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1.
A D Ambartsumian K M Dekhtsunian S Ia Atopek L A Erzinkian 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1983,(8):36-38
The study of antagonism between S. aureus hospital strains and lactic acid bacteria, strain 317/402 "Nariné", revealed that the latter possessed high antagonistic activity. A new method for the sanitation of carriers of S. aureus hospital strains was developed; this method made it possible to limit the epidemiological significance of 82% of these strains. 相似文献
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3.
Kalpoutzakis E Aligiannis N Mitaku S Chinou I Harvala C Skaltsounis AL 《Zeitschrift für Naturforschung. C, Journal of biosciences》2001,56(1-2):49-52
The antimicrobial activity of fifteen semisynthetic labdane-type diterpenes derived from the two major natural compounds 3 and 4 of the resin "ladano" of Cistus creticus is reported. The chloroethyl carbamidic esters 15 and 20 showed the strongest antimicrobial activity against Gram(+), Gram(-) bacteria and pathogenic fungi. 相似文献
4.
Propionibacterium freudenreichii RVS-4-irf is a probiotic bacterium producing antimicrobial exometabolites applicable for foodstuff protection. Production of antimicrobial factors other than low-molecular propionates was observed in media with and without trypton. A method was developed for production of the fraction of high-molecular mass exopolymers from the culture liquid. Their polypeptide nature was confirmed using proteinase K. The preparation of extracellular polypeptides from P. freudenreichii RVS-4-irf exhibited species-specific activity in suppression of fungal and bacterial growth. 相似文献
5.
Andrey Yu Yakovlev Alexander P. Nesin Nina P. Simonenko Natalia A. Gordya Dmitriy V. Tulin Anastasia A. Kruglikova Sergey I. Chernysh 《In vitro cellular & developmental biology. Animal》2017,53(1):33-42
Antimicrobial peptides accumulated in the hemolymph in response to infection are a key element of insect innate immunity. The involvement of the fat body and hemocytes in the antimicrobial peptide synthesis is widely acknowledged, although release of the peptides present in the hemolymph from the immune cells was not directly verified so far. Here, we studied the presence of antimicrobial peptides in the culture medium of fat body cells and hemocytes isolated from the blue blowfly Calliphora vicina using complex of liquid chromatography, mass spectrometry, and antimicrobial activity assays. Both fat body and hemocytes are shown to synthesize and release to culture medium defensin, cecropin, diptericins, and proline-rich peptides. The spectra of peptide antibiotics released by the fat body and hemocytes partially overlap. Thus, the results suggest that insect fat body and blood cells are capable of releasing mature antimicrobial peptides to the hemolymph. It is notable that the data obtained demonstrate dramatic difference in the functioning of insect antimicrobial peptides and their mammalian counterparts localized into blood cells’ phagosomes where they exert their antibacterial activity. 相似文献
6.
M. M. K. Peiris S. S. N. Fernando P. M. Jayaweera N. D. H. Arachchi T. D. C. P. Guansekara 《Indian journal of microbiology》2018,58(3):301-311
Green silver nanoparticle (AgNP) biosynthesis is facilitated by the enzyme mediated reduction of Ag ions by plants, fungi and bacteria. The antimicrobial activity of green AgNPs is useful to overcome the challenge of antimicrobial resistance. Antimicrobial properties of biosynthesized AgNPs depend on multiple factors including culture conditions and the microbial source. The antimicrobial activity of AgNPs biosynthesized by Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and Acinetobacter baumannii (confirmed clinical isolate) were investigated in this study. Biosynthesis conditions (AgNO3 concentration, pH, incubation temperature and incubation time) were optimized to obtain the maximum AgNP yield. Presence of AgNPs was confirmed by observing a characteristic UV–Visible absorbance peak in 420–435 nm range. AgNP biosynthesis was optimal at 0.4 g/L AgNO3 concentration under alkaline conditions at 60–70 °C. The biosynthesized AgNPs showed higher stability compared to chemogenized AgNPs in the presence of electrolytes. AgNPs synthesized by P. aeruginosa were the most stable while NPs of S. aureus were the least stable. AgNPs synthesized by P. aeruginosa and S. aureus showed good antimicrobial potential against E. coli, P. aeruginosa, S. aureus, MRSA and Candida albicans. AgNPs synthesized by S. aureus had greater antimicrobial activity. The antimicrobial activity of NPs may vary depending on the size and the morphology of NPs. 相似文献
7.
