https://repositorio.ufba.br/handle/ufba/562 Mon, 04 May 2026 02:22:37 GMT 2026-05-04T02:22:37Z https://repositorio.ufba.br/handle/ri/44286 Título: Bioprospecção de uma cianobactéria isolada no rio Joanes/BA para síntese de produtos visando aplicações biotecnológicas Autor(es): Pinheiro, Maria Teresa Araujo Primeiro Orientador: Sales, Emerson Andrade Abstract: Cyanobacteria represent the most diverse group of photosynthetic organisms on the planet and hold high potential for the discovery of novel bioactive compounds. Their pigments have well-established applications in food and nutraceutical products and also serve as valuable sources of proteins and other biomolecules. These characteristics broaden their potential use in sectors such as biofuels, food, animal feed, and, more recently, in the emerging field of phyconanotechnology. In this context, the aim of this study was to isolate a cyanobacterial strain from a river located in northeastern Brazil, analyze its potential for cyanotoxin production, and evaluate its application potential for obtaining bioproducts such as phycocyanin and carotenoids, as well as for the synthesis of carbon dots from laboratory-cultivated biomass and post-extraction residual biomass. The strain was isolated using a thermal method. Identification was carried out through a polyphasic approach, and cyanotoxin production potential was assessed by molecular and chemical methods (PCR and LC-MS²). Cultivation and growth kinetics were conducted under controlled temperature and light conditions to produce biomass, which was subsequently used for phycocyanin extraction, carotenoid identification, and carbon dot synthesis from residual biomass after bioactive extraction. The isolated and laboratory-cultivated strain was identified as Leptolyngbya boryana and was non-toxigenic. Phycocyanin extraction followed a protocol combining different solvents with freeze–thaw cycles. The most efficient extraction method employed calcium lactate at pH 9.47, yielding the highest phycocyanin content (153.24 mg/g of biomass). HPLC analysis revealed the presence of echinenone and chlorophyll a homologs in the biomass. Additionally, carbon dots were synthesized via a hydrothermal process from the cultivated species’ biomass (both before and after bioactive extraction), as well as from Chlorella vulgaris for comparison. Characterization of the carbon dot nanomaterials showed high fluorescence, photostability, and consistent performance in potential applications such as bioimaging, fluorescent sensors, and optoelectronic devices. Overall, the results indicate that the identified L. boryana strain possesses significant biotechnological potential, both for the production of phycocyanin and carotenoids and for the generation of nanomaterials of interest, highlighting the prospects for valorizing biomass into high-value products and commercial applications. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese Fri, 06 Mar 2026 00:00:00 GMT https://repositorio.ufba.br/handle/ri/44286 2026-03-06T00:00:00Z https://repositorio.ufba.br/handle/ri/44037 Título: Qualidade, eficiência e sustentabilidade na educação superior: uma análise comparativa entre países em relação ao progresso desigual em direção ao Objetivo de Desenvolvimento Sustentável 4 Autor(es): Oliveira-Melo, Felipe Guilherme Primeiro Orientador: Sant’Anna, Ângelo Márcio Oliveira Abstract: This doctoral thesis aims to develop a comprehensive understanding of countries’ progress toward SDG 4 Target 4.3 by analyzing performance typologies and estimating the efficiency with which tertiary education systems generate outcomes related to access to higher education, participation in vocational education, and engagement in lifelong learning. It is structured as article-based research comprising three independent yet interrelated studies. Grounded in Institutional Theory, Resource Dependence Theory, and the Capability Approach, the research adopts a comparative, multi-level, and cross-national design that integrates qualitative evidence synthesis with quantitative modeling based on secondary data. The first article presents a scoping review that systematically maps how tertiary education institutions operationalize quality and efficiency in support of SDG 4. Following the Joanna Briggs Institute methodology and the PRISMA-ScR protocol, 26 empirical studies published between 2015 and 2024 were analyzed using inductive qualitative content analysis. The findings reveal a growing diversity of strategies combining technological innovation, institutional reform, and collaborative partnerships. However, they also highlight persistent challenges related to fragmented governance, conceptual misalignment between quality and efficiency frameworks, and unequal