According to Federhen (2012) scientific nomenclature “INOS” denotes fibre, “NOTON” denotes back, and “OBLIQUE” denotes unevenness of the sides (Figure 1) (Federhen, 2021).

Common names include Chaga, “Tschaga, Tschagapilz” (Russian), black birch touchwood, malalon mushroom, sterile conk trunk (North America/Europe), “Kreftjuilce” (Cancer polypore) (Norway), “Tikkatee” (Finland) and “Kabanoanatake” (Japan) (Zabel, 1976; Lee et al., 2008; Zhong et al., 2009; Beltrame et al., 2021). Chaga has several common names: in Russia, the fungus is called Chaga, which is derived from “Komi-Permyak,” the language of the Kama Basin, west of the Ural Mountains, but in England and Canada, Chaga is referred to as the birch’s sterile conk trunk (Zabel, 1976; Lee et al., 2008; Zhong et al., 2009; Beltrame et al., 2021). Owing to its therapeutic uses in modern medicine, Chaga is also known as the “Mushroom of Immortality”, in Japan, it is known as the “Diamond of the Forest” and the “King of Plants” in China (Nakajima et al., 2007; Zyryanova et al., 2010).

Chaga is commonly found in cooler climates, extending from the meridian zone in the mountains to the Northern hemisphere in subarctic regions (Figure 2). This mushroom is well known on three continents, including the cold climate regions of North America at latitudes of 45⁰ N– 50⁰ N (Canada, the United States of America), Asia (Russia, Kazakhstan, Siberia, South Korea, Japan), and Central and Northern Europe. Although Western and Southern Europe have cold climates, Chaga is rare in these regions perhaps owing to the length of unfavorable climatic conditions (Zhong et al., 2009; Abu-Reidah et al., 2021; Wasser, 2021).

Huang et al. (2012) extracted and purified five Inonotus obliquus polysaccharides (IOPS) by column chromatography, namely,; IOP1b, IOP2a, IOP2c, IOP4 and IOP3a (Huang et al., 2012). In one study, the authors suggest that the sugar, -(1.3)- β-D-mannan influences β-glucan properties (Baek et al., 2012). Recently, both β-glucan has been found to have a variety of health-promoting properties, including immune modulation, anti-inflammatory effects, and antioxidant activity (Zhu et al., 2015). Yeast, mushrooms, bacteria, and algae are all sources of a dietary fiber compound called β glucan. This compound is widely recognized as a polysaccharide found in Chaga mushrooms along, with galactomannan (Basal et al., 2021; Eid et al., 2021; Peng and Shahidi, 2022). Chaga contains 8.57% β-glucan (Song 2020).

According to a study, by Razumov et al. (2020), they found that chaga hydrolyzed products contain many amino acids with aspartic acid, glycine, and glutamic acid making up, around 40% of the amino acids. The remaining 60% consists of lysine, threonine, methionine, alanine, tyrosine, serine, histidine, proline, tryptophan, arginine, and cysteine (Razumov et al., 2020). Other forms of amino acids such as peptides have also been reported by Hyun et al. (2006). In the study, the author identified a new peptide that prevents platelet aggression. In the study, analysis of the peptide using LC/MS revealed a molecular mass of 365 Da (Hyun et al., 2006).

Chaga has been observed to have a high concentration of elements, with potassium accounting for 50% of the total ash content, sodium accounting for 9%–13%, and manganese accounting for 1.2% (Shashkina et al., 2006). Other minerals such as copper, zinc, aluminum, sulfur, magnesium, phosphorus, and calcium have all been identified in chaga (Razumov et al., 2020).

Chaga also contains a significant number of mineral microelements. In their research, the scientists used x-ray fluorescence and atomic absorption spectroscopy to analyze chaga and determine its composition of macro and micro elements. Their findings revealed that chaga contains amounts of iodine, vanadium, zinc, copper, selenium, manganese, and sulphur (0.02%) rubidium (approximately 0.04%) sodium (approximately 0.05%) phosphorus (approximately 0.23%) chlorine (approximately 0.33%) calcium (approximately 0.37%) nitrogen (approximately 0.4%) magnesium (approximately 0.64%) hydrogen (around 3.6%) potassium (around 9 10%) and carbon constituting approximately 39%. (Razumov et al., 2020). These findings suggest that Chaga mushrooms and their derived products possess essential nutrients that are beneficial for crop cultivation (Peng and Shahidi, 2022).

