Relation of shear stress and Ka on bikaverin production by Fusarium oxysporum CCT7620 in a bioreactor.

This study involved evaluating the effects of rotational impeller speed agitation (N) and specific air flow rate (Ф) on bikaverin production and on the growth of Fusarium oxysporum employing 11 bench-scale bioreactor assays. The results showed that the maximum bikaverin production (close to 300 mg L) was achieved after 48 h of fermentation in rice medium (20 g L milled rice in water) at 28 °C with a volumetric oxygen transfer coefficient (Ka) and shear stress values of approximately 20 h and 17 N m, respectively. We reached this combination of parameters using an N of 340 rpm and Ф of 0.

Recovery and purification of bikaverin produced by CCT7620.

Microbial pigments have a distinguished potential for applications in food and pharmaceutical industries, stimulating the research in this field. The present study evaluated the ideal conditions for extracting bikaverin (red pigment) from the biomass of CCT7620. Among the solvents tested, ethyl acetate extraction resulted in the highest bikaverin concentration and the kinetic study revealed a saturation in bikaverin concentration from 256 min on.

Natural blue pigments and bikaverin.

In last years, the main studied microbial sources of natural blue pigments have been the eukaryotic algae, Rhodophytes and Cryptophytes, and the cyanobacterium Arthrospira (Spirulina) platensis, responsible for the production of phycocyanin, one of the most important blue compounds approved for food and cosmetic use. Recent research also includes the indigoidine pigment from the bacteria Erwinia, Streptomyces and Photorhabdus. Despite these advances, there are still few options of microbial blue pigments reported so far, but the interest in these products is high due to the lack of stable natural blue pigments in nature.

Comparison of Two Methods for Counting Molds in Fermentations Using the Production of Bikaverin by Fusarium oxysporum CCT7620 as a Model.

The dry cell weight (DCW) measurement is one of the preferred methods to determine the growth of filamentous fungi. However, this technique is not applicable to insoluble culture media, besides being possibly influenced by the presence of extracellular biomass. The standard plate counting (SPC) is a reference method for detecting viable cells; however, it is referred as imprecise.