Effects of light quality on reproduction, growth and pigment content of <em>Gracilaria birdiae</em> (Rhodophyta: Gracilariales)

Abstract

Summary: Gracilaria species are the main source of agar worldwide. Since laboratory cultivation is an important means of sustaining such production, this study aimed to assess the influence of two fundamental strategies of physiological algae adjustment, photoacclimation and photomorphogenesis, on G. birdiae physiology. Specifically, the effects of different spectral light qualities on reproduction, growth, and pigment content in two distinct photoperiods (8 and 14 hours) were examined. Tetrasporophytes and gametophytes were submitted to different light qualities: white, green, red, and blue over the course of nine weeks. At the end of this period, chlorophyll a, allophycocyanin, phycocyanin, and phycoerythrin contents were analysed. Gametophytes showed reproductive structures only under monochromatic radiation. A stimulatory effect on tetrasporangium differentiation was mainly observed under red light, but this high fertility was negatively correlated with growth rate, i.e. algae cultivated under red light showed the lowest growth rate. However, while growth rates were higher in algae exposed to white light, they were similar to those observed in algae subjected to green light and 14 hours of daylight. PE was the predominant pigment, irrespective of light quality. Phycocyanin and phycoerythrin concentration increased when algae were cultivated under green and blue light. Therefore, considering future management prospects for G. birdiae mariculture, we suggest that red light could be utilized as a reproductive inductor to produce tetraspores. Furthermore, if the aim is to achieve high phycoerythrin content, continuous blue light could be applied during a short photoperiod. Indeed, the combination of different wavelengths could allow better economic resource exploitation.Keywords: Gracilaria birdiae; growth; light quality; pigment content; photoacclimation; reproduction.Efectos de la calidad de luz en la reproducción, crecimiento y contenido pigmentario de Gracilaria birdiae (Rhodophyta: Gracilariales) Resumen: Las especies del género Gracilaria son la principal fuente de agar en el mundo. El desarrollo de técnicas de cultivo en laboratorio es importante para mejorar la producción, y por ello, este estudio tuvo como objetivo la evaluación de la influencia de dos estrategias de ajuste fisiológico de las algas, la fotoaclimatación y la fotomorfogénesis en G. birdiae. De modo más específico, se evaluaron los efectos de diferentes calidades espectrales de luz sobre la reproducción, crecimiento y contenido pigmentario bajo dos fotoperiodos (8 y 14 horas). Tetrasporofitos y gametofitos fueron sometidos a las siguientes calidades de luz: blanca (WH), verde (GR), rojo (RD) y azul (BL) a lo largo de nueve semanas. Al final del periodo, se analizaron los contenidos de clorofila a (Chl a), aloficocianina (APC), ficocianina (PC) y ficoeritrina (PE). Los gametofitos carecieron de estructuras reproductivas exclusivamente en radiación blanca. La diferenciación de tetrasporangios fue obtenida bajo estímulo de luz roja, pero fue ...

Effect of Different Light Qualities on Growth, Pigment Content, Chlorophyll Fluorescence, and Antioxidant Enzyme Activity in the Red AlgaPyropia haitanensis(Bangiales, Rhodophyta)

“…Moreover, Tsekos et al [40], Franklin et al [41], and Barufi et al [5] also found that B light could, respectively, increase the PE and PC concentration of Pyropia leucosticta , Chondrus crispus, and Gracilaria birdiae . B and G light help promote the nitrogen accumulation, and these wavelengths could induce soluble protein and phycobiliproteins formation [6].…”

“…It has been reported that the bright red and blue light can increase the ratio of fucoxanthin to Chl a and Chl c : a ratio in Laminaria hyperborea [4]. Furthermore, Barufi et al [5] reported that growth rates were higher in Gracilaria birdiae exposed to white light and red light could be utilized as a reproductive inductor to produce tetraspores. Green light could also be beneficial for algal growth of Halymenia floresia .…”

Artificial light source selection in seaweed production: growth of seaweed and biosynthesis of photosynthetic pigments and soluble protein

“…Light-emitting diodes (LEDs) produce monochromatic light in an energy-efficient way, suggesting their potential to provide supplementary light for seaweed growth (Bourget, 2008;Kim et al, 2015). By filtering fluorescent light with band-pass filters, monochromatic lights have been produced to promote seaweed growth, and their influence has been tested on several seaweed species (Figueroa & Niell, 1990;Figueroa et al, 1995;Korbee, Figueroa & Aguilera, 2005;Kim et al, 2015;Bonomi Barufi, Figueroa & Plastino, 2015). In general, compared to fluorescent light culturing, the seaweed growth rate could be increased by 10-60% under suitable LED light conditions (Schulze et al, 2016;Kim, Choi & Lee, 2019;Gong, Liu & Zou, 2020;Öztaşkent & Ak, 2020).…”

“…In general, compared to fluorescent light culturing, the seaweed growth rate could be increased by 10-60% under suitable LED light conditions (Schulze et al, 2016;Kim, Choi & Lee, 2019;Gong, Liu & Zou, 2020;Öztaşkent & Ak, 2020). However, although LED light has been proposed as a light source for Gracilaria cultivation (Kim et al, 2015;Bonomi Barufi, Figueroa & Plastino, 2015), its influence on a broader variety of seaweed species and their biosynthesis remains poorly understood. Besides, different wavelengths of lights vary in their ability to penetrate water.…”

In vitro and in vivo hypolipidemic properties of the aqueous extract of Spirulina platensis, cultivated in colored flasks under artificial illumination

“…Light characteristics have a profound influence on microalgae metabolism and development. Barufi, Figueroa & Plastino (2015) reported that growth rates were higher in Gracilaria birdiae exposed to white light, and Sharmila et al (2018) concluded that the yellow color light could be used for the more lipid production, whereas blue light for biomass and pigments.…”