http://hdl.handle.net/10174/1027 2026-06-05T16:55:15Z http://hdl.handle.net/10174/42122 Title: Heavy Metals Bioremediation: Cd2+, Pb2+ and Zn2+ bioremoval by Serratia marcescens CCMA1010 in aqueous solution Authors: Ferreira, Gustavo; Schwan, Rosane; Silva, Cristina Abstract: Microorganisms offer cost-effective and sustainable solutions for the bioremediation of toxic metals. S. mar- cescens CCMA1010 was investigated for its growth and metal removal potential in aqueous solution with Cd²⁺, Pb²⁺, and Zn²⁺. The bacterium tolerated all three metals, with a minimum inhibitory concentration (MIC) ranking of Zn²⁺ > Pb²⁺ > Cd²⁺. Remarkably, Pb²⁺ had minimal impact on growth compared to the control. A brown coloration in Pb²⁺ treatments suggested the bioprecipitation. FTIR analysis confirmed spectral changes linked to sulphate and phosphate groups, supporting the probability of this mechanism. No similar evidence was found for Cd²⁺ or Zn²⁺. The bioremoval experiment was designed to construct a predictive model and identify the optimal conditions for maximum metal uptake (q), using a Rotatable Central Composite Design (RCCD) with 27 exper- imental runs, including factorial points, axial points, and three central points. The statistical modeling (P-value) showed that quadratic models for Cd²⁺ and Pb²⁺ uptake were significant (p < 0.05), with initial metal concen- tration as the main influencing factor. The p-value for Zn²⁺ (q) was not significant (p > 0.05). The F-values indicate that both models (Cd²⁺ and Pb²⁺) were statistically significant, with only a 0.01% and 0.46% probability, respectively, that such high F-values could have occurred due to random noise. Variables such as pH and in- teractions between multiple metals were not statistically significant under the tested conditions. These results highlight S. marcescens CCMA1010 as a promising candidate for heavy metal bioremediation, particularly for lead removal through bioprecipitation pathways. 2025-01-01T00:00:00Z http://hdl.handle.net/10174/42120 Title: Addition of silicate rock in the composting of poultry manure: Effects on chemical, enzymatic, and microbial properties Authors: Santos, Sandra; Pylro, Victor; Buttros, Victor; Rigobelo, Everlon; Botelho, Flavia; Peron, Rafael; Ferreira, Gustavo; Doris, Joyce Abstract: Composting is a simple and sustainable technique that produces a nutrient-rich organic amendment. This compost can be further enriched with low-cost materials such as silicate rock (SR) powder, offering several benefits for crops like rice, which has the ability to accumulate silicon in its tissues. This study aimed to evaluate the dynamics of chemical, enzymatic, and microbial parameters during the composting of poultry manure (PM) with the addition of SR, and its subsequent application to two rice cultivars under field conditions. Overall, the main properties that varied during the composting process were nitrogen (N), phosphate (P₂O₅), potassium oxide (K₂O), calcium (Ca), magnesium (Mg), and pH. Firmicutes was the most abundant phylum in both treatments, and the addition of SR did not significantly alter the bacterial community composition. Field results showed that fertilization with SR-enriched compost increased the yield of the BRSMG Caçula cultivar, reaching 2.5 t/ha compared to 1.76 t/ha in the treatment without SR 2025-01-01T00:00:00Z http://hdl.handle.net/10174/42097 Title: Serum and saliva immunoglobulin (immunoglobulin G, immunoglobulin A, and immunoglobulin M) dynamics in newborn calves and their association with health status during the first week of life: An exploratory study Authors: Silva, Flávio Gomes; Lamy, Elsa; Conceição, Cristina; Cerqueira, J.O.L.; Ramalho, J.; González-Cabrera, M.; Caetano, Pedro; Martins, Luís; Pereira, Alfredo; Silva, S.; Hernández-Castellano, L.E. Abstract: The transfer of passive immunity is essential to ensure the health and welfare of newborn calves. Although the dynamics of serum Ig concentrations in these animals are well-described, data about saliva Ig are limited. This study aimed to evaluate serum and saliva Ig (i.e., IgG, IgA, and IgM) concentrations during the first week of life in healthy and sick calves. Blood and saliva samples were collected from 20 