Kajian dalam pertumbuhan alga mengabungkan kedua-dua eksperimen dan teknik pemodelan untuk kedua-dua spesies mikroalga, Botryococcus braunii dan Chlorella vulgaris. Persaingan antara kedua-dua spesies ini untuk gizi yang sama (fosfat) juga dipantau. Keduadua spesies ini, iaitu B. braunii dan C. vulgaris, menggunakan Medium Bold’s Basal. Kepekatan fosfat diubah untuk mengkaji kesannya terhadap kadar pertumbuhan kedua-dua alga. Apabila kepekatan fosfat menurun, kadar pertumbuhan untuk kedua-dua spesies alga juga menurun. Dalam eksperimen kultur campuran spesies, B. braunii menunjukkan kadar pertumbuhan yang lebih tinggi daripada C .vulgaris apabila kepekatan fosfat adalah optimum. Namun begitu, apabila kepekatan fosfat berkurang, kadar pertumbuhan C. vulgaris lebih tinggi sedikit daripada B. braunii. Apabila tiada fosfat langsung dalan kultur, kadar pertumbuhan kedua-dua adalah rendah dan lebih kurang sama. Teknik pemodelan yang digunakan berdasalkan persamaan Monod untuk interaksi antara kadar pertumbuhan alga dan kepekatan fosfat. Analisis dwibelah telah digunakan untuk mengkaji pertumbuhan alga dalam persaingan. Tiada kitar had menunjukkan kepekatan gizi adalah mencukupi untuk pertumbuhan B. braunii dan C. vulgaris yang stabil dalam jangka masa yang tertentu.
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The investigation of algae growth combined both experimental and modelling techniques of two species of algae; Chlorella vulgaris and Botryococcus braunii. The competition of both species for the same nutrient (i.e. phosphate) was also monitored. Both species of algae were cultivated using Bold’s Basal Medium. The concentration of phosphate was varied to study its effect to the growth rate of both species of algae. It is observed that when the concentration of phosphate decreased, the growth rate of both species of algae also decreased. In the mixed-species culture experiment, B. braunii had a higher growth rate than C. vulgaris in optimum concentration of phosphate. However, when concentration of phosphate was reduced, the growth rate of C. vulgaris was slightly higher than B. brauni. When there was no phosphate at all in the medium, both algae showed low growth rates which were almost equal. Modelling technique used in this work was based on the Monod equation for the interaction between algae growth rate and the concentration of nutrient. Bifurcation analysis was used to observe the growth rate of algae under competition. No limit cycle was obtained showing that the amount of nutrient was sufficient for the steady growth of algae in a certain period.
The study on the growth of botryococcus braunii and chlorella vulgaris and the competition between the two species_Yeoh Hooi Keng_K4_2011_NI