This study was designed to evaluate the ability of bioemulsifier to inhibit the growth of some pathogenic microorganisms. Fourteen isolates belonged to Serratia sp. were collected and tested for their ability to produce bioemulsifier. Results showed that Serratia marcescens S10 (isolated from the gut of the American cockroach) had the highest ability to produce bioemulsifier, among 14 isolates belong to Serratia spp. and it had the ability to inhibit the growth of some microorganisms. The production of bioemulsifier was detected by determination of emulsification index (E24%), qualitative drop-collapse test, emulsification activity (E.A) and measuring the surface tension (S.T). The results of bioemulsifier produced by Serratia marcescens S10 cultivated in mineral salts broth containing olive oil were: E24%= 87%, E.A= 0.31 and reducing of surface tension from 65mN/m to 41.5mN/m. The bioemulsuifier was extracted by organic solvent (chloroform-methanol and diethylether) and antimicrobial activity (antibacterial and antifungal) of bioemulsifier was tested against some pathogenic microorganisms. Results revealed that bioemulsifier reduced the growth of bacteria (Lesteria spp., Salmonella spp., Klebsiella spp. and Staphylococcus aureus) and inhibited the growth of fungi (Candida albicans, Aspergillus niger and Geotricum spp.).
The present study was conducted to estimate the antimicrobial activity and the potential biological control of the killer toxin produced by
Bacteriocin is an important antimicrobial peptide that can be used in industrial and medical fields due to its characteristics of antibacterial, food preservation and anticancer activities. Fifty isolates of Bacillus sp were collected from different soil samples which were already recognized via morphological and biochemical identification process. The isolates were screened for bacteriocin production effective against Staphylococcus spp in order to select the highest producing isolate. The isolate NK16 showed the maximum bacteriocin production (80 AU/ml) which was further characterized as Bacillus subtilis NK 16 through using API identification system (API 20E and API 50CHB). Then, next step was to detect the optimal conditions for maximum
... Show MoreIn this article Silver nanoparticles have been synthesized through physical method where the Nd-YAG laser has been used.The antimicrobial activities of these silver nanoparticles were investigated on two types of bacteria Escherichia coli and Staphylococcus aureus. These bacteria were used as representatives of Gram-negative and Gram-positive bacteria, respectively. Two experiments have been made The first one was to test the effectiveness of silver nanoparticles as an antimicrobial agent on Gram negative bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus, while the other one (susceptibility Test) was to evaluate antimicrobial agents effective against bacteria resistant to multiple antibiotics. This study showed t
... Show MoreThe tested isolate of Rhizobium leguminosarum bv. viciae was isolated from root nodules of vicia faba plant from Baghdad ,the isolated bacteria was examined for bioemulsifier production when growing in mineral salt medium that containing 1% sunflower oil as sole carbon source . Rhizobium isolate was able to produce bioemulsifier with initial emulsification index E24% was 38%. Many of physical and nutritional cultural conditions for optimum emulsifier production was examined including : pH , temperature ,incubation period ,carbon and nitrogen source. The maximum bioemulsifier production form Rhizobium isolate was 64.5% when bacteria growing in mineral salt medium with pH 9 ,incubated at temperature 30 ºC , incubation period was 10 days ,
... Show MoreProdigiosin, is a natural red pigment produced by various bacteria that firstly
characterized from Serratia marcescens. It is an alkaloid secondary metabolite with
a unique tripyrrol structure.This pigment is a promising drug owing to its reported
characteristics of having antifungal, immunosuppressive and anti-cancer activity. In
this study prodigiosin was produced by Serratia marcescens., which was isolated
from soil identified and characterized by morphology, Gram’s staining, biochemical
and carbohydrate fermentation tested and confirmed by the API 20E test.
From these samples, six isolates of Serratia marcescens( 24) % were obtained out
of 25 soil samples. Ability of these isolates in prodigiosin production
Summary The aim of this study is the evaluation the resistance of S. marcescence obtained from soil and water to metals chlorides (Zn+2, Hg+2, Fe+2, Al+3, and Pb+2). Four isolates, identified as Serratia marcescence and S. marcescena (S4) were selected for this study according to their resistance to five heavy metals. The ability of S. marcescena (S4) to grow in different concentrations of metals chloride (200-1200 µg/ml) was tested, the highest concentration that S. marcescence (S4) tolerate was 1000 µg/ml for Zn+2, Hg+2, Fe+2, AL+3, pb+2 and 300 µg/ml for Hg+2 through 24 hrs incubation at 37 Co. The effects of temperature and pH on bacteria growth during 72 hrs were also studied. S. marcescence (S4) was affected by ZnCl2, PbCl2, FeC12
... Show MorePetroleum is one of the most important substances consumed by man at present times, a major energy source in this century, petroleum oils can cause environmental pollution during various stages of production, transportation, refining and use, petroleum hydrocarbons pollutions ranging from soil, ground water to marine environment, become an inevitable problem in the modern life, current study focused on bioremediation process of hydrocarbons contaminants that remaining in the bottom of gas cylinders and discharged to the soil. Twenty-four bacterial isolates were isolated from contaminated soils all of them gram negative bacteria, bacterial isolates screening to investigate the ability of biodegradation of hydrocarbons, these isolates
... Show MoreBovine milk is one of the richest nutrients that contain minerals and vitamins that enhance immunity, especially in children, but because many children do not want to drink the raw milk, therefore this study aimed to enhance the sensory characteristics of raw milk by using hibiscus plant extract, which is characterized by red color and distinctive flavor as well as studying the effect of aqueous extract of Hibiscus sabdariffa on inhibiting the growth of microorganisms, by using three concentrations of the aqueous extract (0.5, 1.0 and 1.5%), where the statistical results showed a significant difference (P≤0.05) between the concentrations in color, texture and general acceptance, and the best results appeared when using
... Show MoreIn the present study, the effect of vasicine alkaloid separated from Adhatoda vasica as an inhibitor agent on the activity of proteases enzyme isolated from Pseudomonas aeruginosa was investigated. forty isolates of Pseudomonas aeruginosa were collected from local hospital in Baghdad and then their ability for producing proteases was screened using quantification and semi- quantitative methods. Pseudomonas aeruginosa P1 was selected as the highest protease producer, which next identified as P. aeruginosa. It was found that the optimum culture conditions for protease production in submerged culture was in the tryptic - soya broth medium at 37° C with pH 8 for 48 hours. In addition, the study i
... Show MoreBiosynthesis of nanoparticles has received considerable attention due to the growing need to develop environmentally benign nanoparticle synthesis processes that do not use toxic chemicals. Therefore, biosynthetic methods employing both biological agents such as bacteria and fungus or plant extracts have emerged as a simple and a viable alternative to chemical synthetic and physical method .It is well known that many microbes produce an organic material either intracellular or extracellular which is playing important role in the remediation of toxic metals through reduction of metal ions and acting as interesting Nano factories. As a result, in the present study Ag NPs were syn
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