Isolation, characterization, and fermentative pattern of a novel thermotolerant Prototheca zopfii var. hydrocarbonea strain producing ethanol and CO2 from glucose at 40 degrees C.
ABSTRACT A novel thermotolerant strain of the achlorophyllous micro-alga Prototheca was isolated from a hot spring. The isolate was found to produce an appreciable amount of ethanol and CO2 from glucose under anoxic conditions at both 25 and 40 degrees C; this type of alcohol fermentation has not yet been reported in the genus Prototheca. Moreover, it also evolved gas from sucrose after a time lag at 40 degrees C. Its taxonomic characteristics coincided with those of Prototheca zopfii var. hydrocarbonea, and phylogenetic analysis, based on a small-subunit (SSU) rDNA sequence, also revealed a close relationship between the two strains. D-lactic acid, ethanol, CO2 and a trace of acetic acid were produced from glucose, but L-lactic acid, formic acid, and H2 were not. At 25 degrees C, D-lactic acid and ethanol were produced in approximately equimolar amounts under N2/H2/CO2, whereas ethanol production was predominant under N2. More ethanol was produced at 40 degrees C than at 25 degrees C irrespective of the gas composition in the atmosphere. This is the first report on gas production from glucose and on the changes in the fermentative patterns as a function of temperature for the genus Prototheca.
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ABSTRACT: The ability of Pseudomonas viridilivida strain Zagazig University, Faculty of Science (ZUFS) to inhibit Zucchini Yellow Mosaic Virus (ZYMV) in cucumber plants was studied in vitro by mixing it with sap containing virus and in vivo by seed and soil treatments. The production, extraction, purification and characterization of the antiviral substance (s) from strain ZUFS was done. P. viridilivida stimulated the growth of cucumber (Cucumis sativus L.) and inhibit the symptoms of zucchini yellow mosaic virus (ZYMV) by 90%, when mixed with virus suspension in equal volumes (v/v). Treatment of cucumber seeds with bacterial pellets increase the plant growth and showed 100% viral inhibition. The virus concentration was detected by DAS- ELISA technique in leaves of cucumber plants, whose seeds were treated with P. viridilivida. The ELISA value was 0.805 near to the negative control of ZYMV (0.697), while the positive virus control was 1.884. The P. viridilivida detected by electron microscopy inside the root tissue of seed treated cucumber plants, (root-colonizing). The treatment of natural and sterile soil by liquid bacterial culture gave 70 and 89.3% inhibition, the ELISA value of cucumber leaves grown on treated sterile soil was 1.231 compared to (1.884) for positive ZYMV control. ZYMV-infection induced severe modification in number and ultra structure of chloroplast, where lower number and irregular structure of chloroplasts were observed in ZYMV infected leaf in comparison with control and treated plants. Scrolls, pin-wheels, bundles and laminated aggregates were induced in the cytoplasm of infected cells. Physical properties of ZYMV showed that the virus was sap transmissible, its thermal inactivation point is 65°C, dilution end point is 10 -3 and longevity in vitro is 24 h at room temperature. The antiviral substance (s) produced by culture of P. viridilivida were extracted by using different solvents followed by thin layer chromatography (TLC) purification. Two spots blue and green detected under UV lamp had Rf of 0.80 and 0.93, respectively. The IR, UV, NMR, mass spectrum and elemental analysis of blue and green compounds showed that the molecular formula of these compounds suggested to be C19H35O4N and C17H34O4N and molecular weight 341 and 316, respectively. Purified substance (s), were tested against ZYMV in cucumber plants giving inhibition 100%. The ELISA values were 0.975, 0.928 for virus concentration in cucumber leaves extract treated with blue and green compounds, respectively in comparison with 1.884 for mechanically inoculated ZYMV.
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ABSTRACT: Major challenges of the modern world: energy security, oil price, resources depletion and climate change, have prompted significant advances in research and development of biomass-derived energy and fuels. Algal biofuels are seen as one of the most promising solutions of global energy crisis and climate change for the years to come. Major advantages of algae are potentially high yield and no competition with food crops for arable land and fresh water resource. This review summarises recent advances in algal biofuel production and focuses on synthesis of transportation fuel rather than characterising algal feedstocks or their well-documented potential as bioenergy resource. The available literature covering production of bioethanol, biodiesel and other potential liquid fuels are evaluated. Overall finding from this study suggests that to date the most effective methods of producing biofuels from algal feedstocks are: fermentation of microalgae to bioethanol and production of biodiesel via in situ transesterification of microalgal biomass. The real breakthrough however is expected from metabolic engineering of photosynthetic organisms to produce and secrete biofuels that promises significant simplification of down-stream processing. (c) 2012 Elsevier Ltd. All rights reserved.Applied Energy 02/2013; 102(C):1371-1381. DOI:10.1016/j.apenergy.2012.07.031 · 5.26 Impact Factor
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ABSTRACT: Bovine mastitis associated with Prototheca is considered a rare pathology, but is increasing in prevalence all over the world and therefore becoming more relevant to the dairy industry. The biochemical characterization of 47 Prototheca isolates retrieved from mastitic milk was performed in this study using API 20C Aux and two BBL Crystal Kits, followed by an analysis with InforBio software. The usage of this methodology, allowed the identification of discriminative phenotypic characteristics for the strains tested. The differential-character-finding algorithm used by this software permitted the identification of new phenotypic characteristics to discriminate between Prototheca zopfii, P. blaschkeae and P. wickerhamii, such as, citrate, phosphorycholine and arabinoside. The main objective of this study was to determine new phenotypic characteristics that allowed a better characterization of Prototheca spp. Usage of recent bioinformatic tools improved the analyses of several features that are important for a better characterization of Prototheca spp.Research in Veterinary Science 08/2010; 89(1):5-9. DOI:10.1016/j.rvsc.2009.12.017 · 1.51 Impact Factor