Quality assessment of compost prepared from fly ash and crop residue

Fly ash was co-composted with wheat straw and 2% rock phosphate (w/w) for 90 days and different chemical and microbiological parameters monitored to evaluate its effect on the composting process. Fly ash addition at 20% level resulted in the lowest C/N of 16.4:1 and highest available and total phosphorus. Increasing the addition of fly ash from 40 to 60% (w/w) did not exert any detrimental effect on either C:N or the microbial population.     

A two-step fermentation of distillers’ grains using Trichoderma viride and Rhodopseudomonas palustris for fish feed

It is important to provide added value or to make full use of the co-product of grains from ethanol production. In order to convert distillers’ grains into a high-quality feed, the Trichoderma viride and Rhodopseudomonas palustris fermentation were combined and investigated in this study. The T. viride fermentation was carried out in an aerobic fermentation installation in favoring of the growth of the fungi and the degradation of the cellulose, and then the fermentation of R. palustris was performed to increase the content of protein with an anaerobic installation. After the two step fermentations, the true protein content of dried distiller’ grains increased from 11.4 to 33.6 % (w/w) (the content of crude protein from 14.5 to 39.7 %), the crude fiber content decreased from 21.3 to 7.6 % (w/w), the crude fat content increased from 5.5 to 7.9 % (w/w), the crude ash decreased from 14.6 to 10.2 % (w/w), the total phosphorus content increased from 0.4 to 1.2 % (w/w), and the water content was 11.8 % (w/w). The dried and fermented grains contain the R. palustris viable count of 5.3 × 10¹¹ CFU/g dry matter. The results may support a new application of an active photosynthetic bacteria fish feed in fisheries industry and offer a reference for the further study of lignocellulosic materials as raw materials converting into high-quality feed.     

PHOTOBIOTREATMENT: INFLUENCE OF NITROGEN AND PHOSPHORUS RATIO IN WASTEWATER ON GROWTH KINETICS OF SCENEDESMUS OBLIQUUS

Nitrogen and phosphorus concentration in the effluent of a wastewater treatment plant can vary significantly, which could affect the growth kinetic and chemical composition of microalgae when cultivated in this medium. The aim of this work was to study the rate of growth, nutrient removal and carbon dioxide biofixation as well as biomass composition of Scenedesmus obliquus (S. obliquus) when it is cultivated in wastewater at different nitrogen and phosphorus ratio, from 1:1 to 35:1. A more homogeneous method for calculating productivities in batch reactors was proposed. The proper N:P ratio for achieving optimum batch biomass productivity ranged between 9 and 13 (263 and 322 mg L^?1 d^?1 respectively). This was also the ratio range for achieving a total N and P removal. Above and below this range (9–13) the maximum biomass concentration changed, instead of the specific growth rate.The maximum carbon dioxide biofixation rate was achieved at N:P ratio between 13 and 22 (553 and 557 mg CO2 L^?1 d^?1 respectively). Lipid and crude protein content, both depend on the aging culture, reaching the maximum lipid content (34%) at the lowest N:P (1:1) and the maximum crude protein content (34.2%) at the highest N:P (35:1).     

Phosphorus Sequestration in Lake Sediment with Iron Mine Tailings

Internal phosphorus loading can lead to eutrophication in lakes when anoxic sediments release bioavailable phosphorus into the water column. In laboratory experiments, iron mine tailings helped to sequester phosphorus in sediment from a eutrophic lake. Phosphorus release from the sediments after extraction with distilled water or 0.02 N H ₂ SO ₄ was significantly reduced when mine tailings were added (1:1 w/w), even when the system was anaerobic (～ 1 mg O ₂ /L). The degree of sequestration was enhanced when glucose (1% w/w) was added to stimulate the growth of microorganisms, suggesting that the process was microbially mediated. We suggest that oxidized iron in the mine tailings served as an electron sink for microbial respiration via dissimilatory Fe³⁺ reduction. The reduced iron released into solution sequestered phosphorus, either as it re-oxidized and formed hydrous ferric oxide complexes containing phosphorus (HFO-P), or through precipitation. Since mine tailings are inexpensive, they may prove useful for preventing phosphorus from entering surface waters, as well as reducing internal phosphorus loading.     

