ASPECTS OF MUSHROOMS AND THEIR EXTRACTS AS NATURAL ANTIMICROBIAL AGENTS

to minimized efficacy and resulting in substantial economic losses all over the world. A new approach for choosing natural extracts of plants and fungi as medicines and natural antibacterial agents has been developed to address this challenge. According to recent investigations and research, mushrooms and their extracts contain bioactive compounds that can be used as a natural antibacterial alternative against a number of bacterial species. In addition to having medical properties like antibacterial, anticancer, and antioxidant activity, mushrooms are a highly nutritious food source. The present study emphasized on the antimicrobial resistance, mechanisms and antibacterial properties of mushrooms.


INTRODUCTION
Antimicrobial resistance (AMR) is a natural biological phenomenon that occurs when microbes respond to an antimicrobial drug's selective pressure, for example production of beta-lactamases by the bacteria is the most important mechanism associated with beta-lactam antibiotic resistance (Barker, 1999;Sharma et al., 2005;Smith and Cost, 2002).Antimicrobial resistance indicates that organisms can defend themselves against bacteria, fungi, and other microbes.Toxins are secreted by microbes that kill the organisms they attack.Antibiotics are effective against these toxins (Smith and Cost, 2002).The misuse of natural antimicrobial resistance, such as the ongoing use of it for subpar medications, hinders it.This results in the creation of medications with weak disease-prevention capabilities (Kumar et al., 2013).Infectious diseases related to antimicrobial resistance are measured as a parameter to represent vital public health problems.Antibiotics can be resisted by bacteria in two ways: by preventing higher concentration of the antibiotics to reach their target; or by altering the target on which the antibiotics work (Martinez and Baquero, 2014).Several bacterial enzymes that can inactivate the activity of antibiotics are another method of resistance.Betalactamase destroys the beta-lactam ring component of a synthetic antibiotic like penicillin (Tanwar et al., 2014).In order to pump out the antibiotics, bacteria attach an efflux pump to their cell membrane.This pump then expels the antibiotics from the body.When the DNA of bacteria is altered, more pumps are created.The growing burden of AMR around the world has yet to be adequately addressed (Acar and Rostel, 2001).The occurrence of antibiotic resistance presence is linked to microorganisms or humans.Antibiotic resistance refers to specific features of bacterial evolution that humans cannot normally stop, such as bacterial mutation, which is one of the defining determinants of resistance.Even before the emergence of antibiotic resistance in microbes, there was substantial interest in research studies of natural products for the medicinal treatment of disorders caused by these organisms (Harbarth et al., 2015).Mushrooms have long been recognised as useful foods and as a source for medical and nutraceuticals development such as Laetiporus sulphureus, Ganoderma lucidum and Lentinus edodes, are sources of natural antibiotics that have already shown antibacterial activity (Gao et al., 2015;Turkoglu et al., 2007;Garcia et al., 2021).Humans' widespread usage of antimicrobials provides opportunities for bacteria to develop massive antimicrobial resistance responses.If we do not find a solution to the current AMR scenario, it will most likely endure for a long time (Michael et al., 2014).

