## 3 Results and Discussion
### Microalgal Growth Experiments
Compared to such lipids derived from microalgal mixotrophic cultivation that are subsequently extracted and trans-esterified to biodiesel, a bio-oil intermediary product from high temperature fast-pyrolysis or hydrothermal liquefaction will subsequently require a series of more complex and expensive hydrotreatment, fractional distillation, and other bio-refining steps [7]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline  & \multicolumn{4}{c}{**pH Unadjusted**} & \multicolumn{4}{c}{**pH Adjusted Daily to 10**} \\ \hline
**NaHCO3 (g L\({}^{-1}\))** & **ADFW (\%)** & **DCW (g L\({}^{-1}\))** & **Lipid (\%)** & **Lipid (g L\({}^{-1}\))** & **DCW (g L\({}^{-1}\))** & **Lipid (\%)** & **Lipid (g L\({}^{-1}\))** \\ \hline
8.4 & 5 & 0.971 & 24.11 & 0.234 & 1.140 & 34.94 & 0.398 \\  & 10 & 0.905 & 17.28 & 0.156 & 1.389 & 28.50 & 0.396 \\  & 15 & 0.932 & 14.85 & 0.138 & 1.604 & 26.65 & 0.427 \\  & 20 & 0.927 & 11.46 & 0.106 & 1.951 & 25.14 & 0.491 \\
16.8 & 5 & 1.128 & 33.06 & 0.373 & 1.095 & 38.87 & 0.426 \\  & 10 & 1.173 & 23.44 & 0.275 & 1.421 & 29.88 & 0.425 \\  & 15 & 1.173 & 19.53 & 0.229 & 1.619 & 26.11 & 0.423 \\  & 20 & 1.125 & 17.04 & 0.192 & 1.699 & 25.90 & 0.440 \\
25.2 & 5 & 0.883 & 34.91 & 0.308 & 0.785 & 30.69 & 0.241 \\  & 10 & 1.058 & 29.71 & 0.314 & 1.094 & 27.89 & 0.305 \\  & 15 & 1.287 & 21.94 & 0.282 & 1.272 & 23.55 & 0.300 \\  & 20 & 1.211 & 14.86 & 0.180 & 1.213 & 20.41 & 0.248 \\
33.6 & 5 & 0.694 & 25.53 & 0.177 & 0.591 & 15.70 & 0.093 \\  & 10 & 1.109 & 31.28 & 0.347 & 0.938 & 19.76 & 0.185 \\  & 15 & 1.286 & 19.89 & 0.256 & 1.066 & 18.59 & 0.198 \\  & 20 & 1.223 & 15.13 & 0.185 & 0.716 & 19.37 & 0.139 \\ \hline \end{tabular}
\end{table} 
Table 6: Comparative ALP2 lipid content at various NaHCO3 and ADFW levels. Figure 10: Flow cytometric FL1 histogram plots for BODIPY-stained ALP2 cultures on 5% (\(v/v\)) (**a**) and 20% (\(v/v\)) (**b**) anaerobically digested food waste effluent. The two-stage cultivation strategy was finally demonstrated using these alternative sources of organic carbon, nitrogen, and phosphorous. ALP2 rapidly grew microtophically on both glucose-containing hydrolysate and acetate-containing condensate and achieved a cell productivity of \(7.25\times 10^{7}\) cells mL\({}^{-1}\) day\({}^{-1}\) and \(2.25\times 10^{7}\) cells mL\({}^{-1}\) day\({}^{-1}\), respectively (Figure 11). Evidently, ALP2 was able to grow on this condensate and hydrolysate without acclimatory lag phase, suggesting that growth inhibitors were successfully removed. It appears that there are no reports on the feasibility of using the carboxylic acid content of torrefraction liquid condensate in other potential integratable biorefinery applications such as microalgal cultivation. The acidic liquid condensate could alternately be used as organic carbon source for acidogens and methanogens in an integrated AD process to provide biogas for on-site energy or as previously described pH adjustment for second-stage phototrophic outdoor open-ponds. Although ALP2 grew faster and yielded higher biomass and cell density microtophically than heterotrophically, a biorefinery mixotrophic first-stage process for two-stage biofuel production would today likely suffer from limited availability of validated scaled-up studies or high capital costs of photobioreactors (PBRs) [52; 53]. These would require, for example, sterilizable, durable, and non-discoloring enclosed polycarbonate body, flashing red and blue LEDs [54] and fluorescent bulbs, and acrylic light-guides needed for greater light penetration. These high costs of PBRs in the future could be offset by additional high revenues from cGMP-compliant and highly controlled manufacturing of FDA-regulated, high-value neutraceuticals such as lutein or astaxanthin [55]. For instance, the microalgae _Haematococcus pluvialis_ is the highest producer of the high-value astaxanthin most optimally grown mixotrophically using 30 mM acetatein a so-called \"green-stage\" [56].