Resposta de um cultivar de pêssego com caroço aderente à irrigação por défice regulado

Regulated deficit irrigation (RDI) involves inducing water stress during specific fruit growth phases by irrigating at less than full evapotranspiration. The objectives of this research were to study the effects of RDI perfomed at stage II of fruit growth and postharvest, on productivity of clingstone peaches, fruit quality as well as photosynthetic rate and midday leaf water potential. The research was conducted in a commercial clingstone peach (Prunus persica L. Batch cv. A-37) orchard in Greece. Trees were irrigated by means of microsprinklers and their frequency was determined using local meteorological station data and the FAO 56 Pennman-Monteith method. Photosynthetic rate was measured by a portable infrared gas analyzer. Midday leaf water potential was measured by the pressure chamber technique. During the years 2005 and 2006, the treatment RDII with irrigation applied at growth stage II of the peach tree did not affect productivity, fresh and dry mass of fruits. RDII reduced preharvest fruit drop in comparison to the control. RDII as well as the combined treatment RDII plus RDIP with irrigation applied at postharvest, at both years reduced shoot length of the vigorous shoots inside the canopy. RDII in comparison to the control increased the soluble solids content of the fruits and the ratio soluble solids/acidity. However it did not affect fruit acidity and fruit firmness. RDII as well as RDII plus RDIP in 2006 increased 'double' fruits and fruits with open cavity in comparison to the control and RDIP. Water savings were considerable and associated with the climatic conditions of each year.A irrigação por défice regulado (RDI) envolve a indução de défice de água durante fases específicas do crescimento das frutas, irrigando a taxas menores que a evapotranspiração. Os objetivos desse estudo foram verificar os efeitos da RDI no estágio II do crescimento das frutas e no periodo pós-colheita, avaliando a produtividade de pêssegos, a qualidade dos frutos, bem como a taxa fotossintética e o potencial da água na folha. A pesquisa foi desenvolvida em um pomar comercial de pêssegos com caroço aderente (Prunus persica L. Batch cv. A-37) da Grécia. As árvores foram irrigadas por meio de microaspersores e sua frequência foi determinada por meio de dados meteorológicos obtidos em estação automática e o método FAO 56 Pennman-Monteith para determinação de evepotranspiração. A taxa de fotossíntese foi medida por analisador de gás na faixa do infravermelho. O potencial da água na folha foi medido ao meio-dia usando a técnica da câmara de pressão. Durante 2005 e 2006 o tratamento RDII com irrigação aplicada no estágio II não apresentou efeito sobre a produção, pesos seco e fresco dos frutos. RDII reduziu a queda de frutos antes da colheita, em relação ao controle. RDII, como também o tratamento combinado de RDII mais RDIP com irrigação aplicada em pós-colheita, reduziu o comprimento de ramos vigorosos dentro do dossel nos dois anos de estudo. Em comparação com o controle, RDII aumentou o conteúdo de sólidos solúveis dos frutos e a relação sólidos solúveis/acidez, mas não afetou a acidez dos frutos e a firmeza da polpa. Em 2006 RDII e RDII mais RDIP aumentaram os `frutos dobrados' e frutos com cavidade aberta, em comparação com o controle. A economia de água foi considerável e associada às condições climáticas de cada ano

Development of a circular oriented bioprocess for microbial oil production using diversified mixed confectionery side-streams

Diversified mixed confectionery waste streams were utilized in a two-stage bioprocess to formulate a nutrient-rich fermentation media for microbial oil production. Solid-state fermentation was conducted for the production of crude enzyme consortia to be subsequently applied in hydrolytic reactions to break down starch, disaccharides, and proteins into monosaccharides, amino acids, and peptides. Crude hydrolysates were evaluated in bioconversion processes using the red yeast Rhodosporidium toruloides DSM 4444 both in batch and fed-batch mode. Under nitrogen-limiting conditions, during fed-batch cultures, the concentration of microbial lipids reached 16.6−17 g·L−1 with the intracellular content being more than 40% (w/w) in both hydrolysates applied. R. toruloides was able to metabolize mixed carbon sources without catabolite repression. The fatty acid profile of the produced lipids was altered based on the substrate employed in the bioconversion process. Microbial lipids were rich in polyunsaturated fatty acids, with oleic acid being the major fatty acid (61.7%, w/w). This study showed that mixed food side-streams could be valorized for the production of microbial oil with high unsaturation degree, pointing towards the potential to produce tailor-made lipids for specific food applications. Likewise, the proposed process conforms unequivocally to the principles of the circular economy, as the entire quantity of confectionery by-products are implemented to generate added-value compounds that will find applications in the same original industry, thus closing the loop

Rhodosporidium toruloides cultivated in NaCl-enriched glucose-based media: adaptation dynamics and lipid production

In the present report and for the first time in the international literature, the impact of the addition of NaCl upon growth and lipid production on the oleaginous yeast Rhodosporidium toruloides was studied. Moreover, equally for first time, lipid production by R. toruloides was performed under non-aseptic conditions. Therefore, the potentiality of R. toruloides DSM 4444 to produce lipid in media containing several initial concentrations of NaCl with glucose employed as carbon source was studied. Preliminary batch-flask trials with increasing amounts of NaCl revealed the tolerance of the strain against NaCl content up to 6.0% (w/v). However, 4.0% (w/v) of NaCl stimulated lipid accumulation for this strain, by enhancing lipid production up to 71.3% (w/w) per dry cell weight. The same amount of NaCl was employed in pasteurized batch-flask cultures in order to investigate the role of the salt as bacterial inhibiting agent. The combination of NaCl and high glucose concentrations was found to satisfactorily suppress bacterial contamination of R. toruloides cultures under these conditions. Batch-bioreactor trials of the yeast in the same media with high glucose content (up to 150 g/L) resulted in satisfactory substrate assimilation, with almost linear kinetic profile for lipid production, regardless of the initial glucose concentration imposed. Finally, fed-batch bioreactor cultures led to the production of 37.2 g/L of biomass, accompanied by 64.5% (w/w) of lipid yield. Lipid yield per unit of glucose consumed received the very satisfactory value of 0.21 g/g, a value amongst the highest ones in the literature. The yeast lipid produced contained mainly oleic acid and to lesser extent palmitic and stearic acids, thus constituting a perfect starting material for “second generation” biodiese

