RESUMO
Fermentation parameters for phytase production in column-type bioreactor were monitored using a new data acquisition system. There are a number of studies reporting phytase production in flasks, but a lack of data about microorganism respiration behaviour during phytase production using column bioreactor. The objectives of this work were the monitoration of fermentation parameters during phytase production and its relation with fungal growth and forced air. Phytase production by A. niger FS3 increased with forced air. The O(2) consumption and CO(2) production during solid-state fermentation were monitored by sensors (in the bottom and top of the columns) linked to controllers, recorded by acquisition software and processed by Fersol2(®) software tool. Phytase synthesis was associated with fungal growth. Therefore, phytase could be used to estimate FS3 biomass formed in citric pulp degradation.
Assuntos
6-Fitase/biossíntese , Aspergillus/genética , Reatores Biológicos , Fermentação , Microbiologia Industrial/métodos , 6-Fitase/química , Biomassa , Dióxido de Carbono/química , Meios de Cultura/química , Desenho de Equipamento , Microbiologia Industrial/instrumentação , Cinética , Consumo de Oxigênio , Software , Temperatura , Fatores de TempoRESUMO
The present study aimed at investigating the carbon metabolism in terms of carbon dioxide fixation and its destination in microalgae cultivations. To this purpose, analysis of growth parameters, media of cultivation, biomass composition and productivity and nutrients balance were performed. Four microalgae suitable for mass cultivation were evaluated: Dunaliella tertiolecta SAD-13.86, Chlorella vulgaris LEB-104, Spirulina platensis LEB-52 and Botryococcus braunii SAG-30.81. Global rates of carbon dioxide and oxygen were determinated by a system developed in our laboratory. B. braunii presented the highest CO(2) fixation rate, followed by S. platensis,D. tertiolecta and C. vulgaris (496.98, 318.61, 272.4 and 251.64 mg L(-1)day(-1), respectively). Carbon dioxide fixated was mainly used for microalgal biomass production. Nitrogen, phosphorus (calcium for D. tertiolecta), potassium and magnesium consumption rates (mg gX(-1)) were evaluated for the four microalgae. Biomass composition presented a predominance of proteins but also a high amount of lipids, especially in D. tertiolecta and B. braunii.
Assuntos
Dióxido de Carbono/metabolismo , Eucariotos/classificação , Eucariotos/metabolismo , Biodegradação Ambiental , Estudos de Viabilidade , Especificidade da EspécieRESUMO
The aim of this work was to develop an economical bioprocess to produce the bio-ethanol from soybean molasses at laboratory, pilot and industrial scales. A strain of Saccharomyces cerevisiae (LPB-SC) was selected and fermentation conditions were defined at the laboratory scale, which included the medium with soluble solids concentration of 30% (w/v), without pH adjustment or supplementation with the mineral sources. The kinetic parameters - ethanol productivity of 8.08g/Lh, YP/S 45.4%, YX/S 0.815%, m 0.27h(-1) and microX 0.0189h(-1) - were determined in a bench scale bioreactor. Ethanol production yields after the scale-up were satisfactory, with small decreases from 169.8L at the laboratory scale to 163.6 and 162.7L of absolute ethanol per ton of dry molasses, obtained at pilot and industrial scales, respectively.