| Congresso Brasileiro de Microbiologia 2023 | Resumo: 604-2 | ||||
Resumo:Fermentative assays were carried out with different concentrations of orange solid waste − WSO and orange wastewater − WWO gDQO⁄L and calcium carbonate − CaCO3 g⁄L. The experimental design of the assay was defined based on the Rotational Central Composite Design ⟨DCCR⟩ methodology, in order to evaluate a range of values for the independent variables, identifying through the Response Surface Methodology ⟨MSR⟩ an optimized experimental condition for production accumulated hydrogen. Microbial characterization of two samples was performed using Illumina sequencing at the end of the assays. The first sample was from the validation assays of the optimized condition for hydrogen production ⟨OC−H⟩ ⟨21.4 gSTV⁄L of WSO, 4.5 gDQO⁄L of WWO, and 3.4 g⁄L of CaCO3⟩, which obtained high hydrogen production ⟨1249.1 mL⁄L⟩, with acetic acid ⟨1213.6 mg⁄L; 33.1%⟩ and butyric acid ⟨2230.8 mg⁄L; 60.8%⟩ being the predominant soluble metabolites. The second sample referred to the E−10 assay ⟨35.1 gSTV⁄L of WSO, 4.5 gDQO⁄L of WWO, and 3.8 g⁄L of CaCO3⟩, whose characteristic was the low production of hydrogen ⟨507.1 mL⁄L⟩ with absolute predominance of lactic acid ⟨6367.8 mg⁄L; 81.9%⟩ among the soluble metabolites. The Shannon diversity index was 0.30 and 1.30 for the OC −H and E−10 assays respectively. Relative abundance greater than 0.05% of phyla in the OC−H assay were Firmicutes ⟨96.92%⟩, Proteobacteria ⟨3.03%⟩ and others ⟨0.05%⟩. While in the E −10 assay were Firmicutes ⟨93.71%⟩, Proteobacteria ⟨5.87%⟩, Halobacteria ⟨0.22%⟩, Actinobacteria ⟨0.09%⟩, Desulfobacterota ⟨0.08%⟩ and others ⟨0.04%⟩. Relative abundance greater than 0.50% of genera in the OC−H assay were Clostridium ⟨95.66%⟩, Enterobacter ⟨1.57%⟩, Enterobacteriaceae ⟨1.44⟩, Paraclostridium ⟨0.54%⟩ and others ⟨0.80%⟩, and in the E−10 assay were Clostridium ⟨51.60%⟩, Lactobacillus ⟨21.94%⟩, Paraclostridium ⟨19.95%⟩, Enterobacteriaceae ⟨3.99%⟩, Enterobacter ⟨0.73%⟩, Kosakonia ⟨0.63%⟩ and others ⟨1.15%⟩. Increasing the concentration of orange solid waste and CaCO3 in the E−10 assay required a greater diversity of the microbial community when compared to the OC−H assay. In the OC−H assay, Clostridium was mainly responsible for the Clostridial metabolic pathway, in the production of acetic acid and butyric acid and in the high production of hydrogen. While in the E−10 assay, Lactobacillus was mainly responsible for the high production of lactic acid.
Development Agency: Coordination for the Improvement of Higher Education Personnel ⟨CAPES Finance Code no 88882.328915⁄2019−01⟩; Research Support Foundation of the State of Sao Paulo ⟨Processo FAPESP No 2015⁄06246−7⟩.
Palavras-chave: agroindustrial citrus, Clostridium, hydrogen production, Lactobacillus, lactic fermentation. Agência de fomento:Coordination for the Improvement of Higher Education Personnel (CAPES Finance Code nº 88882.328915/2019-01); Research Support Foundation of the State of Sao Paulo (Processo FAPESP Nº 2015/06246-7). | |||||