institutional capacities across contexts. This study contributes by proposing a multi-level analytical framework linking micro-, meso-, and macro-level dimensions of quality and efficiency in tertiary education for sustainable development. The second article empirically investigates global performance patterns related to SDG 4 Target 4.3 by developing a cross-national typology of higher education systems. Using recent data (2022–2024) from the United Nations Educational, Scientific and Cultural Organization (UNESCO) Institute for Statistics for 71 countries, the study applies a two-stage clustering approach that combines self-organizing maps and hierarchical clustering. The results identify four distinct clusters of countries, revealing marked differences in access to tertiary education, vocational training participation, lifelong learning engagement, and gender equity. The analysis shows that countries with integrated lifelong learning policies and stronger institutional arrangements tend to exhibit more inclusive and balanced outcomes, while others face persistent gender gaps and limited vocational integration. This article advances the literature by providing an updated empirical typology and by theoretically linking institutional configurations to capability expansion in higher education systems. The third article assesses the relative efficiency with which national higher education systems transform educational resources into outcomes aligned with SDG 4 Target 4.3. Drawing on data from UNESCO and the World Bank for 112 countries, the study applies an output-oriented bootstrap Data Envelopment Analysis model to account for statistical noise and improve the robustness of efficiency estimates. The findings reveal substantial global disparities: while high-efficiency systems are associated with effective governance and strategic resource allocation, many low- and middle-income countries face structural constraints that limit performance. Notably, several countries with lower levels of economic development outperform wealthier peers, indicating that efficiency is more closely related to governance quality than to income level alone. The doctoral thesis demonstrates that global progress toward SDG 4 Target 4.3 has been uneven and only partially convergent. Although access to higher education has expanded worldwide, this quantitative growth has not consistently translated into improved equity, employability, or lifelong learning opportunities. A pronounced asymmetry persists between the Global North and the Global South. These systemic disparities threaten the achievement of Target 4.3 by 2030 and suggest that, without structural reforms, global inequalities in access and inclusion may persist and potentially deepen. The research provides a comprehensive and evidence-based understanding of the uneven progress toward SDG 4, offering actionable insights for policymakers seeking to enhance the equity, effectiveness, and sustainability of higher education worldwide. Editora / Evento / Instituição: Universidade Federal a Bahia Tipo: Tese Wed, 17 Dec 2025 00:00:00 GMT https://repositorio.ufba.br/handle/ri/44037 2025-12-17T00:00:00Z https://repositorio.ufba.br/handle/ri/43582 Título: Uso de biomassa de microalgas e cianobactérias cultivadas em águas residuais de avicultura como potencial energético na produção de biodiesel e amônia como transportadora de hidrogênio Autor(es): Marques, Isadora Machado Primeiro Orientador: Sales, Emerson Andrade Abstract: Ammonia is used worldwide as a fertilizer, but its application as a hydrogen carrier has recently grown. It has the capacity to store hydrogen at 17.7% by weight (corresponding to 120 g/L), superior to methanol (12.5%). Certain microbial biomasses have the capacity to produce ammonia from gasification. The advantage is that these microorganisms can grow in wastewater, performing a dual role in the treatment of agro-industrial effluents and biomass generation. Thus, the objective of this work is to evaluate the cultivation of the microalga Desmodesmus sp. and the cyanobacterium Brasilonema sp. in poultry wastewater for the dual purpose of removing nutrients, nitrogen and phosphorus, as one of the industrial steps in effluent treatment and biomass reuse with potential generation of ammonia and biodiesel. The microorganisms were propagated in 3-liter borosilicate cylindrical photobioreactors. The growth of the microalga and cyanobacterium was monitored by chlorophyll (a) extraction using the solvent suspension method (SSM). Bacterial growth was monitored by the microdroplet plating technique. Wastewater characterization was performed to determine nitrogen by ion chromatography, phosphorus and chemical oxygen demand by spectrophotometer reading, and