MUSHROOM AS AN ANTIMICROBIAL AGENT
Mushrooms are enormous eatable fruiting bodies with stalks and caps that are part of macrofungi.These mushrooms are large because to their multi-colored appearance, delicious flavours, and fragrances, as well as a nutritional and therapeutic value comparable to high protein content, fat-rich carbs, and vitamin D, as well as their ability to function as medications (Hafdani and Sadeghinia, 2011).Mushrooms tend to naturally produce specific chemicals in various conditions as self mechanism.These chemicals have many health benefits and when exploited more gave immense utilities in developing therapeutic drugs (Valverde et al., 2015).They produce a range of carbohydrates, proteins, adipose acids, phenolic groups, and indole acids.Vitamins like vitamin B7, vitamin B6, vitamin C and vitamin E are few of the examples for the same.The protein that mushrooms make is a kind of macromolecules called biopolymers that include amino acids.They help in the making of bio-molecules that help as building blocks for many different activities.Many researchers in their recent research have found micro-fungi capable of producing higher protein and their nutritional analysis conferred them to be better than the regular plant based protein.Lectin is one of the well known fungal proteins it is known to inactivate the laccase enzyme and caused immunomodulatory affects (Valverde et al., 2015).The lipids produced by the mushroom have immense solubility effect and thus are utilized as organic cleansers.The adipose acids sterols and phospholipids generated by the mushrooms help in growth and reproductive mechanisms.They have extended hydrocarbon chains with methyl group at one end and a carboxyl on the other.Overall they have good characteristic application in the health welfare and biological applications.In recent years natural antimicrobials, such as plants and fungi, have sparked renewed interest in their various properties, including antimicrobial activity, due to their non-harmful impact and effectiveness against microbes.In fact, in the case of antimicrobial resistance, mushrooms are an immense substitute representative which shows potential effects against microbes shown in Tab 1 (Lindequist et al., 2005).Edible and wild mushrooms have a high level of natural bioactive potential, facilitating medical and health benefits.The antibacterial activity of various mushroom bioactive resources has been discovered through research.As a result, the use of various types of mushrooms and their extracts containing bio metabolites can help in for various medical causes.There were few evidences in which it was noticed that the extracts produced by the mushrooms have both bacteriostatic in addition to bactericidal effect on microorganisms (Sitati et

