Enhancement of targeted microalgae species growth using aquaculture sludge extracts

Kasturi Arumugam; Mohd Fadzli Ahmad; Nor Suhaila Yaacob; Wan Muhammad Ikram; Maegala Nallapan Maniyam; Hasdianty Abdullah; Tomoyo Katayama; Kazuhiro Komatsu; Victor S Kuwahara

doi:10.1016/j.heliyon.2020.e04556

Enhancement of targeted microalgae species growth using aquaculture sludge extracts

Heliyon. 2020 Jul 30;6(7):e04556. doi: 10.1016/j.heliyon.2020.e04556. eCollection 2020 Jul.

Authors

Affiliations

¹ Universiti Selangor, Faculty of Engineering & Life Sciences, Department of Science & Biotechnology, 45600, Bestari Jaya, Selangor, Malaysia.
² Institute of Bio-IT Selangor, Universiti Selangor, Jalan Zirkon A7/A, Seksyen 7, 40000, Shah Alam, Selangor, Malaysia.
³ Centre for Foundation and General Studies, Universiti Selangor, Jalan Zirkon A7/A, Seksyen 7, 40000, Shah Alam, Selangor, Malaysia.
⁴ Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo, Tokyo, 113-8657, Japan.
⁵ National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
⁶ Faculty of Education & Graduate School of Engineering, Soka University, 1-236 Tangi-Machi, Hachioji-Shi, 192-8577, Japan.

Abstract

Natural growth-promoting nutrients extracted from aquaculture sludge waste can be used to maximise microalgal growth. This study identified the influence of aquaculture sludge extract (SE) on four microalgae species. Conway or Bold's Basal Media (BBM) was supplemented with SE collected from a Sabak Bernam shrimp pond (SB) and Kota Puteri fish pond (KP), and tested using a novel microplate-incubation technique. Five different autoclave extraction treatment parameters were assessed for both collected SE, i.e., 1-h at 105 °C, 2-h at 105 °C, 1-h at 121 °C, 2-h at 121 °C, and 24-h at room temperature (natural extraction). Microalgae culture in the microplates containing control (media) and enriched (media + SE) samples were incubated for nine days, at 25 °C with the light intensity of 33.75 μmol photons m^-2 s^-1 at 12-h light/dark cycle. The total dissolved nitrogen (TDN) and total dissolved phosphorus (TDP) in KP SE were 44.0-82.0 mg L^-1 and 0.96-8.60 mg L^-1. TDN (8.0%-515.0%) and TDP (105%-186 %) were relatively higher in KP SE compared to SB SE. The growth of microalgae species Nannochloropsis ocenica showed significant differences (p < 0.05) between the five extraction treatments from SB and the control. However, Chlorella vulgaris, Neochloris conjuncta, and Nephroclamys subsolitaria showed no significant differences (p > 0.05) in SB SE. N. ocenica, C. vulgaris, and N. conjuncta showed significant differences (p < 0.05) between five extraction treatments from KP and the control while N. subsolitaria showed no significant difference (p > 0.05). The specific growth rate (SGR) in the exponential phase of all microalgae species were relatively higher in SB SE compared to KP SE. While the organic matter content of KP SE was relatively higher, there were no significant differences in microalgae growth compared to SB SE. Nonetheless, modified SE did influence microalgae growth compared to the control. This study shows that modified SE could be used as enrichment media for microalgae cultivation.

Keywords: Agricultural science; Aquaculture sludge extracts; Autoclave extraction parameters; Chlorella vulgaris; Earth sciences; Environmental science; Nannochloropsis ocenica; Neochloris conjuncta; Nephroclamys subsolitaria.