Assessment of Chlorella sp. as a potential feedstock for biological methane production

Recent advances in black liquor valorization

Lignocellulosic biomass is projected as a prospective renewable alternative to petroleum for the production of fuel and chemicals. Pretreatment is necessary to disrupt the lignocellulosic structure for extraction of cellulose. Biomass after pretreatment is segregated into cellulose rich solid fraction and black liquor (lignin and hemicelluloses) as a liquid stream. The plant polysaccharide-based industry primarily utilizes the cellulosic fraction as raw material, and carbon rich black liquor discarded as waste or burnt for energy recovery. This review highlights the recent advancements in the biological and chemical valorization of black liquor into fuels and chemicals. The recent research attempted for bioconversion of black liquor into Bioplastic, Biohydrogen, Biogas, and chemicals has been discussed. In addition, the efforts to replace the conventional energy recovery method with the advanced chemical process along with their modifications have been reviewed that will decide the sustainability of the lignocellulosic biomass-based industry.

Microalgae-based carbohydrates: A green innovative source of bioenergy

Microalgae contribute significantly to the global carbon cycle through photosynthesis. Given their ability to efficiently convert solar energy and atmospheric carbon dioxide into chemical compounds, such as carbohydrates, and generate oxygen during the process, microalgae represent an excellent and feasible carbohydrate bioresource. Microalgae-based biofuels are technically viable and, delineate a green and innovative field of opportunity for bioenergy exploitation. Microalgal polysaccharides are one of the most versatile groups for biotechnological applications and its content can be increased by manipulating cultivation conditions. Microalgal carbohydrates can be used to produce a variety of biofuels, including bioethanol, biobutanol, biomethane, and biohydrogen. This review provides an overview of microalgal carbohydrates, focusing on their use as feedstock for biofuel production, highlighting the carbohydrate metabolism and approaches for their enhancement. Moreover, biofuels produced from microalgal carbohydrate are showed, in addition to a new bibliometric study of current literature on microalgal carbohydrates and their use.

Characterization of Chlorella sorokiniana and Chlorella vulgaris fatty acid components under a wide range of light intensity and growth temperature for their use as biological resources

This study aims to characterize the potential of three strains of microalgal species (Chlorella sorokiniana KNUA114 and KNUA122; C. vulgaris KNUA104) for use as feedstock, based on their fatty acid compositions. Each strain was molecularly identified using four marker genes (ITS, SSU, rbcL, and tufA) and phylogenetically characterized. C. sorokiniana and C. vulgaris collected from Ulleung Island, South Korea, were homologous with other known species groups. Samples' fatty acid components were measured using GC/MS analysis in growth temperatures of 10 °C, 25 °C, and 35 °C. The growth rate of C. sorokiniana strains was higher than that of C. vulgaris under high-temperature conditions, confirming the potential industrial applicability of the former as feedstock material. Additionally, saturated fatty acid contents and productivities increased as biological resources of the C. sorokiniana strains were higher than those of C. vulgaris under high light intensity and temperature conditions. These results suggest that the fatty acid components of C. sorokiniana strains may potentially be used as biological resources (e.g., feedstock).