Water Yeast Extract Research Articles

Antibiotic Activity of Actinomycetes Isolated from Young Tectona Grandis (L.) Wood and Pith

Actinomycetes are a source for novel bioactive compounds and justify obtaining new species from various sources. Hardwoods such as Tectona grandis (L.) have not been studied for actinomycete isolation. We aim to isolate endophytic actinomycetes from young Tectona grandis wood and pith and screen for antibiotic activity. Five young wood were cut and surface sterilized using ethanol and hypochlorous acid. The wood and pith of each sample are placed in eight plates of Humic acid-vitamin B (HV), Tap water Yeast extract (TWYE), and Yeast Extract Casein Digest (YECD) medium and incubated at 27°C for four weeks. Actinomycetes were isolated from such medium, observed every week, and transferred to an International Streptomyces Project-2 (ISP-2) medium for identification and antibiotic production tested against Staphylococcus aureus, Helicobacter pylori, and Escherichia coli using the Kirby-Bauer method. Seven actinomycetes were isolated from the wood, primarily from YECD and TWYE media, with varying morphological characteristics. One isolate having maroon-colored aerial and vegetative mycelium with grey spores showed moderate antibacterial activity against S. aureus and H. pylori (13.49±1.03 mm and 14.9±0.7 mm, respectively), while two other actinomycetes showed weak activity against these bacteria. However, none of the actinomycetes show any activity against E. coli. Tectona grandis (L.) is a potential source for novel actinomycetes with an antibiotic activity which warrants further exploration

The Synthesis Conditions Influence on Silver Nanostructures Formation Under the Effect of Electromagnetic Radiation

In the present work the influence of the synthesis conditions, particularly the effect of used surrounding media on the silver nanostructures formation with various spatial configuration under the effect of the visible electromagnetic radiation has been studied. Silver nanoparticles were synthesized by photostimulated reduction of silver ions from the silver nitrate water solution in aqueous medium and in water yeast extract. The modification of the configuration of resulting nanoobjects was carried out by irradiating the testing samples with red, green, and blue photon flows under the similar conditions. For this task the unique devise with three isolated cells for irradiating silver colloids under the room temperature was developed. The parameters of obtained silver nanostructures were characterized by spectrophotometry and their optical properties have been researched. For the obtained silver colloids the polydispersity indexes were also determined. Besides, the changes in morphology were confirmed by transmission electron microscopy. The shift of the absorption spectra of the testing colloids to the long-wavelength spectral region and their splitting in some cases after irradiation by different wavelength has been showed. For nanoparticles synthesized in the distilled water after irradiating by red, green, and blue photon flows the additional absorption peaks appeared in the longer-wavelength spectral region. Moreover, the colloidal solutions changed the colors after the electromagnetic radiation effect. This indicates the change in nanostructures shapes. The formation of triangular nanoprisms under the influence of red and green photon flows and formation of decahedral nanostructures under the influence of blue light was found. It has been shown that this method can be successfully used to obtain the large silver nanostructures in aqueous solution of the known spatial and optical parameters. The absorption spectrum of the silver nanostructures obtained in water yeast extract shows one clearly expressed peak. But, after irradiation of this colloid with red and green light, the absorption curves are very close in shape to the initial one. Only under the blue light irradiation an additional weak absorption peak can be observed at the wavelength of 523 nm, which might indicates a partial change in the nanostructures shapes. It has been shown that the use of water yeast extract as a surrounding medium for the synthesis of nanoparticles with different spatial morphology minimizes the photoinduced effect of the shape transformation, which was observed in pure aqueous colloids. The effectiveness and the ability to use of different surrounding media for the silver nanoparticles synthesis by photostimulated reduction for obtaining nanostructures with the predetermined spatial parameters and to shift their absorption peaks to the visible and near infrared spectral region has been shown.Ref. 17, fig. 7, tabl. 1.

