Bacteria In Media Research Articles

Densification and Mechanical and Antibacterial Properties of Low-Cost Powder Metallurgy TiCu Intermetallic Alloy as a Potential Biomedical Material

Ti-Cu intermetallic alloys are considered as a potential substitute for conventional dental cast alloys due to their enhanced mechanical, antibacterial, and biocompatibility behaviors. In this paper, the effects of sintering temperature on the densification, hardness, and antibacterial activity of a Ti-Cu alloy obtained by a solid-state reaction have been studied. The TiCu and Ti2Cu3 phases were identified as the major phases in the microstructure of the synthesized material. The high hardness of ≈ 1000 HV and high antibacterial activity against S. aureus and E. coli were obtained for the Ti-Cu intermetallic alloy. The high hardness of the Ti-Cu alloy was attributed to its nanocrystalline grains, multi-phase structure and the large amounts of hard TiCu and Ti2Cu3 phases in the microstructure, and its antibacterial behavior was due to the release of Cu2+ ions around the sample in culture media of bacteria.

Study of the Antibacterial Activity of Elettaria Cardamomum Extracts on the Growth of Some Gingivitis Inducing Bacteria in Culture Media

The our work was carried out with an objective to appraisal the antibacterial action of cardamom extracted by four different solvents and prepared in a number of concentrations (50, 100 and 200 mg/mL) toward three different pathogenic bacteria responsible mainly for induce gingivitis infection and comparison their action with the action of antibiotics (Ciprofloxacin (5μg), Ampicillin (30μg) in culture media. The results of phytochemical profiles for different extracts of cardamom showed the presence of alkaloids, glycosides, tannins, and terpenes in all used extracts while flavonoids were present in all extracts except watery extract. Saponins were present only in the ethanolic extract, while phenols were found to be present only in ethanolic and chloroformic extracts. The antibacterial screening of the different extracts of cardamom and standard antibiotics showed various degrees of zones of inhibition in the culture media depending largely upon the type of plant extract, the concentration of extract in addition to the type of tested bacterial. Almost all the cardamom extracts were found to have significant activity (p less than 0.05) against all tested bacteria com the pared with a negative control. The highest antibacterial potential was observed for the ethanolic cardamom extract, whereas other cardamom extracts showed closed results in general. At the same time, the current study was recorded that inhibition zones diameter against tested bacteria raised significantly (p less than 0.05) as the extract concentration raised. The MIC values of watery, ethanolic, chloroformic, and acetonic extracts of cardamom ranged from 0.624 to 1.248 mg/mL, 0.078 to 0.312mg/mL, 0.624 to 1.248 and 0.312 to 0.624 mg/mL against tested bacteria respectively. While the MBC values ranged from 1.248 to 10 mg/mL, 0.624 to 2.5 mg/mL, 2.5mg/mL to 5 mg/mL and 2.5mg/mL respectively.

Role of Trapped Air in the Attachment of Staphylococcus aureus on Superhydrophobic Silicone Elastomer Surfaces Textured by a Femtosecond Laser.

Surface texturing is an easy way to control wettability as well as bacterial adhesion. Air trapped in the surface texture of an immersed sample was often proposed as the origin of the low adhesion of bacteria to surfaces showing superhydrophobic properties. In this work, we identified two sets of femtosecond laser processing parameters that led to extreme superhydrophobic textures on a silicone elastomer but showed opposite behavior against Staphylococcus aureus (S. aureus, ATCC 25923) over a short incubation times (6 h). The main difference from most of the previous studies was that the air trapping was not evaluated from the extrapolation of the results of the classical sessile drop technique but from the drop rebound and Wilhelmy plate method. Additionally, all wetting tests were performed with bacteria culture medium and at 37 °C in the case of the Wilhelmy plate method. Following this approach, we were able to study the formation of the liquid/silicone interface and the associated air trapping for immersed samples that is, by far, most representative of the cell culture conditions than those associated with the sessile drop technique. Finally, the conversion of these superhydrophobic coatings into superhydrophilic ones revealed that air trapping is not a necessary condition to avoid Staphylococcus aureus retention on one of these two textured surfaces at short incubation times.

