Mahbuba Moonmoon
National Mushroom Development and Extension Centre, Savar, Dhaka 1340, Bangladesh
Md. Nazim Uddin
National Mushroom Development and Extension Centre, Savar, Dhaka 1340, Bangladesh
Pleurotus eryngii, Saw dust, Rice straw, Biological yield
Crop-Soil-Water Management
Strain of king oyster mushroom-Three strains of P. eryngii such as Pe-1 (native to Bangladesh), Pe-2 (collected strain from China) and Pe-3 (collected strain from Japan) were used in this investigation.
Culture preparation-Pure cultures of different strains were prepared on malt extract agar (MEA) medium. The inoculated Petri dishes were incubated in the growth chamber at 25 ± 2 °C in the dark for about ten days. This culture was used for inoculation of mother culture after completion of the mycelium. Medium of mother culture was prepared by mixing sawdust and wheat bran at the ratio of 2:1 and 0.2% calcium carbonate. The moisture level of the mixture was maintained at 65%. Polypropylene bags of 25 × 17 cm size were filled with 250 g of the mixture and packed tightly. The neck was plugged with cotton and covered with brown paper and tied with a rubber band. The packets were sterilized in an autoclave for 1 h at 121 °C under 1 kg/cm2 pressure. The P. eryngii inoculated packets were placed on a rack in the laboratory at 25 ± 2 °C temperature for incubation. The substrate of the mother culture was colonized by the growth of mycelium within 15–20 days after inoculation. The fully colonized packets were used for spawning.
Spawn preparation-Two different substrates namely, sawdust (SD) and rice straw (RS) were used as culture media. In case of SD, sun dried SD, wheat bran and rice husk were mixed together at 176 g, 88 g and 11 g, respectively for each 550 g substrate. Water was added to adjust moisture content at 65% and CaCO3 was mixed at the rate of 0.2% of the mixture. Substrate mixture was filled into autoclavable polypropylene plastic bottles (900 ml) and a hole of about 2/3 deep of the volume of the bottle was made for space to put the inoculums. The bottles were sterilized at 121 °C for 1 h under 1 kg/cm2 pressure. After cooling down to room temperature the sterilized bottles were inoculated with the mother culture of the selected strains to be tested separately. In case of RS substrate, dried RS was chopped into 2–4 cm length and placed in hot water. After half an hour the burner was stopped and this straw was kept to cool. After cooling, the straw was spread on the polypropylene sheet for removal of excess water. Then the polypropylene bags were filled with substrate of 500 g. During bagging the packets were inoculated separately with the mother culture of selected strains to be tasted. These inoculated bottles and bags were incubated in a dark room at 25 ± 2 °C temperature for mycelium growth.
Cropping and harvesting-After completion of mycelial growth, the bottles of sawdust were uncapped and soaked in water for 3–5 min. But the spawn bags of rice straw were opened by square shaped (1″ × 1″) cut on the different place in a culture house. The temperature, relative humidity and light were maintained at 13–22 °C, 70–85% and about 180–250 lux, respectively. Carbon dioxide concentration was not monitored and controlled instrumentally. Mushroom were harvested when the mushroom cap surface were flat to slightly up-rolled at the cap margins. One flush of mushroom in each bottle or bag was harvested. The yield of mushrooms and their different quality parameters were recorded regularly.
Statistical analysis-The experiment was done completely randomized design with 10 replications (n = 10). Data was analyzed and graph was constructed by statistical program, SPSS-12.0 and Microsoft Excel.
Saudi Journal of Biological Sciences Volume 17, Issue 4, October 2010, Pages 341-345
Journal