Bacteria Enterobacter Aerogenes Research Articles

Potencial antimicrobiano de própolis e cera de diferentes espécies de abelhas sem ferrão

The objective to evaluate antimicrobial activity of propolis and wax different species of stingless bees front of the pathogenic bacteria. Bees wax were collected Canudo (Scaptotrigona sp.), Jandaira (Melipona subnitida) and jati (Plebeia sp.), and two samples of propolis species Cupira (Partamona sp.) and Jati (Plebleia sp). For the analysis of the antimicrobial activity of wax and propolis in hydroalcoholic extracts were produced concentrations of 100, 75 and 50 mg /mL and used diffusion technique discs. To evaluate the antimicrobial activity of the extracts were used strains Enterobacter aerogenes (ATCC 1304), Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538). It was observed that the extracts of Canudo bees wax, and Jandaira Jati showed activity against the tested microorganisms. As for the propolis extracts was verified that the Cupira at concentration of 100 mg / ml had activity against all the tested bacterial strains, as in other concentrations, only Staphylococcus aureus was inhibited their growth. The Jati propolis extract inhibited the bacteria Enterobacter aerogenes and Staphylococcus aureus at a concentration of 100 mg / mL and E. coli suffered no inhibition. So the wax and propolis extracts of bee species assessed sting have antimicrobial potential against strains of microorganisms tested.

Prevalence of multidrug resistant uropathogenic bacteria in pediatric patients of a tertiary care hospital in eastern India.

Today, because systemic infections such as urinary tract infection (UTI) affect even pediatric patients, antibiotic resistant bacteria have become a constant clinical challenge. In the present study, a total of 1054 urine samples were collected from pediatric patients over 18 months. From these samples, 510 isolates of pathogenic bacteria were collected using HiCrome UTI agar. Antibiotic sensitivity tests of isolates were performed using the Kirby-Bauer method. Two Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus) and 7 Gram-negative bacteria (Citrobacter freundii, Enterobacter aerogenes, Escherichia coli, Klebsiella oxytoca, K. pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa) were isolated. Antibiograms of isolated bacteria were ascertained using antibiotics of 4 classes: aminoglycosides, β-lactams, fluoroquinolones and 2 stand-alones (co-trimoxazole and nitrofurantoin). Based on percent values of antibiotic resistance, isolated bacteria were (in decreasing order of number of isolated isolates): E. coli (109)>S. aureus (65)>E. faecalis (82)>E. aerogenes (64)>C. freundii (41)>P. aeruginosa (32)>K. pneumoniae (45)>K. oxytoca (50)>P. vulgaris (22). Surveillance results show that MDR isolates of 9 pathogenic bacteria were prevalent in the environment around the hospital. Thus, revisions to the antimicrobial stewardship program in this area of the country are required to increase clinician confidence in empiric therapy, which is often used for UTI cases.

Purification and antibiofilm activity of AHL-lactonase from endophytic Enterobacter aerogenes VT66

The opportunistic pathogen Pseudomonas aeruginosa uses biofilm lifestyle to resist antibiotic treatment. In our study, endophytic bacterium Enterobacter aerogenes VT66 quenched the N-acyl homoserine lactone (AHL) molecules produced by P. aeruginosa PAO1. The quorum quenching activity was attributed to the presence of AHL-lactonase. The AHL-lactonase was purified using column chromatography and purified AHL-lactonase was applied for the control of biofilm formation in P. aeruginosa PAO1. The results showed that purified AHL-lactonase obtained with a molecular weight about 30kDa was able to inhibit more than 70% of biofilm in P. aeruginosa PAO1 (P<0.001). Antibiofilm activity of AHL-lactonase was correlated well with results from staining technique used to determine inhibition of biomass and viable cell activity. Therefore, results unambiguously confirm that the AHL-lactonase from E. aerogenes VT66 could be used as antibiofilm therapeutics in P. aeruginosa associated biomedical applications.