DIVERSITY OF ENDOPHYTIC BACTERIA ASSOCIATED WITH (Curcuma heyneana) AND THEIR POTENCY FOR NITROGEN FIXATION

Endophytic bacteria shows a high biodiversity and some of the species plays important biological roles in agriculture. The aim of this study was to investigate the endophytic bacteria diversity associated with temu giring (Curcuma heyneana) and to evaluate its nitrogen-fixation activity. Temu giring was collected from Bogor Botanic Garden. The isolation of endophytic bacteria was carried out using two methods (spread plate and plant piece methods) and four different medias (Nutrient Agar (NA), NA contained temu giring extract (NAH), Water Yeast Extract Agar (WYEA), and WYEA contained temu giring extract (WYEAH)). The identification of selected isolates were conducted based on 16S rDNA. The ability of selected isolates to fix the nitrogen on Jensen’s media is then being tested. The results revealed that the suitable method and media of endophytic bacteria isolation were spread plate method and NA. Based on the morphological characteristics differentiation, 30 isolates were obtained from rhizome (27%), stem (50%), and leaves (23%). The sequencing result of 16S rDNA showed that community of endophytic bacteria was divided into six clusters, those are Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Flavobacteriia, Actinobacteria, and Firmicutes,which represented 17 genus consisted of Microbacterium, Leclercia, Brevundimonas, Chromobacterium, Enterobacter, Acinetobacter, Novosphingobium, Chryseobacterium, Curtobacterium, Agrobacterium, Sphingomonas, Herbaspirillium, Bacillus, Variovorax, Mycobacterium, Starkeya, and Rhizobium. A total of eleven isolates could grow in the N free medium. The presence of endophytic bacteria those were able to fix nitrogen are expected to be applied in agricultural sector as a biological fertilizer.

Population and Diversity of Endophytic Bacteria Associated with Medicinal Plant Curcuma zedoaria

Traditionally Curcuma zedoaria (white turmeric) known as herbal medicine which possessing many biological activities. Many endophytic bacteria live in association with their host and may play an important biological roles. The main interest of this study was to investigate the endophytic bacterial diversity associated with white turmeric. White turmerics were collected from three locations in Bogor, West Java, Indonesia. The isolation of endophytic bacteria was carried out using 4 kinds media (Nutrient Agar (NA), NA contained white turmeric extract (NAT), Water Yeast Extract Agar (WYEA), WYEA contained white turmeric extract (WYEAT)), and 2 methods of spread plate and plant piece methods. The identification of selected isolates was conducted by molecular analysis based on 16S DNA. The suitable media and method of isolation endophytic bacteria were NA and spread plate method. A total of 207 bacterial colonies were isolated from rhizomes, stems, and leaves and 73 endophytic bacteria were selected based on morphological characteristics. From them, 32% isolates from Bojong Gede, 22% isolates from Cibinong and 46% isolates from Dramaga were obtained. Endophytic bacteria were predominated 38% in the rhizomes, 32% of stems, and 30% of leaves. Based on 16S rDNA sequence analysis, the isolates were belonging to the cluster Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, and Actinobacteria, with twenty three different genera includes Stenothropomonas, Pseudomonas, Enterobacter, Providencia, Klebsiella, Dickeya, Pantoea, Bacillus, Acinetobacter, Citrobacter , Mycobacterium, Cellulomonas, Microbacterium, Methylobacterium, Penylobacterium, Roseomonas, Agrobacterium, Bosea, Xanthobacter, Rhizobium, Burkholderia, Ralstonia, and Alcaligenes. The plant location, age, part of plant, media and method of isolation seem to influence the endophytic bacterial communities.

