Production of Pigments by Filamentous Fungi Cultured on Agro-Industrial by-Products Using Submerged and Solid-State Fermentation Methods

Abstract

The food and pharmaceutical industries are searching for natural colour alternatives as required by consumers. Over the last decades, fungi have emerged as producers of natural pigments. In this paper, five filamentous fungi; Penicillium multicolour, P. canescens, P. herquie, Talaromyces verruculosus and Fusarium solani isolated from soil and producing orange, green, yellow, red and brown pigments, respectively, when cultured on a mixture of green waste and whey were tested. The culture media with varying pH (4.0, 7.0 and 9.0) were incubated at 25 °C for 14 days under submerged and solid-state fermentation conditions. Optimal conditions for pigment production were recorded at pH 7.0 and 9.0 while lower biomass and pigment intensities were observed at pH 4.0. The mycelial biomass and pigment intensities were significantly higher for solid-state fermentation (0.06–2.50 g/L and 3.78–4.00 AU) compared to submerged fermentation (0.220–0.470 g/L and 0.295–3.466 AU). The pigment intensities were corroborated by lower L* values with increasing pH. The λmax values for the pigments were all in the UV region. Finally, this study demonstrated the feasibility of pigment production using green waste:whey cocktails (3:2). For higher biomass and intense pigment production, solid-state fermentation may be a possible strategy for scaling up in manufacturing industries.

Comparison of Pigment Production by Filamentous Fungal Strains under Submerged (SmF) and Surface Adhesion Fermentation (SAF)

“…Although the pigment production level has been related to genetic and environmental factors [ 58 , 59 ], it was not considered the adhesion influence. That could explain the inverse correlation found between the biomass yield and extracellular pigments (AU) obtained from Penicillium and Talaromyces species under SSF compared to SmF, and corroborates that SSF significantly favors pigment production by this species [ 50 ]. However, optimization is still necessary to improve productivity [ 18 ].…”

“…The same pattern was observed for pigments secreted in BF, except for P. mallochii LMB-HP19 and P. maximae LMB-HP33, which did not show any significant peak; whereas, in SSF, the maximum peaks were observed near 300 nm. In the same way, other authors [ 49 , 50 ] have reported species of Penicillium and Talaromyces with maximum absorption wavelengths in the UV region, although yellow and orange pigments are usually exhibited at 410 and 470 nm, respectively [ 51 ]. Accordingly, Talaromyces albobiverticillius , Talaromyces amestolkiae , and T. purpureogenus have been reported to produce yellow-orange pigments in the visible region, although these species are also able to produce a red pigment [ 37 , 51 , 52 , 53 , 54 , 55 ].…”

“…On the contrary, despite showing the same growth pattern, T. brunneus LMB-HP43 did produce pigments under SmF. It has also been demonstrated that pH has an important impact on pigment production by Penicillium and Talaromyces under SmF, enhancing its production at neutro-alkaline conditions when natural substrates are used [ 50 ].…”

Screening of Pigment Producing Fungi From Floral Waste as a Prospective Anti-Microbial Tool

“…The screened fungal isolates were processed for SSF for enhanced pigment production in accordance with protocols devised by Molelekoa et al, (2021). Briefly, substrate used for the pigment production was partially dried Tagetes sp.…”

Biopigments Produced by Monascus purpureus Through Solid State Fermentation: HPTLC Finger Printing Analysis

“…Makhmur Ahmad 1 and Bibhu Prasad Panda 2 * Species of Monascus are well known for producing pigments like monas-corubrine, rubropunctatine (orange pigment) [13,14]. Monascorubramine and rubropunctamine (red pigments), monascin and ankaflavin (yellow pigments) have also been identified [15,16,17]. More recently monascusones from Monascus mutant [18] have also been recognized.…”