial experiments of docking simulations using bacoside A showed good inhibition of acetyl cholinesterase (binding energy value of ??20 kcal/mol), when comparison was made with other phytocompounds and the synthetic drug for Alzheimer’s disease. In vitro experiments established that B. monnieri cell suspension culture can be developed in Murashige and Skoog medium containing containing 0.1 mg/L benzylaminopurine and 0.5 mg/L naphthalene acetic acid. Plackett–Burman studies predicted that the most effective factors for maximum biomass production were inoculum size (t-value of 4.87), sucrose concentration (t-value of 0.25) and KH2PO4 concentration (t-value of 0.007). The nitrate to ammonium ratio (t-value of ? 0.42) did not have significant effect on the cell suspension biomass. The optimum concentration of the crucial variables obtained from a central composite design were—inoculum size of 2 g/L, sucrose concentration of 30 g/L and KH2PO4 concentration of 1.24 mM in one-sixth strength MS medium. The best model for optimum production of biomass and bacoside A was experimentally verified and the correlation between the predicted and actual values was found to be 99% for biomass and 94% for bacoside A production. The experimental results have been discussed in the present work.  相似文献   

15.
We constructed a non-scar triple-deleted mutant Pseudomonas aeruginosa to improve phenazine-1-carboxylic acid (PCA) yield and then optimized the culture conditions for PCA production. Using a non-scar deletion strategy, the 5′-untranslated region of the phz1 gene cluster and two genes, phzM and phzS, were knocked out of the P. aeruginosa strain M18 genome. The potential ability for high-yield PCA production in this triple-deleted mutant M18MSU1 was successfully realized by using statistical experimental designs. A 25–1 fractional factorial design was used to show that the three culture components of soybean meal, corn steep liquor and ethanol had the most significant effect on PCA production. Using a central composite design, the concentration of the three components was optimized. The maximum PCA production was predicted to be 4,725.1 mg/L. With the optimal medium containing soybean meal 74.25 g/L, corn steep liquor 13.01 g/L and ethanol 21.84 ml/L, a PCA production of 4,771.2 mg/L was obtained in the validation experiments, which was nearly twofold of that before optimization and tenfold of that in the wild-type strain. This non-scar triple-deleted mutant M18MSU1 may be a suitable strain for industrial production of this biologically synthesized fungicide due to its high PCA production, presumed safety, thermal adaptability and cost-effectiveness.  相似文献   

16.
《Process Biochemistry》2007,42(5):878-883
Medium compositions for the production of the novel derivatives of FR-008/Candicidin which was produced by a mutant of Streptomyces sp. FR-008 were optimized using two statistical methods including Plackett–Burman design (P–B), which was applied to find the key ingredients for the best medium composition, and response surface methodology (RSM), which was used to determine the optimal concentrations of these components. Results indicated that peptone, copper sulfate and glycerol had significant effects on the production. Under the proposed optimized conditions, the CS101 experimental yield (191.259 mg/L) closely matched the yield (203.536 mg/L) predicted by the statistical model. The optimization of the medium contributed to 10-fold higher antibiotic production than that of the control. It was first revealed that copper could stimulate FR-008/Candicidin and their derivatives synthesis at an optimal concentration in this paper, moreover, the basis of this phenomenon was also explained by investigating the enhancement of the enzymatic pathways.  相似文献   

17.
ε-Poly-l-lysine (ε-PL)—a natural food preservative with wide antimicrobial activity and high food safety—is increasingly attracting widespread attention. However, the high cost of raw materials severely impairs its economy and utilization. In this study, agro-industrial by-products, i.e., fish meal coupled with corn steep liquor, were employed as alternative organic nitrogen sources for industrial ε-PL production by Streptomyces sp. M-Z18. An economical medium was then developed by using an artificial neural network. Amino acids analyses showed that the improved medium was rich in glutamate, arginine, lysine and aspartate, which not only elevated the acid tolerance capability of the mycelia but also enhanced cell growth and ε-PL production. Subsequently, a cost-effective and efficient strategy for ε-PL production was established on fermenter scale, based on the improved medium and two-stage pH control. Notably, ε-PL production and productivity reached 35.24 g/L and 4.85 g/L day in fed-batch fermentation. Further profit assessment at the 10 m3 scale indicated that application of this strategy resulted in a net profit increase of 9,057 USD. Therefore, the proposed strategy has great potential for industrial production of ε-PL.  相似文献   

