FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W16572499> ?p ?o ?g. }

• W16572499 abstract "The hydrogen production in the green microalga Chlamydomonas reinhardtii was evaluated by means of a detailed physiological and biotechnological study. First, a wide screening of the hydrogen productivity was done on 22 strains of C. reinhardtii, most of which mutated at the level of the D1 protein. The screening revealed for the first time that mutations upon the D1 protein may result on an increased hydrogen production. Indeed, productions ranged between 0 and more than 500 mL hydrogen per liter of culture (Torzillo, Scoma et al., 2007a), the highest producer (L159I-N230Y) being up to 5 times more performant than the strain cc124 widely adopted in literature (Torzillo, Scoma, et al., 2007b). Improved productivities by D1 protein mutants were generally a result of high photosynthetic capabilities counteracted by high respiration rates.Optimization of culture conditions were addressed according to the results of the physiological study of selected strains. In a first step, the photobioreactor (PBR) was provided with a multiple-impeller stirring system designed, developed and tested by us, using the strain cc124. It was found that the impeller system was effectively able to induce regular and turbulent mixing, which led to improved photosynthetic yields by means of light/dark cycles. Moreover, improved mixing regime sustained higher respiration rates, compared to what obtained with the commonly used stir bar mixing system. As far as the results of the initial screening phase are considered, both these factors are relevant to the hydrogen production. Indeed, very high energy conversion efficiencies (light to hydrogen) were obtained with the impeller device, prooving that our PBR was a good tool to both improve and study photosynthetic processes (Giannelli, Scoma et al., 2009).In the second part of the optimization, an accurate analysis of all the positive features of the high performance strain L159I-N230Y pointed out, respect to the WT, it has: (1) a larger chlorophyll optical cross-section; (2) a higher electron transfer rate by PSII; (3) a higher respiration rate; (4) a higher efficiency of utilization of the hydrogenase; (5) a higher starch synthesis capability; (6) a higher per cell D1 protein amount; (7) a higher zeaxanthin synthesis capability (Torzillo, Scoma et al., 2009).These information were gathered with those obtained with the impeller mixing device to find out the best culture conditions to optimize productivity with strain L159I-N230Y. The main aim was to sustain as long as possible the direct PSII contribution, which leads to hydrogen production without net CO2 release. Finally, an outstanding maximum rate of 11.1 ± 1.0 mL/L/h was reached and maintained for 21.8 ± 7.7 hours, when the effective photochemical efficiency of PSII (ΔF/F'm) underwent a last drop to zero. If expressed in terms of chl (24.0 ± 2.2 µmoles/mg chl/h), these rates of production are 4 times higher than what reported in literature to date (Scoma et al., 2010a submitted). DCMU addition experiments confirmed the key role played by PSII in sustaining such rates. On the other hand, experiments carried out in similar conditions with the control strain cc124 showed an improved final productivity, but no constant PSII direct contribution. These results showed that, aside from fermentation processes, if proper conditions are supplied to selected strains, hydrogen production can be substantially enhanced by means of biophotolysis.A last study on the physiology of the process was carried out with the mutant IL. Although able to express and very efficiently utilize the hydrogenase enzyme, this strain was unable to produce hydrogen when sulfur deprived. However, in a specific set of experiments this goal was finally reached, pointing out that other than (1) a state 1-2 transition of the photosynthetic apparatus, (2) starch storage and (3) anaerobiosis establishment, a timely transition to the hydrogen production is also needed in sulfur deprivation to induce the process before energy reserves are driven towards other processes necessary for the survival of the cell.This information turned out to be crucial when moving outdoor for the hydrogen production in a tubular horizontal 50-liter PBR under sunlight radiation. First attempts with laboratory grown cultures showed that no hydrogen production under sulfur starvation can be induced if a previous adaptation of the culture is not pursued outdoor. Indeed, in these conditions the hydrogen production under direct sunlight radiation with C. reinhardtii was finally achieved for the first time in literature (Scoma et al., 2010b submitted). Experiments were also made to optimize productivity in outdoor conditions, with respect to the light dilution within the culture layers.Finally, a brief study of the anaerobic metabolism of C. reinhardtii during hydrogen oxidation has been carried out. This study represents a good integration to the understanding of the complex interplay of pathways that operate concomitantly in this microalga." @default.
• W16572499 created "2016-06-24" @default.
• W16572499 creator A5015686573 @default.
