Showing papers on "Chlorococcum published in 2017"

Protic ionic liquid-assisted cell disruption and lipid extraction from fresh water Chlorella and Chlorococcum microalgae

Abstract: Protic ionic liquids (PILs) with their ability to host labile protons and form hydrogen bonds are likely to be efficient catalyst for bioprocessing. This is one of the first reports investigating PIL-assisted microalgal cell disruption and lipid extraction. The applicability of several PILs with butyrolactam, caprolactam, propylammonium and hydroxypropylammonium cations in combination with formate, acetate and hexanoate anions for cell disruption and lipid extraction from fresh water Chlorella and Chlorococcum sp. have been evaluated in this study. The investigations were performed with de-watered wet microalgae under ambient temperatures and hence do not require any energy intensive drying and/or processing steps. The PILs with formate and hexanoate anions when compared with conventional pre-treatment techniques: sonication, microwave and cellulase provided better microalgal cell disruption efficiencies. The FESEM analysis for the Butyrolactam hexanoate (BTH) treated cells show extensive pattern of microalgal cell disruption. The fluorescence imaging analysis coupled with culturing experiments indicates a near-complete disruption and loss in viability of the PIL-treated microalgal cells. The lipid yield from the formate and hexanoate anions-PILs was statistically comparable and/or higher to the Bligh & dyer control method. Among the PILs, BTH recorded 1.86 and 1.72 folds higher lipid yields than the control method with Chlorella and Chlorococcum sp. respectively. The lipids show predominance of C16 and C18 fatty acids similar to lipid profile obtained with the control method. Furthermore, the PILs were also found to have a beneficial role in reducing the chlorophyll pigments in the final lipid product. Overall, the results show PILs with formate and hexanoate anions can be utilized for a relatively energy efficient, one-step cell disruption and lipid extraction process from wet microalgae.

Enhancement of biomass and lipid productivities of water surface-floating microalgae by chemical mutagenesis

Abstract: Water surface-floating microalgae have great potential for biofuel applications due to the ease of the harvesting process, which is one of the most problematic steps in conventional microalgal biofuel production We have collected promising water surface-floating microalgae and characterized their capacity for biomass and lipid production In this study, we performed chemical mutagenesis of two water surface-floating microalgae to elevate productivity Floating microalgal strains AVFF007 and FFG039 (tentatively identified as Botryosphaerella sp and Chlorococcum sp, respectively) were exposed to ethyl methane sulfonate (EMS) or 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), and pale green mutants (PMs) were obtained The most promising FFG039 PM formed robust biofilms on the surface of the culture medium, similar to those formed by wild type strains, and it exhibited 17-fold and 19-fold higher biomass and lipid productivities than those of the wild type This study indicates that the chemical mutation strategy improves the lipid productivity of water surface-floating microalgae without inhibiting biofilm formation and floating ability

Biochemical characterization of microalgae collected from north east region of India advancing towards the algae-based commercial production

Abstract: Selection of suitable strain of microalgae is the crucial factor for large-scale production of algae-based products. Efforts have been made here for isolation, identification and biochemical characterization of five microalgae strains collected from Tripura (a small state in north-eastern region of India). Two Chlorococcum sp. (NITAAP008 and NITAAP019) demonstrate their high lipid (15–24%), equal amounts of carbohydrate and protein (35–40%), with specific growth rate of 0.13 day−1. These strains are potential resource for biofuel production. After lipid extraction, remaining biomass can be used as source of carbohydrate for the production of other biofuels. One isolated strain is identified as Chlorella sp. (NITAAP009) and shows 22–33% carbohydrate, 41–50% protein and 5% chlorophyll with specific growth rate of 0.125 day−1. Another Chlorella sp. (NITAAP011) isolated from lake area exhibits significant chlorophyll (5–6.4%), 30–50% carbohydrate, 48–60% protein and low lipid (1–10%) with lower specific growth rate (0.10 day−1). Both strains are having industrial competence for chlorophyll production due to their synthesizing ability of significant amount of chlorophyll (5–6.4%). The last one, Korshikoviella sp. (NITAAP017), has 15–18% lipid, 22–34% carbohydrate, 30–43% protein and 3–4% chlorophyll with specific growth rate of 0.12 day−1 and can be used for food supplement production or lipid synthesis. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.