Based on several studies of crude Chaga extracts, numerous bioactive compounds have been isolated and purified (Table 2).

Chaga extract is widely recognized for its properties and multiple studies have shown its ability to counteract the effects of free radicals (Zheng et al., 2011b; Haines, 2013). In one study, to examine Chaga’s ability to operate as a superoxide dismutase (SOD) in scavenging radicals, the researchers utilized alcohol and three distinct hot-water extractions (each with a different temperature). According to Hu et al. (2009), their research revealed that the alcohol extract exhibited SOD activity, among all their investigations. On the hand, hot water extracts also showed SOD activity with higher temperatures resulting in stronger antioxidant abilities (Hu et al., 2009). Additionally, these researchers evaluated the four extracts’ capacity to scavenge 2,2 diphenyl 1 picrylhydrazyl (DPPH). Interestingly the alcohol extract displayed a higher DPPH scavenging ability as compared to hot water extracts (Hu et al., 2009).

Notably present in Chaga extracts is hispidin—a compound, with antioxidant and inflammatory properties. However, Chaga extracts’ composition can vary based on the source of the fungus, the extraction procedure, and the section extracted (Lee and Yun, 2006; Yusoo et al., 2002). Among the hispidin analogs are phelligridins, inoscavins, inonoblins, and davalialactone and its derivatives (Zheng et al., 2011b). These analogs contain the active ingredient that confers antioxidant action on the drug and is used to treat disorders associated with oxidative stress. In other studies, Giridharan et al. (2011) investigated the impact of the antioxidant activity of Chaga extract on the cognitive function of mice with amnesia. Researchers studied its effects on the brain and cognition after using the alkaloid scopolamine to induce cognitive impairment. In both tests, Chaga increased glutathione and superoxide dismutase levels (endogenous antioxidants), and improved learning and memory. The antioxidant properties of Chaga have gained recognition, for their ability to combat cancer promote heart health and help manage diabetes (Zhong et al., 2009; Song et al., 2013; Jiang et al., 2020). Moreover, findings demonstrate that Chaga extracts possess antioxidants that can effectively counteract radicals suggesting its potential in preventive and healing capacities, for various diseases (Mu et al., 2012). Song et al. (2004) examined NF-kB and antioxidant activity in malignant human keratinocytes (SCC-13) to determine whether pine bark extract, Chaga (Inonotus obliquus), and Chaga mycelium were effective. The activity of NF-BNF-B was downregulated in every substance that was evaluated using a cell-based NF-BNF-B monitoring assay. Using AGI-1120 (one to two mg) as the positive control and Chaga mushroom extract (0.05–0.1 mg), demonstrated a significant inhibitory effect on NF-BNF-B activity which implies that the Chaga mushroom extract was successful in scavenging DPPH radicals.

The extracts, from Inonotus obliquus known for their inflammatory properties, have gained popularity in countries like China, Korea, Japan, Russia, and the Baltics. When it was initially discovered in the mid-20th century it was utilized in the treatment of malignancies and digestive issues with no effects (Szychowski et al., 2021). Research has indicated that Chaga extract possesses inflammatory properties. Macrophages can release substances such, as nitric oxide, prostaglandin mediators, and pro-inflammatory cytokines (TNF α, IL 1 β IL 6) (Im et al., 2016). A study on the methanol and ethanol extracts of Chaga has shown that they inhibit macrophage activity by reducing the production of inflammatory mediators such as nitrogen oxides, prostaglandins (PGE2), and certain cytokines (Softa et al., 2019). According to a study conducted by Mishra et al. (2012), it was found that aqueous Chaga extracts have the potential to greatly alleviate effects caused by dextran sodium sulfate (DSS). These effects include reducing edema and mucosal damage and minimizing crypt loss. Additionally, the study revealed that Chaga extracts can effectively suppress the expression of inflammatory cytokines lower the levels of iNOS induced by DSS, and reduce the accumulation of myeloperoxidase in the colon (Mishra et al., 2012). The anti-inflammatory properties of Chaga associated with isolated ergosterol, ergosterol peroxide, and trametenolic acid were further confirmed by Kou et al. (2021). Ishfaq et al. (2022), demonstrated that aqueous extract of chaga possess anti-inflammatory chaacteristics. The study further demonstrated the ability of the extract to suppress expression of p53, caspace-3 and microcystin-LR known to cause inflammation and toxicity to the liver in mice (Ishfaq et al., 2022). In another study, Ishfaq et al. (2021), demonstrated that aqueous extract of chaga suppressed carbon tetrachloride (CCl₄) induced damage in liver tissues in mice. The study also showed that ergosterol peroxide isolated from chaga has the ability to bind and inhibit activity of pro-inflammatory proteins (Ishfaq et al., 2021).