Joseph Selvin S. Shanmughapriya R. Gandhimathi G. Seghal Kiran T. Rajeetha Ravji K. Natarajaseenivasan T. A. Hema 《Applied microbiology and biotechnology》2009,83(3):435-445
The sponge-associated actinomycetes were isolated from the marine sponge Dendrilla nigra, collected from the southwest coast of India. Eleven actinomycetes were isolated depending upon the heterogeneity and stability
in subculturing. Among these, Nocardiopsis dassonvillei MAD08 showed 100% activity against the multidrug resistant pathogens tested. The culture conditions of N. dassonvillei MAD08 was optimized under submerged fermentation conditions for enhanced antimicrobial production. The unique feature of
MAD08 includes extracellular amylase, cellulase, lipase, and protease production. These enzymes ultimately increase the scope
of optimization using broad range of raw materials which might be efficiently utilized. The extraction of the cell free supernatant
with ethyl acetate yielded bioactive crude extract that displayed activity against a panel of pathogens tested. Analysis of
the active thin layer chromatography fraction by Fourier transform infrared and gas chromatography-mass spectrometry evidenced
11 compounds with antimicrobial activity. The ammonium sulfate precipitation of the culture supernatant at 80% saturation
yielded an anticandidal protein of molecular weight 87.12 kDa. This is the first strain that produces both organic solvent
and water soluble antimicrobial compounds. The active extract was non-hemolytic and showed surface active property envisaging
its probable role in inhibiting the attachment of pathogens to host tissues, thus, blocking host–pathogen interaction at an
earlier stage of pathogenesis. 相似文献
8.
Endophytic actinomycetes were isolated from Combretum latifolium Blume (Combretaceae),Western Ghats of Southern India and identified by its characteristic culture morphology and molecular analysis of 16S rRNA gene sequences. In this survey of endophytic actinomycetes, a total of 117 isolates representing 9 different genera of endophytic actinomycetes were obtained using four different isolation media and several of them seemed to be novel taxa. Streptomyces genera (35%) was the most frequently isolated strains, followed by Nocordiopsis (17%) and Micromonospora (13%). ISP-4 medium recovered more isolates (47%) when compared to rest of the media used. Preliminary antibacterial activity of the isolates was carried out by confrontation test. Ethyl acetate fraction of selected isolates in disc diffusion assay exhibited broad spectrum antimicrobial activity against test human pathogens. All Streptomyces spp. strains displayed significant antimicrobial activity against test pathogens. Strain CLA-66 and CLA-68 which are Nocordipsis spp. inhibited both bacterial and fungal pathogens where as other isolates inhibited atleast three test human pathogens in disc diffusion assay. Antimicrobial screening of endophytic actinomycetes from this host may represent a unique potential niche for antimicrobial compounds of industrial and pharmaceutical applications. This work is the first comprehensive report on incidence of potential endophytic actinomycetes inhabiting C. latifolium Blume. 相似文献
9.