dairy calves from a dairy farm located in Portugal, at birth (30 min before colostrum intake) and on d 1, 2, and 7 of life. Calves were fed with 3.8 ± 0.64 L (mean ± SD) of maternal colostrum (44.7 ± 16.56 g/L IgG) within 96 ± 73 min of birth. Calves were examined 2 times daily by the farm staff, and health scores were recorded before sample collection (i.e., d 0, 1, 2, and 7), using a modified version of the Wisconsin calf health scoring system. Based on the health scores, calves were categorized as healthy (HC; n = 11; absence of physical signs of disease, active, and with a positive demeanor during the experimental period) or diarrheic (DC; n = 9; loose or watery feces observed during the experimental period). The Ig and total protein (TP) concentrations in serum and saliva were evaluated with linear mixed models including health status (HC vs. DC), time (d 0, 1, 2, and 7), and the interaction between both as fixed effects. The significance was set as P < 0.05. Except for diarrhea, no other health condition was observed. At birth, all Ig isotypes were present in saliva, with IgA being the most relevant. In serum, IgA and IgG were detected during the entire experimental period, but IgM concentrations were only detectable after d 1. Both serum and saliva Ig concentrations increased after colostrum intake (d 1), although saliva IgG concentration declined on d 2, unlike serum IgG concentration, which only decreased on d 7. All saliva Ig declined from d 1 to 2 but only in the HC group. Saliva Ig concentrations in the DC group did not change from d 1 to 7. A tendency for lower saliva IgA and M concentrations was observed in DC calves compared with HC on d 1. Similarly, DC calves showed a reduced proportion of IgA in saliva relative to serum compared with HC on d 1 and a tendency for higher saliva TP on d 7. In conclusion, calf health status was associated with saliva Ig concentrations during the first week of life, with the calves from the DC group showing lower saliva Ig concentrations before clinical signs were observed. © 2025 American Dairy Science Association 2025-08-31T23:00:00Z http://hdl.handle.net/10174/42080 Title: Salivary Amylase Gene Copy Number Relates with BMI Z-Score and with Response to Lifestyle Intervention for Children with Overweight and Obesity Authors: Monserrat-Mesquida, Margalida; Bouzas, Cristina; Cardoso, Hélia; García, Silvia; Argelich, Emma; Mateos, David; Marques, Monica; Campos, Catarina; Lamy, Elsa; Tur, Josep A Abstract: The prevalence of childhood obesity has risen significantly, with numerous associated health risks. Emerging research suggests a potential role for genetic factors; particularly, copy number variations (CNVs) of the amylase 1 gene (AMY1) may influence obesity through dietary behavior and metabolic regulation. This study aimed to examine the relationship between BMI z-score, dietary intake, and salivary AMY1 gene copy number (CN) in children with overweight and obesity, and to assess the relationship between AMY1 CN and the impact of lifestyle intervention on these parameters. The study included 90 children aged 2–6 years with overweight or obesity. Participants were randomized into either a parent support intervention group or a standard care control group. Anthropometric measurements, dietary intake, and salivary AMY1 gene copy number were assessed at baseline and after a 9-month intervention. Positive correlations were found between AMY1 gene copy number, BMI z-score, and carbohydrate intake, suggesting a potential role of this gene in dietary behavior-related obesity. The parent support intervention led to significant reductions in children’s BMI, BMI z-score, and energy and macronutrient intake compared to standard care. Although there was no direct association between AMY1 copy number and changes in BMI z-score, higher AMY1 copy numbers were associated with greater reductions in polyunsaturated fatty acid intake. These findings highlight an interaction between salivary AMY1 gene copy number, dietary intake, and obesity in children. These results support the relevance of genetic factors in obesity-related dietary patterns and emphasize the effectiveness of targeted family-based lifestyle interventions. 2025-08-31T23:00:00Z