Isolation and Identification of Microalgae From High Nitrate Landfill Leachate

Abstract

This study aims to isolate and identify microalgae capable of growing in high nitrate (N-NO3-) landfill leachate. Source of isolation was collected from a landfill leachate treatment plant and identified according to morphological characteristics and analysis of partial 18S and 28S rRNA genes. The isolates, identified as Chlorella vulgaris UPSI-JRM01 and Tetradesmus obliquus UPSI-JRM02 were capable of growing at high N-NO3- concentration of nitrified landfill leachate, which is up to 1500 mg/L. The biomass productivities of Chlorella vulgaris and Tetradesmus obliquus were 36.28 mg/L/day and 40.49 mg/L/day, with 44% and 37% N-NO3- removal, respectively. The biomass of Chlorella vulgaris and Tetradesmus obliquus consisted of 17.72% and 16.32% lipid and, 21.93% and 25.43% carbohydrate, respectively. The protein contents (>50%) were higher than lipid and carbohydrate contents for both microalgal species. The newly isolated microalgae species will be useful for future applications of high NO3- wastewater treatment and microalgae biomass production.

Growth Performance, Biochemical Composition and Nutrient Recovery Ability of Twelve Microalgae Consortia Isolated from Various Local Organic Wastes Grown on Nano-Filtered Pig Slurry

“…Lipids are one of the major constituents of microalgal biomass, and their content is typically reported to be in the range of 50-500 mg kg −1 DM, depending on the species and cultivation conditions [46]. The lipid content found in this work was, on average, 145 ± 33 g kg −1 DM (n = 12), in line with data reported for Chlorella sp., i.e., 144 ± 98 g kg −1 DM (n = 9) [38,40,41,47,48], and the data reported for Tetradesmus sp., i.e., 216 ± 47 g kg −1 DM (n = 4) [22,41,47] (ANOVA, p < 0.05). The lipid content was, on average, higher than that reported for cyanobacteria, i.e., 99 ± 56 g kg −1 DM [48], indicating that the mixed culture (e.g., AC_10) probably led to lower lipid content than the monospecies culture (Table 3).…”

“…Average protein content (Table 3) was, on average, 368 ± 90 g kg −1 DM (n = 12) and the contents for the fastest growing cultures, i.e., AC_1, AC_10 and AC_12, were 257 ± 0, 382 ± 7 and 273 ± 22 g kg −1 DM proteins, respectively. These contents were lower than those reported in the literature for Chlorella sp., i.e., 440 ± 129 g kg −1 DM (n = 8) [38][39][40][41][42] and Tetradesmus sp., i.e., 522 ± 173 g kg −1 DM (n = 2), both cultivated in different waste streams [39,43] containing more N than that of the NFP (N of 136 ± 0 mg L −1 ) used in this work, i.e., N 594 ± 453 mg L −1 and 314 ± 90 mg L −1 , respectively. These figures can explain the lower protein content characterizing ACs.…”

“…Carbohydrate content in algal cells ranged from 40 to 640 g kg −1 DM depending on different algae species and cultivation conditions [49]. In this work, the carbohydrate content in the ACs presented an average of 445 ± 95 g kg −1 DM (n = 12) (Table 3), much higher than data reported for Chlorella sp., i.e., 270 ± 84 g kg −1 DM (n = 9) [38,40,41,47,48] and Tetradesmus sp., i.e., 244 ± 37 g kg −1 DM (n =4) [22,41,47] (ANOVA, p < 0.05). The three fastest growing ACs, namely AC_1, AC_10 and AC_12, revealed carbohydrate contents of 596 ± 4, 425 ± 9 and 472 ± 27 g kg −1 DM, respectively.…”

PRODUCTION OF LIPID AND CARBOHYDRATE IN Tetradesmus obliquus UPSI-JRM02 UNDER NITROGEN STRESS CONDITION

“…Meanwhile, culture inoculated in BG11 media with 400 mg NaNO3 was used as a control. The cultivation of T. obliquus in both conditions was conducted at pH 9.8, 36 ºC and 23 500 lux of light intensity as obtained from our previous study [15]. The pH and temperature were controlled using 0.1 M HCl and 0.1 M NaOH and heat jacket, respectively.…”