18.
【背景】海洋微生物是复杂海洋生态环境中重要的生物资源之一。海洋微生物所产生的活性天然产物极为丰富,是药物或药物先导化合物的重要来源。【目的】探索海洋中海绵来源链霉菌Streptomycessp.S52-B的优势生长条件,挖掘其次级代谢产物,以期分离具有良好生物活性的天然产物。【方法】根据"One Strain Many Compounds"(OSMAC)策略,寻找利于Streptomyces sp. S52-B生长和次级代谢产物产生的优势培养基,结合质谱及特征性的紫外吸收谱图,选择培养基进行大量发酵。利用正相硅胶柱色谱、葡聚糖凝胶柱色谱和制备型高效液相色谱等进行分离纯化,并应用高分辨质谱和核磁共振光谱进行化合物结构解析。【结果】确定培养基A–D为海洋链霉菌S52-B的优势培养基,基于紫外吸收光谱与质谱分析,从培养基A的大量发酵物中分离鉴定3个具有吡咯并[4,3,2-de]喹啉核心结构的含氯化合物,属于氨酰胺类天然产物,其中Ammosalic acid为新结构化合物。【结论】已知含有吡咯并喹啉母核的氨酰胺类家族化合物具有优良的抗癌活性。本研究从海绵来源链霉菌S52-B中分离鉴定了3个氨酰胺类化合物,其中一个是新结构化合物,不仅丰富了此类化合物家族的结构类型,也为研究其生物合成途径中的未知机理奠定了基础,还有利于结合培养条件和基因组信息从这株海绵来源链霉菌中挖掘新结构的活性天然产物。  相似文献   

19.
Streptomyces sp. CN229 was isolated from Tunisia soil. This strain displayed antimicrobial activity against Gram positive and Gram negative bacteria. In addition it is resistant to most β-lactam antibiotics including imipenem and meropenem (MIC imipenem >70 μg/ml). Metallo-β-lactamase (MβL) production was confirmed by either imipenem MIC decrease in the presence of ethylene diamine tetraactic acid (EDTA) or the inhibition zone enhancement around EDTA-impregnated imipenem, or meropenem discs. Isolectric focusing analysis demonstrated the production of β-lactamase with pI of 5.8 that is inhibited by EDTA.Streptomyces sp. CN229 was screened for the imipenem resistance genes,bla VIM andbla IMP previously identified inPseudomonas aeruginosa. The presence of these genes was not confirmed by specific PCR analysis. We concluded that carbapenem resistance inStreptomyces sp. CN229 strain is mainly due to production of a novel carbapenemase. Our data show for the first time that MβL is produced byStreptomyces sp. MβL-mediated imipenem and meropenem resistance inStreptomyces is a cause for concern in the study of resistance evolution and antibiotic cluster biosynthetic genes.  相似文献   

20.
Rapamycin is a high-value product finding immense use as a drug, in organ transplantation, and as a potential immunosuppressant. Optimization of fermentation parameters of rapamycin production by Streptomyces hygroscopicus NRRL 5491 has been carried out. The low titer value of rapamycin in the original producer strain limits its applicability at industrial level. This study aims at improving the production of rapamycin by optimizing the nutrient requirements. Addition of l-lysine increased the production of rapamycin up to a significant level which supports the fact that it acts as precursor for rapamycin production, as found in previous studies. Effect of optimized medium on the Streptomyces growth rate as well as rapamycin production has been studied. The optimization study incorporates one at a time parameter optimization studies followed by tool-based hybrid methodology. This methodology includes the Plackett–Burman design (PBD) method, artificial neural networks (ANN), and genetic algorithms (GA). PBD screened mannose, soyabean meal, and l-lysine concentrations as significant factors for rapamycin production. ANN was used to construct rapamycin production model. This strategy has led to a significant increase of rapamycin production up to 320.89 mg/L at GA optimized concentrations of 25.47, 15.39, and 17.48 g/L for mannose, soyabean meal, and l-lysine, respectively. The present study must find its application in scale-up study for industrial level production of rapamycin.  相似文献   

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