metals by ICP OES. The biomass was collected and characterized for carbon, nitrogen, oxygen, hydrogen, and sulfur composition through elemental analysis for simulation in Aspen Plus, in addition to lipid extraction and transesterification to evaluate biodiesel generation by fatty acid profile. Through modeling using the Aspen Plus program, the highest biomass generation was obtained from the microalga Desmodesmus sp. cultivated in poultry wastewater (PW) with a production of 1000 kg/h. The lowest production was obtained from the cyanobacterium Brasilonema sp. cultivated in BBM culture medium (CM), with 196.37 kg/h. The highest production of liquid ammonia was obtained from the biomass of the cyanobacterium Brasilonema sp. (PW) with 107.81 kg/h, followed by the microalga Desmodesmus sp. (CM) with 106.92 kg/h. Desmodesmus sp. (PW) showed a higher lipid content (23%) and protein content (42%) with greater CO2 biofixation (0.342 gCO2/L.d), reducing greenhouse gas emissions. Furthermore, it presented ideal proportions of the fatty acids palmitate (53.73% - C16:0) and oleate (8.75% - C18:1), improving the quality of biodiesel with a high cetane index and high oxidative stability. It was observed that for hydrogen generation, the best biomass was from the microalga Desmodesmus sp. cultivated in poultry wastewater, however, for ammonia production, the best species was Brasilonema sp. cultivated in wastewater, providing greater sustainability to the process. The discounted cash flow model indicated that the use of wastewater for ammonia and biodiesel generation reduces operational costs by approximately US$ 632,041.30 with a payback period of 4 years for return on investment. Thus, this study confirms and expands the evidence on the potential of microalgae and cyanobacteria as multifunctional biotechnological platforms, integrating waste treatment with the generation of clean and sustainable energy. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese Tue, 25 Feb 2025 00:00:00 GMT https://repositorio.ufba.br/handle/ri/43582 2025-02-25T00:00:00Z https://repositorio.ufba.br/handle/ri/43529 Título: Avaliação das incertezas nas informações sobre as resistências à tração na flexão e compressão de argamassas cimentícias com lodo de ETA Autor(es): Souza, Thiago Francisco Primeiro Orientador: Kalid, Ricardo de Araújo Abstract: Research on the incorporation of water treatment plant sludge (WTS) into cementitious mortars plays an important role in environmental sustainability by enabling the reuse of solid waste and reducing improper disposal. This study investigated the incorporation of WTS, in both dried (uncalcined) and calcined forms, into Portland cement mortars, with emphasis on the measurement of flexural and compressive strengths, as well as on the evaluation of the uncertainties associated with these measurements. The sludge characterization included thermogravimetric analysis (TGA), X-ray diffraction (XRD), and the Modified Chapelle test. The XRD results indicated a high amorphous fraction in both dried and calcined samples, while the TGA defined 515 °C as the ideal calcination temperature. The consistency index showed that adding 10 % WTS significantly reduced workability (by about 40 %), whereas the mixture with 5 % WTS and superplasticizer maintained a consistency similar to that of the standard mortar. Regarding mechanical performance, the addition of 10 % dried WTS reduced flexural strength by approximately 64 % (2.7 MPa → 7.4 MPa control) and compressive strength by 42 % (14.4 MPa → 24.7 MPa control). The mixture with 10 % calcined WTS showed only a 4 % reduction, and the mixture with 5 % calcined WTS reached 30.9 MPa, about 25 % higher than the control, possibly due to the pozzolanic activity confirmed by the Pozzolanic Activity Index (PAI) and Modified Chapelle tests. The relative standard uncertainties for flexural and compressive strengths were below 5 %, consistent with laboratory measurement conditions. The analysis of the Kessel coefficients indicated that the applied load at the center of the specimens and the maximum failure load were the main contributors to the flexural and compressive strengths, respectively. The comparison of strength results, considering the expanded uncertainty, allowed the assessment of conformity with technical standards and the feasibility of using the mixtures in different applications. The study reinforces the importance of the metrological evaluation of uncertainties in mechanical tests, ensuring greater reliability and traceability of the experimental results of mortars incorporating WTS. Editora / Evento / Instituição: Universidade Federal da Bahia Tipo: Tese Thu, 30 Oct 0010 00:00:00 GMT https://repositorio.ufba.br/handle/ri/43529 0010-10-30T00:00:00Z