تاثيرگلوكز بعنوان منبع كربني بر رشد توده زيستي و توليد رنگدانه از ريزجلبك Spirulina maxima

Influence of glucose on biomass growth and pigment production from Spirulina maxima microalga

اﻣﺮوزه اﺳﺘﻔﺎده از رﻧﮕﺪاﻧﻪﻫﺎي ﻃﺒﯿﻌﯽ ﺑﻪ دﻟﯿﻞ ﮐﺎرﺑﺮد زﯾﺎد ﻣﻮرد ﺗﻮﺟﻪ ﺑﺴﯿﺎري از ﻣﺤﻘﻘﯿﻦ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. Spirulina maxima ﻣﻨﺒﻊ ﻏﻨﯽ از ﭘﺮوﺗﺌﯿﻦ و رﻧﮕﺪاﻧﻪ اﺳﺖ. ﺑﻬﯿﻨﻪﺳﺎزي رﺷﺪ و ﺗﻮﻟﯿﺪ رﻧﮕﺪاﻧﻪﻫﺎي ﻣﺘﺎﺑﻮﻟﯿﺘﯽ ﺑﺎ ﺗﻐﯿﯿﺮ ﻏﻠﻈﺖ و اﻧﺘﺨﺎب روش ﻣﻨﺎﺳﺐ اﻓﺰودن ﮔﻠﻮﮔﺰ ﺑﻪ ﻣﺤﯿﻂ ﮐﺸﺖ اﻣﺮ ﻣﻬﻤﯽ اﺳﺖ. در ﭘﮋوﻫﺶ ﺣﺎﺿﺮ ﺗﺄﺛﯿﺮ ﮔﻠﻮﮐﺰ ﺑﻌﻨﻮان ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﻣﺎزاد و ﺟﺎﯾﮕﺰﯾﻦ ﻣﺤﯿﻂ ﮐﺸﺖ زاروك در ﻏﻠﻈﺖﻫﺎي ﻣﺨﺘﻠﻒ )1/5 ،1 ، 0/5 ،0 ﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( ﺑﺮ رﺷﺪ ﺗﻮده زﯾﺴﺘﯽ و ﺗﻮﻟﯿﺪ رﻧﮕﺪاﻧﻪﻫﺎي ﻓﯿﮑﻮﺑﯿﻠﯽﭘﺮوﺗﺌﯿﻨﯽ، ﮐﺎرﺗﻨﻮﺋﯿﺪ و ﮐﻠﺮوﻓﯿﻞ ﻃﯽ 7 روز ﮐﺸﺖ ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ. ﮐﺸﺖ در ﻗﺎﻟﺐ 8 ﺗﯿﻤﺎر )4 ﺗﯿﻤﺎر ﺣﺎوي ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﻣﺎزاد و 4 ﺗﯿﻤﺎر ﺣﺎوي ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﺟﺎﯾﮕﺰﯾﻦ( ﺑﺎ 3 ﺗﮑﺮار در دﻣﺎي آزﻣﺎﯾﺸﮕﺎه، ﺷﺪت ﻧﻮردﻫﯽ 24±2 ﻣﯿﮑﺮوﻣﻮل ﺑﺮ ﻣﺘﺮﻣﺮﺑﻊ ﺑﺮ ﺛﺎﻧﯿﻪ ﺑﺎ ﻧﻮردﻫﯽ 24 ﺳﺎﻋﺘﻪ اﻧﺠﺎم ﮔﺮدﯾﺪ. ﺣﺪاﮐﺜﺮ ﺿﺮﯾﺐ رﺷﺪ وﯾﮋه و زﻣﺎن دوﺑﺮاﺑﺮ ﺷﺪن ﻣﻄﺎﺑﻖ ﺑﺎ روش ﻣﺪلﺳﺎزي ﻏﯿﺮﺧﻄﯽ ﺑﺎ ﮐﻤﮏ ﻧﺮماﻓﺰار Wolfram Mathematic ﻣﺤﺎﺳﺒﻪ ﮔﺮدﯾﺪ. ﺑﺎﻻﺗﺮﯾﻦ ﻏﻠﻈﺖ ﺳﻠﻮﻟﯽ رﯾﺰﺟﻠﺒﮏ )2/40 ﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( و ﺿﺮﯾﺐ رﺷﺪ وﯾﮋه آن )0/47 ﯾﮏ ﺑﺮ روز( از ﻣﺤﯿﻂ ﮐﺸﺖ ﺑﺎ ﻣﻨﺒﻊ ﮔﻠﻮﮐﺰ ﻣﺎزاد در ﺑﺎﻻﺗﺮﯾﻦ ﻏﻠﻈﺖ اوﻟﯿﻪ ﺑﺪﺳﺖ آﻣﺪ ﮐﻪ اﯾﻦ ﻣﯿﺰان 1/65 ﺑﺮاﺑﺮ ﺑﯿﺸﺘﺮ از زﻣﺎﻧﯽ ﺑﻮده ﮐﻪ ﮔﻠﻮﮐﺰ ﺑﻌﻨﻮان ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﺟﺎﯾﮕﺰﯾﻦ اﻓﺰوده ﮔﺮدﯾﺪ و 3/3 ﺑﺮاﺑﺮ ﺑﯿﺸﺘﺮ از ﻧﻤﻮﻧﻪ ﺷﺎﻫﺪ ﺑﻮد. ﻧﺘﺎﯾﺞ ﺣﺎﮐﯽ از آن اﺳﺖ ﮐﻪ ﻏﻠﻈﺖﻫﺎي ﭘﺎﯾﯿﻦ ﮔﻠﻮﮐﺰ ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺗﻮده زﯾﺴﺘﯽ رﯾﺰﺟﻠﺒﮏ و رﻧﮕﯿﺰهﻫﺎي ﻓﺘﻮﺳﻨﺘﺰي آن ﻧﻤﯽﺷﻮد در ﺣﺎﻟﯽﮐﻪ ﻏﻠﻈﺖ ﺑﺎﻻ ﮔﻠﻮﮐﺰ )1/5 ﮔﺮم ﺑﺮ ﻟﯿﺘﺮ( ﺑﺎﻋﺚ اﻓﺰاﯾﺶ ﺗﻮده زﯾﺴﺘﯽ و ﺗﺠﻤﻊ ﮐﻠﺮﻓﯿﻞ a و ﮐﺎرﺗﻨﻮﺋﯿﺪ در رﯾﺰﺟﻠﺒﮏ ﻣﯽﺷﻮد ﻫﺮﭼﻨﺪ ﺗﺎﺛﯿﺮ ﻣﺜﺒﺘﯽ ﺑﺮ ﺳﻨﺘﺰ ﻓﯿﮑﻮﺑﯿﻠﯽﭘﺮوﺗﺌﯿﻨﯽ ﻧﺪارد. اﮔﺮﭼﻪ ﺑﺎﻻﺗﺮﯾﻦ ﻏﻠﻈﺖ ﮔﻠﻮﮐﺰ ﺑﻌﻨﻮان ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﻣﺎزاد ﺑﻬﺘﺮﯾﻦ ﻧﺘﺎﯾﺞ رﺷﺪزﯾﺴﺖ ﺗﻮده، اﺳﺘﺨﺮاج رﻧﮕﺪاﻧﻪ ﮐﻠﺮوﻓﯿﻞ a و ﮐﺎرﺗﻨﻮﺋﯿﺪ را ﻧﺴﺒﺖ ﺑﻪ ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﺟﺎﯾﮕﺰﯾﻦ ﺑﻪ ﺛﻤﺮ داﺷﺖ اﻣﺎ ﺗﺠﻤﻊ ﺑﯿﺶ از ﺣﺪ زﯾﺴﺖ ﺗﻮده ﺳﺒﺐ ﮐﺎﻫﺶ ﻧﻔﻮذ ﻧﻮر ﺑﻪ داﺧﻞ ﻣﺤﯿﻂ ﮐﺸﺖ و ﺗﻮﻟﯿﺪ رﻧﮕﺪاﻧﻪ ﻓﯿﮑﻮﺑﯿﻠﯽﭘﺮوﺗﺌﯿﻨﯽ ﻃﯽ روزﻫﺎي ﻧﻬﺎﯾﯽ ﮐﺸﺖ ﺷﺪ. اﻟﺒﺘﻪ اﻓﺰودن ﮔﻠﻮﮐﺰ ﭼﻪ ﺑﻌﻨﻮان ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﻣﺎزاد و ﭼﻪ ﺑﻪ ﺻﻮرت ﻣﻨﺒﻊ ﮐﺮﺑﻨﯽ ﺟﺎﯾﮕﺰﯾﻦ ﺗﺎﺛﯿﺮات ﺑﺴﺰاﯾﯽ ﺑﺮ ﺗﻮﻟﯿﺪ رﻧﮕﺪاﻧﻪ ﻓﯿﮑﻮﺑﯿﻠﯽﭘﺮوﺗﺌﯿﻨﯽ ﻧﺪارد.

