Journal de la technologie microbienne et biochimique

Abstrait

Biochemical Composition of Chlorella Sorokiniana Grown in a Novel Design of Hybrid Photobioreactor

Renata Natsumi Haneda, Bruna Horvat Vieira, Sérgio Rodrigues Fontes, Geraldo Ombardi, Carlos Aparecido Casali and Ana Teresa Lombardi

The aim of this study was to assess the feasibility of a 180 L photobioreactor in which a submerged ultrafiltration system was used to maintain continuous nutrient inflow without biomass loss from the culture. After exponential growth, approximately 15% of the total volume was removed and replaced with a modified medium to induce algal physiological responses as a biochemical manipulation procedure. In this system, Chlorella sorokiniana was kept under healthy conditions, according to protein: carbohydrate ratio. C. sorokiniana was grown exponentially for 4 days up to 8.9x106 cells mL-1. The culture medium used for biochemical manipulation (72 h exposure) consisted of LC Oligo medium without nitrates or phosphates, and with 7x10-7 molL-1 total copper. The results confirmed the effectiveness of the submerged membrane and showed that algae exposure to a stressing medium resulted in intracellular carbohydrate increase, thus protein: carbohydrate (P:C) ratios, and affected lipid class composition. This novel photobioreactor configuration has the potential to improve microalgal yields and/or specific intracellular constituents, inasmuch as biochemical manipulation of the biomass is facilitated and the continuous system is operated without biomass loss.