Characteristics of Protists

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User HandbookPhysical & ChemicalCharacteristics of DDGSPhysical & ChemicalCharacteristics of DDGS 08 - Physical & Chemical Characteristics of DDGS 1Physical & Chemical Characteristics of U.S. DDGS Physical and chemical characteristics of distiller’s dried grains with solubles (DDGS) vary among sources and can influence its feeding value and handling characteristics. These characteristics include color, smell, particle size, bulk density, pH, flowability, shelf life stability and hygroscopicity. Color Color of DDGS can vary from being very light yellow in color to being very dark brown in color. Differences in color among DDGS sources are influenced by; • the natural color of the feedstock grain being used, • the amount of solubles added to grains before drying, • drying time, and drying temperature. The color of corn kernels can vary among varieties and has some influence on final DDGS color. Corn-sorghum blends of DDGS are also somewhat darker in color than corn DDGS because of the bronze color of many sorghum varieties. When a relatively high proportion of solubles are added to the mash (grains fraction) to make DDGS, the color becomes darker. Noll et al. (2006) conducted a study where they evaluated color in batches of DDGS where approximately 0, 30, 60 and 100% of the maximum possible of syrup was added to the mash before drying. Actual rates of solubles addition to the mash were 0, 12, 25 and 42 gallons/minute. As shown in Table 1, increasing solubles addition rate to the mash resulted in a decrease in L* (lightness of color) and b* (yellowness of color), with an increase in a* (redness of color). Similar results were also reported by Ganesan et al. (2005). Table 1. The Effect of the Rate of Solubles Addition to Mash on Color Characteristics of DDGS 0 gal/min 12 gal/min 25 gal/min 42 gal/min Pearson Correlation P Value Color (CIE Scale) L* 59.4 56.8 52.5 46.1 - 0.98 0.0001 a* 8.0 8.4 9.3 8.8 0.62 0.03 b* 43.3 42.1 40.4 35.6 - 0.92 0.0001 Adapted from Noll et al. (2006). Dryer temperatures in dry-grind ethanol plants can range from 127 to 621º C. The amount of time DDGS spends in the dryer also influences the color. In general, the higher the dryer temperature and the longer DDGS remains in the dryer, the darker the resulting DDGS will be. Smell High quality DDGS has a sweet, fermented smell. DDGS that has a burned or smoky smell has been overheated. 08 - Physical & Chemical Characteristics of DDGS 2 Particle Size, Bulk Density and pH Particle size and particle size uniformity of feed ingredients are important considerations of livestock and poultry nutritionists when selecting sources and determining the need for further processing when manufacturing complete feeds or feed supplements. Particle size affects: 1. Nutrient digestibility – as particle size is reduced, nutrient digestibility and feed conversion is improved. This is due to the increasing amount of surface area of an ingredient that is exposed and available for digestive enzymes to act upon. 2. Mixing efficiency – a more uniform particle size in a mixture of ingredients will reduce mixing time in order to achieve a uniformly distributed mix of ingredients in a complete feed. 3. Amount of ingredient segregation during transport and handling – particle and ingredient segregation (separation) occurs when particles of different sizes and bulk densities are blended Characteristics of Protists Characteristics of Protists Bởi: OpenStaxCollege There are over 100,000 described living species of protists, and it is unclear how many undescribed species may exist Since many protists live as commensals or parasites in other organisms and these relationships are often species-specific, there is a huge potential for protist diversity that matches the diversity of hosts As the catchall term for eukaryotic organisms that are not animal, plant, or fungi, it is not surprising that very few characteristics are common to all protists Cell Structure The cells of protists are among the most elaborate of all cells Most protists are microscopic and unicellular, but some true multicellular forms exist A few protists live as colonies that behave in some ways as a group of free-living cells and in other ways as a multicellular organism Still other protists are composed of enormous, multinucleate, single cells that look like amorphous blobs of slime, or in other cases, like ferns In fact, many protist cells are multinucleated; in some species, the nuclei are different sizes and have distinct roles in protist cell function Single protist cells range in size from less than a micrometer to three meters in length to hectares Protist cells may be enveloped by animal-like cell membranes or plantlike cell walls Others are encased in glassy silica-based shells or wound with pellicles of interlocking protein strips The pellicle functions like a flexible coat of armor, preventing the protist from being torn or pierced without compromising its range of motion Metabolism Protists exhibit many forms of nutrition and may be aerobic or anaerobic Protists that store energy by photosynthesis belong to a group of photoautotrophs and are characterized by the presence of chloroplasts Other protists are heterotrophic and consume organic materials (such as other organisms) to obtain nutrition Amoebas and some other heterotrophic protist species ingest particles by a process called phagocytosis, in which the cell membrane engulfs a food particle and brings it inward, pinching off an intracellular