Nowadays, the uses of natural colors attract the attention of many researchers due to its high applications. Spirulina maxima is a rich source of proteins and pigments. Thus, it is vital to optimize the production of biomass and pigments to choose appropriate concentration and method of adding glucose. In this paper, the impact of alternative and additive glucose in Zarrouk’s medium at various concentrations (0, 0.5, 1 and 1.5 gL-1) on biomass and pigments production like phycobilioproteins, carotenoid and chlorophyll was investigated during the 7 days of cultivation. Microalga was grown in 8 treatments (4 treatment as an additive and 4 treatment as an alternative carbon source) with 3 replications in laboratory temperature and light intensity of 24 ± 2 µmoles/m2/s (24 hours exposure-time). Maximum specific growth rate and doubling time were calculated using nonlinear modeling by Wolfram-Mathematical software. The highest cell concentration (2.39 gL-1) and specific growth rate (0.47 day-1) were obtained from additive glucose source at the highest initial concentration that was 2 times higher than when the glucose was added as an alternative source and 3.3 times higher than the control treatment. As a result, low concentrations of glucose have not caused growth in biomass and photosynthetic pigments production as well as the highest concentration of glucose. In addition, glucose concentration of 1.5 gL-1 could increase the biomass of Spirulina maxima, the content of carotenoid and chlorophyll a, but has no positive effect on the increase of phycobilioproteins content. Compared with glucose as an alternative source, additive glucose with the highest initial concentration of glucose has shown the highest biomass growth, chlorophyll a and carotenoid production. On the other hand, high accumulation of biomass has reduced light penetration in culture medium and phycobilioproteins production during the last cultivation days. Moreover, adding glucose as an additive and alternative carbon source have not a significant effect on the production of phycobilioproteins pigment.