Fig 1.
Seaweed cultivation platforms of Ulva compressa grown at different JSM (mean ± st.dev., n = 3) concentrations on three different cultivation spray systems for 15 days.
a) Multi-Level Horizontal Design (MLHD); b) Bag-Pocket Vertical Design (BPVD), c) Sloped Design (SD), d) Submerged (SUB). Except for the submerged, the other three designs were recirculating systems where the recycled water was pumped back into a reservoir that collects the water and drips back into the culture through gravity at a flow rate of ~5 ml s-1. Two fluorescent lamps were placed on both sides of the systems set at a 12/12 light/dark cycle. It is a randomized two-factorial design (see S1 Fig for illustration) to test the design and JSM concentration and its interaction effects with growth performance and protein production.
Table 1.
Initial and final nutrient concentrations (mean±st.dev., n = 3) of JSM on three different cultivation design-units (MLHD, BPVD, SD and SUB).
Fig 2.
a) Mean biomass production per day of Ulva compressa grown at different JSM concentrations (1X-8X) on three different cultivation drip-irrigated system cultivations for 15 days in culture; (mean ± st.dev., n = 3 replicates; note: each replicate is an average of 3 trials); b) % Growth rate per day of Ulva compressa grown at different JSM concentrations (mean ± st.dev., n = 3) on three different cultivation spray system cultivation for 15 days.
Table 2.
Biomass data passed normality (Shapiro-Wilk; P = 0.087) after log transformation and equal variance tests (Brown-Forsythe; p = 0.682).
Two-way Analysis of variance of the JSM fertilizer concentrations (1X, 2X, 4 X and 8X) and cultivation design (MLHD, BPVD, SD, SUB) on the daily growth rate of U. compressa. *The mean difference is significant at the 0.05 level.
Table 3.
Pairwise comparison using Holm-Sidak method comparing interaction of effects of design (MLHD, BPVD, SD, SUB) and JSM fertilizer concentrations (1X, 2X, 4 X and 8X).
Overall significance level = 0.05. *The mean difference is significant at the 0.05 level.
Table 4.
Kinetic parameters Vmax of U. compressa.
A small Km for BPVD indicates the enzyme requires only a small amount of substrate to become saturated. Vmax represented as the maximum reaction velocity. Standard error and significance (alpha = 0.05) of the linear regression analysis of the linearized form of the Michaelis-Menten equation (Lineweaver-Burk double reciprocal plot).
Fig 3.
% Protein content of U. compressa grown for 15 days in the different cultivation systems at different concentration of JSM media (mean ± st.dev., n = 3).