MICROBIAL POPULATION OF HOT SPRING WATERS IN ESKİŞEHİR/TURKEY

In order to investigate and find out the bacterial community of hot spring waters in Eskisehir, Turkey, 7 hot spring water samples were collected from 7 different hot springs. All samples were inoculated using four different media (nutrient agar, water yeast extract agar, trypticase soy agar, starch casein agar). After incubation at 50 oC for 14 days, all bacterial colonies were counted and purified. Gram reaction, catalase and oxidase properties of all isolates were determined and investigated by BIOLOG, VITEK and automated ribotyping system (RiboPrinter). The resistance of these bacteria was examined against ampiciline, gentamisine, trimethoprime-sulphamethoxazole and tetracycline. As a result, heat resistant pathogenic microorganisms in addition to human normal flora were determined in hot spring waters (43-50 oC) in investigated area. Ten different species belong to 6 genera were identified as Alysiella filiformis, Bordetella bronchiseptica, B. pertussis, Molexalla caprae, M. caviae, M. cuniculi, M. phenylpyruvica, Roseomonas fauriae, Delftia acidovorans and Pseudomonas taetrolens.

Isolation and characterization of potent antifungal strains of the Streptomyces violaceusniger clade active against Candida albicans

Streptomyces strains were isolated from a sagebrush rhizosphere soil sample on humic acid vitamin (HV) agar and water yeast extract (WYE) agar supplemented with 1.5% (w/w) phenol as a selective medium. Acidic, neutral and alkaline pH conditions were also used in the isolation procedures. The phenol treatment reduced the numbers of both actinomycetes and non-actinomycetes on plates under all three pH conditions. From phenol-amended HV and WYE agar, 16 strains were isolated in pure culture; 14 from the HV agar and two from the WYE agar. All the isolates were tested for their antifungal activities against Pythium ultimum P8 and five yeast strains, including two antifungal drug-resistant Candida albicans strains. HV isolates that showed broad-spectrum antifungal antibiotic activities were all found to be members of the Streptomyces violaceusniger clade, while those that did not were non-clade members. The phenol treatment was not selective for S. violaceusniger clade members. Therefore, we tested the spores of both S. violaceusniger clade and non-clade members using two biocides, phenol and hydrogen peroxide, as selection agents. Spores of non-clade members, such as S. coelicolor M145 and S. lividans TK 21, survived these two biocides just as well as S. violaceusniger clade members. Thus, in our hands, biocide resistance was not S. violaceusniger clade specific as previously reported. However, isolates showing broad-spectrum antifungal and antiyeast activity were all members of the clade. We conclude that screening of isolates for broad-spectrum antifungal/antiyeast activity is the preferred method of isolating S. violaceusniger clade strains rather than biocide-based selection. Phylogenetic analysis of the phenol-resistant isolates revealed that the HV isolates that exhibited broad-spectrum antifungal antibiotic activity were all clustered and closely related to the S. violaceusniger clade, while the isolates that did not exhibit antifungal antibiotic activity were all non-clade members.

Vibrio vulnificus produces quorum sensing signals of the AHL-class

Vibrio vulnificus is an aquatic pathogenic bacterium that can cause vibriosis in humans and fish. The species is subdivided into three biotypes with the fish-virulent strains belonging to biotype 2. The quorum sensing (QS) phenomenon mediated by furanosyl borate diester or autoinducer 2 (AI-2) has been described in human strains of biotype 1, and here we show that the luxS gene which encodes AI-2 is present in all strains of V. vulnificus regardless of origin, biotype or serovar. In this study, we also demonstrate that V. vulnificus produces QS signals of the acylated homoserine lactone (AHL) class (AI-1). AHLs were detected in strains of biotype 1 and 2 from water, fish and human wound infections but not in strains isolated from human septicaemic cases. The AHL compound was identified as N-butanoyl-homoserine-lactone (C(4)-HL) by both reporter strains and by HPLC-high-resolution MS. C(4)-HL was detected when AHL-positive strains were grown in low-nutrient medium [modified sea water yeast extract (MSWYE)] but not in rich media (tryptic soy broth or brain-heart infusion) and its production was enhanced when blood factors were added to MSWYE. C(4)-HL was detected in vivo, in eels infected with AHL-positive biotype 2 strains. No known AHL-related gene was detected by PCR or Southern blot suggesting that AHL-related genes in V. vulnificus are different from those found in other Gram-negative bacteria.