Betulin and betulinic acid have shown promising potential as antimicrobial and anti-inflammatory agents. With anti-inflammatory activities, these compounds are reported to modulate the activities of immune cells and prevent pro-inflammatory production (Oliveira-Costa et al., 2022). This, therefore, demonstrates its potential ability for the treatment of inflammatory ailments.

Ma et al. (2013) evaluated the anticancer properties of chaga using bioassay-guided preparative isolation. Acetate and petroleum ether extracts significantly reduced NO generation and NF-kB luciferase activity in macrophage RAW 264.7 cells and induced cytotoxicity in vitro in human prostate cancer PC3 and breast cancer MDA-MB-231 cells. Inotodiol, ergosterol peroxide, and trametenolic acid were recovered from these two fractions. Both ergosterol peroxide and trametenolic acid were cytotoxic to the human prostatic carcinoma cell PC3 and the human breast cancer MDA-MB-231. These findings may help in understanding Chaga’s anti-cancer activity. Different cancers, including Walker 256 carcinosarcoma, MCF-7 human breast adenocarcinoma, sarcoma 180, and carcinoma 755, are sensitive to the effects of lanolin triterpenoids isolated from Chaga (Shin et al., 2000). Additionally, hot water extracts of Chaga were shown to have anticancer activity against human colon cancer cells HT-29. The main mechanisms involved in this process were increasing the levels of proteins that promote cell death and decreasing the levels of proteins that prevent cell death. This was shown in a study conducted by (Heo et al., 2017). Another study by Mizuno et al. (1999), found that purified endopolysaccharide from cultivated mycelia of Chaga suppressed tumor cell proliferation and activated B cells and macrophages. Moreover, Chaga mycelium, had an effect, on cdc25 phosphatase, an enzyme that regulates the cycle of cancer cells. In a study using Sepharose, researchers found that the drug contains a water-soluble polysaccharide (ISP2a), which showed antitumor activity in vivo and significantly enhanced the immune response in tumor mice. As an added benefit, ISP2a enhanced lymphocyte proliferation and increased the production of TNF-α (Liuping et al., 2012). Satoru et al. (2016) sought to explore whether Chaga water extract might be utilized as a long-term cancer therapy. Chaga water extracts were extremely anti-blastema active in the treatment of cancer. A study published in 2008 by Youn et al. (2008) indicated that Chaga water extract inhibits the growth of cancer cells in vitro and triggers apoptosis (programmed cell death, in which the cell breaks down into distinct apoptotic bodies) in various carcinoma cells.

Particularly betulinic acid has demonstrated promise in cancer research as it has demonstrated potential in shrinking cancer growth cells, inhibiting apoptosis, and shrinking tumors (Zhang et al., 2015). Other researchers, attest to its anticancer activity and demonstrate its selective antagonistic activity towards cancer cells (Saha et al., 2015; Kumar et al., 2018).

In 2015, a study examined the anti-cancer activity of ergosterol peroxide isolated from chaga on colon cancer cells. The study demonstrated that the compound increased apoptosis and suppressed cell growth in colon cell lines. The compound further inhibited the β-catenin signaling pathway, a major player in colon cancer development (Kang et al., 2015). Similarly, Mishra et al. (2013) found that aqueous extract of chaga expresses anti-proliferative and anti-inflammatory activity on colon cancer cells and tumors in mice. The study also demonstrated that extracts suppresses the Wnt/β-catenin and NF-κB signaling pathways that are responsible for colon cancer onset and development (Mishra et al., 2013).

For anti-viral properties, studies report the inhibitory properties of bioactive compounds in Chaga against a host of viruses including hepatitis C, HIV, and herpes simplex virus make them attractive candidates for antiviral therapies (Navid et al., 2014; Paduch and Kandefer-Szerszen, 2014; Xiao et al., 2018).