High-Throughput Optimization of Effective Microbes Nutrient Formulation via Automated Media Optimization System (AMOS)

Fortification of effective microbes (EM) such as Pediococcus acidilactici and photosynthetic bacteria in fertilizer and animal feed exhibiting effective outcomes in enhancing crops and livestock production as well as upholds sustainable agriculture concept. However, the productivity of the EM biomass stocks is unsurpassed to the demand due to non-optimized media. In this study, two sets of nutrient pair comprising of beef extract-manganese and yeast extract-glucose for P. acidilactici and photosynthetic bacteria respectively were studied. The optimum media formulated was based on the highest growth rate in 96-microwell plate system were subsequently tested in 1 L cultures volume for EM biomass production. Results showed that growth rate and dry weight of P. acidilactici in media supplemented with 64 g/L beef extract (0.145 h-1, 0.243 g) and 0.28 g/L manganese (0.1134 h-1, 0.32 g) were higher compared to control medium with an increment of 17.39 % and 54.59 % biomass productivity as compared to MRS medium respectively. Meanwhile, the growth rate and dry weight for Photosynthetic bacteria in media supplemented with 6.63 g/L glucose (0.2538 h-1, 0.167 g) and 0.44 g/L yeast extract (0.2733 h-1, 0.163 g) recorded 11.3 % and 8.73 % biomass productivity increment in comparison to the HCH medium.

The effect of probiotic bacteria in culture media using organic fertilizer for population density, biomass production and nutrient quality of Phronima sp . as natural feed

Phronima sp. is a natural feed with high nutrient content, and it can be an alternative substitute for Artemia. The existence of probiotic bacteria in culture media aims to improve water quality through biodegradation, maintain microbial balance and control pathogenic bacteria, so that nutrients in culture media can be utilized by Phronima sp. This study aimed to determine the effect of fermented organic fertilizer by probiotic bacteria in mass culture media on the population density, biomass production and nutrient content of Phronima sp. and to find the best culture media composition for mass culture of Phronima sp. The study was conducted with a completely randomized design with five treatments and three replications. The treatments were as follows: A: 0% chicken manure, 50% rice bran, 50% tofu waste; B: 25% chicken manure, 37.5% rice bran, 37.5% tofu waste; C: 50% chicken manure, 25% rice bran, 25% tofu waste; D: 75% chicken manure, 12.5% rice bran, 12.5% tofu waste and E: 100% chicken manure. The test animals were Phronima sp., and during cultivation, fertilization was carried out every 3 days. Population density and biomass were observed, and proximate analysis, amino acid profile analysis and fatty acid profile analysis were performed. The highest population density was at treatment B, with a peak population of 98 individuals/L that occurred on the 16th day of maintenance culture, and the highest biomass of 0.51 g was at the same treatment. The highest nutrient content was obtained at treatment B, for which the highest protein proximate analysis value was 58.90%, the proportion of the fatty acids comprised of eicosapentaenoic acid was 7.53%, and lysine amino acids were found at 44.16 ppm.

Isolation, Characterization, and Inactivation of Stenotrophomonas maltophilia From Leafy Green Vegetables and Urban Agriculture Systems

Stenotrophomonas maltophilia is an emerging opportunistic pathogen that, on the one hand, causes severe nosocomial infection in immunocompromised populations with a high mortality rate and, on the other hand, is present ubiquitously in the environment. This study, for the first time to the best of our knowledge, isolated and characterized S. maltophilia from leafy green vegetables produced by hydroponic farms and from a hydroponic farming facility in Singapore. Eleven S. maltophilia isolates were obtained from three types of leafy green vegetables (sweet basil, kale, and parsley) and from the nutrient solution used by a hydroponic farm. The antimicrobial resistance (AMR), biofilm-forming ability, and resistance to UV and quaternary ammonium compound (QAC) treatments were investigated, as was the fate of S. maltophilia in a simulated leafy green vegetable environment during a storage period of 6 days at different temperatures. The results showed that high population levels of S. maltophilia could be reached on leafy green vegetables, especially after being stored at abused temperatures (>8-log CFU/ml in basil juice after 6 days storage at 20°C) and on hydroponic farming facilities, probably due to biofilm formation (8 to 9-log CFU/well in biofilms). At 4°C, S. maltophilia was able to survive, but no growth was observed during storage in either bacteria culture media or basil juice for a period of 6 days. UV treatment, which induced substantial reductions in S. maltophilia in both single-species and dual-species biofilms mixed with Salmonella enterica serovar Typhimurium reference strain (ATCC 14028) or self-isolated Pseudomonas fluorescens (>4-log reductions by 250 mJ/cm2 UV), is recommended for employment by hydroponic farms to treat their nutrient solutions and farming facilities so as to enhance microbial safety.

