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.
"The idea of a unified theory of tolerance to anoxia seems to have no theoretical ground, since distinct tolerance mechanisms, depending on the species and even on the tissue specific. Studies on the variation of the adenylate energy load, imposed on vegetable tissues by anoxia, confirms this variable as the only common possible ways     . Plant cells have the physiological potential to trigger the mechanism under anoxia which maintains satisfactory energy loads under stress . "
[Show abstract][Hide abstract] ABSTRACT: The present study screens activity of different en-zymes in Trapa natans under aerobic and anaerobic physiological conditions. Experimental analysis was carried out to assay the activities of ALDH and ADH in the seed extract of T. natans. These enzymes are as-sociated with the alcohol metabolism of the T. natans. It was observed that a metabolic pathway shifts from aerobic respiration to anaerobic fermentation under anoxic conditions. Physiological stress related re-sponse in trapa seeds gives the leads to understand the other model for better fermentable products. During the experiment it was found that there is dif-ference between the concenteration of enzymes in anaerobic and aerobic conditions. Concentration was check with the help of spectrophotometer at 340 nm.
"For example, although clusters 7G and 7H did not assimilate GAL, FGN and FGS they could be distinguished by the weak assimilation of INO, PRO and PLN and for the assimilation of URE of the later cluster. Despite this study accomplishing the purpose of finding discriminative characters for characterization of Prototheca spp., the practical results revealed a high variability within P. zopfii, which are in concordance with previous reports (Kerfin and Kessler, 1978; Huss et al., 1999; Ueno et al., 2002; Roesler et al., 2006; Marques et al., 2008) referring to the presence of heterogeneities in biochemical assimilation and fermentation patterns of P. zopfii strains. Although these findings suggest novelty, and since there is no species consistency on the assimilation of these subtracts some caution should be taken considering the weak or late assimilations as discriminatory, because weak positives can be due to small amounts of impurities and late assimilations can be due to subtract decomposition. "
[Show abstract][Hide abstract] 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 · 1.41 Impact Factor
[Show abstract][Hide abstract] 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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