Satoru et al. (2016), shows that Chaga extracts have been found to impede the replication of both hepatitis C virus and human immunodeficiency virus (HIV). The intriguing potential benefits of Chaga, in treating diseases have captured the attention of researchers. Jin et al. (2017) investigated the antiviral effects of Chaga extracts on feline viruses. They proved that Chaga therapy was effective in cell assays and had minimal cytotoxicity by using feline calicivirus cell models. According to research on adhesion’s mode of action, the treatment of calicivirus causes an inhibitory effect on viral particles by preventing viral binding and absorption. Research has shown that cats may experience gastrointestinal issues due, to the herpes virus panleukopenia virus, and infectious peritonitis virus. These viruses have a range of activities. In this study, scientists discovered that Chaga polysaccharides could potentially serve as an antiviral treatment, for both feline and human pathogens. Moreover, researchers from Poland have shown in 1998 that botulin and betulinic acid found in Chaga can stop blastema development (Liang et al., 2009). They discovered that betulin and betulinic acid are now potential anti-HIV medicines that inhibit HIV reverse transcriptase, in turn inhibiting HIV type 1 (Gogineni et al., 2015). Human influenza A and B and horse influenza A are also inhibited by constituents of the black exterior surface of Chaga (Zheng et al., 2010). Betulin, mycosterol, and lupeol, which are all found in mushrooms, are thought to be the primary antiviral agents (Pan et al., 2013). Polkovnikova et al. (2014), examined the antiviral efficacy of Chaga extract on Vero cells using Vero cell cultures and HSV (herpes simplex virus) type 1 infected Vero cells. Most of the HSV-infected Vero cells were protected by non-toxic sub-components. Deletion of viral DNA in Chaga-infected cells suggests that it protects Vero cells from HSV cytotoxicity.

More recent research by Eid et al. (2021) has shed light on the impact of Chaga on the novel coronavirus (SARS-CoV-2) that has been responsible for widespread outbreaks around the globe. In this study, the S1-carboxy-terminal domain of the SARS-receptor-binding CoV-2 domain was discovered to be closely related to -glucan, galactomannan, and betulinic acid. At the TRP-436, ASN-437, and ASN-440 sites, this interaction was substantial. The receptor binding domain of the most recent SARS-CoV-2 isolates had a furin cleavage site that was not seen in prior isolates. Since this response interacted with ACE-2 more often, this virus was able to infect more people. Chaga, according to those who took part in the research, might be used in conjunction with other medications to combat SARS-CoV-2. Hence, future anti-SARS-CoV-2 therapeutic development may be aided by the development of naturally derived anti-coronavirus therapies that include Chaga (Eid et al., 2021).

Platelet aggregation is a complicated event that is most likely the product of several metabolic pathways working in concert. The use of platelet inhibition in the prevention of thrombosis is a potential new treatment. According to a report by Hyun et al. (2006), water and ethanol extracts from 55 different kinds of mushroom mycelium or fruiting bodies were tested for platelet aggregation inhibitory activities in vitro. The ethanol extracts of Chaga ASI 74006 mycelia demonstrated the highest platelet aggregation inhibitory activity (71.2%), whereas the impacts of extracts from its fruiting bodies had very low inhibitory activity. The isolated peptide was found to have a strong inhibitory activity of 91.6% and a low molecular mass of 365 Da. It is assumed that the peptide from Chaga which inhibits platelet aggregation is quickly absorbed in the gut, and is commonly employed in the creation of antithrombotic medications and nutritional supplements for human consumption (Huang et al., 2012).

Chaga produces ligninolytic enzymes that act as biocatalysts in oxidoreductase processes such as degrading lignin and other parts of the cell wall (Dashtban et al., 2010). Particularly, ligninolytic peroxidase degrades polymers and other complex components in an oxidative process, splitting the entire lignin structure (Silvat, 2013). In a similar fashion, the enzyme degrades polysaccharide compounds in hemicellulose and cellulose. By breaking down these materials, Chaga can access the nutrients present in the wood and utilize them for its growth and survival (Cajthaml and Svobodová, 2012).

