The Synergistic Action of Electro-Fenton and White-Rot Fungi in the Degradation of Lignin

A cellulosomal yeast reaction system of lignin-degrading enzymes for cellulosic ethanol fermentation

Biofuel production from lignocellulose feedstocks is sustainable and environmentally friendly. However, the lignocellulosic pretreatment could produce fermentation inhibitors causing multiple stresses and low yield. Therefore, the engineering construction of highly resistant microorganisms is greatly significant. In this study, a composite functional chimeric cellulosome equipped with laccase, versatile peroxidase, and lytic polysaccharide monooxygenase was riveted on the surface of Saccharomyces cerevisiae to construct a novel yeast strain YI/LVP for synergistic lignin degradation and cellulosic ethanol production. The assembly of cellulosome was assayed by immunofluorescence microscopy and flow cytometry. During the whole process of fermentation, the maximum ethanol concentration and cellulose conversion of engineering strain YI/LVP reached 8.68 g/L and 83.41%, respectively. The results proved the availability of artificial chimeric cellulosome containing lignin-degradation enzymes for cellulosic ethanol production. The purpose of the study was to improve the inhibitor tolerance and fermentation performance of S. cerevisiae through the construction and optimization of a synergistic lignin-degrading enzyme system based on cellulosome.

Synergistic lignin degradation between Phanerochaete chrysosporium and Fenton chemistry is mediated through iron cycling and ligninolytic enzyme induction

Removal of recalcitrant lignin from wastewater remains a critical bottleneck in multiple aspects relating to microbial carbon cycling ranging from incomplete treatment of biosolids during wastewater treatment to limited conversion of biomass feedstock to biofuels. Based on previous studies showing that the white rot fungus Phanerochaete chrysosporium and Fenton chemistry synergistically degrade lignin, we sought to determine optimum levels of Fenton addition and the mechanisms underlying this synergy. We tested the extent of degradation of lignin under different ratios of Fenton reagents and found that relatively low levels of H2O2 and Fe(II) enhanced fungal lignin degradation, achieving 80.4 ± 1.61 % lignin degradation at 1.5 mM H2O2 and 0.3 mM Fe(II). Using a combination of whole-transcriptome sequencing and iron speciation assays, we determined that at these concentrations, Fenton chemistry induced the upregulation of 80 differentially expressed genes in P. ch including several oxidative enzymes. This study underlines the importance of non-canonical, auxiliary lignin-degrading pathways in the synergy between white rot fungi and Fenton chemistry in lignin degradation. We also found that, relative to the abiotic control, P. ch. increases the availability of Fe(II) for the production of hydroxyl radicals in the Fenton reaction by recycling Fe(III) (p < 0.001), decreasing the Fe(II) inputs necessary for lignin degradation via the Fenton reaction.

The potential of white-rot fungi for algal control: Mechanisms, Strategies, and Challenges

As human society and industrialization have progressed, harmful algal blooms have contributed to global ecological pollution which makes the development of a novel and effective algal control strategy imminent. This is because existing physical and chemical methods for dealing with the problem have issues like cost and secondary pollution. Benefiting from their environmentally friendly and biocompatible properties, white-rot fungi (WRF) have been studied to control algal growth. WRF control algae by using algae for carbon or nitrogen, antagonism, and enhancing allelopathies. It can be better applied to practice by immobilization. This paper reviews the mechanism for WRF control of algae growth and its practical application. It demonstrates the limitations of WRF controlling algae growth and aids the further study of biological methods to regulate eutrophic water in algae growth research. In addition, it provides theoretical support for the fungi controlling algae growth.

Live Biomass of Rigidoporus vinctus: A Sustainable Method for Decoloration and Detoxification of Dyes in Water

In this study, white-rot fungus, Rigidoporus vinctus, collected from an unidentified fallen twig from Pathankot, Punjab, India, was used for biosorption of anionic Congo red and cationic Methylene blue dyes from an aqueous medium. The biosorption efficiency of the live biomass of Rigidoporus vinctus was investigated to optimize biosorbent dosage, process time, concentrations of dyes, and pH of solutions. The results indicated that Rigidoporus vinctus is more efficient than other reported bio-adsorbents for Congo red and Methylene blue dyes. The maximum biosorption activity of Rigidoporus vinctus for Congo red was found at pH 2, and that for Methylene blue was at pH 10, after 24 h of the reaction period. The process followed pseudo-second-order kinetics, which indicated that the interaction of both dyes to the adsorption sites on the surface of Rigidoporus vinctus was responsive to biosorption. The biosorption process could be well explained by the Langmuir isotherm for both dyes. The maximum monolayer biosorption capacity of Rigidoporus vinctus for Congo red and Methylene blue was observed to be 54.0 mg/g and 80.6 mg/g, respectively. The seed germination test was carried out, and it was assessed that the toxicity of dyes was reduced up to significant levels. Based on the present experimental findings, it can be concluded that biosorption using the live biomass of Rigidoporus vinctus can effectively decolorize dye-containing wastewater, thus reducing the hazardous effects of dyes on human beings.

