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The present study entitled “Standardization of biomedicinal enrichment in edible
oyster mushroom, Pleurotus sp.” was conducted at Department of Plant Pathology,
College of Agriculture, Vellayani, Thiruvananthapuram during 2019-2021, to
standardize the substrate(s) amended with medicinal plants for the cultivation of
edible oyster mushroom, P. florida and analysis of the uptake of bioactive compounds
of pharmaceutical importance by P. florida.
In vitro evaluation of the effect of medicinal amendments (adathoda, neem and
ocimum) on mycelial growth of P. florida revealed that there was a significant
variation with respect to growth pattern and mycelial density. The radial growth of
mycelium in PDA media amended with adathoda 1000 ppm, neem 1000 ppm and
ocimum 250 ppm concentration was on par with control. The addition of medicinal
amendments had no inhibitory effect on mycelial growth of P. florida. The basidial
size from the sporocarp of amended mushrooms varied widely with maximum size in
amended ones when compared to control. The mycelial width did not vary
significantly among all the treatments.
In vivo evaluation of medicinal amendments by soaking and spraying method
revealed that addition of amendments reduced the days for spawn run, pin head
initiation and first harvest. Desirable sporophore characters for enhanced yield was
also observed when compared to control. Maximum yield was recorded in soaked
beds when compared to sprayed beds and control. Ocimum was found to be the best
amendment with an average yield of 448.75 g from soaked beds (T5) and 434.5 g
from sprayed beds (T6). Sporophore characters of P. florida showed significant
variation among the different treatments.
There was enhanced shelf life of amended mushrooms under both room
temperature and refrigerated condition. Neem sprayed (T4) and adathoda soaked (T1)
samples had a better shelf life of 5 and 4 days respectively under refrigerated
conditions as well as in room temperature (3 days respectively). Sensory evaluation
scores of P. florida from different treatments were obtained for parameters viz.,
appearance, colour, flavor, texture and taste. The maximum scores for appearance was
obtained by ocimum amendment. Mushroom from neem sprayed treatment was
adjudged the tastiest.
The major pests observed in the beds were sciarids, Megaselia sp. and
staphylinid beetle. Neem amended beds showed reduced pest incidence (10-15%)
when compared to control (20%). Trichoderma was the common contaminant
observed along with Coprinus and bacteria. Least disease incidence of 10 per cent was
observed in neem sprayed, adathoda sprayed and ocimum soaked treatments. Least
disease incidence was recorded in sprayed beds than soaked beds.
GC-MS studies of mushroom and substrate samples revealed the identification
of many important compounds of pharmaceutical importance. The different classes of
compounds observed were aldehydes, ketones, organic acids, esters, ethers, furan
derivatives, sterol and nitrogen derivatives. Exclusive compounds could be identified
viz., pidolic acid, ethyl iso-allocholate and erucic acid from mushroom samples
whereas quinolone, myristyl monoethoxylate, epoxylanostan, adenosine and digitoxin
from substrate samples.
Biochemical analysis of beta-carotene, flavonoids, terpenoids and polyphenols
from the mycelium and sporocarps revealed that there was enhanced concentration of
above said bioactive compounds in sporocarp when compared to mycelia. Adathoda
amended mycelia recorded maximum beta-carotene, flavonoid, terpenoid and
polyphenol content. In the case of sporocarps, maximum beta-carotene content was
recorded in adathoda soaked treatment. Neem amended sporocarp recorded maximum
flavonoid content. Ocimum amended sporocarp recorded maximum terpenoid and
polyphenol content.
In the current study entitled ‘Standardization of biomedicinal enrichment in
edible oyster mushroom, Pleurotus sp.’ it was observed that there was pronounced
enhancement of yield attributes in amended mushrooms. Reduced pest and disease
incidence was also observed. There was improvement in shelf life and organoleptic
characters in amended mushrooms. New compounds of pharmaceutical importance
could be identified by GC-MS analysis. The bioactive compounds viz., beta-carotene,
flavonoid, terpenoids and polyphenols were also found to be enhanced when
compared to control.