Lipid production by Cryptococcus albidus using biowastes hydrolysed by indigenous microbes

Area of Science:

• Biotechnology
• Microbiology
• Waste Valorization

Background:

• Agricultural waste, such as onion and apple byproducts, presents a disposal challenge.
• Microbial lipid production offers a sustainable alternative for valuable compound generation.

Purpose of the Study:

• To evaluate Cryptococcus albidus for lipid production using onion waste (OW) and apple waste (AW) hydrolysates.
• To optimize lipid yield through cell retention culture.

Main Methods:

• Hydrolysis of OW and AW at 2% total solids using indigenous microbes under mesophilic conditions.
• Microbiome analysis to identify dominant microbial genera.
• Cell retention culture of C. albidus at a dilution rate of 0.01 h⁻¹ for lipid accumulation.

Main Results:

• Effective hydrolysis of OW and AW, yielding 4.8 g/L and 10.8 g/L reducing sugars, respectively.
• Microbiome dominated by Bacillus, with significant α- and γ-proteobacteria presence.
• Cell retention culture achieved 13.5 g/L dry cell weight with 20.0% intracellular lipid content.
• Dry cell weight and lipid concentration increased by 3.48-fold and 2.37-fold, respectively, compared to batch fermentation.

Conclusions:

• Cryptococcus albidus is a viable yeast for lipid production from agricultural waste hydrolysates.
• Cell retention culture significantly enhances lipid production efficiency.
• This approach offers a sustainable method for converting waste into valuable lipids.