Coupling of Fenton reaction and white rot fungi for the degradation of organic pollutants

Advanced oxidation processes (AOPs) are a class of highly efficient pollution remediation technologies that produce oxidising radicals under specific conditions to degrade organic pollutants. The Fenton reaction is a commonly applied AOP. To combine the advantages of AOPs and biodegradation in the remediation of organic pollutants, some studies have developed coupled systems between Fenton AOPs and white rot fungi (WRF) for environmental organic pollutant remediation and have achieved some success. Moreover, a promising system, termed as advanced bio-oxidation processes (ABOPs), mediated by the quinone redox cycling of WRF, has attracted increasing attention in the field. In this ABOP system, the radicals and H₂O₂ produced through the quinone redox cycling of WRF can strengthen Fenton reaction. Meanwhile, in this process, the reduction of Fe³⁺ to Fe²⁺ ensures the maintenance of Fenton reaction, leading to a promising application potential for the remediation of environmental organic pollutants. ABOPs combine the advantages of bioremediation and advanced oxidation remediation. Further understanding the coupling of Fenton reaction and WRF in the degradation of organic pollutants will be of great significance for the remediation of organic pollutants. Therefore, in this study, we reviewed recent remediation techniques for organic pollutants involving the coupled application of WRF and the Fenton reaction, focusing on the application of new ABOPs mediated by WRF, and discussed the reaction mechanism and conditions of ABOPs. Finally, we discussed the application prospects and future research directions of the joint application of WRF and advanced oxidation technologies for the remediation of environmental organic pollutants.

Microbial β-glucanases: production, properties, and engineering

Lignocellulosic biomass, which mainly consists of cellulose and hemicellulose, is the most abundant renewable biopolymer on earth. β-Glucanases are glycoside hydrolases (GHs) that hydrolyze β-glucan, one of the dominant components of the plant cell wall, into cello-oligosaccharides and glucose. Among them, endo-β-1,4-glucanase (EC 3.2.1.4), exo-glucanase/cellobiohydrolase (EC 3.2.1.91), and β-glucosidase (EC 3.2.1.21) play critical roles in the digestion of glucan-like substrates. β-Glucanases have attracted considerable interest within the scientific community due to their applications in the feed, food, and textile industries. In the past decade, there has been considerable progress in the discovery, production, and characterization of novel β-glucanases. Advances in the development of next-generation sequencing techniques, including metagenomics and metatranscriptomics, have unveiled novel β-glucanases isolated from the gastrointestinal microbiota. The study of β-glucanases is beneficial for research and development of commercial products. In this study, we review the classification, properties, and engineering of β-glucanases.

Journey of lignin from a roadblock to bridge for lignocellulose biorefineries: A comprehensive review

The grave concerns arisen as a result of environmental pollution and diminishing fossil fuel reserves in the 21st century have shifted the focus on the use of sustainable and environment friendly alternative resources. Lignocellulosic biomass constituted by cellulose, hemicellulose and lignin is an abundantly available natural bioresource. Lignin, a natural biopolymer has over the years gained much importance as a high value material with commercial importance. The present review provides an in-depth knowledge on the journey of lignin from being considered a roadblock to a bridge connecting diverse industries with widescale applications. The successful valorization of lignin for the production of bio-based platform chemicals and fuels has been the subject of intensive investigation. A deeper understanding of lignin characteristics and factors governing the biomass conversion into valuable products can support improved biomass consumption. The components of lignocellulosic biomass might be totally transformed into a variety of value-added products with the improvements in bioprocess techniques that valorize lignin. In this review, the recent advances in the lignin extraction and depolymerization methods that may help in achieving the cost-economics of the bioprocess are summarized and compared. The industrial potential of lignin-derived products such as aromatics, biopolymers, biofuels and agrochemicals are also outlined. Additionally, assessment of the recent research trends in lignin valorization into value-added chemicals has been done and present scenario of technological-industrial applications of lignin with economic perspectives is highlighted.

