Effects of Sampling Days and Critical Levels of CdCl۲ on Glycerol Production of Dunaliella salina

Background and Aim: Due to exposure of waterways with industrial wastewaters, variant algal communities are exposed to critical levels of different components such as salts, minerals or heavy metals. Microalgae are studied because of their resistance to various critical situations. Different kinds of heavy metals show various effects on microalgal cultures depending on dosage, days of application and days of sampling. Dunaliella salina is a green microalgae with noticeable resistance in severe environmental conditions such as salinity, pH or heavy metals. Since glycerol is the last production in photosynthesis cycle in D. salina, it can be used as a natural source of glycerol for producing biofuel or other products.Methods: In this study effects of CdCl۲ on glycerol production was studied in a ۲۰-day duration. Three different dosages of CdCl۲ (۳۰, ۶۰ and ۹۰ mg/L) were added to D. salina culture in one step to maintain it as a source of stress. Sampling took place on pre-planned days after stress to study effects of time as well as heavy metal on algal culture.Results: All levels of heavy metal caused reduction in glycerol production comparing to control culture in all sampling days. The highest glycerol level produced in ۱۰ and ۱۸th day of sampling in control culture. Among heavy metal treated cultures the highest glycerol amount was seen in ۹۰ mg/L and ۱۰th sampling.Conclusion: Results of this study showed that in general presence of heavy metals doesn’t highly affect the glycerol production in D. salina and demonstrates the resistance of this alga to high levels of heavy metals.

کلیدواژه ها:

Cadmium chloride ، Dunaliella salina ، Glycerol ، Heavy metal ، Microalgae.