Isolation and characterization of an endoparasite from the culture of oleaginous microalga Graesiella sp. WBG-1

Abstract: Oleaginous microalgae are an important potential feedstock for biodiesel production. However, a problem in mass cultivation of microalgae is the frequent occurrence of infection by algal parasites. In the present study, an endoparasite WZ01 was isolated from an open raceway pond of oleaginous Graesiella sp. WBG-1, and caused epidemics resulting in algal population collapse. According to 18S rDNA-based phylogenetic analyses, morphology, ultrastructure and life cycle, strain WZ01 was identified as a member of Aphelidea, Amoeboaphelidium protococcarum, although it had some minor differences from A. protococcarum X-5 and FD95. Examination via transmission electron microscopy demonstrated that zoospores of the parasite WZ01 were amoeboid, which can produce two types of pseudopodia (multiple filopodia and short anterior lamellipodium), but the pseudocilium was not observed. Interestingly, amoeboid zoospores contained numerous dense-body vesicles, which have not been previously described. Moreover, our results revealed the presence of a microtubule inside the penetration tube, indicating that the contents of the cyst were injected into the host not only by vacuole pressure but also by using a microtubule-mediated mechanism. In addition, of the 42 tested algal species, only cultures of coccoid green algae Chlorococcum sp. A213 and Chlorococcum sp. GP1 rapidly and intensively developed infections by parasite WZ01. This is the first report on endoparasitic infection in oleaginous coccoid green algae. Our results will enhance understanding of parasite–host relationships, which will be beneficial in developing strategies for infection control.

Cultivation of freshwater microalgae in biodiesel wash water.

Abstract: Biodiesel wash water is a contaminating industrial effluent that must be treated prior to disposal. The use of this effluent as a low-cost alternative cultivation medium for microalgae could represent a viable supplementary treatment. We cultivated 11 microalgae species with potential use for biodiesel production to assess their growth capacities in biodiesel industrial washing waters. Only Monoraphidium contortum, Ankistrodesmus sp., Chlorococcum sp., and one unidentified Chlorophyceae species grew effectively in that effluent. M. contortum showed the highest growth capacity and had the second highest fatty acid content (267.9 mg g-1 of DW), predominantly producing palmitic (20.9%), 7,10,13-hexadecatrienoic (14%), oleic (16.2%), linoleic (10.5%), and linolenic acids (23.2%). In the second phase of the experiment, the microalgae were cultivated in biodiesel wash water at 75% of its initial concentration as well as in WC (control) medium. After 21 days of cultivation, 25.8 and 7.2% of the effluent nitrate and phosphate were removed, respectively, and the chemical oxygen demand was diminished by 31.2%. These results suggest the possibility of cultivating biodiesel producing microalgae in industrial wash water effluents.

Aspects of carbon dioxide mitigation in a closed microalgae photo-bioreactor supplied with flue gas

Abstract: The aim of the present study is to investigate the potential of flue gases to be efficiently and economically applied in production of algal biomass in a photobioreactor (PBR). Various microalgae strains (Chlorella sorokiniana 211-234, Bracteacoccus minor 61.80, Radiosphaera negevensis 87.80, Chlorosarcinopsis negevensis 67.80 and Chlorococcum novae-angliae 5.85) had been tested for CO2 mitigation, growth and tolerance to high CO2 levels. The flue gas and CO2 bubbling induced a significant algal mass growth compared to control (ambient air). Removal of CO2 and NO by the studied microalgae strains was found to be 44% and 33% along daily intervals, respectively. A growth rate of ~0.4g L−1 d−1 was obtained for all algal species tested. Growth conditions for tested algae can be optimised through PBR technology in order to obtain highest biomass yield for production of valuable biochemicals (i.e., low-cost biofuel).

