Dataset on the expression level of the genes involved in the synthesis of structural molecules in carbon-deficient microalgae

The data presented in this article are related to the research article entitled “Bicarbonate-rich wastewater as a carbon fertilizer for culture of Dictyosphaerium sp. of a giant pyrenoid” (Cheng et al., 2018) [1]. This article provides data about the expression levels of the genes involved in the synthesis of structural molecules in the carbon-deficient algal cell and the carbon-treated algal cell, which can be helpful for analyzing the observed disruption of the structural integrity in the carbon-deficient microalgae at molecular level.


a b s t r a c t
The data presented in this article are related to the research article entitled "Bicarbonate-rich wastewater as a carbon fertilizer for culture of Dictyosphaerium sp. of a giant pyrenoid" (Cheng et al., 2018) [1]. This article provides data about the expression levels of the genes involved in the synthesis of structural molecules in the carbondeficient algal cell and the carbon-treated algal cell, which can be helpful for analyzing the observed disruption of the structural integrity in the carbon-deficient microalgae at molecular level.

Subject area
Environmental science and Biology More specific subject area Wastewater; Algal culture and Algal physiology Type of data Raw and filtered.

Experimental factors
The microalgae was isolated from wastewater.

Experimental features
Algae culture in an incubator, microscopic observation and RNAsequence.

Data source location
Hangzhou City, Zhejiang Province, China Data accessibility The data is available within this article Related research article Cheng et al. 2018. Bicarbonate-rich wastewater as a carbon fertilizer for culture of Dictyosphaerium sp. of a giant pyrenoid. Journal of Cleaner Production (in press).

Value of the data
The data provided comparative transcriptomic analysis for the related Dictyosphaerium sp. genes encoding synthesis of structural molecules in the algae cultured in the modified Hoagland þWastewater medium and the modified Hoagland medium.
The obtained data from the RNA-seq analysis can be used for analysis of the disruption of structural integrity in the carbon-deficient microalgae at molecular level.

Data
The dataset of this article provides information on the expression levels of the genes involved in synthesis of structural molecules in the microalgae. Tables 1-3 show the expression levels of extensin protein genes, proline-rich structural protein genes, gline-rich structural protein genes, and soluble starch synthase genes and granule-bound starch synthase genes, respectively. Figs. 1 and 2 show the expression levels of lipid synthase genes and cellulose synthase catalytic subunit genes and cellulose synthase genes, respectively.

Experimental design, materials, and methods
The green algae strain Dictyosphaerium sp. was isolated from wastewater originating from the Experimental Farm at Zhejiang University. Prior to cultivation experiments, the species was cultured in BG11 medium until reaching log phase. A batch of algal culture experiments were conducted in a model ACM À 168 algal incubator (Jiangnan Instrument Co., Ningbo, China). Two treatments with three replications were conducted with 0 and 0.25 L/L of the autoclaved swine wastewater to modified Hoagland solution [2], and the wastewater-added medium contained 0.8 g/L bicarbonate. Microalgae seeds were added to different culture media in 250 mL triangular glass flasks with 200 mL of working solution, and with initial optical density values adjusted to between 0.05 and 0.07 absorbance at a wavelength of 680 nm (OD 680 ).
RNA sampling and extraction was performed according to methods described in [3]. On the 13th day, 10 mL of cultures were collected by centrifugation (10,000 g, 7 min) from each replicate. The supernatant was discarded and the resulting cell pellets were immediately flash-frozen with liquid nitrogen and stored at À80°C. Prior to RNA extraction, cell pellets were resuspended in lysis buffer and then ground using a micropestle. Total RNA was then extracted following the manufacturer's instructions. Total RNA was maintained as replicates, rather than pooling, and then stored at À 80°C. An Agilent 2100 Bio analyzer (Agilent RNA 6000 Nano Kit) was used to determine QC:RNA concentrations, RIN values, 28 S/18 S, and fragment length distributions. A NanoDropTM spectrophotometer was used to assess the purity of the RNA. Aliquots from mRNA samples were used to construct cDNA libraries. Table 1 Comparative transcriptomic analysis for the related Dictyosphaerium sp. genes encoding extensin proteins (E-Ps) in the algae cultured in the modified Hoagland þ Wastewater medium (C wc , Control treatment) and the modified Hoagland medium (C 0 ). Data are means of three replications. L-R-leucine-rich, E-P-extensin, GI-gene ID, length-gene length, log 2 FC-log2 transformed fold change between control and treat samples, Padj-Statistic of adjusted pvalue (DEseq. 2 method used).

GI
Length ( After quality filtering sequence reads, clean reads were mapped to the genomic reference using Bowtie2 [2], and gene expression levels were calculated with RSEM [4]. Differentially expressed genes (DEGs) were determined with DEseq. 2 [5]. Table 2 Comparative transcriptomic analysis for the related Dictyosphaerium sp. genes encoding gline-rich structural proteins (GR-Ps) in the algae cultured in the modified Hoaglandþ Wastewater medium (C wc , Control treatment) and the Hoagland medium (C 0 ). Data are means of three replications. GI-gene ID, length-gene length, log 2 FC-log2 transformed fold change between control and treat samples, Padj-Statistic of adjusted p value (DEseq. 2 method used).

GI
Length (