Combining urban wastewater treatment with biohydrogen production – An integrated microalgae-based approach

The aim of the present work was the simultaneous treatment of urban wastewater using microalgae and the energetic valorization of the obtained biomass. Chlorella vulgaris (Cv), Scenedesmus obliquus (Sc) and a naturally occurring algal Consortium C (ConsC) were grown in an urban wastewater. The nutrient removals were quite high and the treated water fits the legislation (PT Dec-Lei 236/98) in what concerns the parameters analysed (N, P, COD). After nutrient depletion the microalgae remained two more weeks in the photobioreactor (PBR) under nutritional stress conditions, to induce sugar accumulation (22–43%). The stressed biomass was converted into biohydrogen (bioH2), a clean energy carrier, through dark fermentation by a strain of the bacteria Enterobacter aerogenes. The fermentation kinetics were monitored and fitted to a modified Gompertz model. The highest bioH2 production yield was obtained for S. obliquus (56.8mL H2/gVS) which was very similar when using the same algae grown in synthetic media.

Use of aiiA gene amplification for AHL-lactonase production from endophytic bacterium Enterobacter species

AHL-lactonase has gained renewed interest due to biotechnological applications such as antiquorum sensing, antibiofilm strategies, biofouling, etc. In our study, the production of AHL-lactonase from endophytic bacteria Enterobacter aerogenes VT66 was optimized by response surface methodology (RSM) using central composite design (CCD) for four different cultural conditions. The relative activity of AHL-lactonase was correlated with amplification of aiiA homologous gene amplification with respect to cultural conditions. Statistical analysis by ANOVA of the quadratic regression model showed that the RSM model constructed is highly significant, as indicated by F-test with a low probability value (pmodel<0.0001) and high regression coefficient (0.9997) as well as lower coefficient of variation (1.86%) indicate that suitability of variable parameters. The quadratic regression model of AHL-lactonase production in terms of relative activity was built and the optimal cultural conditions for maximum enzyme production were determined as 32.5°C temperature, pH 7.0, 350μM of substrate concentration and 33h of incubation time. The enhanced AHL-lactonase yielded 1.33 fold increases in relative activity and it positively correlated with the amplification of aiiA gene.

Bioconversion of Jatropha curcas seed cake to hydrogen by a strain of Enterobacter aerogenes

Hydrogen (H2) gas is considered the future energy carrier as a clean fuel. Biological processes to produce hydrogen are very attractive due to less energy expenditures and the possibility to use organic wastes as substrate. In this work, Jatropha curcas L. seed cake (JSC), a solid residue remaining after oil extraction from J. curcas seeds for biodiesel production, was used as substrate in a dark fermentation process by a pure strain of the bacteria Enterobacter aerogenes. Batch assays were performed using the substrate (2.5gVolatile Solid/LFermentation Medium) submitted to thermal pretreatment in an autoclave for two different exposure times (15 and 30min) and the results were compared with the ones obtained when the JSC was used without pretreatment. The best specific biohydrogen production (68.2mL H2/gVSiJSC) was attained for the conditions of no substrate pretreatment, which is an advantage from the viewpoint of energy saving. In the best conditions, the increase of the initial JSC concentration from 2.5 to 10gVS/LFM led to the increase of the cumulative hydrogen production and to higher bioH2 production rates. However a decrease on the specific H2 production from 68.2 to 23.5mL H2/gVSiJSC was observed.

The presence of antibiotic-resistant nosocomial pathogens in endotracheal tube biofilms and corresponding surveillance cultures

Mechanically ventilated patients often develop ventilator-associated pneumonia (VAP). Soon after intubation, a mixed biofilm harboring microbial pathogens is formed on the endotracheal tube (ET). It is believed that this biofilm contributes to the development of VAP. Unfortunately, the causative agent is often not known at the time VAP is suspected, and early therapy often relies on the identification of surveillance cultures (SC). It is thus important to know whether these SC can predict the microbial flora in ET biofilms. In this study, we compare the presence of a number of antibiotic-resistant nosocomial bacteria (Enterobacter aerogenes, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis) and of Candida albicans in cultures from ET biofilms and SC (i.e. sputum samples, nose swabs, and throat swabs) of 20 mechanically ventilated patients. Our data indicate that there is a good correlation between the presence of (antibiotic-resistant) pathogens in ET biofilms and SC.

