Crystalline Domains Nested on Two-Dimensional Nanosheets as Heterogeneous Nanomachineries for the Sustainable Production of Bioactive Compounds from Chlorella sorokiniana

Abstract

Naturally occurring bioactive compounds have attracted significant interest from the perspective of scientific and industrial aspects owing to the wide range of technological, economic, and healthcare benefits. Their synthetic origin still suffers from several impeding challenges, such as expensive extraction and low yield. To address these critical issues, a unique hybridized system termed “algal-nanohybrids” was established by integrating green microalgae, Chlorella sorokiniana, with carbon-based heterostructured nanomaterials (CHNs), enhancing the microalgal growth for the sustainable augmentation of bioactive compounds as renewable sources of secondary metabolites. Hitherto, this work presents a new avenue in the formation of CHNs comprising propene-bridged cyanurate tetramer crystals nested on two-dimensional (2D) nanosheets, possessing excellent photocatalytic activity along with biocompatibility for the sustainable production of bioactive compounds. Mechanistic insights into the formation of CHNs and their plausible interaction with the algal cells were deciphered using a suite of characterization techniques. The conceptual significance of CHNs was elaborated, as an efficient nanomachinery for bolstering the enhanced production of lutein (97%) from C. sorokiniana, which is higher than that reported for other lutein-producing microalgae grown under photoautotrophic conditions. Interestingly, CHNs not only promoted microalgal biomass by 88% but also enhanced the production of chlorophyll a and carotenoids by 42 and 75%, respectively. This unprecedented work advances the synthesis of biocompatible CHNs, which can provide a breakthrough in the industry for the production of natural lutein and other bioactive compounds from microalgae.