Stimulating biogas production from steam-exploded birch wood using Fenton reaction and fungal pretreatment

Delignification of steam-exploded birch wood (SEBW) was stimulated using a pretreatment method including Fenton reaction (FR) and fungi. SEBW was employed as a substrate to optimize the Fe(III) and Fe(II) dosage in FR. Maximum iron-binding to SEBW was obtained at pH 3.5. FR pretreatment increased biological methane yields from 257 mL/g vS in control to 383 and 352 mL/ g vS in samples with 0.5 mM Fe(II) and 1.0 mM Fe(III), respectively. Further enzymatic pretreatment using a commercial cellulase cocktail clearly improved methane production rate but only increased the final methane yields by 2-9 %. Finally, pretreatments with the fungi Pleurotus ostreatus (PO) and Lentinula edodes (LE), alone or in combination with FR, were carried out. SEBW pretreated with only LE and samples pretreated with PO and1 mM Fe(III) + H₂O₂ increased the methane production yield to 420 and 419 mL/g vS respectively. These pretreatments delignified SEBW up to 25 %.

Isolation and test of novel yeast strains with lignin usage capability and phenolic compound resistance

Five yeast fungi strains (i.e., two Cryptococcus albidus, one Candida guillermondii, and two Candida tropicalis) were isolated from sugarcane and tested for their use of lignin as sole carbon source and their potential to grow in the presence of phenol and phenol derivatives (i.e., pentachlorophenol and p-nitrophenol). The full set of isolated yeasts showed ligninolytic activity, achieving at least 36% lignin degradation after 25 days. The C. albidus JS-B1 strain had the highest ligninolytic activity, achieving 27% lignin degradation within 4 days. This increased activity was associated with the production of ligninolytic laccase enzymes. All the tested yeast fungi strains showed growth in the presence of high concentrations of phenolic compounds (i.e., 900 mg/L phenol, 200 mg/L p-nitrophenol, 50 mg/L pentachlorophenol) and showed significant potential for lignin and lignin by-product degradation. Each of these five strains has the potential to be used in biological treatment processes for contaminated effluents from paper pulping and bleaching or phenol and phenol-derivative biodegradation processes for other industrial wastewater effluents.

Recent Advancements and Challenges in Lignin Valorization: Green Routes towards Sustainable Bioproducts

The aromatic hetero-polymer lignin is industrially processed in the paper/pulp and lignocellulose biorefinery, acting as a major energy source. It has been proven to be a natural resource for useful bioproducts; however, its depolymerization and conversion into high-value-added chemicals is the major challenge due to the complicated structure and heterogeneity. Conversely, the various pre-treatments techniques and valorization strategies offers a potential solution for developing a biomass-based biorefinery. Thus, the current review focus on the new isolation techniques for lignin, various pre-treatment approaches and biocatalytic methods for the synthesis of sustainable value-added products. Meanwhile, the challenges and prospective for the green synthesis of various biomolecules via utilizing the complicated hetero-polymer lignin are also discussed.

A mechanistic study on electro-Fenton system cooperating with phangerochate chrysosporium to degrade lignin

The combined catalytic system of Electro-Fenton (E-Fenton) and Phanerochaete chrysosporium (P. chrysosporium) was constructed in liquid medium with additional potential to overcome the limitations of lignin degradation by white rot fungi alone. To further understand the mechanism of synergistic catalysis, we optimized the optimum potential for lignin catalysis by P. chrysosporium and built synergistic versus separate catalyses. After 48 h of incubation, the optimum growth environment and the highest lignin degradation rate (43.8%) of P. chrysosporium were achieved when 4 V was applied. After 96 h, the lignin degradation rate of the cocatalytic system was 62% (E-Fenton catalysis alone 22% and P. chrysosporium catalysis alone 19%), the pH of the growth maintenance system of P. chrysosporium was approximately 3.5, and the lignin peroxidase (LiP) and manganese-dependent peroxidase (MnP) enzyme activities, were significantly better than those of the control. The qPCR results indicated that the expression of both MnP and LiP genes was higher in the cocatalytic system. Meanwhile, FTIR and 2D-HSQC NMR confirmed that the synergistic catalysis was effective in breaking the aromatic functional groups and the side chains of the aliphatic region of lignin. This study showed that the synergistic catalytic process of electro-Fenton and P. chrysosporium was highly efficient in the degradation of lignin. In addition, the synergetic system is simple to operate, economical and green, and has good prospects for industrial application.

