Screening of cellulose-degrading yeast and evaluation of its potential for degradation of coconut oil cake

Abstract

Coconut oil cake (COC), a byproduct of oil extraction, contains high levels of cellulose. The aim of this study was to isolate a cellulose-degrading yeast from rotten dahlia that can effectively use COC as the only carbon source for cellulase secretion. Based on screening, Meyerozyma guillermondii CBS 2030 (M. guillermondii) was identified as a potential candidate, with the highest cellulolytic activity among the yeast strains isolated, with the carboxymethyl cellulase (CMCase) activity reaching 102.96 U/mL on day 5. The cellulose in COC samples was evaluated before and after degradation by M. guillermondii. Analysis based on field emission scanning electron microscopy (FESEM) revealed that the COC structure was changed significantly during the treatment, indicating effective hydrolysis. Fourier transform infrared spectroscopy (FTIR) of the modified functional groups indicated successful depolymerization of coconut cake. X-ray diffraction (XRD) and analysis of color differences established effective degradation of COC by M. guillermondii. The results demonstrate that M. guillermondii effectively secretes CMCase and degrades cellulose, which has important practical significance in COC degradation.

Construction of cellulose-degrading microbial consortium and evaluation of their ability to degrade spent mushroom substrate

“… Yan et al (2021) found that the CrI value of corn stover increased after treatment, as the degradation of amorphous biomass, including hemicellulose, which exposed more binding sites. Our research results are also consistent with those of Fu et al (2022) , who found that the crystallinity index of coconut oil residue increased after treatment with M. guillermondii .…”

Optimization, Isolation, Purification, and Characterization of a Thermally Stable, Acidophilic Cellulase from Aspergillus awamori AFE1 for Industrial and Biotechnological Applications

“…Screening for the decomposition of cellulose has been widely performed using Congo red. Cellulolytic microorganisms possess the ability to degrade non-crystalline sections of cellulose, leading to a loss of Congo red binding and a visible halo around the colony (Fu et al 2022). The larger the size of the transparent zone around the colony diameter, the higher the activity of the cellulose produced (Li et al 2022).…”

Identification of Cellulose-Degrading Bacteria and Assessment of Their Potential Value for the Production of Bioethanol from Coconut Oil Cake Waste

“…Briefly, the color of the samples was determined using an SPH 860 colorimeter (Colorlite, Katlenburg-Lindau, Germany). COC color was evaluated from three aspects using the CIE Lab color system, where an appropriate amount of dry powder was placed on the sample plate to directly measure the color L*, a* and b* coordinates [ 19 ]. Each value was measured nine times, and the average value was taken.…”

“…As an alternative to fungi, bacteria are now being explored for use in the enzymatic hydrolysis of lignocellulose due to their high rate of enzyme production, expression of multi-enzyme complexes, tolerance to extreme environments, and the ability to be genetically engineered [ 5 , 18 ]. Previous studies have reported the isolation of cellulose-degrading bacteria from nature to modify the recalcitrant structure of cellulose to add value [ 19 ]. Therefore, the screening and identification of high-efficiency cellulolytic bacteria can provide insight into cellulose degradation mechanisms and inspire methods to improve the utilization rate of cellulose resources.…”