Purnita Bhattacharyya Bikash Agarwal Madhurankhi Goswami Debasish Maiti Sunandan Baruah Prosun Tribedi 《Antonie van Leeuwenhoek》2018,111(1):89-99
Biofilms are structured consortia of microbial cells that grow on living and non living surfaces and surround themselves with secreted polymers. Infections with bacterial biofilms have emerged as a foremost public health concern because biofilm growing cells can be highly resistant to both antibiotics and host immune defenses. Zinc oxide nanoparticles have been reported as a potential antimicrobial agent, thus, in the current study, we have evaluated the antimicrobial as well as antibiofilm activity of zinc oxide nanoparticles against the bacterium Streptococcus pneumoniae which is a significant cause of disease. Zinc oxide nanoparticles showed strong antimicrobial activity against S. pneumoniae, with an MIC value of 40 μg/ml. Biofilm inhibition of S. pneumoniae was also evaluated by performing a series of experiments such as crystal violet assay, microscopic observation, protein count, EPS secretion etc. using sub-MIC concentrations (3, 6 and 12 µg/ml) of zinc oxide nanoparticles. The results showed that the sub-MIC doses of zinc oxide nanoparticles exhibited significant anti-biofilm activity against S. pneumoniae, with maximum biofilm attenuation found at 12 μg/ml. Taken together, the results indicate that zinc oxide nanoparticles can be considered as a potential agent for the inhibition of microbial biofilms. 相似文献
10.
Eggs of the tick Amblyomma hebraeum Koch (Acari: Ixodidae) inhibited the growth of Escherichia coli and Serratia marcescens (Gram-negative bacteria) in solid culture, but not the growth of Staphylococcus epidermidis, and only marginally the growth of Bacillus subtilis (Gram-positive bacteria). When egg wax was extracted with chloroform/methanol (2:1), the extract contained antibacterial activity, but the denuded eggs did not. When assayed against bacteria in liquid culture, the aqueous phase inhibited the growth of S. epidermidis. However, the activity against E. coli was lost during extraction. The antimicrobial component of the aqueous phase was heat stable (100°C for 10 min), resistant to proteinase K (15 min at 55°C) and to pronase (30 min at 37°C). The antibacterial activity in the aqueous phase increased the permeability of the cell membrane of susceptible bacterial cells within 30 min. However, lysis of the cells was detected by optical density measurements (OD600 nm) only after 1.5 h. The most evident cytological changes observed by transmission electron microscopy were a thickening of the cell wall and the appearance of numerous electron lucent areas within the cytoplasm of treated bacteria. Gené’s organ, the egg-waxing organ in ticks, grew enormously during the first 16 days post-engorgement, and gained antimicrobial activity by day 10 (when oviposition began). This suggests that Gené’s organ is the major source of the antibacterial substance in the egg wax. The vitellogenic hormone in A. hebraeum, 20-hydroxyecdysone, when injected into recently engorged females, did not stimulate growth of Gené’s organ or precocious secretion of antimicrobial activity. 相似文献
11.
D S Irwin T P Anastassiades 《Comparative biochemistry and physiology. B, Comparative biochemistry》1987,88(2):529-534
1. Bovine bone contains an extractable activity which stimulated the synthesis of glycosaminoglycans by bovine synovial, human synovial and mouse 3T3 fibroblastic cells in culture. Human cells were used to develop an assay for purification of the stimulatory activity ("matrigenin" activity) from bovine bone. 2. Partial purification of "matrigenin" activity was achieved by precipitation of the EDTA extract at pH 3.5 and Sepharose CL-6B chromatography in 4 M guanidinium HCl. Dissociative conditions were necessary to prevent aggregation. 3. On SDS-polyacrylamide gel electrophoresis the activity ran with a mobility equivalent to a Mr = 27,500 and could be recovered from the SDS gels. 相似文献
12.
