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Microalgae feedstock production can be integrated with wastewater and industrial sources of carbon dioxide. This study reviews the literature on algae grown on wastewater and includes a preliminary analysis of algal production based on anaerobic digestion sludge centrate from the Howard F. Curren Advanced Wastewater Treatment Plant (HFC AWTP) in Tampa, Florida and secondary effluent from the City of Lakeland wastewater treatment facilities in Lakeland, Florida. It was demonstrated that a mixed culture of wild algae species could successfully be grown on wastewater nutrients and potentially scaled to commercial production. Algae have demonstrated the ability to naturally colonize low-nutrient effluent water in a wetland treatment system utilized by the City of Lakeland. The results from these experiments show that the algae grown in high strength wastewater from the HFC AWTP are light-limited when cultivated indoor since more than 50% of the outdoor illumination is attenuated in the greenhouse. An analysis was performed to determine the mass of algae that can be supported by the wastewater nutrients (mainly nitrogen and phosphorous) available from the two Florida cities. The study was guided by the growth and productivity data obtained for algal growth in the photobioreactors in operation at the University of South Florida. In the analysis, nutrients and light are assumed to be limited, while CO2 is abundantly available. There is some limitation on land, especially since the HFC AWTP is located at the Port of Tampa. The temperature range in Tampa is assumed to be suitable for algal growth year round. Assuming that the numerous technical challenges to achieving commercial-scale algal production can be met, the results presented suggest that an excess of 71 metric tons per hectare per year of algal biomass can be produced. Two energy production options were considered; liquid biofuels from feedstock with high lipid content, and biogas generation from anaerobic digestion of algae biomass. The total potential oil volume was determined to be approximately 337,500 gallons per year, which may result in the annual production of 270,000 gallons of biodiesel when 80% conversion efficiency is assumed. This production level would be able to sustain approximately 450 cars per year on average. Potential biogas production was estimated to be above 415,000 kg/yr, the equivalent of powering close to 500 homes for a year.  相似文献   
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Short-season fallow with legumes and/or grasses can restore the soil organic C and nitrogen (N) and improve soil structure. In this study, we accessed the effects of 2-season legume and grass fallow on structural properties and C/N relationships in aggregates of a sandy loam soil. Two legumes (Calopogonium mucunoides and Centrosema pubescens), and two grasses (Guinea grass (Panicum maximum) and goose grass (Eleusine indica) were used. Results showed that Calopogonium and Centrosema increased soil total porosity and reduced soil bulk densities, while goose grass increased bulk density and reduced total porosity of the soils at 0–15 and 15–30?cm depths. Guinea grass significantly increased the saturated hydraulic conductivity (50.4?cm?h?1) and water holding capacity of the soils. Aggregates, 4.75 to 0.5?mm were greater in Guinea grass and least in goose grass fallowed soils. Calopogonium increased macro-aggregates at 0–15?cm soils by 48%, and mean weight diameter (MWD) by 44%. Organic carbon in 0.5–0.25?mm and <0.25?mm aggregate sizes was higher in Guinea grass soils. Generally, grasses had 4-fold increases of C:N contents in dry aggregates. In conclusion, short-season fallow with Guinea grass, Calopogonium and Centrosema, increased soil C and N and protected them from losses in stable aggregates.  相似文献   
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Ethanolic extracts derived from three species of the Piperaceae (pepper) family, Piper longum L., P. ribesoides Wall., and P. sarmentosum Roxb. ex Hunt., were evaluated for efficacy against early 4th instar larvae of Aedes aegypti mosquitoes using larvicidal bioassays. The highest larvicidal efficacy was established from P. longum, followed by P. sarmentosum and P. ribesoides, with LC50 values of 2.23, 4.06, and 8.13 ppm, respectively. Observations of morphological alterations on treated 4th instar larvae revealed that most organs, except anal papillae, had a normal structural appearance that was similar to controls. Under light microscopy, the internal structures of anal papillae in the treated larvae showed shrinkage, while the external features were normal in appearance. Ultrastructural studies, however, clearly demonstrated external destruction, with extensive damage and shrunken cuticle of the anal papillae. The structural deformation of anal papillae probably led to their dysfunction, which may be intrinsically associated with the death of the larvae. This study affords some evidence regarding the action site of the pepper extracts and suggests their potential in developing new types of larvicides used for mosquito control.  相似文献   