Cadmium and Selenate Exposure Affects the Honey Bee Microbiome and Metabolome, and Bee-Associated Bacteria Show Potential for Bioaccumulation.

Honey bees are important insect pollinators used heavily in agriculture and can be found in diverse environments. Bees may encounter toxicants such as cadmium and selenate by foraging on plants growing in contaminated areas, which can result in negative health effects. Honey bees are known to have a simple and consistent microbiome that conveys many benefits to the host, and toxicant exposure may impact this symbiotic microbial community. We used 16S rRNA gene sequencing to assay the effects that sublethal cadmium and selenate treatments had over 7 days and found that both treatments significantly but subtly altered the composition of the bee microbiome. Next, we exposed bees to cadmium and selenate and then used untargeted liquid chromatography-mass spectrometry (LC-MS) metabolomics to show that chemical exposure changed the bees' metabolite profiles and that compounds which may be involved in detoxification, proteolysis, and lipolysis were more abundant in treatments. Finally, we exposed several strains of bee-associated bacteria in liquid culture and found that each strain removed cadmium from its medium but that only Lactobacillus Firm-5 microbes assimilated selenate, indicating the possibility that these microbes may reduce the metal and metalloid burden on their host. Overall, our report shows that metal and metalloid exposure can affect the honey bee microbiome and metabolome and that strains of bee-associated bacteria can bioaccumulate these toxicants.IMPORTANCE Bees are important insect pollinators that may encounter environmental pollution when foraging upon plants grown in contaminated areas. Despite the pervasiveness of pollution, little is known about the effects of these toxicants on honey bee metabolism and their symbiotic microbiomes. Here, we investigated the impact of selenate and cadmium exposure on the gut microbiome and metabolome of honey bees. We found that exposure to these chemicals subtly altered the overall composition of the bees' microbiome and metabolome and that exposure to toxicants may negatively impact both host and microbe. As the microbiome of animals can reduce mortality upon metal or metalloid challenge, we grew bee-associated bacteria in media spiked with selenate or cadmium. We show that some bacteria can remove these toxicants from their media in vitro and suggest that bacteria may reduce metal burden in their hosts.

Removal of Diesel Oil in Soil Microcosms and Implication for Geophysical Monitoring

Bioremediation of soils polluted with diesel oil is one of the methods already applied on a large scale. However, several questions remain open surrounding the operative conditions and biological strategies to be adopted to optimize the removal efficiency. This study aimed to investigate the environmental factors that influence geophysical properties in soil polluted with diesel oils, in particular, during the biodegradation of this contaminant by an indigenous microbial population. With this aim, aerobic degradation was performed in soil column microcosms with a high concentration of diesel oil (75 g kg−1 of soil); the dielectric permittivity and electrical conductivity were measured. In one of the microcosms, the addition of glucose was also tested. Biostimulation was performed with a Mineral Salt Medium for Bacteria. The sensitivity of the dielectric permittivity versus temperature was analyzed. A theoretical approach was adopted to estimate the changes in the bulk dielectric permittivity of a mixture of sandy soil-water-oil-gas, according to the variations in the oil content. The sensitivity of the dielectric permittivity to the temperature effects was analyzed. The results show that (1) biostimulation can give good removal efficiency; (2) the addition of glucose as a primary carbon source does not improve the diesel oil removal; (3) a limited amount of diesel oil was removed by adsorption and volatilization effects; and (4) the diesel oil efficiency removal was in the order of 70% after 200 days, with different removal percentages for oil components; the best results were obtained for molecules with a low retention time. This study is preparatory to the adoption of geophysical methods to monitor the biological process on a larger scale. Altogether, these results will be useful to apply the process on a larger scale, where geophysical methods will be adopted for monitoring.

Selective biodegradation of recalcitrant black chicken feathers by a newly isolated thermotolerant bacterium Pseudochrobactrum sp. IY-BUK1 for enhanced production of keratinase and protein-rich hydrolysates.