Moxidectin Efficacy in a Goat Herd with Chronic and Generalized Sarcoptic Mange

A case of sarcoptic mange affecting almost all the animals of a dairy goat herd is described. This pruritic skin disease led progressively to high mortality and dramatic drop of milk yield. The lesions of the affected goats were typical of a chronic and generalized-diffuse sarcoptic mange. Diagnosis was confirmed by skin scrapings and histopathology in which many mites were demonstrated. All surviving goats were treated with injectable moxidectin solution 1% (CYDECTIN-Fort Dodge) at the dose of 0.2 mg/kg, applied every 15 days for four times, subcutaneously. Although pruritus had decreased soon after the first treatment, a satisfactory healing of cutaneous lesions was witnessed 6 weeks after the beginning of moxidectin trial. Parasitological cure was achieved in all affected animals by the end of the trial. In the four monthly followups, no evidence of sarcoptic mange could be found

Valorisation of side streams from wheat milling and confectionery industries for consolidated production and extraction of microbial lipids

Crude enzymes produced via solid state fermentation (SSF) using wheat milling by-products have been employed for both fermentation media production using flour-rich waste (FRW) streams and lysis of Rhodosporidium toruloides yeast cells. Filter sterilization of crude hydrolysates was more beneficial than heat sterilization regarding yeast growth and microbial oil production. The initial carbon to free amino nitrogen ratio of crude hydrolysates was optimized (80.2 g/g) in fed-batch cultures of R. toruloides leading to a total dry weight of 61.2 g/L with microbial oil content of 61.8 % (w/w). Employing a feeding strategy where the glucose concentration was maintained in the range of 12.2 – 17.6 g/L led to the highest productivity (0.32 g/L∙h). The crude enzymes produced by SSF were utilised for yeast cell treatment leading to simultaneous release of around 80% of total lipids in the broth and production of a hydrolysate suitable as yeast extract replacement

Biotechnological production of fumaric acid: The effect of morphology of Rhizopus arrhizus NRRL 2582

Fumaric acid is a platform chemical with many applications in bio-based chemical and polymer production. Fungal cell morphology is an important factor that affects fumaric acid production via fermentation. In the present study, pellet and dispersed mycelia morphology of Rhizopus arrhizus NRRL 2582 was analysed using image analysis software and the impact on fumaric acid production was evaluated. Batch experiments were carried out in shake flasks using glucose as carbon source. The highest fumaric acid yield of 0.84 g/g total sugars was achieved in the case of dispersed mycelia with a final fumaric acid concentration of 19.7 g/L. The fumaric acid production was also evaluated using a nutrient rich feedstock obtained from soybean cake, as substitute of the commercial nitrogen sources. Solid state fermentation was performed in order to produce proteolytic enzymes, which were utilised for soybean cake hydrolysis. Batch fermentations were conducted using 50 g/L glucose and soybean cake hydrolysate achieving up to 33 g/L fumaric acid concentration. To the best of our knowledge the influence of R. arrhizus morphology on fumaric acid production has not been reported previously. The results indicated that dispersed clumps were more effective in fumaric acid production than pellets and renewable resources could be alternatively valorised for the biotechnological production of platform chemicals

Biotechnological production of fumaric acid: The effect of morphology of Rhizopus arrhizus NRRL 2582

Fumaric acid is a platform chemical with many applications in bio-based chemical and polymer production. Fungal cell morphology is an important factor that affects fumaric acid production via fermentation. In the present study, pellet and dispersed mycelia morphology of Rhizopus arrhizus NRRL 2582 was analysed using image analysis software and the impact on fumaric acid production was evaluated. Batch experiments were carried out in shake flasks using glucose as carbon source. The highest fumaric acid yield of 0.84 g/g total sugars was achieved in the case of dispersed mycelia with a final fumaric acid concentration of 19.7 g/L. The fumaric acid production was also evaluated using a nutrient rich feedstock obtained from soybean cake, as substitute of the commercial nitrogen sources. Solid state fermentation was performed in order to produce proteolytic enzymes, which were utilised for soybean cake hydrolysis. Batch fermentations were conducted using 50 g/L glucose and soybean cake hydrolysate achieving up to 33 g/L fumaric acid concentration. To the best of our knowledge the influence of R. arrhizus morphology on fumaric acid production has not been reported previously. The results indicated that dispersed clumps were more effective in fumaric acid production than pellets and renewable resources could be alternatively valorised for the biotechnological production of platform chemicals

Actinobacillus succinogenes: Advances on succinic acid production and prospects for development of integrated biorefineries

Actinobacillus succinogenes is a wild-type bacterial strain, isolated from bovine rumen, known as one of the most efficient natural producers of succinic acid. Herein, the factors contributing to the fermentative production of succinic acid by A. succinogenes are reviewed with particular focus on raw materials, culture conditions, significance of carbon dioxide availability and downstream separation and purification. The metabolic potential of this strain is evaluated through discussion of the pathways involved in succinic acid production, genome analysis as well as the development of A. succinogenes mutants. The review also addresses the importance of by-product formation during fermentation that constitutes an important aspect regulating succinic acid production by A. succinogenes. The prospect of integrating succinic acid production in future biorefineries is assessed