ANTIBACTERIAL ACTIVITY OF BIOMETABOLITES FROM MUSHROOM EXTRACTS
Mushrooms coming from the basidiomycete's family have multitudinous varieties of mushroom species.They have different varieties of metabolites with nutraceutical and curative implication.The therapeutic and nutritional properties of mushrooms are being studied all over the world.Experimenters were providing crucial data on bioactive composites in it (Anusiya et al., 2021).Boletes are the tube-bearing or poroid components, while lamellate members are referred to as "mushrooms" or "toadstool" depending on whether they are edible or toxic (Barros et al., 2012).Consumable mushrooms are also obtained from nature or produced and harvested under strict quality control standards for size, shape, tenderness, and delectability.Secondary metabolites are created primarily after active growth, and many of them have peculiar chemical structures.Intervenes in the conflation of cell elements such as amino acids and nucleotides, as well as the product of lipids, vitamins, and polysaccharides, are also of enormous beneficial relevance in today's assiduity.Secondary metabolites, such as therapeutic proteins and peptides, are a significant source of antimicrobial bioactive components produced by various mushroom species (Sharma et al., 2014).
Agaricus bisporus, also known as white button mushroom, is an edible mushroom that is widely cultured in India, Europe, and North America and its surface consists of a stalk white or brownish cap and dark brown gills ( Auricularia auricula, also recognised as the jelly mushroom, is an edible mushroom that grows primarily on wood logs, dead trees, and the roots of woody plants.Its fruiting body is divided into two sections: the upper sterile portion and the lower fertile portion (Ziaf et al., 2016).A. auricula ethyl acetate extracts having antibacterial properties against S. aureus (Cai et al., 2015).A. auricula concentrated extract contains alkaloids (ethanol), tannins, and steroids/triterpenoids, which were active compounds with antimicrobial activity against S. aureus, E. coli, B. cereus and P. aeruginosa by altering the properties of the targeted bacteria's cell walls and destroys the cytoplasmic membrane (Sukmawati et al., 2019).Sometime some extracts, such as chloroform and ethanol extracts of Auricularia, have lower antimicrobial activity and there are a few reasons behind this, first is the lack of bioactive compounds in the extracts, second is the destruction of functionality due to variances in the amount and last one is the type of active compounds present in the extracts (Vallavan et al., 2020).Volvariella volvacea is an edible mushroom commonly known as paddy straw because of its texture, which includes pink-coloured spores, free lamellae, and a velvet base (Roy et al., 2014).V. volvacea which is a basidiomycete fungi used for research and studied antimicrobial screening against E. coli (Perara et al., 2001).Secondary metabolite of V. volvacea consist of Homoglucans which have pharmaceutical importance (Mandal, 2019).V. volvacea methanol extracts were found to have antibacterial action against S. aureus, K. pneumoniae, P. aeruginosa, and S. pyogenes (Appiah et al., 2017).Stereum ostrea, also known as "false turkey tail," grows densely on dead hardwood wood, forming a shape resembling a fuzzy cup with different colour zones such as brown, red, and orange (Prust et al., 2014).Mushroom S. osterus has two components: methanol extract and crude cultural filtrate.Methanol extracts have a strong inhibitory effect on Micrococcus sp. and crude cultural filtrate has the highest antimicrobial activity against B. subtilis, followed by Micrococcus sp., P. aeruginosa, and Klebsiella sp.(Praveen et al., 2012).Calocybe indica, also known as milky white mushroom or "Dhuth chatta," is a tropical edible mushroom native to India that is found in West Bengal and eastern India.It has a high nutritional value and high-quality protein (Vijaykumar et al., 2014).Petroleum ether extract of C. indica, illustrated the antimicrobial action against S. aureus, S. pyrogenes and P. aeruginosa (Padmavathy et al., 2014).The methanolic extract of C. indica gave significant response against P. aeruginosa (Roy and Prasad, 2014).
Pleurotus eryngii also known as the king oyster mushroom is a nutritional and medicinal mushroom that is widely distributed and used in North Africa, Europe, and Asia (Stazic et al., 2009).In the another study, chitosan nanoparticles of P. eryngii's extract given antimicrobial inhibition for E. coli and B. subtilis.Turmeric chitosan nanoparticles have antimicrobial activity against T. mentagrophyte and F. oxysporum (Acay et al., 2020).P. eryngii ethyl acetate and chloroform extract was found to be effective against B. megaterium, K. pneumoniae, S. aureus and M. luteus (Samsudin et al., 2020).Pleurotus eryngii was predicted to have high polysaccharide content and antibacterial capabilities to prevent E. coli bacteria from growing (Akyuz and Kirbag, 2009).Lactarius species are also known as saffron milk cap mushrooms because they have a good texture, delicious taste, and aromas.(Adanacioglu et al., 2017).L. deliciosus and L. piperatus are two edibles wild Lactarius species found in Portugal.These two mushroom species contain different bioactive compounds such as flavonoids, phenol, ascorbic acid, B-carotene and lycopene.E. coli activity was inhibited by L. piperatus and the antimicrobial activity of L. deliciosus against K. pneumoniae was determined (Barros et al., 2007).Cordyceps sinensis is a traditional Chinese medicinal mushroom with potent pharmaceutical properties (Chant et al., 2013).C. sinensis mushroom contains various polyyphenolic flavonoids components with six subgroups (chalcones, flavonol, flavanone, flavone, anthocyanins, and isoflavanoids).Moreover, these components showed antimicrobial activity against E. coli, P. aeruginosa, and B. Subtilis (Mehrotra et al., 2015).An antibacterial protein from C. sinensis, was isolated from cultured mycelia of C. sinensis (CSAP), had potent antibacterial activity against S. aureus, S. typhi and E. coli (Zheng et al., 2006).B. subtilis, E. coli, S. typhi, S. aureus, V. cholerae, and K. pnuemoniae were all examined and C. sinensis butanolic extract had the highest zone of inhibition against all of them (Agrawal and Sandhu, 2020).Cantharellus cibarius, which is mostly cultivated in Europe, is a fruiting mushroom with an apricot-like aroma and a great texture (Valentao et al., 2005).C. cibarius antimicrobial activity shown in their methanol extract, which were primarily effective against S. aureus, E. faecalis, B. cereus and L. monocytogenes (Kozarski et al., 2015)

MODE OF ACTION AGAINST BACTERIA BY MUSHROOM EXTRACT
Organic compounds produced from methanol and ethanol extracts of mushroom Coriolus versicolor are being studied for their effect and activity against gram positive and negative bacteria, figure 2. The hydroxyl group in phenol and phenolic acid determines their toxicity to microorganisms.Quinones are another bioactive molecule that reacts irreversibly with nucleophilic amino acids in proteins, resulting in protein inactivation and loss of function (Matijasevic et al., 2016).Other chemicals, such as p-coumaric acid, are effective against gramnegative bacteria such as S. typhimurium, S. dysenteriae, and E. coli.These acids affect cell membrane permeability, DNA binding capacity, and cell function by slowing or inhibiting it (Alves et al., 2013).Natural extract antimicrobials change the pH of the cytoplasm and have the capacity to damage microbe membranes through their processes (Gonelimali et al., 2018).Moreover, mushroom extracts (organic compounds) with the antimicrobial activity genrally involves in interaction with bacterial cell wall polypeptides, membrane-bound enzymes and surface-exposed adhesins to kill the bacteria (Matijasevic et al., 2016).

