Induction of defense-related enzymes, such as phenylalanine ammonia lyase (PAL), peroxidase (PO), polyphenol oxidase (PPO), superoxide dismutase (SOD) and catalase (CAT) due to bacterial antagonists viz., Pseudomonas fluorescens (Pf1) and Bacillus subtilis (EPCO16) and plant-derived lipoxygenase volatile compound hexanal, were studied in mango fruits against Lasiodiplodia theobromae causing stem-end rot disease. The results showed increased induction of all the defense-related enzymes in mango fruits 3–5 days after dipping treatment with combination of bacterial antagonists and hexanal when compared to untreated control treatment and treatment with fungicide carbendazim in storage condition. The increased activity was observed up to 3 days after treatment and thereafter declined. Further, increased expression of specific isoforms of PO, PPO, SOD and CAT were also observed in the treatment effect of P. fluorescens (0.5%) + hexanal (0.02%) treated fruits against L. theobromae. From the results obtained, it is inferred that due to the enhancement of defense-related enzymes via the phenylpropanoid pathway and due to secretion of secondary metabolites that would play significant role in hindering the pathogen quiescence and further invasion in mango fruits and thereby prevent the fruit rot.

The present investigation is focused on exploring the possibilities of identifying biomolecules from the fruiting body of the medicinal mushroom Ganoderma lucidum against the mango anthracnose pathogen Colletotrichum gloeosporioides. The fruiting body (cap and stipe portion) of G. lucidum extracted with ethyl acetate solvent at a maximum inhibitory concentration of 1 percent exhibited the maximum mycelial growth inhibition of C. gloeosporioides with 70.10 percent and 40.77 percent, respectively. Furthermore, subjecting the ethyl acetate extracts from the cap portion of G. lucidum through thin layer chromatography (TLC) revealed the presence of two bands with Rf values of 0.38 and 0.35. The compounds eluted from band 1 recorded with the maximum mycelial growth inhibition of C. gloeosporioides by 53.77 percent followed by band 2 (46.33 percent) using an agar well diffusion test. Similarly, the analysis of ethyl acetate extracts from the cap portion of G. lucidum through Gas Chromatography-Mass spectroscopy (GC-MS) revealed the presence of the organoheterocyclic compound benzothiazole, as expressed in the highest peak area at 22.03 RT with the highest probability percentage (97%). Confirmation of the antifungal nature of benzothiazole was obtained by testing the standard sample of benzothiazole which showed a cent percent of inhibition on mycelial growth of C. gloeosporioides at 50 ppm minimum fungicidal concentration. Furthermore, benzothiazole caused abnormality in the mycelial structures, viz., distortion, shrinkage, clumping of mycelium, conidial malformation, and complete arrestment of conidial germination of C. gloeosporioides as observed through Scanning Electron Microscopy. The research on biomolecular extract of G. lucidum could be a novel and interesting concept for the possibility in suppression of plant pathogenic microbes in the natural field.

Mushrooms are low-calorie foods with a high content of proteins, vitamins B and D, minerals, carbohydrates and fibers (1). Many researchers have shown that edible mushrooms contain numerous bioactive compounds with multiple health-promoting effects such as antiulcer, antioxidant, antiviral, anticancer, antibacterial, hepatoprotective, immunomodulatory antitumor, anticholesterol, anti-inflammatory and antihaemorrhagic effects (2). There arises a pressing need to tap into the potential of medicinal mushrooms like L. squarrosulus which has ethnomedicinal values and are used in treating anaemia, ulcer, fever, cough, infertility and fungal infections, as well as to reduce the risk of metabolic diseases (3-5). Global multidrug resistance calls for a search for new potential lead compounds as therapeutic agents. Many macromycos still remain understudied as sources of bioactive compounds. Further investigation of bioactive components found in L. squarrosulus, will be informative regarding the biological activity of the organisms as medicinal agents. The ethanol extract of the ethnomedicinal macromycos L. Squarrosulus was subjected to GC-MS analysis for bioactive compounds among these thirteen compounds of hits were achieved with bioactive compounds in the ethnomedicinal macromycos. Of these compounds (2E)-Dodec-2-en-1-yl methyl ether (13.95%) formed the largest number while 1,2-15,16-Diepoxyhexadecane (9.03%) constituted the next high number of such compounds. Other amino acids, fatty acids, ethyl esters and other compounds identified included 2-Methyl-4-(4-methyl-1-piperazinyl)-4-oxo-2-butenoic acid (2.12%), L-Alanine, N-L-alanyl- (0.94%), Benzofuran, 3-methyl- (1.63%), Tauroursodeoxycholic acid (3.75%) and 2'-Hydroxy-à-naphthoflavone (2.53%). Some of these compounds have antioxidant, hepatoprotective, hypocholesterolemic, anti-diabetic, anti-inflammatory, antioxidant, antimicrobial, antiarthritic, anticoronary and immune suppression as well as cancer preventive activities. The present study has identified bioactive components with therapeutic potential in L. squarrosulus; it forms a basis for screening, isolating and identifying various bioactive compounds which may be valuable in treating a wide range of ailments, disorders and diseases soon.

The ethnomedicinal subtropical mushroom Lentinus squarrosulus Mont. is a polypore with high wood-degrading potential. This study aimed to collect L. squarrosulus isolates, analyze lignocellulolytic enzymes - Laccase (Lac), Lignin peroxidase (LiP) and Manganese peroxidase (MnP) and evaluate substrates for mass production. Sporophores of Lentinus sp. (Isolate L1 to L5) were collected from different regions of Tamil Nadu and characterized morphologically and molecularly. Qualitative screening tests with guaiacol substrate demonstrated the production of laccase by all the isolates; however, isolate L3 showed maximum reddish-brown zonation. Additionally, isolate L3 produced the highest green colouration on the ABTS (2,2’-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) substrate. This confirmed the oxidation of ABTS to ABTS-azine in the presence of laccase, outperforming the other L. squarrosulus isolates. All the isolates tested with Azure-B agar for LiP and MnP showed faint discolouration, suggesting lower secretion of peroxidase enzymes. Quantitative analysis using a lignolysis basal medium also confirmed that isolate L3 secreted Lac predominantly, followed by LiP and MnP enzymes extracellularly. All isolates showed peak Lac activity at pH 4.5, while LiP and MnP production were highest at pH 5.0. The optimal temperature for all lignolytic enzymes was 28±2ºC. Maximum laccase secretion occurred between the 5th - 7th day after inoculation (DAI), with LiP and MnP peaking at 7 DAI. Nine agro-waste substrates were evaluated, with isolate L3 showing the highest biological efficiency on Paddy straw (99.62%), followed by Arecanut sheath (97.43%) and Groundnut shell (95.15%). This study enhances our understanding of L. squarrosulus enzymatic capabilities. It provides insights for mass production, which has strong potential for industrial bioremediation and waste management due to its high laccase production.