Pretreatment of rice straw by newly isolated fungal consortium enhanced lignocellulose degradation and humification during composting

The slow decomposition rate of the reluctant structure of lignocellulose in agricultural waste is the great limitation of composting processes, which can be averted by pretreatment-strategies. This study focused on the impacts of pretreating rice straw using a consortium of newly isolated fungal species on lignocellulose degradation and humic substances during composting. Fungal pretreatment had a significant impact on lignocellulose degradation (84%) of rice straw by producing higher lignocellulytic enzymes than chemical pretreatments (79%) or the control (61%). The compost with fungal pretreated rice straw (FPT) showed significantly high composting temperature in the late mesophilic stage, which enhanced the degradation of lignocellulose. The fluorescence excitation emission spectroscopy revealed that significantly more humic acid-like compounds were formed in FPT. These findings suggest that fungal pretreatment is a feasible method to accelerate straw degradation and humification.

Effect of Ammoniated and/or Basidiomycete White-Rot Fungi Treatment on Rice Straw Proximate Composition, Cell Wall Component, and In Vitro Rumen Fermentation Characteristics

Various pretreatments are employed to increase the utilization of rice straw as a ruminant feed ingredient to minimize its negative environmental impact. However, an efficient alternative is still needed. The purpose of this study was to evaluate the ability of ammonia and/or white-rot fungi (Pleurotus ostreatus) to degrade lignin, increase the nutritional value, and enhance the rumen fermentability of rice straw. Rice straw was treated with ammonia and/or basidiomycete white-rot fungi (P. ostreatus) with untreated straw as control under solid-state fermentation employing a completely randomized design. The crude protein increased from 2.05% in the control to 3.47% in ammoniated rice straw, 5.24% in basidiomycete white-rot fungi (P. ostreatus), and 6.58% in ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw. The ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw had the least lignin content (3.76%). Ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw had improved in vitro dry matter digestibility (65.52%), total volatile fatty acid (76.56 mM), and total gas production (56.78 mL/g) compared to ammoniated rice straw (56.16%, 67.71 mM, 44.30 mL/g) or basidiomycete white-rot fungi-treated (P. ostreatus) rice straw (61.12%, 75.36 mM, 49.31 mL/g), respectively. The ammoniated-basidiomycete white-rot fungi (P. ostreatus) treatment improved rice straw’s nutritional value, in vitro dry matter digestibility, volatile fatty acids, and gas production.

Microbial Degradation of Aldrin and Dieldrin: Mechanisms and Biochemical Pathways

As members of the organochlorine group of insecticides, aldrin and dieldrin are effective at protecting agriculture from insect pests. However, because of excessive use and a long half-life, they have contributed to the major pollution of the water/soil environments. Aldrin and dieldrin have been reported to be highly toxic to humans and other non-target organisms, and so their use has gradually been banned worldwide. Various methods have been tried to remove them from the environment, including xenon lamps, combustion, ion conversion, and microbial degradation. Microbial degradation is considered the most promising treatment method because of its advantages of economy, environmental protection, and convenience. To date, a few aldrin/dieldrin-degrading microorganisms have been isolated and identified, including Pseudomonas fluorescens, Trichoderma viride, Pleurotus ostreatus, Mucor racemosus, Burkholderia sp., Cupriavidus sp., Pseudonocardia sp., and a community of anaerobic microorganisms. Many aldrin/dieldrin resistance genes have been identified from insects and microorganisms, such as Rdl, bph, HCo-LGC-38, S2-RDL^A302S, CSRDL1A, CSRDL2S, HaRdl-1, and HaRdl-2. Aldrin degradation includes three pathways: the oxidation pathway, the reduction pathway, and the hydroxylation pathway, with dieldrin as a major metabolite. Degradation of dieldrin includes four pathways: oxidation, reduction, hydroxylation, and hydrolysis, with 9-hydroxydieldrin and dihydroxydieldrin as major products. Many studies have investigated the toxicity and degradation of aldrin/dieldrin. However, few reviews have focused on the microbial degradation and biochemical mechanisms of aldrin/dieldrin. In this review paper, the microbial degradation and degradation mechanisms of aldrin/dieldrin are summarized in order to provide a theoretical and practical basis for the bioremediation of aldrin/dieldrin-polluted environment.