This ability of Chaga’s enzymes to degrade lignin and other woody materials has attracted interest for potential applications in various industries. One such application is bioremediation, where these enzymes play a role in the cleanup of polluted environments. By breaking down lignin and other organic pollutants, such as pesticides, dyes, and industrial chemicals, these enzymes contribute to the degradation of toxic compounds, leading to the remediation of contaminated sites and a reduction in environmental pollution (Singh et al., 2021). Another notable application lies in biofuel production. In one study, lignocellulosic biomass, including wood and agricultural residues, was reported to be beneficial as a feedstock for biofuel production. Ligninolytic peroxidase enzyme hydrolyzed the lignocellulosic materials, breaking them down into simpler sugars. These sugars were then fermented to produce biofuels like ethanol. By facilitating the degradation of biomass, these enzymes present a promising avenue for the advancement of biofuel technologies (Ilić et al., 2023).

In the paper and pulp industry, these enzymes have been reported to provide a more environmentally friendly alternative to the conventional pulping and bleaching processes. The enzymes activate the bond between ink and paper particles through hydrolysis which is subsequently removed via a flotation technique (Lee et al., 2013).

Traditionally, these industries rely on harsh chemicals and energy-intensive methods (Kaur et al., 2020). However, the enzyme was found to selectively degrade lignin, increasing the efficiency of the pulping process while reducing the dependence on chemicals. Furthermore, these enzymes can be employed in the bleaching process, minimizing the use of chlorine-based bleaching agents that pose harm to the environment (Singh et al., 2021).

Chaga enzymes have also shown potential in the textile and detergent industries. As bio-catalysts, they can be utilized in the processing of natural fibers like cotton and hemp (Pavithra et al., 2023; Asemoloye et al., 2021 reported that by effectively removing lignin and impurities from these fibers, the ligninolytic peroxidase enzyme contributed to the production of cleaner and higher-quality textiles. In the detergent industry, Chaga enzymes were found to enhance the efficiency of laundry detergents by aiding in stain removal and facilitating the degradation of organic matter (Asemoloye et al., 2021).

The use of these mushrooms as lignocellulosic materials were conceptualized more than a century ago by Falck (1902), who proposed their use for improving agricultural waste and subsequently animal nutrition. After almost a century, several newer studies also focus on improving lignocellulosic materials for fodder (Lindenfelser et al., 1979; Hadar and Cohen-Arazi, 1986). This includes investigating the underlying biochemical mechanisms of the fungal degradation of agricultural waste. Studies have also considered the lignocellulose complex in straw and plant residues, and the reaction mechanisms connecting lignin polymers and hydrolytic enzymes such as cellulases and hemicelluloses (Hadar et al., 1992; Honda et al., 2000).

Antibiotics have become a major aspect of livestock production, especially in developed countries (Rathgeber et al., 2008). The initial evidence, reported by Moore et al. (1946) showed the benefits of administering doses of antibiotics to chickens (Moore et al., 1946). Their study indicated that the inclusion of streptomycin improved the growth rate of the chicks (Moore et al., 1946). Chaga mushrooms contain a concentration (8.57%) of β glucan which is recognized for its immune system support properties and has been shown to improve the growth rate of fowls (Chandrasekaran et al., 2011). Currently, few studies conducted to confirm that incorporating β glucan, into animal feed has an overall impact, on the system and the growth of livestock.

Several studies have shown that the addition of β-glucan to animal feed positively affects the immune system and the growth of farm animals. One study, in particular, demonstrated that broiler feed supplemented with β glucan increased the weight of the broilers significantly as compared to broilers given feed without supplemented β glucan (Chae et al., 2006). Rathgeber et al. (2008) conducted studies that revealed β glucan to be equally effective, as virginiamycin, in promoting the growth of broiler chickens. Similarly, Dritz et al. (1995) demonstrated that the addition of β glucan improved the growth of nursery pigs while incorporating Chaga into their diet enhanced piglet growth and facilitated weight gain. Not are β glucans utilized in the food and pharmaceutical industries as anticancer and immune-modulating agents. They are also employed within the aquaculture and livestock sectors to enhance animals’ innate immunity (Jung et al., 2007; Zhu et al., 2016). According to (Jung et al., 2007), β-glucan from Paenibacillus polymyxa JB115 can be added to animal feed to enhance immunity and may act as an anticancer agent in livestock. Additionally, rainbow trout (Oncorhynchus mykiss) were fed β-glucan pellets, increasing the secretion of specific antibodies and Ig levels in serum (Skov et al., 2012). Owing to the emergence of new diseases and government efforts to prohibit antibiotics that promote growth while enhancing the efficacy of commercial agriculture, new opportunities for natural, highly effective, and inexpensive immunomodulators like Chaga mushrooms can compensate by inducing and enhancing disease resistance while reducing losses. Moreover, these mushrooms produce significant quantities of β-glucan that can be used in feed supplements (Cueno et al., 2004). These supplements can improve immunity, reducing the excessive use of antibiotics. This has been confirmed by the immunostimulation of fowl after being fed with Pleurotus ostreatus, which considerably improved without affecting the size or quality of the meat (Li et al., 2006; Zhang et al., 2008).

