Biogas slurry – An alternative growth media for algae cultivation in algiculture systems with simultaneous reduction algal predation

• Main Authors: Abitha R, Chanakya H. N., Afreen Aman, Shwetha U.
• Format: Article
• Language: English
• Published: Applied Science Innovations Private Limited 2015-04-01
• Series: Carbon: Science and Technology
• Subjects: Algae; Slurry; Biogas; Nitrogen; Algal grazers; Algal biofuel
• Online Access: http://www.applied-science-innovations.com/cst-web-site/CST-7-2-2015/CST-131.pdf
• ISSN: 0974-0546; 0974-0546

Biogas slurry provides a complete and high growth rate producing algal cultivation medium thus offsetting the high cultivation costs of raising algal cultures in synthetic growth media. Robust mixed algal consortia can also be cultivated in non-traditional media such as wastewater or biogas slurry along with flooded agricultural crops such as paddy (Algiculture). This greatly enhances the Nsustainability of the algae cultivation. However, since the biogas slurry contains its own set of predators of algal biomass (grazers), it is now important to study the productivities attainable by using slurry in the conventional open ponds and Algiculture setup and understand its impact on grazer population dynamics. In this study we have used diluted biogas slurry (1:10) as growth media and compared algal growth and grazing /predation characteristics for algae cultivated under four treatments namely, Bold’s basal media (M), biogas slurry (S), Algiculture (ALGI), Algiculture with biogas slurry as growth stimulant (ALGI-S). The algal biomass cultivated in slurry based systems gave rise to a productivity of 6.8 g/m2/d as harvestable biomass with simultaneous reduction in the algal mass sacrificed to grazers. We thus attempt to show that biogas slurry may be used as a potential growth media especially in Algiculture system which tends to be vulnerable to grazer attack and loss of algal population.