Long-term monitoring of the biomass and production of lipids by Nitzschia palea for biodiesel production

Abstract

Pennate diatom Nitzschia palea can be cultured in outdoor vertical-bed photobioreactors to produce biodiesel. To assess the production of biomass and lipids, non-axenic cultures of Nitzschia palea were grown outdoors, and the growth of these cultures was measured biweekly. During the annual cycle of algal culture, the culture temperature ranged from 17.3 °C to 33.5 °C, the dry weight biomass ranged from 0.11 g l −1 to 0.25 g l −1 , light energy] ranged from 1.94 Wm −2 to 3.9 Wm −2 and intracellular lipid content ranged from 7.1% to 11.4% of biomass weight after drying at 60 °C. Gas chromatography/mass spectroscopy (GC/MS) analysis of n-hexane extracts showed that the intracellular lipids were primarily C14:0 myristic acid (9.01%), C15:0 pentadecyclic acid (8.26%) and two types of C16:0, palmitic acid (41.13%) and palmitoleic acid (29.25%). Gel permeation analysis showed that carboxylic acids comprised 28.9% of lipids, 16.3% of monoglycerides, 27.3% of diglycerides and 24.3% of triglycerides. Alcoholysis of lipids resulted in the conversion of about 93.9% of fatty acids to equivalent fatty acid methyl esters (FAME) or biodiesel, which, on basis of wt%, consisted primarily of C15:0 methyl myristate (8.3%), C16:0 methyl pentadecanoate] (7.2%), C17:1methyl palmitoleate (28.7%) and methyl palimtate](39.8%).

VIII International Symposium on Marine Sciences (ISMS 2022). Libro de Abstracts

“…The relevance of OD and Fo was demonstrated during the exponential phase only (days 4 -17), as they both positively correlated with cell density in a linear regression model (R 2 > 0.89, n = 45). Preliminary results on the fatty acid (FA) composition indicated that the major FAs produced by N. palea were palmitic acid (18 -41 %) and palmitoleic acid (12 -25 %), in accordance with a previous study (Touliabah et al, 2020). As for the ω-3 FAs, DHA was poorly produced (≤ 3%), while EPA constituted a major FA for two of the strains (21% and 13%).…”

Enhanced Scenedesmus obliquus Cultivation in Plastic-Type Flat Panel Photobioreactor for Biodiesel Production

“…The relatively high percentage of palmitoleic acid as well as palmitic acid in the S. obliquus under the study conditions indicates its suitability as a feedstock for the production of biodiesel. A similar conclusion was stated by Touliabah et al [53]; according to their lipid analysis, more than 70% of the lipids were composed of C16:0 and C16:1 palmitic and palmitoleic acids. There was a high percentage of low-density fatty acids, which are thought to be the best fatty acids for producing biodiesel with a very high technical grade [23].…”

Combined effect of salinity and pH on lipid content and fatty acid composition of Tisochrysis lutea

“…Many previous studies have examined the microalgal lipids as a sustainable and environmentally friendly source for biodiesel ( Griffiths and Harrison, 2009 , Schnurr and Allen, 2015 , Almarashi et al, 2020 ). However, to be economically feasible, microalgal cultivation must have high productivity of biomass and efficient production of lipids ( Go et al, 2012 , Touliabah et al, 2020 ). In order to enhance the productivity of biomass and lipids, researchers have applied different abiotic stresses to the microalgal cells (e.g., nutrient deprivation, low pH, high salinity, high light level, high temperature, and UV radiation) to stimulate the synthesis and accumulation of lipids ( Gomaa, 2018 , El-Sheekh et al, 2019 , Abomohra et al, 2019 , Chen et al, 2017 , Paliwal et al, 2017 ).…”