Biosynthesis, characterization and antimicrobial activity of copper oxide nanoparticles (CONPs) produced using brown alga extract (Bifurcaria bifurcata)

Recently, biosynthesis of nanoparticles has attracted scientists’ attention because of the necessity to develop new clean, cost-effective and efficient synthesis techniques. In particular, metal oxide nanoparticles are receiving increasing attention in a large variety of applications. However, up to now, the reports on the biopreparation and characterization of nanocrystalline copper oxide are relatively few compared to some other metal oxides. In this paper, we report for the first time the use of brown alga (Bifurcaria bifurcata) in the biosynthesis of copper oxide nanoparticles of dimensions 5–45 nm. The synthesized nanomaterial is characterized by UV–visible absorption spectroscopy and Fourier transform infrared spectrum analysis. X-ray diffraction confirms the formation and the crystalline nature of copper oxide nanomaterial. Further, these nanoparticles were found to exhibit high antibacterial activity against two different strains of bacteria Enterobacter aerogenes (Gram negative) and Staphylococcus aureus (Gram positive).

Development of electric rust preventive machining method system — safe water using for machining fluid: complete removal of bacteria (Enterobacter aerogenes)-

It is great concern that is environmental load in manufacturing. In machining site, metal working fluid (coolant) such as cutting oil, grinding fluid is used. It contains several chemicals that are oil, surface active agent, extreme pressure additive, antirust agent, antifoaming agent, preservative, biocide etc.. It is thought that it is not good for environment and human body. Machining fluid mist and splash contained several chemicals that are cause of danger for worker’s health while machining. Furthermore, time elapses, fluid is rotten by bacteria. Bad smell and degradation of machining performance occurs. Therefore, after using machining fluid, waste fluid is disposed. Incineration or coagulative precipitation and landfill etc. are necessary. It arise great disposal cost and environmental load as discharging of huge amount green house gas (CO2 etc.). Then, machining fluid decreasing or non-using is demanded in industry. So, in this investigation, new environmental machining method: the electric rust preventive machining method system that uses only water as machining fluid has been developed. In this paper, water purification recycle system in water machining system development is mentioned. Therefore, complete removal of bacteria (Enterobacter aerogenes) without using chemicals such as biocide is examined for corruption, malodor prevention and safe machining water.

English

&nbsp;With the rapid growth of urbanization, the discharge of industrial, agricultural and municipal wastewater into water resources is increasing. Cyanobacteria are a dominant component of the phytoplankton that causes problems in water reservoirs. The aim of this study is to evaluate the performance of bacteria in the removal of cyanobacteria algae from water reservoirs. In this study, a biological method with four types of bacteria was applied for algae removal. First of all, species of cyanobacteria were identified, and then their specific medium BG-11 was prepared. The species of bacteria (Pseudomonas aeroginosa,&nbsp;Enterobacter aerogenes,&nbsp;Klebsiella oxytoca,&nbsp;and&nbsp;Citrobacter freundii) were used for removing cyanobacteria for a period of 0 to 10 days. Variables such as chlorophyll&nbsp;a, nitrate, phosphate, dissolved oxygen, heterotrophic plate count, and algal cell count were measured during the study period. The results of the present study showed that&nbsp;P. aeroginosa&nbsp;and&nbsp;C. freundii&nbsp;were effective for the removal of chlorophyll&nbsp;a&nbsp;in the first five to six days of the study period with removal efficiency of 63.5 and 56.59% respectively. The other parameters such as phosphate, nitrate, and algal cells decreased relatively. This method is relatively efficient and effective for removing algae from water resources and can be used for removing nutrients and cyanobacteria algae from water resources.&nbsp;&nbsp; &nbsp; Key words:&nbsp;Algae, biological, biotechnology, cyanobacteria, water.&nbsp;

Comparative study of biohydrogen production by four dark fermentative bacteria

Dark fermentation is a promising biological method for hydrogen production because of its high production rate in the absence of light source and variety of the substrates. In this study, hydrogen production potential of four dark fermentative bacteria (Clostridium butyricum, Clostridium pasteurianum, Clostridium beijerinckii, and Enterobacter aerogenes) using glucose as substrate was investigated under anaerobic conditions. Batch experiments were conducted to study the effects of initial glucose concentration on hydrogen yield, hydrogen production rate and concentration of volatile fatty acids (VFA) in the effluents. Among the four different fermentative bacteria, C. butyricum showed great performance at 10 g/L of glucose with hydrogen production rate of 18.29 mL-H2/L-medium/hand specific hydrogen production rate of 3.90 mL-H2/g-biomass/h. In addition, it was found that the distribution of volatile fatty acids was different among the fermentative bacteria. C. butyricum and C. pasteurianum had higher ratio of acetate to butyrate compared to the other two species, which favored hydrogen generation.

