MOESM2 of Feasibility of biodiesel production and CO2 emission reduction by Monoraphidium dybowskii LB50 under semi-continuous culture with open raceway ponds in the desert area

Additional file 2: Table S1. Ingredients of industrial salt

MOESM1 of Feasibility of biodiesel production and CO2 emission reduction by Monoraphidium dybowskii LB50 under semi-continuous culture with open raceway ponds in the desert area

Additional file 1: Figure S1. Outdoor cultivation system of large-scale raceway ponds

MOESM6 of Feasibility of biodiesel production and CO2 emission reduction by Monoraphidium dybowskii LB50 under semi-continuous culture with open raceway ponds in the desert area

Additional file 6: Figure S2. Irradiance, temperature and pH of three microalgae in 5 m2 ORPs

MOESM4 of Feasibility of biodiesel production and CO2 emission reduction by Monoraphidium dybowskii LB50 under semi-continuous culture with open raceway ponds in the desert area

Additional file 4: Table S3. LC, BP, and LP of M. dybowskii LB50, Micractinium sp. XJ-2 and P. falcata XJ-176 cultivated indoors

Images of Φ_PSII, qP and qN measured under different photosynthetically active radiation in the rehydrated lichen thallus.

<p>Different colors (bar at the bottom) indicate different values of each parameter, and the maximum value of each parameter has been adjusted to 1. All these pictures are a vertical section of the lichen thallus with its upper cortex up. Each fluorescence parameter just show the results of one sample from the three similar repetitions, and the other repetitive results are given in the Figure C in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0172537#pone.0172537.s001" target="_blank">S1 File</a>.</p

Chlorophyll fluorescence parameters of upper layer and lower layer in the rehydrated lichen thallus.

<p>Data indicate means ± SD (<i>n</i> = 3).</p

Photosynthetic recovery and acclimation to excess light intensity in the rehydrated lichen soil crusts

<div><p>As an important successional stage and main type of biological soil crusts (BSCs) in Shapotou region of China (southeastern edge of Tengger Desert), lichen soil crusts (LSCs) often suffer from many stresses, such as desiccation and excess light intensity. In this study, the chlorophyll fluorescence and CO₂ exchange in the rehydrated LSCs were detected under a series of photosynthetically active radiation (PAR) gradients to study the photosynthetic acclimation of LSCs. The results showed that although desiccation leaded to the loss of photosynthetic activity in LSCs, the fluorescence parameters including Fo, Fv and Fv/Fm of LSCs could be well recovered after rehydration. After the recovery of photosynthetic activity, the effective photosynthetic efficiency Φ_PSII detected by Imaging PAM had declined to nearly 0 within both the lichen thallus upper and lower layers when the PAR increased to 200 μE m^-2 s^-1, however the net photosynthesis detected by the CO₂ gas analyzer in the LSCs still appeared when the PAR increased to 1000 μE m^-2 s^-1. Our results indicate that LSCs acclimating to high PAR, on the one hand is ascribed to the special structure in crust lichens, making the incident light into the lichen thallus be weakened; on the other hand the massive accumulation of photosynthetic pigments in LSCs also provides a protective barrier for the photosynthetic organisms against radiation damage. Furthermore, the excessive light energy absorbed by crust lichens is also possibly dissipated by the increasing non-photochemical quenching, therefore to some extent providing some protection for LSCs.</p></div

The contents of Chl-<i>a</i>, carotenoids and scytonemin in cyanobacterial soil crusts and lichen soil crusts.

<p>Data indicate means ±SD (<i>n</i> = 3).</p

CO₂ exchange rate of the rehydrated LSCs under different photosynthetically active radiation.

<p>Data indicate means ±SD (<i>n</i> = 3).</p

Chlorophyll fluorescence parameters used in the experiment and relative physiological significance.

<p>Chlorophyll fluorescence parameters used in the experiment and relative physiological significance.</p