Review on the preparation of fuels and chemicals based on lignin

Lignin is by far the most abundant natural renewable aromatic polymer in nature, and its reserves are second only to cellulose. In addition to the rich carbon content, the structure of lignin contains functional groups such as benzene rings, methoxyl groups, and phenolic hydroxyl groups. Lignin degradation has become one of the high value, high quality and high efficiency methods to convert lignin, which is of great significance to alleviating the current energy shortage and environmental crisis. This article introduces the hydrolysis methods of lignin in acidic, alkaline, ionic liquids and supercritical fluids, reviews the heating rate, the source of lignin species and the effects of heating rate on the pyrolysis of lignin, and briefly describes the metal catalysis, oxidation methods such as electrochemical degradation and photocatalytic oxidation, and degradation reduction methods using hydrogen and hydrogen supply reagents. The lignin degradation methods for the preparation of fuels and chemicals are systematically summarized. The advantages and disadvantages of different methods, the selectivity under different conditions and the degradation efficiency of different catalytic combination systems are compared. In this paper, a new approach to improve the degradation efficiency is envisioned in order to contribute to the efficient utilization and high value conversion of lignin.

Review on the preparation and application of lignin-based carbon aerogels

Carbon aerogels (CAs) are excellent carrier materials with a large surface area and high porosity. In addition to the above-mentioned wonderful characteristics, aerogel with lignin as a precursor is also a material with high bioactivity and degradability. Lignin carbon aerogels (LCAs) have a wide range of applications, and can be used in supercapacitors, adsorbents and catalysts, etc., but their preparation process is more complex. In this paper, we review the preparation and influencing factors of LCAs, analyze their properties and structural characterization, and aim to provide references for the optimal preparation, effective characterization, and expansion of applications of LCAs.

Toward Microbial Recycling and Upcycling of Plastics: Prospects and Challenges

Annually, 400 Mt of plastics are produced of which roughly 40% is discarded within a year. Current plastic waste management approaches focus on applying physical, thermal, and chemical treatments of plastic polymers. However, these methods have severe limitations leading to the loss of valuable materials and resources. Another major drawback is the rapid accumulation of plastics into the environment causing one of the biggest environmental threats of the twenty-first century. Therefore, to complement current plastic management approaches novel routes toward plastic degradation and upcycling need to be developed. Enzymatic degradation and conversion of plastics present a promising approach toward sustainable recycling of plastics and plastics building blocks. However, the quest for novel enzymes that efficiently operate in cost-effective, large-scale plastics degradation poses many challenges. To date, a wide range of experimental set-ups has been reported, in many cases lacking a detailed investigation of microbial species exhibiting plastics degrading properties as well as of their corresponding plastics degrading enzymes. The apparent lack of consistent approaches compromises the necessary discovery of a wide range of novel enzymes. In this review, we discuss prospects and possibilities for efficient enzymatic degradation, recycling, and upcycling of plastics, in correlation with their wide diversity and broad utilization. Current methods for the identification and optimization of plastics degrading enzymes are compared and discussed. We present a framework for a standardized workflow, allowing transparent discovery and optimization of novel enzymes for efficient and sustainable plastics degradation in the future.

Bibliometric analysis of global research on white rot fungi biotechnology for environmental application

In recent years, white rot fungi (WRFs) have received tremendous attention as a biotechnological tool for environmental pollution control. In order to systematically and comprehensively describe the progress, trends, and hotspots of WRF biotechnology in the field of environmental pollution control, the 3967 related publications from 2003 to 2020 were collected from Web of Science Core Collection database, and the bibliometric characteristics including publication output, country, institution, journal, author, citation frequency, h-index, and research focus were evaluated by using Excel 2007, CiteSpace V, and VOSviewer. The results indicated that the number of research publications increased rapidly before 2009, but after that, the number of publications fluctuated in a certain range. China and USA were the most productive countries and the most active country in international cooperation. In this field, most authors tend to cooperate within a small group. The journal and subject category with the largest number of publications are "International Biodeterioration & Biodegradation" and "Biotechnology Applied Microbiology", respectively. The analysis of high-frequency keywords revealed that "laccase", "biodegradation", "decolorization", and "Phanerochaete chrysosporium" were the most cited terms among all publications. The pretreatment of biomass waste, decolorization of dye wastewater, and bioremediation of polluted environment are the key research directions of WRF biotechnology. Finally, the frontier topics and active authors in this research field were identified using burst detection. We believe that this bibliometric study provides a comprehensive and systematic overview and promoted the future cooperative research and knowledge exchange in this field of WRF biotechnology for environmental applications.

