Sustainable Microalgal Harvesting Process Applying Opuntia cochenillifera: Process Parameters Optimization

Microalgae harvesting by coagulation can use coagulant agents such as alum, synthetic polymers or biocoagulants. Biocoagulants have attracted the attention of researchers because they are natural, biodegradable, and promote high microalgal harvesting efficiencies. This study aims to optimize the harvesting of Chlorella vulgaris based on the dosage of the Opuntia cochenillifera extract and the choice of eluent for biopolymer extraction. The outdoor cultivation of C. vulgaris achieved a specific growth rate of 0.455 d(-1) and a maximum biomass concentration of 1.28 g(DW) L-1. In order to harvest the microalgal biomass, the polymer present in the mucilage of O. cochenillifera was extracted using NaOH and HCl. Coagulation and sedimentation assays were performed with different coagulant dosages: 3.5, 5.9, and 8.2 g L-1. The maximum harvesting efficiencies using the acid and alkaline extract coagulant solutions were 80.8% and 99.5%, respectively, with a dosage of 3.5 g L-1. According to the results, the C. vulgaris biomass can be harvested with the mucilage from O. cochenillifera in acid and alkaline eluents. The application of this biocoagulant constitutes a sustainable solution for microalgal harvesting

Case Study: Rosai-Dorfman Disease and Its Multifaceted Aspects

Daniela Oliveira Werneck Rodrigues,1,2 Roberta Wolp Diniz,2 Leonardo Cunha Dentz,1 Monica de Albuquerque Costa,3 Roberto Heleno Lopes,2 Lucas Fernandes Suassuna,4 Jane Rocha Duarte Cintra,2 Christian Domenge2 1Department of Medicine, Centro Universitário Presidente Antônio Carlos, Juiz de Fora, MG, Brazil; 2Department of Oncohematology, Hospital 9 de Julho/ Instituto Oncológico de Juiz de Fora, Juiz de Fora, MG, Brazil; 3Department of Dematology, Secretaria de Saúde da Prefeitura Municipal de Juiz de Fora, Juiz de Fora, MG, Brazil; 4Department of Medicine, Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG, BrazilCorrespondence: Daniela Oliveira Werneck Rodrigues, Instituto Oncológico de Juiz de Fora, R. Santos Dumont, 56 - Granbery, Juiz de Fora, MG, 36010-510, Brazil, Tel +553232573126, Email [email protected]: Rosai-Dorfman Disease (RDD) is a rare non-Langerhans histiocytosis, usually self-limited and presenting with massive, painless, bilateral cervical lymphadenopathy, with or without constitutional symptoms. Extranodal disease is frequently present, and may happen in the absence of lymph node involvement, symptomatology and differential diagnosis will depend on the site affected and fatal cases may occur. The authors present two cases of Rosai-Dorfman disease (RDD), diagnosed through immunohistochemistry, with different progressions, one with complete remission and one culminating in death, highlighting the variety of presentations and the diagnostic difficulty. RDD is a rare condition with clinical presentations similar to several diseases, and should be considered in the differential diagnosis of lymphadenopathy with extranodal lesions.Keywords: Rosai Dorfman disease, immunohistochemistry, diagnosis, differential diagnosis (MeSH-NCBI