Poly(hydroxyalkanoate) production by Cupriavidus necator from fatty waste can be enhanced by phaZ1 inactivation

PHA production from waste oils or fats requires microorganisms that should be both excellent PHA producers and equipped with enzymatic activities allowing hydrolysation of triglycerides. Unfortunately, microbes with the combination of substrate-utilization and PHA production are not currently available, and the strategies to be adopted are the use of costly commercial enzymes, or genetic modification of microorganisms exhibiting high PHA product yields. In the present work, after a general investigation on the ability of Cupriavidus necator to grow on a number of fatty substrates, the possibility to enhance PHA production by limiting intracellular depolymerisation, was investigated. By knocking out the related phaZ1 gene, the construction of C. necator recombinant strains impaired in depolymerase (PhaZ1) activity was achieved. The polymer yield of the recombinant strain was finally compared to that of the parental C. necator DSM 545

Innately robust yeast strains isolated from grape marc have a great potential for lignocellulosic ethanol production

Bioethanol from lignocellulose is an attractive alternative to fossil fuels, and Saccharomyces cerevisiae is the most important ethanol producer. However, yeast cells are challenged by various environmental stresses during ethanol production on an industrial scale, and robust strains with a high tolerance to inhibitors, temperature and osmolality are needed for the effective feasibility of lignocellulosic ethanol. To search for such innately more resistant yeast, we selected grape marc as an extreme environment due to limited nutrients, exposure to solar radiation, temperature fluctuations, weak acids and ethanol. Using a temperature of 40 A degrees C as the key selection criterion, we isolated 120 novel S. cerevisiae strains from grape marc and found high ethanol yields (up to 92 % of the theoretical maximum) when inoculated at 40 A degrees C in minimal media with a high sugar concentration. For the first time, this work assessed yeast tolerance to inhibitors at 40 A degrees C, and the newly isolated yeast strains displayed interesting abilities to withstand increasing levels of single inhibitors or cocktails containing a mixture of inhibitory compounds. The newly isolated strains showed significantly higher fermentative abilities and tolerance to inhibitors than the industrial and commercial benchmark S. cerevisiae strains. The strong physiological robustness and fitness of a few of these S. cerevisiae yeast strains support their potential industrial application and encourage further studies in genetic engineering to enhance their ethanol performance in terms of rate and yield through the co-fermentation of all available carbon sources

Production of bioethanol from multiple waste streams of rice milling

This work describes the feasibility of using rice milling by-products as feedstock for bioethanol. Starch-rich residues (rice bran, broken, unripe and discolored rice) were individually fermented (20% w/v) through Consolidated Bioprocessing by two industrial engineered yeast secreting fungal amylases. Rice husk (20% w/v), mainly composed by lignocellulose, was pre-treated at 55 degrees C with alkaline peroxide, saccharified through optimized dosages of commercial enzymes (Cellic (R) CTec2) and fermented by the recombinant strains. Finally, a blend of all the rice by-products, formulated as a mixture (20% w/v) according to their proportions at milling plants, were co-processed to ethanol by optimized pre-treatment, saccharification and fermentation by amylolytic strains. Fermenting efficiency for each by-product was high (above 88% of the theoretical) and further confirmed on the blend of residues (nearly 52 g/L ethanol). These results demonstrated for the first time that the co-conversion of multiple waste streams is a promising option for second generation ethanol production

Utilisation of wheat bran as a substrate for bioethanol production using recombinant cellulases and amylolytic yeast

Wheat bran, generated from the milling of wheat, represents a promising feedstock for the production of bioethanol. This substrate consists of three main components: starch, hemicellulose and cellulose. The optimal conditions for wheat bran hydrolysis have been determined using a recombinant cellulase cocktail (RCC), which contains two cellobiohydrolases, an endoglucanase and a beta-glucosidase. The 10% (w/v, expressed in terms of dry matter) substrate loading yielded the most glucose, while the 2% loading gave the best hydrolysis efficiency (degree of saccharification) using unmilled wheat bran. The ethanol production of two industrial amylolytic Saccharomyces cerevisiae strains, MEL2[TLG1-SFA1] and M2n [TLG1-SFA1], were compared in a simultaneous saccharification and fermentation (SSF) for 10% wheat bran loading with or without the supplementation of optimised RCC. The recombinant yeasts. cerevisiae MEL2[TLG1-SFA1] and M2n[TLG1-SFA1] completely hydrolysed wheat bran's starch producing similar amounts of ethanol (5.3 +/- 0.14 g/L and 5.0 +/- 0.09 g/L, respectively). Supplementing SSF with RCC resulted in additional ethanol production of about 2.0 g/L. Scanning electron microscopy confirmed the effectiveness of both RCC and engineered amylolytic strains in terms of cellulose and starch depolymerisatio