Black chicken feathers generated in large amount from poultry and slaughter houses are highly recalcitrant to microbial degradation due to their tough structural nature. A novel keratinolytic bacterium that possessed high affinity for black feather was isolated from chicken manure and identified as Pseudochrobactrum sp. IY-BUK1. Keratinase and feather soluble protein were effectively produced by the free living cells of the bacterium in media containing only black feathers and a mixture of equal amount of black-, brown- and white-coloured feathers. Complete degradation of 5g/L of black feathers was completed in 3days following optimisation of physico-chemical conditions. However, the bacterium selectively completed the degradation of black feather in a medium containing mixture of feathers in 144h leaving behind approximately 33% and 45% of brown and white feathers in the medium respectively. Gellan gum-immobilised cells of strain IY-BUK1 enhanced the keratinase production by about 150% and were used repeatedly for ten cycles to degrade 5g/L of black feather in a semi continuous fermentation of 18h per cycle with enhanced and stable production of soluble protein. The study demonstrated the potential use of Pseudochrobactrum sp. IY-BUK1 not only in biodegradation of highly recalcitrant black feathers, but also in producing keratinase enzymes and valuable soluble proteins for possible industrial usage.

Effects of ferrous ion concentration on microbiologically influenced corrosion of carbon steel by sulfate reducing bacterium Desulfovibrio vulgaris

Ferrous ion (Fe2+) in a sulfate reducing bacteria (SRB) culture medium is known to enhance microbiologically influenced corrosion (MIC) of carbon steel, but the underlining mechanism is controversial. This work showed that it was due to better sessile cell growth that was likely attributed to Fe2+ detoxification of H2S. Two hundred ppm (w/w) initial Fe2+ in the ATCC 1249 medium achieved a 4.7 times higher Desulfovibrio vulgaris sessile cell count and 5.0 times higher C1018 carbon steel weight loss, compared to 20 ppm. Linear polarization resistance, electrochemical impedance spectroscopy and potentiodynamic polarization measurements corroborated weight loss and pitting data trends.

A selective culture medium for screening linezolid-resistant gram-positive bacteria

The SuperLinezolid medium was developed for screening resistance to linezolid (LZD) in Gram-positive bacteria (Staphylococcus spp., Enterococcus spp.). It was evaluated using LZD-susceptible (n = 20) and LZD-resistant (n = 17) Gram-positive isolates. The sensitivity was found to be 82% at 24 h (3 out of 17 isolates being missed), and reached 100% at 48 h. At 48 h, a single LZD-susceptible isolate grew (specificity 95%). By testing stools spiked with LZD-resistant Gram-positive strains, an excellent performance of the medium was observed, with a lowest detection limit ranging from 101 to 102 CFU/ml. Overall, this medium is accurate for detection of LZD-resistant Gram-positive isolates after 24 h of culture.

Incidence, root causes, and outcomes of surgical site infections in a tertiary care hospital in Rwanda: a prospective observational cohort study

BackgroundSurgical Site Infections (SSI) are the most reported health acquired infection and common surgical complication in both developed and developing countries. In developing countries such as Rwanda, there is a paucity of published reports on the pattern of SSI, therefore this study aimed at assessing the incidence, risk factors and the antibiotic profile of pathogens responsible of SSI.MethodsThis prospective study included 294 patients admitted between October 10, 2017 and February 12, 2018 to the surgical department of the University Teaching Hospital of Kigali. Patients data were collected using a structured and pretested questionnaire in English version. Regular follow-up was maintained until at least 30 days postoperatively. Samples were collected from suspected wounds and identified using different bacteria culture media. Data were analyzed using Statistical Package for the Social Sciences (SPSS) software word version 20.0. P-value < 0.05 was considered statistically significant.ResultsThe overall incidence of SSI was 10.9%. The associated risk factors were found to be an increased age, ASA class, wound classification, skills and experience of the surgeon, longer duration of surgery (> 2 h), prolonged duration of hospital stay, blood transfusion and emergency surgery. The most common pathogens isolated were Klebsiella ssp (55%), followed by Escherichia coli (15%) and Proteus ssp (12%), Acinectobacter (9%), Staphylococcus aureus (6%) and coagulase-negative staphylococci (3%).The pathogens revealed different levels of antibiotic resistance; amoxy-clavilinic acid (98.8%), gentamicin (92.6%), ciprofloxacin (78.1%) and ceftriaxone (53.3%). On the other hand, Amikacin and imipinem were the only two most effective antibiotics for all isolated pathogens with 100% sensitivity.ConclusionSSI incidence rate was revealed to be within acceptable international ranges. However, multi drug resistance was seen in half of the isolates leaving clinicians with few choices of drugs for the treatment of patients with SSI. Periodic surveillance of bacteria and antibiotic susceptibility coupled with the implementation of strict protocol for antibiotic administration and operative room regulations are important to minimize the burden of SSI with resistant bacteria pathogens.