A process for high yield and scaleable recovery of high purity eicosapentaenoic acid esters from microalgae and fish oil

A low expense process is developed for recovering esterified eicosapentaenoic acid (EPA) from microalgae and fish oil. Over 70% of the EPA content in the esterified crude extract of microalgae were recovered at purities exceeding 90%. The recovery scheme utilizes either wet or freeze-dried algal biomass. The process consists of only three main steps: 1) simultaneous extraction and transesterification of the algal biomass; 2) argentated silica gel column chromatography of the crude extract; and 3) removal of pigments by a second column chromatographic step. Argentated silica gel chromatography recovered about 70% of the EPA ester present in the crude fatty ester mixture of fish oil, but at a reduced purity ( approximately 83% pure) compared to the microalgal derived EPA. The optimal loading of the fatty ester mixture on the chromatographic support was about 3% (w/w) but loadings up to 4% did not affect the resolution significantly. The process was scaled up by a factor of nearly 320 by increasing the diameter of the chromatography columns. The elution velocity remained constant. Compared to the green alga Monodus subterraneus, the diatom Phaeodactylum tricornutum had important advantages as a potential commercial producer of EPA. For a microalgal EPA process to be competitive with fish oil derived EPA, P. tricornutum biomass (2.5% w/w EPA) needs to be obtained at less than $4/kg. If the EPA content in the alga are increased to 3.5%, the biomass may command a somewhat higher price. The quality of microalgal EPA compares favorably with that of the fish oil product. Compared to free fatty acid, EPA ester is more stable in storage. Shelf-life is extended by storing in hexane. The silver contamination in the final purified EPA was negligibly small (<210 ppb).     

Optimization of carbohydrate fatty acid ester synthesis in organic media by a lipase from Candida antarctica

The effect of solvents and solvent mixtures on the synthesis of myristic acid esters of different carbohydrates with an immobilized lipase from C. antarctica was investigated. The rate of myristyl glucose synthesized by the enzyme was increased from 3.7 to 20.2 micromol min(-1) g(-1) by changing the solvent from pure tert-butanol to a mixture of tert-butanol:pyridine (55:45 v/v), by increasing the temperature from 45 degrees C to 60 degrees C, and by optimizing the relative amounts of glucose, myristic acid, and the enzyme preparation. Addition of more than 2% DMSO to the tert-butanol:pyridine system resulted in a reduction of enzyme activity. Lowering the water content of the enzyme preparation below 0.85% (w/w) resulted in significant decreases in enzyme activity, while increasing the water content up to 2.17% (w/w) did not significantly affect the enzyme activity. The highest yields of myristyl glucose were obtained when an excess of unsolubilized glucose was present in the reaction system. In this case, all of the initially solubilized and a significant amount of the initially unsolubilized glucose was converted to the ester within 24 h of incubation, resulting in a myristyl glucose concentration of 34 mg/mL(-1). Myristic acid esters of fructose (22.3 micromol min(-1) g(-1)), alpha-D-methyl-glucopyranoside (26.9 micromol min(-1) g(-1)) and maltose (1.9 micromol min(-1) g(-1)) could also be prepared using the tert-butanol:pyridine solvent system. No synthesis activity was observed with maltotriose, cellobiose, sucrose, and lactose as substrate.     

Archaeal nucleic acids in picoplankton from great lakes on three continents

Phylogenetic analysis of PCR-amplified 16S rRNA genes revealed the presence of archaea in picoplankton collected from the Laurentian Great Lakes in North America, Africas Lake Victoria, and Lakes Ladoga and Onega in northeastern Eurasia. From 1 to 10% of the rRNA extracted from size-fractionated picoplankton (>0.2 µm but <1.2 µm) collected in the epilimnion and hypolimnion of these lakes was specific to the Archaea, whereas the majority of rRNA was derived from Bacteria. Analysis of the 16S rRNA genes cloned from these samples indicated they were closely related to crenarchaeal sequences that have been widely characterized from marine environments. The presence of nearly identical 16S rDNA clones in several of these geographically disparate lakes suggests a cosmopolitan distribution of specific subgroups of these Archaea in freshwater environments. Despite their abundance in the water column of freshwater lakes, we have no representatives of these crenarchaea in pure culture, and so their physiological characteristics and ecological role remain unknown. Present address (B.P. Keough): Department of Microbiology and Molecular Genetics, Bio-Physical Sciences Building, Michigan State University, East Lansing, MI 48823, Phone: (517) 355-6463; Fax: (517) 353-8957     

Phytoremediation Potential of Selected Plants for Nitrate and Phosphorus from Ground Water