Marcelo Rodrigues de Melo Luzia Doretto Paccola-Meirelles Terezinha de Jesus Faria Noemia Kazue Ishikawa 《Mycoscience》2009,50(1):78-81
Enokipodins A, B, C, and D are α-cuparene-type sesquiterpenoids antimicrobial metabolites produced in the stationary stage
of Flammulina velutipes mycelia development in malt extract broth. This study assessed the influence of nutritional and environmental factors on
F. velutipes mycelia culture for the production of these metabolites. The mycelia growth and antimicrobial activity were assessed by determining
dry matter and the diffusion in agar method, respectively. The best F. velutipes mycelia growth was observed in dextrose potato broth, and greater antimicrobial metabolite production occurred in complete
Pontecorvo’s culture medium. Environmental modifications, such as a rise in temperature from 25° to 37°C on the 15th day of
F. velutipes mycelia culture in malt extract and peptone broth, also optimized antimicrobial metabolite production. The metabolites produced
in these treatments were correlated with the enokipodins A and B in thin-layer chromatography (TLC) and the antifungal activity
test by TLC bioautography. This study showed that there was no correlation between biomass production and antimicrobial metabolite
production, but there may be a correlation between culture medium composition and enokipodins biosynthesis. 相似文献
13.
Alejandro Hernández-Morales Ramón-Alvar Martínez-Peniche Jackeline-lizzeta Arvizu-Gómez Sofía-María Arvizu-Medrano Areli Rodríguez-Ontiveros Miguel-Angel Ramos-López Juan-Ramiro Pacheco-Aguilar 《Indian journal of microbiology》2018,58(2):208-213
Bacillus sp. strain MA04 a plant growth-promoting rhizobacteria (PGPR) showed hemolytic activity on blood agar plates, and the supernatant from liquid culture in nutrient broth at 24 h exhibited emulsification activity, suggesting the production of biosurfactants. In antagonist assays, the supernatant showed antifungal activity against phytopathogenic fungi such as Penicillium expansum, Fusarium stilboides, Sclerotium rolfsii y Rhizoctonia solani, finding a reduction of mycelial growth of all fungi tested, ranging from 35 to 69%, this activity was increased with time of culture, accomplishing percentages of inhibition up to 85% with supernatants obtained at 72 h. Then, the crude biorsurfactant (CB) was isolated from the supernatant in order to assay its antagonistic effect on the phytopathogens previously tested, finding an increase in the inhibition up to 97% at 500 mg/L of CB. The composition of CB was determined by infrared spectroscopy, identifying various functional groups related to lipopeptides, which were purified by high-performance liquid chromatography and analyzed by MALDI-TOF/TOF–MS, revealing a mixture of fengycins A and B whose high antifungal activity is been widely recognized. These results show that PGPR Bacillus sp. MA04 could also contribute to plant health status through the production of metabolites with antimicrobial activity. 相似文献
14.
Nelson H. Caicedo Birgit Heyduck-Söller Ulrich Fischer Jorg Thöming 《Journal of applied phycology》2011,23(5):811-818
The synthesis of bioactive compounds with antimicrobial activity, excreted by marine cyanobacteria, strongly depends on their
growth conditions. Due to the wide variety of biomolecules which could show properties as growth inhibitors and their low
concentrations within the culture medium, the activity of their crude extracts also seems to be related to the extraction
method used. Using the marine filamentous cyanobacterium Geitlerinema strain Flo1, we demonstrate a systematic approach for identifying optimal culture conditions to obtain culture media extracts
with antimicrobial activity. The changes in the culture conditions, such as the addition of NaBr to the medium, cell immobilisation
in vegetable sponge pieces, or temperature, effected the production of these bioactive compounds. The crude extract, containing
middle polar molecules, obtained by extraction with Amberlite XAD-1180 had a higher antifouling activity upon a number of
bacteria and fungi than the extract obtained by extraction with Amberlite XAD-16. The lowest inhibitory concentration obtained
upon Rhodosporidium sphaerocarpum was still ten times higher than that of bis(tributyltin)oxide, but compared to zinc pyrithione, it was two times more active. 相似文献
15.