Morphological, phytochemical, and anti-bacterial properties of wild and indigenous plant (Amorphophallus commutatus)

This study was undertaken to investigate the phytochemical and anti-bacterial properties of Amorphophallus commutatus var. wynadensis tubers using solvents of increasing polarity (viz: petroleum ether, hexane, and water). The chemical constituents of various extracts were obtained by the phytochemical analysis. For the anti-bacterial studies, both gram positive bacteria ( Streptococcus pyogenes , Streptococcus faecalis and Bacillus cereus ) and gram negative bacteria ( Enterobacter aerogenes, Escherichia coli, Salmonella typhi, and Proteus mirabilis ) were used. Among the various extracts, the petroleum ether extract (PEE) showed maximum zone of Inhibition (ZOI) against S. typhi and P. mirabilis with ZOI as 35 and 34 mm, respectively. The morphological aspects of A. commutatus are also present.

Simultaneous production of hydrogen and ethanol from waste glycerol by Enterobacter aerogenes KKU-S1

Factors affecting simultaneous hydrogen and ethanol production from waste glycerol by a newly isolated bacterium Enterobacter aerogenes KKU-S1 were investigated employing response surface methodology (RSM) with central composite design (CCD). The Plackett-Burman design was first used to screen the factors influencing simultaneous hydrogen and ethanol production, i.e., initial pH, temperature, amount of vitamin solution, yeast extract (YE) concentration and glycerol concentration. Results indicated that initial pH, temperature, YE concentration, and glycerol concentration had a statistically significant effect (p ≤ 0.05) on hydrogen production rate (HPR) and ethanol production. The significant factors were further optimized using CCD. Optimum conditions for simultaneously maximizing HPR and ethanol production were YE concentration of 1.00 g/L, glycerol concentration of 37 g/L, initial pH of 8.14, and temperature of 37 °C in which a maximum HPR and ethanol production of 0.24 mmol H2/L h and 120 mmol/L were achieved.

Microbiological and physico-chemical characteristics of stored &lt;i&gt;tsire-suya&lt;/i&gt;, a roasted meat product

The physico-chemical and microbiological characteristics of tsire-suya, a roasted meat product, stored at varying temperatures (4 oC, 28 oC, 40 oC, 50 oC, and 60 oC) for 5 days were studied. The bacteria isolatedinclude Bacillus subtilis, B. brevis, B. megaterium, Pseudomonas aeruginosa, Enterobacter aerogenes, Staphylococcus aureus, S. albus, Klebsiella sp, Acinetobacter mullei and Corynebacterium sp. The fungalisolates include Saccharomyces cerevisiae, Candida spp, Rhodotorula sp, Aspergillus niger, A. Fumigatus, Fusarium moniliforme, and Penicillium sp. Only Bacillus subtilis and B. megaterium, were isolated from tsiresuyastored at 50 oC and at 60 oC, and there were no physical signs of spoilage, unlike samples stored at 4 oC and 28 oC on which there was discolouration and production of off-odour on the 4th day and 2nd dayrespectively, and slime production on the 4th day in samples stored at 28 oC in addition to isolation of spoilage organisms like Pseudomonas and even pathogenic organisms like S. aureus. The microbial count decreased at all storage temperatures except at 28 oC where there was an increase. However, 50 oC and 60 oC were good for safe storage of tsire-suya as no spoilage organisms or pathogenic organisms were isolated at thesetemperatures. But we will recommend storage at 50 oC because samples here were not as hard as those stored at 60 oC. The usual practice of storing tsire-suya at 28 oC should be discouraged as the product is not safe and it is of poor quality when stored at this temperature. The development of the suya industry would be greatly enhanced by this study on time / temperature limits related to storing of tsire-suya.

Screening of various extracts of Gymnema sylvestre (Retz.) R.Br. ex Schult. for antimicrobial activity

Rising appearance of resistance to the presently existing antibiotics has necessitated sustained search for new antimicrobial compounds. The present study was designed to confirm ethno-medicinal assert of Gymnema sylvestre possessing antimicrobial activity that could be a superior alternative for synthetic antimicrobial agents, if proved to be successful enough. For this, the antimicrobial properties of G. sylvestre were tested against seven bacteria (Shigella flexneri, Staphylococcus aureus, Salmonella typhi,Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, and Enterobacter aerogenes) and three fungi (Aspergillus niger, Candida albicans, and Trichophyton rubrum)by using different solvents like petroleum ether, chloroform, benzene, ethyl acetate, ethanol and distilled water. The result showed that all the solvent extracts exhibited considerable activity against the tested microorganisms. The antibacterial activity increased with the increasing concentration of the extract. Petroleum ether solvent extract of G. sytvestre is less active against all test microorganisms than five other solvent extracts, and distilled water extract is highly active against all test microorganisms. All solvent extracts at lower concentration of 50 mg/ 20 disc showed very smaller amount of activity against all test microorganisms. Key words: Gymnema sylvestre, antibacterial activity, bacterial infections, medicinal plant.