Bacterial Growth in Saturated and Eutectic Solutions of Magnesium Sulphate and Potassium Chlorate with Relevance to Mars and the Ocean Worlds.

Liquid water on Mars might be created by deliquescence of hygroscopic salts or by permafrost melts, both potentially forming saturated brines. Freezing point depression allows these heavy brines to remain liquid in the near-surface environment for extended periods, perhaps as eutectic solutions, at the lowest temperatures and highest salt concentrations where ices and precipitates do not form. Perchlorate and chlorate salts and iron sulfate form brines with low eutectic temperatures and may persist under Mars near-surface conditions, but are chemically harsh at high concentrations and were expected to be incompatible with life, while brines of common sulfate salts on Mars may be more suitable for microbial growth. Microbial growth in saturated brines also may be relevant beyond Mars, to the oceans of Ceres, Enceladus, Europa and Pluto. We have previously shown strong growth of salinotolerant bacteria in media containing 2 M MgSO4 heptahydrate (~50% w/v) at 25 °C. Here we extend those observations to bacterial isolates from Basque Lake, BC and Hot Lake, WA, that grow well in saturated MgSO4 medium (67%) at 25 °C and in 50% MgSO4 medium at 4 °C (56% would be saturated). Psychrotolerant, salinotolerant microbes isolated from Basque Lake soils included Halomonas and Marinococcus, which were identified by 16S rRNA gene sequencing and characterized phenetically. Eutectic liquid medium constituted by 43% MgSO4 at -4 °C supported copious growth of these psychrotolerant Halomonas isolates, among others. Bacterial isolates also grew well at the eutectic for K chlorate (3% at -3 °C). Survival and growth in eutectic solutions increases the possibility that microbes contaminating spacecraft pose a contamination risk to Mars. The cold brines of sulfate and (per)chlorate salts that may form at times on Mars through deliquescence or permafrost melt have now been demonstrated to be suitable microbial habitats, should appropriate nutrients be available and dormant cells become vegetative.

Effects of sub-minimal inhibitory concentrations of antibiotics on the morphology and surface hydrophobicity of periodontopathic anaerobes

It has been reported that sub-minimal inhibitory concentrations (sub-MICs) of antibiotics are capable of altering bacterial surface properties and phenotype. In this study, the effects of sub-MICs of certain antibiotics on surface hydrophobicity, cell morphology, and protein profile were ascertained using Fusobacterium nucleatum, Porphyromonas gingivalis and Treponema denticola strains, which are pathogenic bacterial species in periodontal diseases. The MICs of antibiotics were determined by culturing bacteria in media supplemented with serially diluted antibiotic solutions, and sub-MIC of antibiotics was used. The effect of sub-MIC of antibiotics on cell morphology was determined by scanning electron microscopy. Microscopic observation of F. nucleatum and P. gingivalis grown at a sub-MIC of amoxicillin revealed cell enlargement. T. denticola grown at a sub-MIC of doxycycline also showed cell elongation. The relative surface hydrophobicity determined by measuring the ability of the bacteria to absorb n-hexadecane revealed an increase in surface hydrophobicity of F. nucleatum grown at sub-MIC of penicillin and amoxicillin, but a decrease with metronidazole; whereas increased hydrophobicity was observed in T. denticola grown at sub-MIC of doxycycline, metronidazole and tetracycline. The surface hydrophobicity of P. gingivalis increased only when grown in sub-MIC of metronidazole. The protein expression profile of the treated bacteria differed from their respective controls. These results confirmed that sub-MIC concentrations of antibiotics can affect the phenotype, surface properties and morphology of periodontal pathogenic anaerobic bacteria.