CONCLUSIONS
Antimicrobial resistance has exploded into a major public health issue with economic and social level.The issue of switching resistance patterns will continue to pose a threat to both developed and developing countries and it will cause a tremendous deal of disruption in the healthcare industry, making it harder to cure infections.In this time of widespread threat, natural antimicrobial agents like plants and fungi seem to be a significant advantage.As a result, mushrooms have a significant antibacterial activity.Earlier studies showed that various kinds of mushrooms such as edible mushrooms, wild mushrooms, and therapeutic mushrooms showing the antimicrobial activity in different solvent extracts such as in methanol, ethanol, acetone, n-hexane, diethyl ether, water, chloroform and phenol, as well as also contains bioactive compounds i.e., ascorbic acid, phenolic compounds, flavonoids, flavonol, organic acids and sterols.These extracts have either a significant activity or a mild inhibition zone in bacterial cells.Some Grampositive bacteria are more susceptible to these natural antibacterial mushroom extracts than gram negative bacteria, according to research.These extract activities revealed potential modifications in bacteria resistance mechanisms in two ways: they deliberate the function, and fully break down their resistance mechanism.These novel antimicrobial drugs are significant since they are widely available, inexpensive and nearly without adverse effects.Natural antimicrobials are more effective than manufactured antibiotics, according to a study (Quinto et al., 2019).More research and exploration of the numerous mushroom bioactive components as antibacterial agents is required.To substantiate pre-clinical and clinical information based on relevant data and to advance the assessment of mushrooms' therapeutic benefits, new studies are required.This research paper focused to connect the medicinal and antibacterial capabilities of mushroom extract, indicating that it will revolutionize the medical field which is particularly economically advantageous in underdeveloped nations.
al., 2021; Gebreyohannes et al., 2019).Every year nearly four million people are affected due to such infections in Europe alone.This in turn results in raise in the mortality rate (Barros et al., 2008) Apart from this, the antimicrobial medicines were already used in precautionary purposes for various serious illness related treatment.The growth in the new antimicrobial substances has resulted in pathogenic resistant to conventional treatments, figure 1.

Figure 1
Figure 1 Various problems related to antimicrobial resistance Table1 Antimicrobial action of bioactive compounds of different mushrooms against various microorganisms

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Two metabolites of C. cibarius such as pleuromutilin and chanterellins hold antimicrobial property (Salihovic et al., 2019).Other extract of C. cibarius consists of dichloromethane, cyclohexane and methanol which give significant response against S. aureus and H. pylori respectively (Kolundzic et al., 2017).

Figure 2
Figure 2 Antimicrobial mechanism of mushroom extracts Lepista nuda is an edible woodland mushroom that is primarily cultivated in Asia, Africa, America, Australia and Europe.It has an iilac-colored texture, a strong aroma, and delicate flavours with pharmacological properties (Hsu et al., 2015).The antimicrobial activity of L. nuda was determined by ethanol extract which inhibited the activity of M. luteus, M. flavus, S. aureus, B. cereus and S. enteritidis (Marcan et al., 2006).B. subtilis, E. coli, P. aeruginosa and S. aureus were also found to be susceptible to L. nuda methanolic extract (Dulger et al.,2002).Laetiporus sulphureus appeared as a sulphur yellow with bright pores and is locally known as the "Chicken of the woods".It has high nutritional value along with the beneficial medicinal effects(Khatua et al., 2017).Antimicrobial properties of L. sulphureus were determined by ethyl alcohol extract which showed significant response against B. subtilis, B. cereus and M. luteus(Turkoglu et al., 2007).M. flavus and L. monocytogenes were strongly suppressed by the

