High-Throughput Biochemical Fingerprinting of Oleaginous Aurantiochytrium sp. Strains by Fourier Transform Infrared Spectroscopy (FT-IR) for Lipid and Carbohydrate Productions

Abstract

The traditional biochemical methods for analyzing cellular composition of oleaginous microorganisms are time-consuming, polluting, and expensive. In the present study, an FT-IR method was used to analyze the cellular composition of the marine oleaginous protist Aurantiochytrium sp. during various research processes, such as strains screening, medium optimization, and fermentation, and was evaluated as a green, low-cost, high throughput, and accurate method compared with the traditional methods. A total of 109 Aurantiochytrium sp. strains were screened for lipid and carbohydrate production and the best results were found for the strains No. 6 and No. 32. The yields and productivities could reach up to 47.2 g/L and 0.72 g/L/h for lipid, 21.6 g/L and 0.33 g/L/h for docosahexaenoic acid (DHA) in the strain No. 6, and 15.4 g/L and 0.18 g/L/h for carbohydrate in the strain No. 32, under the optimal conditions, respectively. These results confirmed potentials of the two Aurantiochytrium sp. strains for lipid, DHA, and carbohydrate productions at industrial scales. The FT-IR method in this study will facilitate research on the oleaginous Aurantiochytrium sp., and the obtained two strains for lipid and carbohydrate productions will provide the foundations for their applications in medical, food, and feed industries.

GROWTH, CARBOHYDRATE PRODUCTIVITY AND GROWTH KINETIC STUDY OF Halochlorella rubescens CULTIVATED UNDER CO2-RICH CONDITIONS

“…Figure 3(a) and (b) spectrum show that peaks at region 3000-2800 cm -1 have increased significantly in band intensity by up to 141.74% corresponding to the lipid content of microalgal biomass when cultivation shifts from pH 8.00 to pH 10.00. Similar result was seen in Figure 3(b) when cultivation was carried out using 5% instead of 0.04% (v/v) of CO 2 concentration (Yu et al, 2019). This phenomenon can be explained by the activation of the lipid synthesis mechanism in the metabolism of microalgae, which produces large amounts of lipid content, in particular neutral lipids, such as triacylglycerol (TAG), which are then accumulated in microalgal biomass under stress conditions (Lv et al, 2010).…”

“…In addition, Figure 3 (a) and (b) also show significant changes for peaks in the 1200-900 cm -1 region, which is a direct response to the v(C-O-C) stretching vibration corresponding to the carbohydrate component of the microalgae biomass (Yu et al, 2019). Increased band intensity in this region up to 113.06% was observed when cultivation shift from pH 8.00 to pH 10.00.…”

Strain Development in Microalgal Biotechnology—Random Mutagenesis Techniques

“…The principle of these approaches is based on conducting a high number of parallel experiments, such as agar streaking or shake flasks, which are traditional methods requiring large, time-consuming and polluting equipment [ 123 , 124 , 125 , 126 , 127 ]. Process control options are, moreover, limited in these systems [ 22 ].…”

Recycling Fermentation Strategy for Waste Cellular Residues in the Production of Polyunsaturated Fatty Acids

“…These methods have been applied to the disposal of waste microbial cellular residues. However, the DHA producer, Aurantiochytrium sp., has been reported to have a protein content ranging from 15% to 54% under different cultivation conditions [20,[24][25][26][27], and it also contains carbohydrates [28]. On the other hand, the ARA producer, Mortierella alpina, has a protein content of 23.2% and is enriched with various vitamins [29].…”