Geomorphological map of the Lipari volcanic island (Aeolian Archipelago – Italy)

A 1:10,000-scale geomorphological map of the Lipari volcanic island (Aeolian Archipelago – Italy) is presented in this paper. The associated map, which includes volcanic and epivolcanic landforms, is obtained combining the available geological information with data derived from the analysis of a digital terrain model, integrated with aerial photographic observations and field surveys. The map shows that the location of the main volcanic morphologies is strongly controlled by local tectonic structures striking NNW-SSE, while the epivolcanic morphologies are mainly related to the continuous uplift induced by the prevalence of regional tectonic processes. The aim of this work is to provide an improved geomorphological map, with a reasonably comprehensive overview of the landforms present in the most densely populated island of the Aeolian Archipelago. This map can be also used as a support for future studies of land management on the island

Whey Lactose as a Raw Material for Microbial Production of Biodegradable Polyesters

Fossil fuel technologie

Bacterial Production of PHAs from Lipid-Rich by-Products

Background and Objective: Due to oil shortage and environmental problems, synthetic plastics will surely be replaced by alternative, biodegradable materials. A possible good example could be polyhydroxyalkanoates, and the inexpensive agricultural fatty byproducts could be usefully converted to polyhydroxyalkanoates by properly selected and/or developed microbes.Material and Methods: Among the more common by-products available, a variety of lipid-rich residues have been explored as substrate, such as crude glycerol from biodiesel, biodiesel obtained from fatty residues, and, from slaughterhouse, bacon rind, udder and tallow. In this paper, several new isolates and collection PHA-producing microbes have been screened for both lipolytic activities and polyhydroxyalkanoates production. The soil proved to be the most promising mining place to find new interesting microbial species, even better than more specific and selective environments such as slaughterhouses.Results and Conclusion: Remarkably, two of the collection strains used here, known to be polyhydroxyalkanoates producers, resulted as really promising, being able to grow directly on all the substrates tested and to produce variable amounts of the polymer, including the co-polymers P (3HB-co-3HV).Conflict of interest: The authors declare no conflict of interest

MICROBIAL PROCESSING OF ORGANIC WASTE STREAMS INTO PHAs AND OTHER HIGH VALUE BIO-PRODUCTS

In the last years, economic and environmental concerns arose for oil shortage and climate change; for these reasons the scientific community focused on possible oil substitutes. In this perspectives, the production of new energy, materials and chemicals of non-fossil origin, could be based on biological resources such as biomasses. The efforts of the microbiology group of DAFNAE are mainly devoted to the exploitation of waste and residual biomasses for the production of high value bio-products such as polyhydroxyalkanoates (PHAs), bioethanol and biohydrogen. PHAs are today considered among the most promising substitutes for petrol-based plastics nevertheless their substitution over the conventional plastics is limited by their expensive manufacturing because of the costly raw materials used as carbon sources and the complex downstream phase of PHAs recovery from bacterial cells. Possible solutions could be i) the utilization of cheap wastes of agro-food origin as carbon sources and ii) the simplification of downstream purification processes. To these aims, Cupriavidus necator DSM545, a well-known PHAs accumulator, has been genetically modified in order to acquire the ability of metabolizing lactose from whey (dairy industry) or lipids (from slaughterhouse) and the capacity to produce nuclease to facilitate downstream processes. In the first case, the modified strains resulted able to grow using whey or lipids as carbon sources, accumulating up to 30 and 60% of PHAs, respectively. In the second case, the recombinant C. necator DSM 545 resulted in an effective decrease of viscosity of bacterial cells lysates, thus avoiding the use of costly commercial nucleases for an efficient downstream. Bioethanol is a fuel obtained from renewable resources and it could be a promising alternative to petrol fuels. First generation bioethanol is mainly produced from corn and sugarcane, thus conflicting with food and feed production . On the contrary, bioethanol from residual and lignocellulosic biomass has environmental impact lower than fossil fuels and would not threaten food supplies. Unfortunately, Saccharomyces cerevisiae, the yeast used for industrial bioethanol production, is not equipped with suitable hydrolytic activities and thus cannot directly utilize starchy and lignocellulosic wastes as feedstock without the use of commercial enzymes. Recent studies were focused to develop a \u201cConsolidated bioprocessing\u201d (CBP), approach where a single yeast is able to hydrolyse starch and lignocellulose and ferment the resulting sugars into ethanol. . With this purpose, novel and robust S. cerevisiae strains were recently engineered at DAFNAE to secrete efficient cellulases and amylases for the efficient saccharification and fermentation of starchy and cellulosic by-products up to 65 g/L ethanol