Antimicrobial and antioxidant activities of Mimosaceae plants; Acacia modesta Wall (Phulai), Prosopis cineraria (Linn.) and Prosopis juliflora (Swartz)

In the present study the methanolic leaf extracts of three plant species of familyMimosaceae viz., Acacia modesta Wall (Phulai), Prosopis cineraria (Linn.) Druce andProsopis juliflora (Swartz) DC. were used to evaluate their antibacterial antifungal and antioxidant activity. Simple maceration method was used for the preparation of plant extracts. The extracts were tested against four strains of bacteria (Bacillus subtilis,Escherichia coli, Vibrio cholera and Enterobacter aerogenes) and two strains of fungi (Aspergillus niger and Aspergillus fumigatus). At 15 mg/ml extract concentration the maximum inhibitory zones observed in Acacia modesta, P. cineraria and P. juliflora were 20, 18 and 25 mm, respectively. P. cineraria gave best response against A. niger and A. fumigatus by producing 15.38 and 8% inhibition, respectively. P. juliflora showed 7.69% inhibition against A. niger. While A. modesta showed 11.53% activity against A. niger and 0.8% against A. fumigatus. The Antioxidant activities of these medicinal plants also showed significant results. Maximum radical scavenging activity (%RSA) was observed in P. cineraria and P. juliflora, that is, 60.48 and 47.82%, respectively, as compared to A. modesta which gave minimum %RSA value of 41.42%. Key words: Medicinal plants, Mimosaceae plants, methanol extracts, antibacterial, antifungal, antioxidant.

Effectiveness of gamma irradiation in the inactivation of histamine-producing bacteria

Histamine is a cause of scombroid foodborne poisoning. The control of histamine-producing bacteria is a method that can be used to avoid the accumulation of histamine. This study examined the effectiveness of gamma irradiation in inactivating histamine-producing bacteria. The histamine-producing bacteria Morganella morganii (JCM 1672), Enterobacter aerogenes (ATCC 43175) and Raoultella planticola (ATCC 43176) were suspended in tryptic soy broth and were gamma-irradiated at 0.5–4.0 kGy at room temperature. The bacterial populations declined with higher absorbance doses, and the radiation D10 (the dose of radiation required to cause a 90% reduction in the number of survivors) values ranged from 0.32 to 0.42 kGy. Histamine-producing bacteria were inoculated on tuna and were gamma-irradiated; the D10 values were between 0.31 and 0.34 kGy, depending on the type of bacteria. Complete inactivation of the histamine-producing bacteria that were inoculated on tuna was achieved at 4.0 kGy. Although gamma irradiation was effective in controlling histamine-producing bacteria in order to reduce the risk of histamine poisoning, excessive doses were associated with color changes in the tuna.

Surveillance of multidrug resistance of 10 enteropathogens in a teaching hospital and in vitro efficacy of 25 ethnomedicinal plants used by an Indian aborigine

