Coproduction of Microbial Oil and Carotenoids within the Circular Bioeconomy Concept: A Sequential Solid-State and Submerged Fermentation Approach

Abstract

The main objective of integrative biorefinery platforms is to propose efficient green methodologies addressed to obtain high-value compounds with low emissions through biochemical conversions. This work first screened the capacity of various oleaginous yeast to cosynthesize high-value biomolecules such as lipids and carotenoids. Selected strains were evaluated for their ability to coproduce such biocompounds in the waste-based media of agro-food (brewer’s spent grain, pasta processing waste and bakery waste). Carbon and nitrogen source feedstock was obtained through enzymatic hydrolysis of the agro-food waste, where up to 80% of total sugar/starch conversion was obtained. Then, the profitability of the bioprocess for microbial oil (MO) and carotenoids production by Sporobolomyces roseus CFGU-S005 was estimated via simulation using SuperPro Designer®. Results showed the benefits of establishing optimum equipment scheduling by identifying bottlenecks to increase profitability. Sensitivity analysis demonstrated the impact of MO price and batch throughput on process economics. A profitable process was achieved with a MO batch throughput of 3.7 kg/batch (ROI 31%, payback time 3.13 years). The results revealed areas that require further improvement to achieve a sustainable and competitive process for the microbial production of carotenoids and lipids.

Sustainable Co-Production of Xylanase, Cellulase, and Pectinase through Agroindustrial Residue Valorization Using Solid-State Fermentation: A Techno-Economic Assessment

“…However, it is noteworthy that eliminating process bottlenecks at this stage would necessitate a significant increase in investment, without a significant increase in the number of batches produced [10]. As a result, only the main bioreactor, the inoculum step, and the dryer were operated in staggered mode.…”

“…Furthermore, as the processing of biowaste increased across all three scenarios, the capacity of batches per year diminished due to the emergence of new process bottlenecks. Moreover, a surge in capital investment was observed beyond 5000 kg/batch [10]. This increase can be attributed to equipment capacity and associated costs which are closely tied to batch throughput.…”

Sustainable Production of Novel Oleogels Valorizing Microbial Oil Rich in Carotenoids Derived from Spent Coffee Grounds

“…Batch fermentations with Rhodotorula sp. and Sporobolomyces roseus, cultivated on enzymatic food waste-based hydrolysates, led to satisfying carotenoid production (0.8–2.2 mg/L) but rather low MO accumulation (0.5–2.6 g/L) …”

“…C14:0, C16:1, C18:0, and C18:2 were found in low amounts varying between 0.5 and 2.7%. The combined production of MO and carotenoids that are susceptible to light, air, and temperature is tremendously advantageous due to the protective action of the former . The incorporation of MOC into innovative food systems via oleogelation could lead to food products of a high nutritional value and functionality and prolonged life span …”

“…and Sporobolomyces roseus, cultivated on enzymatic food waste-based hydrolysates, led to satisfying carotenoid production (0.8−2.2 mg/L) but rather low MO accumulation (0.5−2.6 g/L). 24 The fatty acid composition of MO (Table 1) was typical of R. toruloides strains 25 with C18:1 accounting for 63.1%, followed by C16:0 (32.1%). C14:0, C16:1, C18:0, and C18:2 were found in low amounts varying between 0.5 and 2.7%.…”