The phytoremediation potential of three aquatic plants namely, water lettuce(Pistia stratioes), water hyacinth (Eichhornia crassipes), and water spinach (Ipomoea aquatica) for nitrate N and phosphorus from nutrient treated ground water was assessed. A total of twelve treatment combinations including four levels of nitrate (expressed as nitrate N 0, 20, 40, and 60 mg/l) and three levels of phosphorus (0, 20, and 40 mg/l) were treated for the total volume of 1 and 20 liters of water respectively, for Pistia stratiotes and Eichhornia crassipes. For Ipomoea aquatica ten treatment combinations with five levels of nitrate N (0, 10, 20, 40, and 50 mg/l) and two levels of phosphorus (0 and 5 mg/l) were treated to 3 liters of water. The design used was a two factor factorial with three replicates. Water was analyzed at weekly interval for nitrate N and phosphorus. Pistia stratiotes, Eichhornia crassipes and Ipomoea aquatica had the potential to remove nitrate N between 61.5–91.8%, 40–63.5%, and 29.3–75% during the period of six, three and three and weeks, respectively. In addition, 90–99%, 75–97.2%, and 75–83.3% of phosphorus was removed from water by Pistia stratiotes, Eichhornia crassipes and Ipomoea aquatica respectively, during the same period.     

鄱阳湖沙山优势植物种叶片氮磷特征

对鄱阳湖沙山14种优势植物的叶片氮、磷含量进行研究,以探讨沙山植物的生理生态适应机制,为鄱阳湖沙化土地的植被恢复提供科学依据。结果表明:鄱阳湖沙山14种优势植物叶片氮含量变化范围为3.10～16.5mg·g^-1,平均值10.21mg·g^-1;叶片磷含量变化范围为0.70～2.10mg·g^-1,平均值1.24mg·g^-1。其中,叶片氮含量仅相当于中国及全球不同植物叶片氮平均含量的一半,叶片磷含量则分别是中国及全球不同植物叶片磷平均含量的85%、70%。鄱阳湖沙山植物较低的叶片氮、磷含量主要受低土壤养分含量控制。蔓荆子作为沙山普遍分布的物种,其叶片氮、磷含量受沙山土壤养分含量低的影响,总体保持较低水平,同时表现出随沙化程度的增加而增加的趋势,这是一种对于水分胁迫的生理适应,以提高水分利用效率。鄱阳湖沙山植物叶片N:P平均比值为9.0,表明沙山植物生长更多地受氮的限制。     

Nutrient and energy content of freshwater fishes

The analyses of fresh total body homogenates of 2385 freshwater fishes from 17 species originating in natural waters and aquaculture facilities resulted in average values of 19.1–37.8% dry matter, 13.6–18.3% crude protein, 0.8–18.3% crude fat, 0.16–2.17% nitrogen-free extracts (NFE), 2.2–2.9% nitrogen and 0.39–1.02% phosphorus. The gross energy content ranged from 3.83 to 11.49 MJ/kg. With increasing fat content in the fishes, water content decreased and dry matter content increased. Through this interdependence, a significant correlation was found between dry matter and crude fat and energy content (r²=0.92–0.97). The values of crude protein, crude ash, NFE, nitrogen and phosphorus did not show any significant influence on dry matter content (r²=0.0005–0.46). Based on the significant correlation between dry matter and gross energy (gross energy [MJ/kg]=0.0253 dry matter [%]^1.6783), the energy content of freshwater fishes can easily be estimated by the dry matter content in the total body.     

养分和水添加对弃耕草地土壤无机磷组分的影响

合理的养分和水分管理措施是提高退化草地生产力和生物多样性的有效途径,但养分和水添加对弃耕草地土壤无机磷组分的影响研究较少.本文依托内蒙古多伦县2005年建立的养分(N∶ 10 g·m-2·a-1、P∶ 10g·m-2·a-1)和水分(植物生长季增水180 mm)添加田间试验,研究了表土(0～10 cm)无机磷组分及有效...     

Phosphorus concentration in sediment, water and tissues of␣three submerged macrophytes of Myall Lake, Australia

