Influence of airflow intensity on phytase production by solid-state fermentation

Abstract

Phytase production by Aspergillus niger F3 by solid state fermentation (SSF) on citrus peel was evaluated at pilot scale under different aeration conditions. The best airflow intensity was 1 VkgM (Lair kg medium(-1) min(-1)), which allowed to produce 65 units of phytases per gram in dry basis (65 Ug(-1) d.b.) as it removed the metabolic heat generated by the microorganism, Agitation did not improve heat removal. Airflow intensity was considered as scale-up criterion. When the airflow intensity was maintained at 1 VkgM for SSF with 2 and 20 kg of medium, the kinetics parameters for biomass and enzyme concentration at the end of fermentation differed by less than 2. The air flow intensity was required to maintain the temperature and cool the SSF and to provide oxygen for microbial growth. Air flow intensity is a key a factor that must be considered when scale-up of SSF is attempted.

The Effect of Aeration for 6-Pentyl-alpha-pyrone, Conidia and Lytic Enzymes Production by Trichoderma asperellum Strains Grown in Solid-State Fermentation

“…Filamentous fungi have a long been the subject of research. Indeed, many of them have been used as biopesticides because they are ubiquitous colonizers of their habitats as well as for their secretion capacity for antibiotic metabolites and enzymes [6]. Trichoderma is an important fungus genus used for biological control, these fungi could be a good model for biocontrol (BC) application because of their mechanisms of action: nutrients and space competition, antibiotics production, lytic enzymes production and mycoparasitism [7].…”

From flasks to single used bioreactor: Scale-up of solid state fermentation process for metabolites and conidia production by Trichoderma asperellum

“…On a culture media during SSF, the development of mycelial biomass and subsequently high sporulation yields are related to a desiccation process, possibly owe to stress by the culture conditions, causing, thus, an increase in the concentration of conidia (Rodríguez-Fernández et al, 2012;Carboué et al, 2017). This effect has a direct impact on the technical feasibility of conidia production because under such culture conditions, it is possible to use reactors like flasks, trays or bags resulting in energy saving, as far as air control and the laborious handling on the preparation of the fermentation process is concerned.…”

Modeling Schemes for Control of Bed-Temperature Gradients in Solid-State Fermentation

“…The first step on the studies in SSF over an specific metabolism or growth of the microorganism is on laboratory scale, using commonly Erlenmeyer flask because of the facilities to control the fermentation [6] or Petri dishes for the selection of strain and substrate [7]. But these kinds of methods are not developed using a specific bioreactor design; there is not air force or substrate mixing as a characteristic on the operation mode of bioreactors [6,9]. However, some important parameters as temperature of incubation, pH of the medium, moisture content and particle size of the substrate can be analyzed on this pathway (Erlenmeyer flask) [32,33].…”

“…However, some important parameters as temperature of incubation, pH of the medium, moisture content and particle size of the substrate can be analyzed on this pathway (Erlenmeyer flask) [32,33]. Still on laboratory-scale, some studies on bioreactors are made in columns as packed bed bioreactors [8,34], rotating [8,9] or column-tray [9] where the operation conditions could be taking place to improve the productivity or evaluation between reactors and purposes of scale-up.…”

“…But in the real, the experiments are developed in laboratory scale based on different types of bioreactors design, most of them on petri dishes or Erlenmeyer flasks [6,7]. When packed-bed bioreactors are employed for SSF the performance is better, because they maintain stable the substrate during the fermentation, where microorganisms sensitive to agitation forces do not suffer damages that could reduce their growth [8,9]. However, when scale up strategies is followed by researches, the disadvantages of the processes appear.…”