membranous sac, or vesicle, called a food vacuole ([link]) 1/5 Characteristics of Protists The vesicle containing the ingested particle, the phagosome, then fuses with a lysosome containing hydrolytic enzymes to produce a phagolysosome, and the food particle is broken down into small molecules that can diffuse into the cytoplasm and be used in cellular metabolism Undigested remains ultimately are expelled from the cell via exocytosis The stages of phagocytosis include the engulfment of a food particle, the digestion of the particle using hydrolytic enzymes contained within a lysosome, and the expulsion of undigested materials from the cell Subtypes of heterotrophs, called saprobes, absorb nutrients from dead organisms or their organic wastes Some protists can function as mixotrophs, obtaining nutrition by photoautotrophic or heterotrophic routes, depending on whether sunlight or organic nutrients are available Motility The majority of protists are motile, but different types of protists have evolved varied modes of movement ([link]) Some protists have one or more flagella, which they rotate or whip Others are covered in rows or tufts of tiny cilia that they coordinately beat to swim Still others form cytoplasmic extensions called pseudopodia anywhere on the cell, anchor the pseudopodia to a substrate, and pull themselves forward Some protists can move toward or away from a stimulus, a movement referred to as taxis Movement toward light, termed phototaxis, is accomplished by coupling their locomotion strategy with a light-sensing organ 2/5 Characteristics of Protists Protists use various methods for transportation (a) Paramecium waves hair-like appendages called cilia to propel itself (b) Amoeba uses lobe-like pseudopodia to anchor itself to a solid surface and pull itself forward (c) Euglena uses a whip-like tail called a flagellum to propel itself Life Cycles Protists reproduce by a variety of mechanisms Most undergo some form of asexual reproduction, such as binary fission, to produce two daughter cells In protists, binary fission can be divided into transverse or longitudinal, depending on the axis of orientation; sometimes Paramecium exhibits this method Some protists such as the true slime molds exhibit multiple fission and simultaneously divide into many daughter cells Others produce tiny buds that go on to divide and grow to the size of the parental protist Sexual reproduction, involving meiosis and fertilization, is common among protists, and many protist species can switch from asexual to sexual reproduction when necessary Sexual reproduction is often associated with periods when nutrients are depleted or environmental changes occur Sexual reproduction may allow the protist to recombine genes and produce new variations of progeny that may be better suited to surviving in the new environment However, sexual ...Modeling the Statistical Time and Angle of ArrivalCharacteristics of an Indoor Multipath ChannelQuentin H. SpencerA Thesis Presented toThe Department of Electrical and Computer EngineeringBrigham Young UniversityProvo, Utah, USACommittee Members:Brian D. Jeffs, chairMichael D. RiceMichael A. JensenNovember 22, 1996 AbstractMost previously proposed statistical models for the indoor multipath channel in-clude only time of arrival characteristics. However, in order to use statistical models insimulating or analyzing the performance of array processing or diversity combining, it alsonecessary to know the statistics of the angle of arrival and its correlation with time of arrival.In this paper, a system is described which was used to collect simultaneous time and angleof arrival data at 7 GHz. Data processing methods are outlined, and results of data taken intwo different buildings are presented. Based on the results, a model is proposed that employsthe clustered “double Poisson” time of arrival model proposed by Saleh and Valenzuela [1].The observed angular distribution is also clustered, with uniformly distributed clusters, andarrivals within clusters that have a Laplacian distribution.1 Chapter 1INTRODUCTIONRadio has recently become an increasingly viable option for indoor communica-tions applications. The availability of higher frequency bands in the 900 MHz and 2.4 GHzrange has made wireless an attractive option for high bandwidth digital communications ap-plications such as local area networks. Wireless networks can be particularly advantageousfor applications which require portability, or where installation of wiring is undesirable orimpractical.Multipath interference, or interference due to the reception of multiple copies of asignal due to reflections, is known to be a problem in many outdoor communication channels.However, multipath can also be particularly problematic in an indoor environment. At UHFand microwave frequencies, the presence of walls and large objects in rooms makes the indoormultipath environment quite different from most outdoor scenarios. As a result, the studyof indoor propagation characteristics has become an area of increased study.In order to analyze or simulate the performance of a communications system, somekind of model for the channel is needed. One of the first statistical models for the indoormultipath channel was proposed by Saleh and Valenzuela [1]. Their data showed multipatharrivals which were grouped in clusters over time. The relative delay between clusters wasrepresented by a Poisson distribution, and the separation between elements within clusterswas modeled by a second Poisson distribution with a different delay parameter.There