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Forty-seven strains representing 14 different Bacillus species isolated from clinical and food samples were grown in reconstituted infant milk formulae (IMF) and subsequently assessed for adherence to, invasion of, and cytotoxicity toward HEp-2 and Caco-2 cells. Cell-free supernatant fluids from 38 strains (81%) were shown to be cytotoxic, 43 strains (91%) adhered to the test cell lines, and 23 strains (49%) demonstrated various levels of invasion. Of the 21 Bacillus cereus strains examined, 5 (24%) were invasive. A larger percentage of clinically derived Bacillus species (20%) than of similar species tested from the food environment were invasive. Increased invasion occurred after growth of selected Bacillus species in reconstituted IMF containing glucose. While PCR primer studies revealed that many different Bacillus species contained DNA sequences encoding the hemolysin BL (HBL) enterotoxin complex and B. cereus enterotoxin T, not all of these isolates expressed these diarrheagenic genes after growth in reconstituted IMF. Of the 47 Bacillus isolates examined, 3 isolates of B. cereus and 1 isolate of B. subtilis produced the HBL enterotoxin after 18 h of growth in brain heart infusion broth. However, eight isolates belonging to the species B. cereus, B. licheniformis, B. circulans, and B. megaterium were found to produce this enterotoxin after growth in reconstituted IMF when assessed with the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (RPLA) kit. It is concluded that several Bacillus species occurring occasionally in clinical specimens and food samples are of potential medical significance due to the expression of putative virulence factors.  相似文献   
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Atherosclerosis-related vascular complications in beta-thalassemia/hemoglobin E (beta-thal/Hb E) patients may result from iron induced oxidation of lipoproteins. To identify the specific site of oxidative damage, changes in lipid fluidity at different regions in LDL and HDL particle were investigated using two fluorescence probes and two ESR spin probes. The magnitude of increased lipid fluidity in thalassemic lipoproteins was dependent on the location of the probes. In hydrophobic region, the rotational correlation times for 16-doxyl stearic acid and DPH anisotropy were markedly changed in LDL and HDL of the patients. In the surface region, there was only a slight change in the order parameter (S) for 5-doxyl stearic acid and TMA-DPH anisotropy. Lipid fluidity at the core of LDL and HDL showed good correlation with oxidative stress markers, the ratio of CL/CO, and the level of alpha-tocopherol, suggesting that hydrophobic region of thalassemic lipoprotein was a target site for oxidative damage.  相似文献   
8.
Background. Dyspepsia is a very common problem in Thailand. Etiology of gastritis, incidence of Helicobacter pylori and mode of transmission of Helicobacter pylori infection in the country was proposed. Methods. A nation‐wide study of gastric biopsy in 3776 dyspeptic patients from six different geographic regions for incidence of gastritis, type of gastritis, incidence of H. pylori infection, gastric atrophic change and intestinal metaplasia in three age‐groups of each region was done. Results. 58.7% of dyspeptic patients had histological gastritis. Pangastritis was the most common type (77.3%) with mostly mild active inflammation (60.6%) and was found most commonly in the age group 31–60 years. Incidence of gastritis was slightly lower in the coastal and peninsular community compared with the mountain, jungle, semiarid plateau and fertile plain communities. Geographic factor, socioeconomic status and dietary habit were proposed to be important factors in inducing gastritis. H. pylori infection was found in 48.2% of dyspeptic patients with high incidence in the age‐group 31–60 years (63.7%) and 98.2% of H. pylori infection was found to be associated with gastritis. Semi‐arid plateau, mountain, jungle and fertile plain communities had high incidences of H. pylori infection varying from 54.0 to 67.1% while the coastal and peninsular communities had low incidences of 32%. Oral to oral spread is proposed to be the mode of bacterial transmission. Incidences of gastric atrophic change and intestinal metaplasia were low in this country and were found in 11.6% and 8.2% of subjects, respectively, with no significantly different distribution in geographic regions. Type I or intestinal type was found to be the most common type of intestinal metaplasia.  相似文献   
9.
Forty-seven strains representing 14 different Bacillus species isolated from clinical and food samples were grown in reconstituted infant milk formulae (IMF) and subsequently assessed for adherence to, invasion of, and cytotoxicity toward HEp-2 and Caco-2 cells. Cell-free supernatant fluids from 38 strains (81%) were shown to be cytotoxic, 43 strains (91%) adhered to the test cell lines, and 23 strains (49%) demonstrated various levels of invasion. Of the 21 Bacillus cereus strains examined, 5 (24%) were invasive. A larger percentage of clinically derived Bacillus species (20%) than of similar species tested from the food environment were invasive. Increased invasion occurred after growth of selected Bacillus species in reconstituted IMF containing glucose. While PCR primer studies revealed that many different Bacillus species contained DNA sequences encoding the hemolysin BL (HBL) enterotoxin complex and B. cereus enterotoxin T, not all of these isolates expressed these diarrheagenic genes after growth in reconstituted IMF. Of the 47 Bacillus isolates examined, 3 isolates of B. cereus and 1 isolate of B. subtilis produced the HBL enterotoxin after 18 h of growth in brain heart infusion broth. However, eight isolates belonging to the species B. cereus, B. licheniformis, B. circulans, and B. megaterium were found to produce this enterotoxin after growth in reconstituted IMF when assessed with the B. cereus enterotoxin (diarrheal type) reversed passive latex agglutination (RPLA) kit. It is concluded that several Bacillus species occurring occasionally in clinical specimens and food samples are of potential medical significance due to the expression of putative virulence factors.  相似文献   
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