3.2 Screening for colorant production
Based on the visual evaluation of
the colorants produced by fungi in the culture medium, eight isolates
stood out for producing the most intense colorants and were submitted to
submerged bioprocesses, extraction, and evaluation of the solubility of
the colorant.
In Fig. 1, more colorful fractions were obtained from the extraction
with different solvents from the mycelial mass, and the fraction of the
culture filtrate, which has a greater polarity, showed the most intense
extracellular colorants.
The isolates Penicillium sp. P3SO332, Clonostachys sp.
P2SO329 and Penicillium sp. P3SO224 were selected to evaluate the
absorptivity of the colored extracts, which was obtained in the UV/VIS
region. The colored fractions were scanned at 400–700 nm to determine
the maximum absorption wavelength (λmax) in ethyl acetate. Scanning
spectrophotometry showed that the three colorants evaluated have a
maximum absorbance around 400 nm.
The four fungi highlighted in the production of colorants
(Penicillium sp. P3SO332,Clonostachys sp. P2SO329,Penicillium sp. P3SO224,Monascus sp. C02172R) were
subjected to DNA sequencing of the targets ITS1-5.8S rDNA-ITS2 to
confirm their genus and possible DNA identification. The phylogenetic
tree constructed is shown in Fig.
2. The isolate Penicilliumsp. P3SO332 was identified as Penicillium gravinicasei P3SO332
(99% accession: MG600581.1). Clonostachys sp. P2SO329 was
identified as Clonostachys rosea P2SO329 (99% accession:
MN452057.1). Penicillium sp. P3SO224 was identified asPenicillium sclerotiorum P3SO224 (99% accession: MN639705.1).Monascus sp. C02172R was identified as Monascus purpureusC02172R (99% accession: MT355839.1). The nucleotide sequences obtained
after amplification and sequencing were submitted to NCBI GenBank and
the accession numbers
OP563023,
OP563026,
OP563024 and
OP563023, respectively, were obtained.