为获得广谱抗菌功能野生菌株并提高其发酵产物中抗菌物质的含量。采用管碟法和菌丝生长速率法筛选功能菌株,ITS序列分析鉴定功能菌株,通过响应面法和正交设计优化发酵生产抗菌物质的工艺。筛选到一株强效、广谱抗菌功能菌株,鉴定为Cerrena sp.,其发酵产物对金黄色葡萄球菌、大肠杆菌、白色念珠菌、枯草芽孢杆菌和水稻纹枯病菌有显著拮抗作用。该菌株的摇甁发酵配方及培养条件为:马铃薯13.99 g/L,蔗糖 41.58 g/L,VB1 0.027 g/L,麸皮7 g/L,KH2PO4 2 g/L,MgSO4·7H2O 2 g/L;摇床温度28 ℃、发酵周期10 d、种龄4 d、接种量8%、初始pH为5.0、装液量110 ml/250 ml。该菌株有明显抑菌活性,发酵工艺优化后抗菌活性提高了30.37%,为该菌株今后的应用、抗菌剂的分离提纯和产业化提供了实验依据。 相似文献
16.
Chang-Ho Kang YuJin Shin YongGyeong Kim Jae-Seong So 《Biotechnology and Bioprocess Engineering》2016,21(1):46-52
Microorganisms intended for use as probiotics in aquaculture should exert antimicrobial activity and be regarded as safe not only for their aquatic hosts but also for their surrounding environments and humans. The objective of this work was to investigate antimicrobial activity against various pathogens, bile salt tolerance, and acid tolerance of 65 presumptive Lactobacillus spp. isolated from shellfish samples. Four strains (HL1, HL12, HL20, and JL28) were selected after qualitatively identifying high levels of antimicrobial activity against bacteria including Staphylococcus aureus, Salmonella typhimurium, Salmonella enteritidis, Escherichia coli O157:H7, Vibrio ichthyoenteri, Edwardsiella tarda, Streptococcus iniae, and V. parahaemolyticus. The sequence analysis of their 16S rRNA genes revealed that the four strains belong to the Lactobacillus plantarum species. In addition, their survivability was tested in bile salt and acidic conditions to show their potential use as probiotics in the gastrointestinal tract. 相似文献
17.
Jigni Mishra Rakhee Rajput Kaushlesh Singh Sanjeev Puri Meenakshi Goyal Anju Bansal Kshipra Misra 《International journal of peptide research and therapeutics》2018,24(4):543-554
Natural peptides are emerging as a leading alternative to conventional drugs and antibiotics, owing to their remarkable potency, better stability and less toxicity. Such peptides encompass numerous healing properties such as antimicrobial, anti-inflammatory, immunomodulatory, etc. Though plant- derived peptides have been widely studied for their therapeutic benefits, however, fungal peptides are still lesser explored. Ganoderma lucidum, a highly medicinal oriental mushroom comprises a vast array of phytoconstituents, namely flavonoids, phenolics, terpenoids, polysaccharides, proteins, glycolipids, etc and hence, is being used since several decades in traditional Chinese medicine (TCM) for its various ameliorative effects e.g. anti-inflammatory, antimicrobial, anti-proliferative and antioxidant properties. This study presents the isolation and characterization of antibacterial peptide fractions from fruiting body (GLF) and mycelium (GLM) of Indian G. lucidum. Representative amide bonds were identified in the fractions using established standard techniques. Peptide mass fingerprinting and HPLC confirmed the presence of cationic and hydrophobic amino acids in the peptide fractions which are known to be major structural features of antimicrobial peptides. Secondary structure prediction showed abundance of α-helices and random coils in GLF and GLM fractions respectively. The fractions exhibited appreciable antioxidant potential. Besides, these also possessed substantial antibacterial activity against Escherichia coli and Salmonella typhi wherein it was observed that generation of reactive oxygen species and induction of intracellular protein leakage within the bacterial cells were the possible mechanisms of inhibitory action. 相似文献
18.