Phosphorus content in sediment, water and tissues of three macrophyte species growing in Myall Lake, Australia were studied from January to November, 2004. The sites investigated were North–West (NW), North–East (NE), South–West (SW) bays and Central deep area of the lake (CL). The objective of this study was to investigate how total phosphorus (TP) in plant tissues relate to phosphorus pools and the role played by the aquatic macrophyte species under investigation in phosphorus recycling in the lake. Of the four investigated sites of the lake, TP in plant tissues were significantly higher in North–West and South–West bays compared to the rest. Najas marina had significantly higher TP content (e.g., 1.55 and 1.44 mg/g dw.; P < 0.05) for NW and SW respectively, than the other two species. N. marina is a rooted macrophyte while charophytes (C. fibrosa and Nitella hyalina) are pseudo-rooted macrophytes. Total phosphorus in the sediment and water column were significantly higher in Central deep area of the lake compared to the other three bays (P < 0.05, n 5). Soluble reactive phosphorus (SRP) and total dissolved phosphorus (TDP) in sediment pore water correlated significantly with phosphorus content in the tissue of N. marina ( ; ) as well as TP in sediment (␣ and ). Using the two-compartmental uptake model, it was observed that, sediment was the main compartment through which Ni. hyalina obtained phosphorus while for the other two species, water column was the uptake route for the phosphorus. These correlations suggest that, water column and sediments are important pathways for phosphorus uptake in plants.     

Production and potential applications of a xylanase from a new strain of Streptomyces cuspidosporus

Enzyme production by a new mesophilic Streptomyces isolate was investigated which grew optimally on 1% (w/v) xylan and 10% (w/v) wheat bran at pH 7 and 37 °C. Xylan induced only CMCase (0.29 U/ml) besides xylanase (22–35 U/ml, 40–49 U/mg protein). Wheat bran induced xylanase (105 U/ml, 17.5 U/mg protein), CMCase (0.74 U/ml), -xylosidase (0.009 U/ml), -glucosidase (0.026 U/ml), -L-arabinofuranosidase (0.049 U/ml), amylase (1.6 U/ml) and phytase (0.432 U/ml). The isolate was amenable to solid state cultivation and produced increased levels of xylanase (146 U/ml, 28 U/mg protein). The pH and temperature optima of the crude xylanase activity were 5.5 and 65 °C respectively. The pI was 6.0 as determined by PEG precipitation. The crude enzyme was applied in treatment of paper pulp and predigestion of poultry feed and was found to be effective in releasing sugars from both and soluble phosphorus from the latter.     

Nitrogen and phosphorus content of flow from drains fertilized with cow manure slurry

Summary The rate of flow and nitrate and phosphorus content of the water from four drained sandy and clayey plots of size 12×60 m cropped to continuous corn were determined following two annual applications of different rates (0, 260, 390 and 520 kg N/ha) of cow manure slurry. The drain flow was directly related to the rainfall and was greatly influenced by soil texture. The N losses were greater in 1972 (7.8 to 19.1 kg N/ha) than in 1971 (0.4 to 7.8 kg N/ha) because of more summer rainfall. Nitrogen and phosphorus losses were larger from the sandy plots than from the clayey plots. The manure application rates had no apparent effect on nitrogen losses in the drain water.     

Hydrocarbon accumulation by picocyanobacteria from the Arabian Gulf

AIMS: The objective of this work was to study picocyanobacteria in the Arabian Gulf water in relation to oil pollution. METHODS AND RESULTS: Epifluorescent microscopic counting showed that offshore water samples along the Kuwaiti coast of the Arabian Gulf were rich in picocyanobacteria which ranged in numbers between about 1 x 10(5) and 6 x 10(5) ml(-1). Most dominant was the genus Synechococcus; less dominant genera were Synechocystis, Pleurocapsa and Dermocarpella. All isolates grew well in an inorganic medium containing up to 0.1% crude oil (w/v) and could survive in the presence of up to 1% crude oil. Hydrocarbon analysis by gas liquid chromatography (GLC) showed that representative strains of the four genera had the potential for the accumulation of hydrocarbons (the aliphatic n-hexadecane, aromatic phenanthrene and crude oil hydrocarbons) from aqueous media. Electron microscopy showed that the cells of these strains appeared to store hydrocarbons in their inter thylakoid spaces. Analysis by GLC of constituent fatty acids of total lipids and individual lipid classes from representative picoplankton strains grown in the absence and presence of hydrocarbons showed, however, that the fatty acid patterns were not markedly affected by the hydrocabon substrates, meaning that the test strains could not oxidize the accumulated hydrocarbons. CONCLUSION: The Arabian Gulf is among the water bodies of the world richest in picocyanobacteria. These micro-organisms accumulate hydrocarbons from the water body, but do not biodegrade these compounds. It is assumed that hydrocarbon-utilizing bacteria that were always found associated with all picocyanobacteria in nature may carry out the biodegradation of these compounds. SIGNIFICANCE AND IMPORTANCE OF THE STUDY: The results shed light on the potential role of picocyanobacteria in controlling marine oil pollution.     