Isolation and Characterization of Lactic Acid Bacteria (Lactobacillus sp) from Tomato (Solanum lycopersicum)

Prebiotics are good coumpounds used in the growth of lactic acid bacteria (LAB) in digestion, prebiotics come from vegetables, fruits and seeds. Tomatoes are thought to be one of the natural media of bacteria because tomatoes contain various chemical compositions that are needed as a substrate for LAB. The purpose of this study is to isolate and determine the type of LAB produced microscopically. The ingredients used are tomatoes obtained from Padang Panjang market, with Merck NA media, oxoid MRSa, 0,9% NaCl, and crystal violet paint. Isolation LAB from tomatoes done in two ways, the first with plant tomato tissue directly into the NA medium and the second with fermentation tomato and then plant the tomato into the MRSa medium with streak plate methods. The isolates obtained were identified microscopically using a microscope with gram staining method. From the research that has been done, the following result are obtained : (1) Plant tomatoes tissue direcly into NA medium and gram staining, there were 1 colonies of gram positive bacteria with bacil cell form. (2). Fermentation tomatoes from the results, there were 2 colonies gram positive bacteria with bacil cell form. We can identify this colonies as Lactobacillius bulgaricus.

Clinical Outcomes of Kidney Transplant Recipients with Positive Perfusion Fluid Cultures

Introduction Transplant perfusion fluid (TPF) optimises the storage of organs for transplantation; however it can be a culture medium for pathogenic bacteria. Clinical practice in UK involves routine culture of TPF however results take several days. We did a retrospective study to assess the value of TPF in deceased donor renal transplant recipients. Materials and Methods 173 patients who received renal transplants between January 2014 and October 2016 were included in the study. Electronic data records were used to collect TPF culture result, antibiotics used, length of hospital stay and presence of septic complication in recipients. Results 106 patients received DBD and 67 had DCD organs. 54.3% (n=94) had a negative TPF culture (Cl 46.88-61.72) and 45.7% (n=79) had a positive TPF culture (CI 38.28-53.12).21% (n=36) were diabetic and 4.3% (n=6) had post transplantation diabetes mellitus. Coagulase negative staphylococci represented 55% of positive samples. E.Coli was the most common pathogenic bacteria found (11.3%, n= 9). Infection developed in 45.7% (n=43) of patients receiving a kidney with negative TPF culture compared with 32.9% (n=26) with a positive TPF culture. 7.7% (n=6) of patients with a positive TPF culture developed an infection identified to be caused as the same organism as that from the TPF. Recipients with delayed graft function (DGF) had an infection rate of 54.9% (n =51). Patients without DGF had infection rate of 32.8% (n=116). This association is not statically significant (p=0.07) but may warrant further investigation. Patients with positive TPF culture who received prophylactic antibiotics had similar length of hospital stay as patients not receiving antibiotics. Urinary tract was the commonest site of infection (50%). Patients with diabetic nephropathy or chronic pyelonephritis had higher rates of infection.Conclusion Positive TPF culture was not associated with higher rates of infection or DGF. The likelihood of infection was higher in diabetic patients. Length of hospital stay was not reduced by use of prophylactic antibiotic, even in patients with positive TPF culture. We suggest that a decision to give antibiotic should be based on patient's clinical status and virulence of pathogens found. Further studies are needed to establish role of prophylactic antibiotics in preventing septic complication in recipients with positive TPF culture results.

A culture medium for screening 16S rRNA methylase-producing pan-aminoglycoside resistant Gram-negative bacteria

The amikacin plus gentamicin-containing SuperAminoglycoside medium was developed for screening multiple-aminoglycoside resistance in Gram-negative bacteria (Enterobacteriaceae, Pseudomonas aeruginosa, and Acinetobacter baumannii). It was evaluated using aminoglycoside-susceptible (n=12) and aminoglycoside-resistant (n=59) Gram-negative isolates, including 16S rRNA methylase producers (n=20). Its sensitivity and specificity of detection were, respectively, of 95% and 96% for detecting multiple aminoglycoside-resistant methylase producers.

Electrode Distances Of Microbial Fuel Cell System On Salted Boiled Fish Processing Wastewater To Electricity And Pollution Load