Zheng et al., 2006; Agrawal and Sandhu, 2020; Sułkowska-Ziaja et al., 2018; Petrović et al., 2014)
(Usman et al., 2021)011)particles when incorporated with pathogen as an effect of antibacterial activity with both gram bacteria like E. coli, Staphylococcus sp., Pseudomonas sp. and Bacillus sp.(Narasimha et al., 2011).Ethanol and a coldwater extract from A. bisporus effectively suppressed the growth of two bacterial species, E. coli and S. aureus(Usman et al., 2021).Ganoderma lucidum, also known as Reishi, is a medicinal mushroom that grows on both alive and deceased wood of deciduous trees and this mushroom produces (Gebreyohannes et al., 2019)2010).Stripes and total protein extract from A. bisporus, as well as silver nanoparticles (AgNPs), a biosynthetic product of white button mushroom, were found to have antibacterial action against S. Aureus(Atila et al., 2019).fruitingbodieswithred,shiny,andreddish-browncaps(Siwulskietal., 2015).Antibacterial property of G. lucidum mushroom methanol extract consists of terpenes and flavonoids bioactive compounds gives significant response against human pathogenic bacteria including S. aureus, E. coli, B. subtilis and S. Typhimurium(Kamra and Bhatt, 2012).Antibacterial activity of acetone extract of similar mushroom gives a noticeable response against K. pneumoniae, E. coli and S.Typhi (Qureshi et al., 2010).G. lucidum ethanol extract has a considerable antibacterial effect, especially against S. aureus and P. Aeruginosa (Tamilselvan and Rajesh, 2019).Ganoderma pfeifferi another species revealed that it consists of bioactive compounds called farnesyl hydroquinones named ganomycins and triterpenoids having antibacterial properties mainly against gram-positive bacteria(Lendequist  et al., 2015).The volatile oil of G. pfeifferi was tested for antimicrobial activity and it expresses the highest antibacterial activity against B. subtilis, S. aureus and E. coli(Al-Fatimi et al., 2016).Pleurotus ostreatus (oyster mushroom) primarily grown in tropical and subtropical climates.It has a broad, fan form and is white, grey, or dark brown in colour (Deepalakshmi and Mirunalini, 2014).Oyster mushrooms consist of two extracts, mainly petroleum ether and ethanol, which are evidenced for antibacterial properties against gram positive and gram-negative bacteria (Pauliic and Dorica, 2013).Acetone and Ethyl acetate extracts of the oyster mushroom illustrated the antibacterial activity against B. subtilis and E. coli(Han et al., 2015).Oyster mushrooms consist mainly β-D-Glucan as a secondary metabolite which have antibacterial activity(Cohen et al., 2002).Antimicrobial activity of P. ostreatus extracts against P. aeruginosa and S. aureus(Perez et al., 2020).P. sajor-caju is also known as grey oyster mushroom due to its resemblance to an oyster shell which is mainly harvesting in tropical and subtropical regions (MohdRashidi and Yang, 2016).P.sajor-caju mushroom consist of methanolic extract which inhibits microbial growth and holds antibacterial activity against S. typhi strain(Kandasamy et al., 2020).The antibacterial activity of P. sajor-caju methanolic extract and most potent inhibitory activity were observed against S. aureus.The lowest inhibitory activity was found against B. Cereus (Gogavekr et al., 2014).Trametes versicolor, also known as Coriolus versicolor or turkey tail, is another type of medicinal mushroom.White rot fungi that can be found on a variety of trees such as prunus and oak, as well as conifers such as fin of pine trees(Puia et al., 2018).Bacterial species, mainly S. aureus was inhibited by Coriolus versicolor extracts in methanol, ethyl acetate, dichloromethane, and acetone whereas Bacillus sp., S. enteritidis and P. aeruginosa were sensitive to methanol extract and acetone extract, respectively due to the presence of high concentration of polyphenols(Matijasevic et al., 2016).It also showed highest antibacterial activity against S. aureus, P. aeruginosa, B. subtilis, and E. coli(Pranitha et al., 2014).The inhibitory antimicrobial activities of hot water extract of Trametes spp., chloroform and ethanol (70%) were observed against S. aureus and P. aeruginosa(Gebreyohannes et al., 2019).