have been many different approaches to overcoming the problem of multi-path interference, both in outdoor and indoor applications. Some of them include channelequalization, directional antennas, and multiple antenna systems. Each of these tends to bemore particularly suited to different applications. This thesis will focus on multiple antennasystems. The signals from different antennas can be combined in various ways, including di-versity combining, phased array processing, and adaptive array algorithms. Adaptive arraysytems are becoming increasingly feasible for high bandwidth applications with continuingimprovements in digital signal processors. The Journal of Water and Environment Technology, Vol.1, No.2, 2003 - 177 - Characteristics of hydrogen production from food waste and waste activated sludge *Hang-Sik Shin 1 , Sang-Hyoun Kim 1 and Byung-Chun Paik 2 1 Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Korea 2 Division of Civil and Environmental Engineering, Yosu National University, San 96-1, Dundeok-dong, Yeosu-si, Jeollanam-do, 550-749, Korea ABSTRACT This study was conducted for microbial hydrogen production from food waste and sewage sludge. Thirty three batch tests with different VS concentration (from 0.5 to 5.0 %, w/v) and mixing ratio of food waste to sewage sludge (from 0:100 to 100:0) were performed at 35°C. Heat-treated anaerobic sludge was used to seed the serum bottles. In all the tests, cumulative hydrogen production reached the maximum values within 2.5 days. n-Butyrate was produced simultaneously with hydrogen production, of which the amount was proportional to that of n- butyrate. Clostridium sp. are, therefore, considered to be the dominant microorganisms in this study because these microorganisms are responsible for n-butyrate fermentation. The hydrogen production potential of food waste was found over 34.0 mL/g VS at all the VS concentration. The maximum potential of 59.2 mL/g VS was found at 3.0 % of VS concentration. The potential decreased as sewage sludge composition increased due to the methanogens contained in sewage sludge and low carbohydrate concentration; however, the addition of sewage sludge to food waste enhanced hydrogen yield because of sufficient protein. The maximum hydrogen yield of 1.01 mole H 2 /mole hexose added was achieved at the food waste to sewage sludge ratio of 80:20 at the VS concentration of 3.0 %. The specific hydrogen production rate increased up to 22.6 mL H 2 /g VSS/h as both food waste composition and VS concentration increased. Key Words: Food waste, hydrogen, mixing ratio, sewage sludge, VS concentration INTRODUCTION Due to the finite quantities and pollutants emission (CO 2 , CO, C n H m , So x , NO x , ashes, etc.), fossil fuels should be alternated by renewable and non-polluting energy sources in recent Journal of Water and Environment Technology, Vol.1, No.2, 2003 - 178 - future (Momirlan and Veziroğlu, 1999). As a sustainable energy source with minimal or zero use of hydrocarbons, hydrogen is a promising alternative to fossil fuels. With high energy yield (122 kJ/g), hydrogen is clean and renewable. In addition, hydrogen can be directly used to produce electricity through fuel cells (Rifkin, 2002). Since conventional physico-chemical production methods (e.g. water electrolysis or chemical cracking of hydrocarbons) require electricity derived from fossil fuel combustion, interest in biohydrogen production has increased significantly (BenneHawkes et al., 2002). Between two biological processes, fermentative process that uses refuse or organic wastes seems technically simpler than photosynthetic process. Clostridium species (sp.) are the representative anaerobic fermentative hydrogen producing bacteria (Hawkes et al., 2002). Due to the ability to produce endospore, they can be easily selected from natural environments such as anaerobic sludge, compost and soil by inhibiting other bacteria using heat, acid/base, ultrasound, chemicals, Surface characteristics of acidogenic sludge in H 2 -producing process Yang Mu, Yi Wang, Guo-Ping Sheng, Han-Qing Yu* School of Chemistry, University of Science & Technology of China, Hefei, 230026 China *Corresponding author. Fax: +86 551 3601592; E-mail: hqyu@ustc.edu.cn ABSTRACT The surface characteristics, including rheological, fractal characteristics, hydrophobicity as well as surface free energy, of H 2 -producing sludge in acidogenic fermentative process were investigated in this study. Both rheological and fractal characteristics of the H 2 -producing sludge changed slightly in the acidogenesis. The sludge fractal dimension was larger than those of other microbial aggregates, whereas the affinity of the microbial cells for the hydrocarbon had a peak value in the fermentation process. Both specific H 2 and volatile fatty acids/ethanol production rates of the sludge had a peak of 108 mL-H 2 L -1 h -1 g-VSS -1 and 480 mg L -1 h -1 g-VSS -1 . There was a relationship between the hydrophobicity of the H 2 -producing sludge and its specific H 2 -producing activity. The surface free energy of the H 2 -producing microorganisms had a lowest value in their growth process. KEYWORDS: Acidogenesis; H 2 -producing sludge; Hydrophobicity; Rheological; Surface characteristics; Surface free energy INTRODUCTION The surface characteristics of sludge, such as rheology, fractal properties hydrophobicity and surface free energy, are significant factors influencing the performance of a wastewater treatment process (Johnson et al., 1996; Dentel, 1997; Zita and Hermansson, 1997). Rheology is a powerful tool