A Field Trail To Estimate The Effect Of Lactobacillus And Yeast As Antimycotoxin In Broiler\'s Ration

An evaluation of the efficacy of different treatment trails using two probiotics (active dry yeast and lactobacilli) in controlling aflatoxicosis in broiler chicks was done. Seven days old chicks were randomly divided into four groups each 50 birds Group(1) was given basal diet only and kept as control negative, group II was given basal diet contaminated with 5 mg/kg ration (AFB1) and kept as control positive, group III was given basal diet contaminated with AFB1 5 mg/kg ration and given 0.5 gm/liter water yeast extract, group IV was given basal diet contaminated with AFB1 5 mg/kg ration and given 0.5 gm/liter Lactobacilli. At the one and 2 month of the experiment period biochemical analysis (Liver, Kidney function and some mineral) were applied. The result revealed the use of probiotics were effective in reducing the mortality rates, severity of intoxication, enhance liver and kidney function to nearly approach normal values improve the biochemical parameters of all groups as Liver, Kidney function and protein probiotics were proved to have synergistic effect in controlling Aflatoxicosis in broiler chicks.New Egyptian Journal of Microbiology Vol. 17 (2) 2007: pp. 121-128

Effect of low temperature on starvation-survival of the eel pathogen Vibrio vulnificus biotype 2

At present, no reports exist on the isolation of the eel pathogen Vibrio vulnificus biotype 2 from water samples. Nevertheless, it has recently been demonstrated that this biotype can use water as a route of infection. In the present study, the survival of this pathogen in artificial seawater (ASW) microcosms at different temperatures (25 and 5 degrees C) was investigated during a 50-day period, with biotype 1 as a control, V. vulnificus biotype 2 was able to survive in the culturable state in ASW at 25 degrees C in the free-living form, at least for 50 days, entering into the nonculturable state when exposed to low temperature. In this state, this microorganism survived with reduced rates of activity, showing marked changes in size and morphology. The rate at which cells became nonculturable was dependent on their physiological age. The capsule seems not to be necessary for the survival of biotype 2 in aquatic environments as a free-living organism. Culturability remained the highest on modified salt water yeast extract agar, which is closer in salt and nutrient composition to ASW than heart infusion agar. Biotype 2 cells recovered culturability on solid media after an increase of incubation temperature from 5 to 25 degrees C. Culturable cells of this bacterium maintained infectivity for either eel or mice, while dormant cells seemed to lose their virulence. The former finding suggests that the aquatic environment is a reservoir and vehicle of transmission of this pathogen.

Fine Structure of Bacteria Grown in the Presence of Acriflavine

The effect of acridine derivatives on bacterial growth has been shown to be dependent upon the concentration used, pH, temperature, and the position of the amino substituents on the acridine molecule. These factors, in turn, affect the amount of acridine bound to cell constituents. Many bacterial species, when grown in media containing acridities, become filamentous, or pleomorphic, or growth may be entirely prevented. The fine-structure of two species of bacteria treated with acriflavine was investigated. Both were Gram-positive bacilli, one was a Corynebacterium, and the other an aerobic spore-bearing Bacillus.Organisms were incubated at 21°c in the presence of concentrations of acriflavine ranging from 0.25 ug/ml to 12 ug/ml in phosphate buffered peptone water yeast extract medium at pH 7.5. Viable counts were carried out and the amount of acriflavine bound, either reversibly or irreversibly, was estimated at 450 mu, using a DB spectrophotometer. Cultures were observed by light microscopy and, after four days growth, were processed for electron microscopy by fixation in veronal-acetate pH 6.1 buffered 0.8% Os O4 for one hour and embedding in Epon 812 resin.