Effect of Chemical Fertilizer in Culture Media on Biomass, Protein and Pigments in Spirulina platensis

Abstract

The aim of this research was to investigate effects of two NPK-16:16:16 chemical fertilizers: H (high price grade) and L (low price grade) in modified culture media. Chemical fertilizer were analyzed for contaminated heavy metals. It was found that lead and cadmium were lower than the notification of Ministry announcement of the Ministry of Agriculture and Cooperatives. Lead in H type (1.490 ± 0.096 mg/kg) was lower than L type (5.199 ± 0.137 mg/kg), while cadmium was showed no significantly difference. Spirulina platensis were cultured in 15 different formulas under 24 hrs in continuous fluorescence light at room temperature (23.5-28.2oC) for 30 days. The biomass, protein and pigment were then analyzed. The result showed that the production of Spirulina’s filament was highest at 18 days of cultivation but had showed no different among formula N, CH1 and CL1. Therefore, three modified culture media, N, CH1 and CL1 were considerately selected for biomass enrichment in 5 L for 18 days cultivation. The biomass were subsequently harvested and the protein and pigment were investigated. It was found that protein and phycoerythrin content in Spirulina platensis cultured in standard medium (Z) and modified media (N, CH1 and CL1) were not significantly different. Protein ranged from 65.01-70.03% cell dry weight and phycoerythrin ranged from 1.00-1.52 mg/g. The highest chlorophyll a content (13.97 mg/g) was found in Spirulina platensis cultured in CH1 media. The highest total carotenoids (3.18 mg/g) was found in Spirulina platensis cultured in CL1 media. While Z media influences on the highest production of phycocyanin as 100.14 mg/g, followed by CH1 and CL1 ranging from 94.09-91.81 mg/g. However, allowphyocyanin in Spirulina platensis cultured medium were not significantly different ranged from 33.72-34.17mg/g.

In conclusion, the modified medium containing H and L type NPK-16:16:16 chemical fertilizer could potentially substitute costly standard medium. This study could be used as an alternative culture medium for small entrepreneurs in order to effectively reduce the production cost.

งานวิจัยนี้มีวัตถุประสงค์เพื่อทราบผลของปุ๋ยเคมี NPK-16:16:16 2 ชนิด ได้แก่ H และ L (ราคาแพงและราคาถูก) ในอาหารเพาะเลี้ยงสูตรปรับปรุง 15 สูตร ต่อปริมาณชีวมวล โปรทีน และรงควัตถุของสาหร่าย Spirulina platensis ที่เพาะเลี้ยงภายใต้แสงจากหลอดฟลูออเรสเซนต์ 24 ชั่วโมง ที่อุณหภูมิห้อง (23.5-28.2oC) เป็นเวลา 30 วัน โดยปุ๋ย H มีปริมาณตะกั่วน้อยกว่าปุ๋ย L เท่ากับ 1.490 ± 0.096 และ 5.199 ± 0.137 มก./กก. ตามลำดับ (p