Catalytic Production of Liquid Fuels from Organic Residues of Rendering Plants

Anaerobic low temperature conversion (LTC) converts organic residues such as animal meal or meat and bone meal (MBM) to bio‐crude, a solid product, containing carbon and phosphorus, reaction water and non‐condensable gases. The yield of bio‐crude increases with the content of volatile solids. The efficiency of the conversion as well as the calorific value of the liquid fuel produced are favorably affected by the partial recycling of inorganic constituents, high amounts of volatile solids and a low percentage of heteroatoms present in the feeding material. Heating values are 32.3 MJ/kg for bio‐crude from animal meal and 19.5 MJ/kg for bio‐crude from MBM. Both bio‐crude and animal fat produced were effectively converted in a vertical reactor construction with a fixed bed of aluminosilicates of the zeolite family or acidic clays, respectively. Products are bio‐fuels of varying chemical qualities. Depending on the reaction temperature and the catalyst type, aliphatic hydrocarbons (T = 400 °C, ～97 %) or alkylbenzenes (T = 550 °C) are the main products. The calorific values of these bio‐fuels are in a range from 40.1 to 41.9 MJ/kg and the kinematic viscosities are between 0.9 and 2.29 mm²/s. The solid products of LTC from different biomass (sludge, animal meal, MBM) contain a significant amount of phosphorus. In the case of the solid product from MBM it was as high as 242 mg P₂O₅/g. Solubility in citric acid showed that in the case of MBM, 98.8 % of total phosphorus is potentially available to plants. Pot experiments demonstrated a similar plant growth as with other organic fertilizers.     

Purification of C-phycocyanin from Spirulina (Arthrospira) fusiformis

C-phycocyanin was purified from Spirulina (Arthrospira) fusiformis by a multi-step treatment of the crude extract with rivanol in a ratio 10:1 (v/v), followed by 40% saturation with ammonium sulfate. After removal of rivanol by gel-filtration on Sephadex G-25, the pigment solution was saturated to 70% with ammonium sulfate. After the last step of purification, C-phycocyanin had an emission and absorption maxima at 620 and 650 nm, respectively and absorbance ratio A(620)/A(280) of 4.3, which are specific for the pure biliprotein. Its homogeneity was demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, yielding two bands of molecular masses 19500 and 21500 kDa, corresponding to alpha and beta subunits of the pigment, respectively. The yield of C-phycocyanin was approximately 46% from its content in the crude extract.     

竹茶混交模式对表层土壤有机碳储量及组分的影响

为探究毛竹林下种植茶树对土壤有机碳储量与碳组分的影响,该研究以毛竹纯林、竹茶混交林和常绿阔叶林为研究对象,采集这3种林分类型的表层(0～10 cm)土壤,测定土壤有机碳(SOC)、碳组分、生物与非生物因素指标。结果表明:(1)竹茶混交林林下植物多样性相较于毛竹纯林显著降低,但其土壤有机碳密度(22.54±2.09)t·hm^-2、碳组分与毛竹纯林无显著差异(P>0.05)。竹茶混交林的矿物结合态有机碳(MOC)为(20.13±1.83)g·kg^-1,占总有机碳的92.66%。常绿阔叶林土壤有机碳密度比竹茶混交林和毛竹纯林高土壤有机碳密度分别高41.15%和41.00%(P<0.05)。(2)3种林分类型土壤微生物量碳(MBC)含量范围为0.58～3.08 g·kg^-1,土壤16S rRNA丰度范围为2.18×10¹⁰ ～5.65×10¹⁰copies·g^-1,固碳基因cbbL丰度范围为0.37×10⁸～ 1.10 ×10⁸ copies·g^-1,土壤微生物碳利用效率范围为0.03～0.28; 3种林分类型之间微生物相关指标不存在显著差异(P>0.05)。(3)3种林分类型SOC与土壤pH、砂粒含量和地上凋落物生物量呈显著负相关,与土壤黏粒含量、粉粒含量、总氮、C:N、总磷和铵态氮含量呈显著正相关(P<0.05)。(4)就不同碳组分而言,颗粒有机碳(POC)和MOC均与土壤pH、砂粒含量和根系生物量呈显著负相关,与土壤含水量、黏粒含量、粉粒含量、总氮、C:N、总磷和铵态氮含量呈显著正相关(P<0.05)。综上表明,竹茶混交改造会造成原生毛竹纯林林下植被多样性下降,但并未造成土壤碳储量下降; 而相较于常绿阔叶林,毛竹经营措施需要改进,以提升其碳汇效益。