for characterizing the non-Newtonian properties of sludge suspensions, as it can quantify flow behaviors in real processes on a scientific basis (Dentel, 1997). Properties of sludge permeability, density, and porosity can be calculated from the fractal dimension and have important implications for the aggregation kinetics, floc break-up, and settling velocities of sludge as a function of their fractal structure (Johnson et al., 1996). Thus, measurement of the fractal dimension of sludge is of considerable interest. Hydrophobicity of sludge plays an important role in the self-immobilization and attachment of cells to a surface (Zita and Hermansson, 1997; Zheng et al., 2005). The biological H 2 production from anaerobic fermentation of organic wastes is an economical and sustainable technology for both pollution control and clean energy generation (Chen et al., 2001; Levin et al., 2004). In anaerobic fermentative H 2 -producing process, majority of the removed organic matters is converted to H 2 , CO 2 , and volatile fatty acids (VFA) and alcohols. This fermentative process is greatly influenced by many factors, such as substrate composition, substrate concentration, hydraulic retention time, pH and temperature (Yu et al., 2002; Lin and Jo, 2003; - 1 - Journal of Water and Environment Technology, Vol.5, No.1, 2007 Zheng and Yu, 2004). The surface characteristics of H 2 -producing sludge might also be a significant factor affecting the fermentative H 2 production. However, little information concerning the surface characteristics of H 2 -producing sludge in acidogenic fermentative process is available in literature. Therefore, the main objective of this study was to explore the surface characteristics of H 2 -producing sludge, including rheological and fractal properties as well as Journal of Water and Environment Technology, Vol. 8, No.4, 2010 Address correspondence to Tushara CHAMINDA G. G, Environmental Science Center, The University of Tokyo, Email: chaminda@env.t.u-tokyo.ac.jp Received May 10, 2010; Accepted September 13, 2010. - 403 - Biological Alteration of Zinc Complexation Characteris- tics of Dissolved Organic Matter in Domestic Wastewa- ter Treatment Plant Effluent under River Water Environment Tushara CHAMINDA G. G*, Fumiyuki NAKAJIMA*, Ikuro KASUGA** *Environmental Science Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo, 113- 0033, Japan **Department of Urban Engineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-8656, Japan ABSTRACT Naturally occurring processes such as biological reaction might modify the properties of dissolved organic matter (DOM) for binding with heavy metals. Complexation of heavy metals with DOM determines their environmental and ecological impacts. In this study, biodegradation experiments were carried out separately for river water and river water spiked with DOM in wastewater treatment plant (WWTP) effluent to evaluate the biological alteration of zinc complexation characteristics of DOM under river water environment. Zinc complexation parameters, conditional stability constant and binding site concentrations were determined using anodic stripping voltammetry with Scatchard linearization. Total ambient zinc binding site concentration of river water DOM was reduced from 410 nM to 74 nM (82% decline) during two weeks of incubation. Compared to the river water DOM, 1-month incubation of DOM in WWTP effluent under the river water environment, showed only 22% decline in total ambient Zn binding sites. On the other hand, conditional stability constants, for Zn binding sites of DOM from WWTP effluent, did not vary during 1 month of incubation. The result suggests that metal (Zn) binding sites of DOM from WWTP effluents are biologically persistent in the urban river water environment. Keywords: biodegradation, dissolved organic matter, river water, wastewater treatment plant effluent, zinc complexation. INTRODUCTION AND BACKGROUND Dissolved organic matter (DOM) is important in the transport of metals in aquatic systems. It also provides protection to the aquatic organisms from heavy metal stress by forming strong complexes, which results in the decline of the free metal ion concentration. Many water bodies in the urban environment, such as rivers and bays, receive effluent from wastewater treatment plant (WWTP) which may contain considerable concentrations of toxic metals as well as DOM that control the metal speciation. The chemical structure of DOM, which originated from biological wastewater treatment plant, is much complicated and includes organic compounds in different groups (Ma et al., 2001). Recent studies have revealed that DOM in treated effluent tends to bind with many metals (eg; Zn and Cu) to a greater degree than natural organic matter (NOM) does (Sarathy and Allen., 2005; Cheng and Allen., 2006; Chaminda et al., 2008). No matter how strong the complexations of metals are with DOM, naturally occurring processes such as biological degradation and ... nutrients are available Motility The majority of protists are motile, but different types of protists have evolved varied modes of movement ([link]) Some protists have one or more flagella, which... Which of these locomotor organs would likely be the shortest? a flagellum a cilium an extended pseudopod a pellicle 4/5 Characteristics of Protists B Alternation of generations describes which of. .. Summary Protists are extremely diverse in terms of their biological and ecological characteristics, partly because they are an artificial assemblage of phylogenetically unrelated groups Protists