Table 4.

Summarizing of factors affecting biotechnological production of carotenoids.

Factor	Micro-Organism	Tested Condition	Main Finding	Reference
pH	Rodothorula glutinis	pH 5.91	Production of the highest total carotenoid contents and biomass production	[5]
	Rodothorula glutinis	pH 6.2	The highest content of total carotenoids was observed after 5 days of growth.	[35]
	Rodothorula glutinis	pH ≈ 4.0	High total carotenoid contents in a medium containing imidazole as an inducer of lycopene production.	[86]
	Rodothorula glutinis	pH 5.0	Production of the highest total carotenoid contents and biomass production	[77]
	Rodothorula mucilaginosa	pH 5.0	Increase in the production of carotenoid and biomass	[87]
	Rodothorula acheniorum	pH 5.85	Resulted in a 4.62-fold increase in accumulation of β-carotene	[88]
	Sporidiobolus salmonicolor	pH 4.0	Maximum concentration of total carotenoids	[42]
	Rhodosporidium diobovatum	pH 5.0	Production of the highest total carotenoid contents	[89]
	Rodothorula rubra	pH 5.0	Production of the maximum pigment and cell concentration	[61]
	Rodothorula rubra	pH 5.0	Optimum yeast growth, but also observed that torularhodin production was favored in the pH 6.0–7.0	[90]
	Rhodotorula mucilaginosa and Rhodotorula toruloides	pH 5.0	R. mucilaginosa produced the lowest amount of total carotenoids, while R. toruloides produced the highest total carotenoid	[91]
Temperature	Rodothorula glutinis	15 and 25 °C	The optimum temperature to produce carotenoids was 15 °C, while cell growth at 25 °C.	[35]
	Rodothorula glutinis	30 °C	The highest production of biomass and carotenoids	[37]
		25–30 °C	The production rate of carotenoids increased at temperatures above 30 °C	[6]
	Rodothorula mucilaginosa	25–30 °C	Increase in the carotenoid production rate; however, at temperatures above 30 °C, carotenoid biosynthesis appeared to be reduced	[52]
	Rodothorula mucilaginosa	22–34 °C	Maximum biomass production was obtained at 34 °C (pH 5.0), while maximum carotenoid synthesis was observed at 22 °C (pH 7.0)	[92]
	Rodothorula mucilaginosa	10–30 °C	Both biomass yield and carotenoid contents increased with temperature increase	[87]
	Rodothorula acheniorum	23 °C	Maximum optimized production of β-carotene	[88]
	Rodothorula rubra	20–30 °C	None significant difference for both production of carotenoids and biomass growth	[90]
	Rodothorula diobovatum	30 °C	Maximum cell growth	[89]
	Sporidiobolus salmonicolor	25 °C	The highest production of carotenoid	[93]
Agitation and aeration rate	Rodothorula glutinis	100 to 150 rpm	Lower cell growth due to the reduction of the availability of nutrients on the cell surface, while cell rupture was observed at > 250 rpm	[5]
	Rodothorula glutinis	100 rpm	The highest carotenoid contents after cultivation at 25 °C	[35]
	Rodothorula glutinis	125 rpm	Production of the highest total carotenoid concentrations	[86]
	Rodothorula mucilaginosa	150 rpm	Maximized carotenoid production after 72 h	[87]
	Rhodosporidium toruloides	160 rpm	The accumulation of carotenoids increased over time, reaching the maximum after 96 h of fermentation	[94]
	Sporidiobolus salmonicolor	1.5 vvm and 180 rpm	Maximized the production of carotenoids	[42]
	Sporidiobolus pararoseus	1.2 vvm and 158 rpm	Production of carotenoids was 3.5-fold higher in a stirred tank than agitation in shaking flasks (100–200 rpm)	[95]
Light irradiation	Rodothorula glutinis	weak white light irradiation	Inhibited cell growth; however, simultaneously, it showed a substantial increase in torularhodin production	[80]
	Rodothorula glutinis	light-emitting diodes (LEDs)	Carotenoid production increased when the yeasts were subjected to illumination by three LED lamps (800 mol/m2s)	[37]