Comparison of nano-hydroxyapatite productivity by Pseudomonas aeruginosa and Serratia marcescense through encapsulation method

The production of nano-hydroxyapatite by two encapsulated bacterial strains was the goal of current research. Serratia marcscens ATCC 14756 and Pseudomonas aeruginosa PTCC 1570 were used by two methods including encapsulated form in 2% [w/v] alginate sodium powder and inoculated form [10%] in nutrient broth medium containing alginate sodium blank beads. In both cases alginate beads transferred to calcium and phosphorus precursors mineral medium for 48 h and were incubated at 32-35 °C for 14 days. To obtain hydroxyapatite powder, alginate beads were dried at 60 °C and rubbed. Sol-gel as chemical method was used for comparing with microbial analysis. The nature of produced powders was evaluated in each step by XRD, FTIR and scanning electron microscopy. The results showed that the yield rate of sol-gel method was 18.3% and it was much more than encapsulated method [3.032 and 3.203 w/w dried alginate bead]. The size of the particles in microbial method were smaller [8-68 nm cylindrical particles and 12-55 and 15-37 nm spherical particles] than chemical method [350-880 nm of cylindrical and 34-67 nm of spherical particles]. Nanoparticle sizes and distribution of microbial nano-hydroxyapatite powder samples shows that it has excellent physical properties similar to natural bone and may be to produce dense and porous bioactive bone implants with desired properties

[Pyoverdin pigment as a biomarker for Pseudomonas detection in foods and hygienic products]

Pseudomonas aeruginosa is a common hospital-acquired bacterium which has ability to produce fluorescent pigment like pyorubin and nonfluorescent pigment like pyocyanine. The aim of this study was exciting of production of pyoverdin pigments as biomarker for quick detection of this bacterium in foods and hygienic products. In this research, different concentrations of cadmium sulfate were used for showing the exciting of pyoverdin pigments. Pigment type was evaluated according to the maximum absorbance and its solubility in water, acetic acid and chloroform. Also, bacterium growth pattern was determined according to pigment production in optimal conditions of agitation, temperature, cultivate media, sources of carbon and nitrogen. Relation between pigment production and number of bacteria was calculated by absorbance and cell accumulation. Bacteria tracking was investigated using pigment production as biomarker in foods [spaghetti and apple juice] and hygienic products [hand and dish washing liquids] and compared to standard method. This study showed maximum absorbance of extracted pigment at 403 nm and its solubility in water and acetic acid. Production of fluorescent pigment in bacterium was observed at concentrations 0.3-0.5 mM of cadmium sulfate. Maximum production of florescent pigments based on cell accumulation was established by agitation in 150 rpm, temperature of 35oC, 0.5 mM solution of cadmium and concentration of 330 mgml-1of 1% sucrose and potassium nitrate. Monitoring of Pseudomonas aeruginosa in contaminated foods and hygienic products based on fluorescent pigments production was reduced from 72 to 20 hours

Evaluation of the enterococcus role in treatment of infectious diseases produced by Staphylococcus aureus

The aim of this study was to evaluate the Enterococcus role in treatment of infectious diseases produced by Staphylococcus aureus by producing of Tyrothricin antibiotic. After the culture of Enterococcus faecalis [PTCC 1394] in the BHI agar, centrifuging and isolation of microbial mass, antimicrobial compound of this strain was purified by dialysis and molecular weight was estimated by SDS-PAGE electrophoresis. Antimicrobial effect and minimum inhibitory concentration of antibiotic was evaluated. Molecular weight of antimicrobial compound was approximately 66 KDa. It was similar to molecular weight of tyrothricin as antimicrobial compound of Enterococcus. After dialysis, activity unit, specific activity, purification factor increased and total activity, amount of total protein decreased. The most antimicrobial effect and the lowest inhibitory concentration produced by tyrothricin were against Staphylococcus aureus. Enterococcus faecalis [PTCC1394] can produce antimicrobial compound with broad specterum, so it can play important role in treatment of angina and intestinal inflammations

[Growth inhibition of Pseudomonas aeroginosa by degree of deacetylation values of chitosan]