Cyanobacteria and cyanobacterial toxins in the alkaline-saline Lakes Natron and Momela, Tanzania

Abstract: Physicochemical parameters, phytoplankton communities, microcystin (MC) concentrations and potential MC-producing cyanobacteria were investigated in Lakes Natron and Momela, Tanzania. In Lake Big Momela, concentrations of soluble reactive phosphorus, nitrate and ammonia were 7.1, 2.6 and 0.9 μg/L, respectively, while dissolved oxygen, salinity, conductivity and pH were 9.4 mg/L, 19‰, 30 mS/cm and 9.7, respectively. The concentrations of soluble reactive phosphorus, nitrate and ammonia in Lake Natron were 129.4, 8.1 and 58 μg/L, respectively, while dissolved oxygen, conductivity and pH were 8 mg/L, 52 mS/cm and 9.5 respectively. The phytoplankton communities in both lakes were dominated by cyanobacteria, particularly Arthrospira fusiformis. Navicula and Nitzschia diatoms, and Chlorella, Chlorococcum and Scenedesmus green algae were common in Lakes Momela and Natron. Liquid chromatography–mass spectrometry (LC-MS) analysis phytoplankton detected four microcystin variants namely MC-RR, -YR, -LR and -RY. The total MC concentrations in Lake Natron were 0.1–4.5 μg/mL of phytoplankton scum and in Lake Momela were below quantifiable levels. Polymerase chain reaction analysis of phytoplankton revealed presence of Microcystis and the Microcystis mcyB gene in some samples. Finding of potential MC-producing cyanobacteria and MCs in study lakes poses a health risk to Lesser Flamingo which feed on cyanobacteria.Keywords: alkaline-saline lakes, microcystins, phytoplankton, physicochemical parameters

Testing system for controlling kumquat epiphytic chlorococcum by using wood vinegar

Abstract: The invention relates to a testing system for controlling kumquat epiphytic chlorococcum by using wood vinegar. The testing system comprises a classification module used for all contrast tests, a monitoring module used for monitoring situations of the kumquat epiphytic chlorococcum in all sites of the contrast tests, an image recognition module used for carrying out image recognition according to the monitoring module so as to judge whether the kumquat epiphytic chlorococcum exists or not, a statistical calculation module which is connected with the image recognition module for performing image datamation and then transmits data to a disease index module, and a control effect module for respectively generating a disease index list and a control effect list. The testing system can monitor in real time, obtains disease indexes and a control effect by means of image recognition, and directly reflects the effect of controlling kumquat epiphytic chlorococcum by using the wood vinegar, thus being convenient, fast, accurate and effective.

The isolation and screening of microalgae for the production of oil

Abstract: The biodiesel production has gained increasing attention of the researches in recent years. Current commercial biodiesel production involves transesterification of oil derived from oil crops. Since this production is no more sustainable, the use of microalgae represents a good alternative. Microalgae have high growth rate, high oil content and can be cultured in the environment which are not suitable for agriculture. Additionally, microalgae cultivation improves the reduction of carbon dioxide in the atmosphere. Selection of microalgae for oil production must take into consider certain criteria which include growth rate, oil content, fatty acids profile and ease of separation. In order to analyze the possibility of the use of microalgae for the production of oil, isolation of freshwater microalgae was performed. The isolation was done by the use of traditional techniques from freshwaters near Leskovac. A total number of 6 microalgae strains were isolated and identified as the representatives of the genera Chlorococcum (1 isolate), Chlorella (1 isolate), Scenedesmus (1 isolate) and Desmodesmus (3 isolates). Isolates of microalgae were screened for the growth rate, biomass and oil productivity and oil content. The highest content of biomass was 1.5 g/l and it was observed in the strains Chlorococcum sp. and Desmodesmus sp. 1. The highest value of specific growth rate was calculated during the growth of microalgae Chlorella sp., Scenedesmus sp. and Desmodesmus sp.1, while the lowest value was observed for Chlorococcum sp. Oil productivity was the highest for Chlorella sp. and Desmodesmus sp.1 (0,4 g/l) and the lowest for Desmodesmus sp.2, Desmodesmus sp.3 and Chlorococcum sp. (0,2 g/l). The oil content was in the range from 15.8% (Chlorococcum sp.) to 33% (Chlorella sp). Since the microalgae isolates Chlorella sp. and Scenedesmus sp. had the highest oil productivity, high growth rate and high oil content, these strains are the most suitable for further investigation in order to improve the oil yield and analyse the possibility of the use in the production of biodiesel.