Impact of culture conditions on the chlorophyll content of microalgae for biotechnological applications

Abstract

Chlorophyll is a commercially important natural green pigment responsible for the absorption of light energy and its conversion into chemical energy via photosynthesis in plants and algae. This bioactive compound is widely used in the food, cosmetic, and pharmaceutical industries. Chlorophyll has been consumed for health benefits as a nutraceutical agent with antioxidant, anti-inflammatory, antimutagenic, and antimicrobial properties. Microalgae are photosynthesizing microorganisms which can be extracted for several high-value bioproducts in the biotechnology industry. These microorganisms are highly efficient at adapting to physicochemical variations in the local environment. This allows optimization of culture conditions for inducing microalgal growth and biomass production as well as for changing their biochemical composition. The modulation of microalgal culture under controlled conditions has been proposed to maximize chlorophyll accumulation. Strategies reported in the literature to promote the chlorophyll content in microalgae include variation in light intensity, culture agitation, and changes in temperature and nutrient availability. These factors affect chlorophyll concentration in a species-specific manner; therefore, optimization of culture conditions has become an essential requirement. This paper provides an overview of the current knowledge on the effects of key environmental factors on microalgal chlorophyll accumulation, focusing on small-scale laboratory experiments.

Increasing the Protein Amount of Chlorella vulgaris [Chlorphyta] Strains Isolated from Different Fresh Water Ponds

“…The researchers put forward that the intracellular chlorophyll content decreased in the absence or lack of magnesium, which resulted in a negative impact upon photosynthesis amount in Chlorella sp. [15,36]. Magnesium source of growth media used in authors' study was MgSO 4 .…”

“…Different Fresh Water Ponds 202 [15]. Mulders, K. J., et al [16] identified the structure of chlorophyll as "a hydrocarbon tail connected to chlorin, an aromatic ring that contains a tetrapyrrole in which the central magnesium ion is bound to four pyrrole rings".…”

A Non-Vector Approach to Increase Lipid Levels in the Microalga Planktochlorella nurekis

“…Besides their important roles in the process of photosynthesis and pigmentation, microalgal pigments may promote a number of beneficial biological effects such as antioxidant, anticancer, anti-inflammatory, anti-obesity, anti-angiogenic and neuroprotective effects and thus may be considered as high-value nutraceuticals and pharmaceuticals [9,33]. The chlorophyll yield may be improved by light intensity, culture agitation, and changes in temperature and nutrient availability [34]. For example, optimum light-dark cycle, decreased light intensity, red light, high availability of phosphorus and increased temperature may promote chlorophyll accumulation in microalgae [34].…”

“…The chlorophyll yield may be improved by light intensity, culture agitation, and changes in temperature and nutrient availability [34]. For example, optimum light-dark cycle, decreased light intensity, red light, high availability of phosphorus and increased temperature may promote chlorophyll accumulation in microalgae [34]. However, such modulations may be also species-dependent [34].…”

“…For example, optimum light-dark cycle, decreased light intensity, red light, high availability of phosphorus and increased temperature may promote chlorophyll accumulation in microalgae [34]. However, such modulations may be also species-dependent [34]. We have analyzed the effect of CC co-treatment on the levels of chlorophyll a and b as well as the content of carotenoids and the ratio of carotenoids to chlorophyll a ( Figure 5).…”