Microbial valorization of lignin: Prospects and challenges

Lignin is the world's second most prevalent biomaterial, but its effective value-added product valorization methods are still being developed. The most common preparation processes for converting lignin to platform chemicals and biofuels are fragmentation and depolymerization. Due to its structural diversity, fragmentation generally produces a variety of products, necessitating tedious separation and purifying methods to isolate the desired products. Bacterial-based techniques are commonly utilized for lignin fragmentation due to their high metabolitic activity. Recent advancements in lignin valorization utilizing bacteria, such as lignin decomposing microbes and major pathways involved that can breakdown lignin into various valuable products namely lipids, furfural, vanillin, polyhydroxybutyrate, poly lactic acid blends were discussed in this review. This review also covers the genetic and fermentation methodologies to enhance lignin decomposition, challenges and future trends of microbe based lignin valorization.

Fungal lignocellulolytic enzymes and lignocellulose: A critical review on their contribution to multiproduct biorefinery and global biofuel research

The continuous increase in the global energy demand has diminished fossil fuel reserves and elevated the risk of environmental deterioration and human health. Biorefinery processes involved in producing bio-based energy-enriched chemicals have paved way to meet the energy demands. Compared to the thermochemical processes, fungal system biorefinery processes seems to be a promising approach for lignocellulose conversion. It also offers an eco-friendly and energy-efficient route for biofuel generation. Essentially, ligninolytic white-rot fungi and their enzyme arsenals degrade the plant biomass into structural constituents with minimal by-products generation. Hemi- or cellulolytic enzymes from certain soft and brown-rot fungi are always favoured to hydrolyze complex polysaccharides into fermentable sugars and other value-added products. However, the cost of saccharifying enzymes remains the major limitation, which hinders their application in lignocellulosic biorefinery. In the past, research has been focused on the role of lignocellulolytic fungi in biofuel production; however, a cumulative study comprising the contribution of the lignocellulolytic enzymes in biorefinery technologies is still lagging. Therefore, the overarching goal of this review article is to discuss the major contribution of lignocellulolytic fungi and their enzyme arsenal in global biofuel research and multiproduct biorefinery.

Lignin degradation by microorganisms: A review

Lignin is an abundant plant-based biopolymer that has found applications in a variety of industries from construction to bioethanol production. This recalcitrant branched polymer is naturally degraded by many different species of microorganisms, including fungi and bacteria. These microbial lignin degradation mechanisms provide a host of possibilities to overcome the challenges of using harmful chemicals to degrade lignin biowaste in many industries. The classes and mechanisms of different microbial lignin degradation options available in nature form the primary focus of the present review. This review first discusses the chemical building blocks of lignin and the industrial sources and applications of this multifaceted polymer. The review further places emphasis on the degradation of lignin by natural means, discussing in detail the lignin degradation activities of various fungal and bacterial species. The lignin-degrading enzymes produced by various microbial species, specifically white-rot fungi, brown-rot fungi, and bacteria, are described. In the end, possible directions for future lignin biodegradation applications and research investigations have been provided.

Fir bark modified by Phanerodontia chrysosporium: A low-cost amendment for cd-contaminated water and agricultural soil

In this study, a modified fir barks (MFB) was prepared by mixing fir barks (FB) and white-rot fungi (Phanerodontia chrysosporium) under aerobic fermentation. The potential of MFB for Cd²⁺ adsorption was investigated by batch experiments combined with kinetic, isotherm, and thermodynamics analyses. The results revealed that the modification greatly increased the porous structures on the surfaces of fir barks and the surface area of MFB was much higher than that of FB. As a result, the adsorption capacity of Cd²⁺ on MFB (17.4 mg g^-1) was more than two times higher than that on FB (7.2 mg g^-1), and the adsorption of Cd²⁺ on MFB was controlled by physisorption and chemisorption. The immobilization of Cd by MFB in a contaminated agricultural soil was also investigated. The effect of MFB on the bioavailability of Cd was investigated using a leaching test (the European standard EN 12457-2) combined with a typical sequential extraction procedure (the community bureau of reference, BCR). The experimental results showed that the Cd leachability was reduced by 71% when the added MFB dosage was 30 mg g^-1. Besides, the MFB amendment could transform Cd from unstable geochemical fractions into more stable fractions. In total, the MFB, as a chemical-free and eco-friendly material, could be potentially employed for in-situ remediation of Cd-contaminated agricultural soils.