Aliandra G. de Medeiros Daiani C. Savi Prithiba Mitra Khaled A. Shaaban Amit K. Jha Jon S. Thorson Jürgen Rohr Chirlei Glienke 《Folia microbiologica》2018,63(4):499-505
Antibiotic-resistant bacteria have been observed with increasing frequency over the past decades, driving the search for new drugs and stimulating the interest in natural products sources. Endophytic fungi from medicinal plants represent a great source of novel bioactive compounds useful to pharmaceutical and agronomical purposes. Diaporthe terebinthifolii is an endophytic species isolated from Schinus terebinthifolius, a plant used in popular medicine for several health problems. The strain D. terebinthifolii LGMF907 was previously reported by our group to produce secondary metabolites with biological activity against phytopathogens. Based on these data, strain LGMF907 was chosen for bioprospecting against microorganisms of clinical importance and for characterization of major secondary metabolites. In this study, different culture conditions were evaluated and the biological activity of this strain was expanded. The crude extracts demonstrated high antibacterial activity against Escherichia coli, Micrococcus luteus, Saccharomyces cerevisiae, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant S. aureus. The compounds diaporthin and orthosporin were characterized and also showed activity against the clinical microorganisms evaluated. This study discloses the first isolation of diaporthin and orthosporin from D. terebinthifolii, and revealed the potential of this endophytic fungus to produce secondary metabolites with antimicrobial activity. 相似文献
19.
Sandesh Panthi Yun Hee Choi Jun-Pil Jee Seung Sik Cho Yoon Seok Choi G. C. Pradeep Jin Cheol Yoo Joo Won Suh 《International journal of peptide research and therapeutics》2017,23(4):419-430
Microorganisms secrete antimicrobial peptides (AMPs) which are part of the innate immune system and rapidly increase in concentration in the host upon challenge by pathogens, which they produce themselves. Kimchi, a traditional Korean food fermented by Bacillus organisms, is found to be ideal for AMP production. Our aim was to investigate the therapeutic potential of antimicrobial substances produced by Bacillus species. Peptide K1R was subjected to fermentation in a culture media containing carbon and nitrogen sources and metal ions. A protein band around 4.6 kDa was detected in tricine-SDS-PAGE and confirmed by in situ inhibitory activity of the gel. Peptide K1R was stable over a broad range of pH (6.5–9), thermo tolerant up to 60?°C and showed unaltered activity at low temperatures (0–4?°C). The complete amino acid sequence of peptide K1R was AVQGTLEDALNLSKGALNQVQKAIQNGDXLTVXGXLGTIXLAVSX. The antagonistic effect of peptide K1R against multiple drug resistant (MDR) pathogens such as Salmonella Typhimurium and Enterococcus sp. verified its potential application in treating MDR cases. The antioxidant activity of peptide K1R was also comparable to that of standard ascorbic acid. 相似文献
20.
The antimicrobial activity of marinocine, synthesized by Marinomonas mediterranea, is due to hydrogen peroxide generated by its lysine oxidase activity 总被引:2,自引:0,他引:2
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Marinocine is a broad-spectrum antibacterial protein synthesized by the melanogenic marine bacterium Marinomonas mediterranea. This work describes the basis for the antibacterial activity of marinocine and the identification of the gene coding for this protein. The antibacterial activity is inhibited under anaerobic conditions and by the presence of catalase under aerobic conditions. Marinocine is active only in culture media containing l-lysine. In the presence of this amino acid, marinocine generates hydrogen peroxide, which causes cell death as confirmed by the increased sensitivity to marinocine of Escherichia coli strains mutated in catalase activity. The gene coding for this novel enzyme was cloned using degenerate PCR with primers designed based on conserved regions in the antimicrobial protein AlpP, synthesized by Pseudoalteromonas tunicata, and some hypothetical proteins. The gene coding for marinocine has been named lodA, standing for lysine oxidase, and it seems to form part of an operon with a second gene, lodB, that codes for a putative dehydrogenase flavoprotein. The identity of marinocine as LodA has been demonstrated by N-terminal sequencing of purified marinocine and generation of lodA mutants that lose their antimicrobial activity. This is the first report on a bacterial lysine oxidase activity and the first time that a gene encoding this activity has been cloned. 相似文献