In addition, these medicinal mushrooms have been investigated extensively as prospective materials for improving the quality of agricultural lignocellulose waste (Bogan et al., 1999). In one study, Chaga mushroom helped to breakdown lignin, releasing cellulose that can be used by ruminants (Kamra and Zadražil, 1986). This breakdown mechanism was linked to the ligninolytic system of the mushroom made up of oxidative enzymes. In another study, the direct use of mushrooms as lignocellulosic residues in animal feed played an important role in the diet of ruminants (Streeter et al., 1982). Studies have also examined the use of Pleurotus spp in breaking down wheat straw under different conditions and substrate treatments (Zadrazil, 1997; Salmones et al., 2005; Khan et al., 2013; Muswati et al., 2021). A significant increase in digestibility of wheat straw was observed after treatment with the mushroom. Similarly, Hadar et al. (1992) found that the lignin constituents in wheat straw significantly decreased during 4 weeks of treatment with P. ostreatus. In vitro digestion also increased and the product was degraded by up to 40% in animals’ diets (Hadar et al., 1992).

A major barrier to the upgrade of straw to fibre is the expensive materials and equipment needed for the preparation of fungal substrates (Hüttermann et al., 2000). Hüttermann et al. (2000) described a new process for degrading agricultural wastes using Pleurotus spp. This included using solar heating for pasteurization, and treatment using detergents, tomato pomace, and potato pulp. These methods generated positive results in on-farm applications (Hüttermann et al., 2000). Moreover, in both in vitro and in vivo studies, Pleurotus spp. significantly improved the availability of roughage in animal diets due to its action on cellulose and lignin (Van Kuijk et al., 2015). In a feeding experiment by Hüttermann et al. (2000), rams fed with mushroom-treated straw increased in body weight. At the same time, the treated group demonstrated an increase in nutritive value (Hüttermann et al., 2000).

In a study by Nwafor et al. (2022), a significant increase in the mineral composition of animal feed produced from agro -waste was observed after treatment with extracts of mushrooms. Its amino acid and carbohydrate contents also increased significantly as compared to the positive control, confirming the potential for mushrooms to improve the nutritional composition of animal feed (Nwafor et al., 2022).

Boulet and Bussières (2018) mentioned that an arborist in Quebec employed Chaga powder and paste to treat beech tree blight caused by Cryphonectria parasitica. The incision healed over 2 years, and the trees became immune to blight. This means that Chaga might be used as an inoculation or crop-protection strategy for other tree species. Chaga is also used as a fertilizer to protect cultivated plants from Phytophthora, and as a plant growth stimulant to promote development (Shashkina et al., 2006). Some Russian researchers, especially P. A. Yakimov and others (Bulatov et al., 1959; Shashkina et al., 2006; Sysoeva et al., 2012), conducted detailed investigations of Chaga and its concentrated extracts along with those of other porous fungi about a century ago (Bulatov et al., 1959). The chemical composition of Chaga is significantly different from other polypores. An X-ray fluorescence approach, atomic absorption spectrum, and gravimetric analysis demonstrated that Chaga contains the following: carbon (39%), potassium (9%–10%), hydrogen (3.6%), nitrogen (0.4%), magnesium (0.64%), calcium (0.37%), chlorine (0.33%), phosphorus (0.23%), sodium (0.04%). The nitrogen content of Chaga is primarily part of proteins. The products of hydrolysis exposed 15 different amino acids, the most prevalent of which were glycine, aspartic, and glutamic acids (accounting for approximately 40%), as well as tyrosine, serine, threonine, leucine, methionine, lysine, and histidine (Shashkina et al., 2006).