Chitin, which entails the most abundant biopolymer in nature after cellulose, having found numerous applications in food processing, cosmetics, agriculture, medical and environment. Natural sources of this polymer are component of exoskeletons of crustaceans and insects as well as cell walls from some bacteria and fungi. Chitosan is a partially deacetylated polymer of chitin, which is more soluble than chitin. The goal of this research is to investigate the diversity of antimicrobial effects of deacetylated chitosan extracted from a certain Persian Gulf shrimp waste [Penaeus semisculcatus], against clinical Pseudomonas aeroginosa. At first, chitin and chitosan were extracted from Penaeus semisulcatus waste by chemical and microbial methods at optimum situation. Deacetylation process of chitin was carried out in alkaline solution at 85°C for 15, 20, 45 minutes and 10 hours respectively and subsequently washed with anhydrous EtOH to remove the residual water. Degree of deacetylation of chitosan samples and its structure were measured by FTIR and Scanning electronic microscopy respectively. Antimicrobial activity was tested against clinical Pseudomonas aeroginosa by agar disc diffusion method. Finally, wound band was made by these compounds and antimicrobial activity was studied invitro. The result of present study confirmed the degree of deacetylation of chitosan samples up to 65% by FTIR method. There was no indication of shift on increasing acetylation degree by heating duration from 15 minutes to 10 hours. Pore diameter was decreased from 0.5-1 micro to 0.065-0.25 micro by the increasing of heating duration. Increased clinical Pseudomonas aeroginosa growth inhibitory up to 50% was obtained by usage of more effective materials up to 3 times on disc. The result of our study showed that there was no relationship between increased heating duration and deacetylation degree. Membrane pores were smaller and antimicrobial activity was more effective by increasing of deacetylation and Ca[+2] presences. The method which was used in this research to prepare porous chitosan membranes with different pore diameter, is suitable and cost effective. Because chitin and chitosan are not toxic, better antimicrobial activity results can be obtained by using more concentrated versions of these components

Light requirement for the carotenoids production by Mucor hiemalis

Fungi produce many different carotenoids and some are attractive in medical and industrial sources. In this work the ability of Mucor hiemalis [PTCC 5292] to produce carotenoids in media with different nitrogenous and carbon sources and incubation with white, yellow, blue and red lights [15W, 220V, E27] against dark-grown were studied. The microorganism cultivation in SDA medium, with or without aeration [120 rpm] at 25°C. Mycelia were collected and dried at 50°C. The dried mycelia were homogenized in hexane, acetone and H2SO4 [0.5 M] solvents. The carotenoids determined by TLC and HPLC methods. The results showed that M. hiemalis accumulated astaxanthin [mono-esters, di-esters and free], echinenone and canthaxanthin in the mycelia in different conditions. Blue and white lights incubation was the best for production of carotenoid pigments with 1.2 and 1.33 mg/g dried mycelia respectively, but the red light incubation not only did not have an amplifying effect on the production of carotenoid but also slightly reduced this effect. Also, the effect of intervention of lactose sugar showed more effectiveness in producing carotenoid than yeast extract and dextrose or in the presence of both of them. The information reported in this study on the comparative ability of M.hiemalis for producing carotenoids, should be useful for assessing the biotechnological production of carotenoid pigments if it incubates with white or blue lights

Cadmium, nickel and vanadium accumulation by three strains of marine bacteria

Three marine bacteria, Pseudomonas putida PTCC 1664, Bacillus cereus PTTC 1665 and Pseudomonas pseudoalkaligenes PTCC 1666 isolated from the East Anzali wetland sediments of the Caspian Sea, were resistant to heavy metals of Cadmium [Cd], Nickel [Ni] and Vanadium [V]. Pseudomonas pseudoalkaligenes PTCC 1666 was found to be resistant to all 3 metals Ni, Cd, V. Heavy metal uptake was determined in both the biomass and supernatant by the Atomic Absorption Spectrophotometer [AAS]. These bacteria showed enhanced absorption and growth in the presence of Cd and Ni at 80-100 mg/l and V at 40 mg/l concentrations. The high uptake of Cd, Ni and V was directly proportional to their respective concentrations, 5-100 mg/l for Cd and Ni and 5 - 40 mg/l for V. The maximum amount of heavy metal uptake occurred during stationary phase when cells were incubated at 30[degree]C for 72h. The results revealed that these bacteria accumulated approximately 40-50% Cd, 5-6% Ni and 10-12% V. Bacterial cells Immobilized in alginate gel showed more efficiency in biosorbing heavy metals than free cells [80%]. Scanning Electron Microscopy [SEM] results indicated that the marine bacteria were capable of accumulating several metals, showing that the isolated bacterial strains can be used as potential candidates for bioremediation, with respect to Cd, Ni and V removal from aqueous effluents