A Method Paper: The Effects of Different Soil Aqueous Extraction Methods on Carbon, Nitrogen and Phosphorus as Enhancer towards Growth of Desmodesmus sp
Purpose: This project was conducted to evaluate the effects of different soil extraction methods as enhancer towards Desmodesmus sp.
Background: Soil extracts have been found to be effective to enhance microalgae productivity. Nutrients such as carbon, nitrogen, phosphorus and other trace metals can be utilised to enhanced microalgae growth. Hence, increasing the extraction yield of these elements by using different extraction methods can be examined in relation to microalgae growth.
Design/Methodology/Approach: Soil samples were obtained from 2 different locations, Sungai Beruang (Chini Lake) and Semelai Bera, Bera Lake. The soil extraction methods were performed based on 2 different methods, natural (room temperature incubation for 24 hours) and autoclaved extraction methods (105oC and 121oC for 1 and 2 hours for each temperature). Incubation of microalgae Desmodesmus sp. strain (TRG-D01) was then carried out by using the soil extracts under climate chamber with 2,500 lux, 12L:12D and 25oC for 9 days.
Results/Findings: Extraction yield for C,N and P for autoclaved were significantly higher compared with natural extraction for both soils (P<0.05) with the highest yield can be observed at 121oC 2×. Soil extracts from all sites using 105oC 2× and 121oC 2× did not enhanced the algae growth (P>0.05) and the exponential phase is not yet observed till 9 days.
Conclusion and Implications: Autoclaved treatment increased the extractable C,N and P concentration compared to the natural extraction method. However, the soil extracts did not give positive results in enhancing the growth of Desmodesmus sp.