Invitro studies have shown these mushrooms to be useful in the degradation of industrial dyes, phenols, soil decontamination, and wastewater treatment. Yet, no further analysis such as in situ tests has been done to further confirm these claims (Irie et al., 2001). Roy et al. (2015) investigated the improvement of plant health for Capsicum annuum L by treating it with spent mushroom substrate from button and oyster mushrooms. After several weeks of treatment, growth parameters such as height, branches, and yield improved significantly (Roy et al., 2015; Somnath et al., 2015). Apart from that, the substrate played a role in reducing soil phosphate and increasing root and leaf phosphate. The c9hlorophyll and carotenoid content of the leaves also significantly increased following soil treatment with the mushroom substrate (Roy et al., 2015).

Currently, mushroom substrates are recognized as inexpensive, ecologically friendly sources of organic fertilizers. Features such as high moisture, nutrient retention, high air permeability, loose texture, and rich pellet structure are known to improve soil structure and maintain a beneficial environment for soil microorganisms. Among the numerous applications of mushrooms to crop farming, the use of spent mushroom substrate remains the most effective and economical (Lou et al., 2017). The spent substrate, from mushrooms contains an amount of matter and essential nutrients like nitrogen, phosphorus, and potassium. These elements play a role in promoting plant growth. Through the utilization of mushroom substrate, as a soil amendment, farmers can enhance the quality and fertility of their soil without having to rely on synthetic fertilizers (Esmaielpour et al., 2017). Secondly, the use of spent mushroom substrate can help to reduce waste and save resources. After the mushrooms are harvested, the remaining substrate can be recycled and used as a soil amendment instead of being disposed of as waste (Cunha Zied et al., 2020). Third, the production of spent mushroom substrate is relatively low-cost compared to other types of organic amendments, such as compost or manure. This is because the substrate is already produced as a byproduct of mushroom cultivation, so there are no additional costs associated with its production (Meng et al., 2018).

Another study demonstrated that treatment with beneficial microorganisms improved the biological and nutritional activity of the substrate thereby improving soil structure, efficiency, quality, and ecological function (Mohd Hanafi et al., 2018). In another study, after composting, elements such as phosphorus, potassium, and nitrogen increased after treatment with the mushroom (Akdeniz, 2019; Sánchez, 2010). Moreover, during the composting process, mushroom substrates diminished the function of pathogenic microorganisms and by extension plant diseases, while supplying these essential nutrients.

Other studies have demonstrated the benefits of combining mushroom substrates with organic waste or sludge (Meng et al., 2018; Meng et al., 2019). In another study, substrate-compost mixes improved nitrogen content in plants by more slowly releasing nitrogen from the substrate, increasing overall uptake (Uzun, 2004). Grimm and Wosten (2018) also illustrated that mushroom substrates can be used to replace chemical fertilizers.

Field experiments by Courtney and Mullen (2008) compared a chemical fertilizer to an organic mushroom substrate. The application of mushroom substrate improved soil properties and the yield of barley by 50% relative to the 40% improvement from the chemical fertilizer (Courtney and Mullen, 2008). This improved performance was attributed to the increase of mineral contents by 3 times for the mushroom substrate, the chemical fertilizer yielded no increase. As mentioned earlier medicinal mushrooms like Chaga contain compounds such as polysaccharides, polyphenols, steroids, and terpenoids that have antibacterial and antioxidant properties (Glamočlija et al., 2015). Moreover, the application of mushroom-spent substrate to soils slowly releases these bioactive compounds into the soil. This can potentially benefit plants by acting as a defense against diseases. For example, a research study demonstrated that using this type of biofertilizer led to plant growth and increased resistance against the fungal pathogen Fusarium oxysporum (Awad-Allah et al., 2022). In another study focused on chili pepper plants affected by root rot disease scientists explored the potential of a biofertilizer derived from Bacillus subtilis bacteria. The findings revealed that applying this biofertilizer significantly reduced both disease incidence and severity while also promoting plant growth and higher yields (Sivasakthi et al., 2014). Similarly in a study involving tomato plants infected with Rhizoctonia solani fungus researchers investigated the effects of a biofertilizer derived from Trichoderma fungus, on growth and disease resistance levels (Sivasakthi et al., 2014). According to Awad-Allah et al. (2022) when the biofertilizer was applied it led to plant growth. Increased protection, against the pathogen (Awad-Allah et al., 2022). This claim is further supported by Othman et al. (2020) research, which showed that mushroom substrates have properties that can combat plant pathogens. Apart from agriculture, the antibacterial effect of these mushrooms has also been used to suppress food and clinical pathogens (Hearst et al., 2009).