ObjectiveTo have an antibiogram of hospital acquired (HA) and community acquired (CA) enteropathogens against 16 antibiotics to assess the infection dynamics for plausible help to the antimicrobial stewardship. To check extracts of 25 lesser-known plants used by an Indian aborigine, for antimicrobial efficacy in vitro and as complementary and alternate medicines against resistant pathogens. MethodsTen strains of enteric bacteria (Enterobacter aerogenes, Escherichia coli, Klebsiella sp., Salmonella paratyphi, S. typhi, Shigella boydii, S. dysenteriae, S. flexneri, S. sonnei and Vibrio cholerae) were isolated from clinical samples in 6 months and their antibiotic sensitivity was assessed by the disc-diffusion method. Concentrated aqueous and ethanolic extracts of leaves and barks of plants were used for monitoring their antibacterial potencies, by the agar-well diffusion method. ResultsIsolated bacterial strains were invariably multidrug resistant (MDR). E. coli was the most frequently isolated organism from HA and CA samples, followed next by Klebsiella sp. From the surveillance, it was evident that the distribution of MDR strains of each was more in HA than CA isolates. Aqueous and ethanolic extracts of Aegle marmelos, Azadirachta indica, Cassia fistula, Holarrhena antidysenterica, Salvadora persica and Terminalia arjuna were highly effective against the all isolated enteropathogenic strains. From the preliminary phytochemical analysis, it was confirmed that both extracts of A. indica, T. arjuna and T. alata contained all the detected phytochemicals (alkaloids, glycosides, terpenoids, reducing sugars, saponins, tannins, flavonoids and steroids), which plausibly attributed to their significant antibacterial activity. ConclusionsPhytoextracts were highly effective against the all enteropathogenic bacterial isolates, in vitro. These 25 plants could be used further for the isolation of pure compounds for use as complementary medicines.

Evaluation of antibacterial activity of selected medicinal plant extracts from south India against human pathogens

ObjectiveThe present study was to evaluate the antibacterial properties of 21 crude extracts from leaf and flower of Aristolochia indica (A. indica), Cassia angustifolia (C. angustifolia), leaf of Catharanthus roseus (C. roseus), Diospyros melanoxylon (D. melanoxylon), Dolichos biflorus (D. biflorus), Gymnema sylvestre (G. sylvestre) and Justicia procumbens (J. procumbens). MethodsThe ethyl acetate, acetone and methanol extract of medicinal plants were evaluated against Gram-positive Bacillus cereus (B. cereus) and Gram-negative bacteria Aeromonas hydrophila (A. hydrophila), Enterobacter aerogenes (E. aerogenes), Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) by using well diffusion assay and minimum inhibitory concentration (MIC). ResultsThe crude plant extracts demonstrated broad spectrum activity against all bacteria. The highest inhibitory zone was observed in leaf methanol extract of A. indica against E. aerogenes (25 mm), and E. coli (20 mm), flower methanol extract of C. angustifolia against B. cereus (22 mm) and leaf acetone extract of G. sylvestre against B. cereus (22mm). The MIC values of leaf methanol extract of A. indica against K. pneumonia (22.6μg/ml), and flower extract showed against E. coli (MIC: 24.2μg/ml), leaf ethyl acetate extract of C. angustifolia against K. pneumoniae (MIC: 28.4μg/ml). Acetone ethyl acetate and methanol extracts of D. melanoxylon and D. biflorus showed the lowest MIC activity value of >30 μg/ml against all tested pathogens. ConclusionThe antibacterial activity could be confirmed in most species used in traditional medicine in South India. Nevertheless, traditional knowledge might provide some leads to elucidate potential candidates for future development of new antibiotic agents.

Natural resistance of rose petals to microbial attack

Petals of red, yellow and white roses (Rosa damascene Mill.) of the family Rosaceae were extracted with (1:1) methylene chloride/methanol and tested for their antimicrobial activities against four species of Gram-positive bacteria (Bacillus cereus, Bacillus subtilis, Micrococcus luteus and Staphylococcus aureus), five species of Gram-negative bacteria (Enterobacter aerogenes, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Serratia marcescens) and five species of fungi (Penicillium notatum, Aspergillus niger, Rhizopus stolonifer, Saccharomyces cerevisiae and Fusarium oxysporum). All of the crude extracts showed a wide range of antimicrobial activities according to the tested organism and rose's type. Micrococcus luteus was found to be the most susceptible bacteria to all crude extracts. Red and yellow petal extracts showed much higher antibacterial activity than the white petals extract. Bacillus subtilis was found to be the least susceptible to all extracts. The fungus, Penicillium notatum was found to be the most susceptible with white petal extract being the most effective. Saccharomyces cerevisiae and Fusarium oxysporum were the least susceptible to all extracts. White roses extract showed much higher antifungal activities against Penicillium notatum than red or yellow roses, therefore, it was subjected to several bioassay guided chromatographic fractionations and purification to isolate the active chemical(s) responsible for the antifungal activity. Chemical structure of the isolated antifungal compounds were identified by spectroscopy techniques and found to be a γ-sitosterol and (Z,Z)-9,12-octadecadienoic acid. Antibacterial activity of the various types of rose extracts were due to complex mixtures of organic compounds which are still under chemical investigation and will be published later.