Microbial fuel cell (MFC) is a technology that can produce electricity with helping exoelectrogenic&lt;br /&gt;bacteria. The technology can also utilize fishery processing wastewater as a media for bacteria to live, so&lt;br /&gt;it can reduce organic pollution load in the wastewater. Purpose of this research was to identify the effect&lt;br /&gt;of electrodes distance to electricity and water quality parameters of fisheries processing wastewater using&lt;br /&gt;MFC technology.. The MFC system used was single chamber system. The distance between electrodes used&lt;br /&gt;were 2 cm, 4 cm and 6 cm and the electrodes were made of stainless wire mesh coated with chitosan and&lt;br /&gt;active carbon. The results showed that electrodes distance affected to MFC electricity within salted boiled&lt;br /&gt;fish wastewater media. The average value of electric current during 48 hours observation on the distance&lt;br /&gt;of 2 cm, 4 cm and 6 cm were 0.17±0.06 mA, 0.46±0.17 mA and 0.44±0.16 mA, respectively. Average values&lt;br /&gt;of electric voltage on the distance of 2 cm, 4 cm and 6 cm were 0.12±0.03 V, 0.34±0.07 V and 0.37±0.08 V,&lt;br /&gt;respectively. The research also showed that MFC system can decrease average value of BOD 20.5%, COD&lt;br /&gt;30.41%, and TAN 21.2 % of salted boiled fish wastewater media.&lt;br /&gt;&lt;br /&gt;

Resistencia a cadmio (Cd) de bacterias endófitas y bacterias rizosféricas aisladas a partir de Oriza sativa en Colombia

El presente estudio tuvo como objetivo evaluar in vitro la resistencia de bacterias endófitas y rizosféricas a diferentes concentraciones de Cadmio (Cd). Se evaluó in vitro la promoción de crecimiento vegetal mediante la fijación de nitrógeno, solubilización de fosfato y producción de sideróforos de bacterias endófitas aisladas de diferentes tejidos de variedades de arroz comerciales y de bacterias aisladas de la rizósfera en las plantaciones de arroz de los corregimientos de Nechí (Antioquía) y Achí (Bolívar). Se colectaron muestras de raíz, tallos y hojas de plantas de arroz y de muestras de suelo rizosférico. A cada muestra se les determinó la densidad poblacional por medio de conteo en UFC/ g de tejido y se separaron morfotipos por forma, color, tamaño y apariencia en medios de cultivos. Se observaron diferencias significativas para densidad poblacional de bacterias con respecto a tejido, con mayores valores en raíz (4x1011 g/raíz), seguida de tallo (3x1010 g/tallo), hoja (5x109 g/hoja), hoja bandera (3x109 g/hoja bandera) y menor densidad en panícula (4x108 g/panícula). Los resultados de la identificación con kit API20E confirmaron la presencia de la bacteria endófita Burkholderia cepaceae y la bacteria rizosférica Pseudomona fluorescens con capacidad de tolerar diferentes concentraciones de Cd, fijar nitrógeno, solubilizar fosfatos y producir sideróforos.

Culture Environmental Management Innovation Optimisation of Enrichment Factor Lactobacillus Acidophilus

Objectives The study of lactic acid bacteria with independent intellectual property resource library, and on this basis, screening and development for our industry, the dairy industry and the development of lactobacillus probiotic lactic acid bacteria, starter cultures and probiotics is particularly necessary. Methods Optimisation of this experimental test is to promote the growth of Lactobacillus acidophilus, a high density culture. Single factor experiments, Plackett-Burman experiment, Box-Behnken experiment and response surface analysis were used to find the levels of vitamin C, sorbitol, glutamic acid, leucine, arginine, lysine, methionine, xylose, Phe, Pro needed to promote a better factor of Lactobacillus acidophilus. Results The culture medium contains the basic nutrients for eosinophilic Lactobacillus, but it cannot reach the content of amino acid in cell growth because its protein hydrolysis ability is limited, so in order to improve the purity and activity of eosinophilic Lactobacillus, the culture medium requires added amino acids on demand. The predicted value of the Plackett-Burman experiment is 97.85%, while it can achieve 96.95%. The most important factor and the best composite bacteria culture medium included vitamin C, glutamic acid and lysine, sorbitol, leucine, arginine, methionine, phenylalanine, proline and xylose; the optimum enrichment medium ratio is glutamic acid 0.0276 g/L, lysine 0.0243 g/L, vitamin C 0.0308 g/L. Conclusions The best ratio of enrichment medium was: glutamate, lysine, vitamin C. Culture temperature was 37°C, initial fermentation pH was 6.5, 4% inoculation, harvest time was 20 hours after fermentation. Acknowledgements Supported by a project grant from Longdong University doctoral research (Grant No. XYBE1605). Central finance forestry science and technology extension demonstration project [2015] ZYTG8 Qingyang science and technology support program (NK2011-41).