Endovascular and open repair for blunt aortic injury, treated in one clinical institution in Brazil. A case series

OBJECTIVE: The objective of this retrospective study is to analyze and compare the results of conventional surgical repair and endovascular treatment of blunt aortic injury over the past 8 years. METHODS: Twenty-eight patients (25 male; mean age, 35 years) were treated for blunt aortic injury between April 2001 and March 2009 in a university hospital in Brazil. Twenty-six patients were included in the study: five were treated with operative repair (OR) and 21 with endovascular treatment (TEVAR). Two patients were excluded from analysis: one was managed conservatively, and one was treated with endovascular treatment for chronic dissection related to aortic trauma. RESULTS: Mean age was lower in the OR group than in the endovascular treatment group (17.8 vs. 38 years, P = .003). There was one death in the OR group and four deaths in the endovascular treatment group. Mean follow-up for the overall group was 33.6 months, with 48.7 months (range 8-83 months) for the OR group, and 29.8 months (range 2-91 months) for the TEVAR group. Mean time elapsed from injury to repair was 23.4 hours (range 8-48 h, median 20 h) for the OR group and 30.3 hours (range 2-240 h, median 18 h) for the TEVAR group (P = .374). The duration of surgery was shorter in the endovascular treatment group (142 versus 237 minutes; P = .005). There were no significant differences with respect to the number of postoperative days requiring mechanical ventilation, duration of ICU stay or duration of hospital stay. CONCLUSION: In this retrospective analysis, endovascular treatment was a safe method for repair of blunt aortic trauma, with immediate and midterm results that were comparable to those results obtained with operative repair. No complications from the stent graft were identified during follow-up. Nevertheless, long-term follow-up is necessary to confirm the effectiveness of this treatment

Prime stime mediante simulazioni numeriche delle velocita' di lancio di ejecta allo stromboli e valutazioni sul rischio vulcanico indotto

The typical strombolian activity of Stromboli volcano ranges from a nearly continuous venting of ash and gases (normal strombolian activity) to moderate, up to violent explosive pulses (violent strombolian activity). Moreover, both regimes are sometimes punctuated without warning by phases of scaled up, distinct and more energetic huge bursts separated by time intervals ranging from minutes to hours (paroxysmal activity). As this eruptive style causes the blasting from the summit vents of hot fragments of new lava and blocks with different velocities, densities and impact sites, the main volcanic risk at Stromboli is related to the hazard due to ballistic showers of these ejecta on the built-up areas of the island (Stromboli and Ginostra villages). For that reason i) a land use map of the island has been produced and ii) a number of numerical simulations of ballistic trajectories for to constrain the velocity ranges of the three different explosive regimes has been performed with the "Eject!" software (L.G. Mastin, 2001) by using the average density of dense blocks (2800 kg/m3) and juvenile bombs (1970 kg/m3) from a set of 44 ejecta that we collected on the flanks of the volcano. The reliable ranges of initial velocity at the takeoff point (summit vents) that we obtained are: 40 m/s ÷ 60 m/s for normal strombolian activity, 70 m/s ÷ 100 m/s for violent strombolian activity and 120 m/s ÷ 200 m/s for paroxysmal strombolian activity. Without wind, the cross-correlation of the land use - velocity data indicates that both for the villages of Stromboli and Ginostra an ejecta impact probability is realistic only in paroxysmal activity periods, while it’s definitively absent during normal and violent strombolian regimes. Following tail-winds = 25 m/s simulations (wind velocity sometimes observed at the Stromboli island), the resulting hazard increases with respect to the tail-winds = 0 m/s simulations for both Stromboli and Ginostra during the paroxysmal regime, and become appreciable for the Ginostra village even during violent strombolian activity