• W16572499 date "2010-03-25" @default.
• W16572499 modified "2023-09-28" @default.
• W16572499 title "Physiology and Biotechnology of the Hydrogen Production with the Green Microalga Chlamydomonas reinhardtii" @default.
• W16572499 doi "https://doi.org/10.6092/unibo/amsdottorato/2321" @default.
• W16572499 hasPublicationYear "2010" @default.
• W16572499 type Work @default.
• W16572499 sameAs 16572499 @default.
• W16572499 citedByCount "0" @default.
• W16572499 crossrefType "dissertation" @default.
• W16572499 hasAuthorship W16572499A5015686573 @default.
• W16572499 hasConcept C104317684 @default.
• W16572499 hasConcept C1124016 @default.
• W16572499 hasConcept C121332964 @default.
• W16572499 hasConcept C134537524 @default.
• W16572499 hasConcept C138777275 @default.
• W16572499 hasConcept C143065580 @default.
• W16572499 hasConcept C150903083 @default.
• W16572499 hasConcept C178790620 @default.
• W16572499 hasConcept C183688256 @default.
• W16572499 hasConcept C185592680 @default.
• W16572499 hasConcept C202189072 @default.
• W16572499 hasConcept C2777727519 @default.
• W16572499 hasConcept C31903555 @default.
• W16572499 hasConcept C512968161 @default.
• W16572499 hasConcept C53991642 @default.
• W16572499 hasConcept C55493867 @default.
• W16572499 hasConcept C59822182 @default.
• W16572499 hasConcept C62520636 @default.
• W16572499 hasConcept C86803240 @default.
• W16572499 hasConceptScore W16572499C104317684 @default.
• W16572499 hasConceptScore W16572499C1124016 @default.
• W16572499 hasConceptScore W16572499C121332964 @default.
• W16572499 hasConceptScore W16572499C134537524 @default.
• W16572499 hasConceptScore W16572499C138777275 @default.
• W16572499 hasConceptScore W16572499C143065580 @default.
• W16572499 hasConceptScore W16572499C150903083 @default.
• W16572499 hasConceptScore W16572499C178790620 @default.
• W16572499 hasConceptScore W16572499C183688256 @default.
• W16572499 hasConceptScore W16572499C185592680 @default.
• W16572499 hasConceptScore W16572499C202189072 @default.
• W16572499 hasConceptScore W16572499C2777727519 @default.
• W16572499 hasConceptScore W16572499C31903555 @default.
• W16572499 hasConceptScore W16572499C512968161 @default.
• W16572499 hasConceptScore W16572499C53991642 @default.
• W16572499 hasConceptScore W16572499C55493867 @default.
• W16572499 hasConceptScore W16572499C59822182 @default.
• W16572499 hasConceptScore W16572499C62520636 @default.
• W16572499 hasConceptScore W16572499C86803240 @default.
• W16572499 hasLocation W165724991 @default.
• W16572499 hasOpenAccess W16572499 @default.
• W16572499 hasPrimaryLocation W165724991 @default.
• W16572499 hasRelatedWork W132062798 @default.
• W16572499 hasRelatedWork W1987635712 @default.
• W16572499 hasRelatedWork W2000510614 @default.
• W16572499 hasRelatedWork W2012684008 @default.
• W16572499 hasRelatedWork W2022132371 @default.
• W16572499 hasRelatedWork W2024493744 @default.
• W16572499 hasRelatedWork W2030721878 @default.
• W16572499 hasRelatedWork W2060410671 @default.
• W16572499 hasRelatedWork W2083785250 @default.
• W16572499 hasRelatedWork W2084851042 @default.
• W16572499 hasRelatedWork W2169332573 @default.
• W16572499 hasRelatedWork W2382894504 @default.
• W16572499 hasRelatedWork W2390985139 @default.
• W16572499 hasRelatedWork W242721205 @default.
• W16572499 hasRelatedWork W2889401549 @default.
• W16572499 hasRelatedWork W2947522649 @default.
• W16572499 hasRelatedWork W2990585307 @default.
• W16572499 hasRelatedWork W3009727389 @default.
• W16572499 hasRelatedWork W3038043943 @default.
• W16572499 hasRelatedWork W3127925675 @default.
• W16572499 isParatext "false" @default.
• W16572499 isRetracted "false" @default.
• W16572499 magId "16572499" @default.
• W16572499 workType "dissertation" @default.