Direct use of spent mushroom substrate from Pleurotus pulmonarius as a readily delignified feedstock for cellulase production

The feasibility of spent mushroom substrate (SMS) as an alternative fermentation feedstock for cellulase production has been demonstrated in this work. Utilization of SMS as a substrate has been attempted widely due to its high cellulose content and readily available in smaller particle size. On top of that, the availability of delignified SMS by the action of Pleurotus pulmonarius during mushroom cultivation offers another benefit to its use whereby no chemical pretreatment would be required prior to fermentation. The recovery of crude laccase and manganese peroxidase from delignified SMS were found to be 3 and 1.4 U/g, respectively. Further to this, the cellulase production from SMS by Trichoderma asperellum UPM 1 under solid state fermentation was optimized by applying central composite design, resulted in increment of 1.4-fold in CMCase (171.21 U/g) and 1.5-fold in β-glucosidase (6.83 U/g), with the optimum temperature of 27.5 °C, initial moisture content 81% and initial pH of fermentation 4.5. Therefore, this study showed that the direct utilization of SMS is feasible for promising cellulase production by T. asperellum UPM 1

Characterization and optimization of fruit body yield in <em>Volvariella volvacea</em> white strain

112-120The paddy straw mushroom [Volvariella volvacea (Bull.) Singer] normally forms dark grey or brownish coloured fruit bodies, and it leads to lesser acceptance in market compared to button mushroom with white or off-white fruit bodies. In the present study, we attempted morphological and molecular characterization of the white strain of V. volvacea vis-a-vis brown strains, standardization of its cultivation technology and nutritional profiling of fruit bodies. The white strain (GVv-01) formed a separate clade in phylogenetic tree deduced from the 5.8S rRNA gene sequences compared to brown strains along with a 21 nucleotides long deletion in ITS-2 region. It exhibited highest downward mycelial growth on paddy straw and formed morphologically distinct colony on malt extract agar medium. It gave highest fruit body yield both at 25-28 and 30-35°C conditions with shortest first harvest period. It also yielded well on cotton ginning mill waste, cotton ginning mill waste + paddy straw (1:1, w/w) and paddy straw based substrates. Its mean fruit body weight (16.89 to 23.31 g) on different substrates was also higher compared to brown strains. The fruit bodies had higher crude fibre, ash and contents of calcium, potassium, sodium, zinc, magnesium, copper and iron compared to brown strains

Indigenous technical knowledge about the use of spent mushroom substrate

242-248The study on indigenous technical knowledge (ITK) about use of spent mushroom substrate (SMS) for agriculture revealed wide variations in age of the SMS applied in different crops at mushroom grower’s farm and it ranged between 0 month (fresh) to 36 months (old). Similarly, the quantity of SMS applied also varied between a minimum of 4.75 q to maximum of 1,000 q/ha in field crops and 4-6 kg/plant in apple orchard. The mushroom growers as well as researchers noticed yield enhancement and lower incidence of diseases in agricultural and horticultural crops along with changes in soil physical conditions on using SMS as manure. On the basis of empirical data and experience gained during the process of verification and refinement of ITKs about use of SMS as manure in crops, it is concluded that SMS should be decomposed for at least 12 months using scientific methods of composting such as natural weathering in pits, aerobic recomposting and anaerobic recomposting instead of disposing off in open on road side. Similarly, the doses of recomposed SMS for various crops should be worked out on the basis of total nutrients (NPK) requirement of the respective crops and the nutrients status of SMS. The recomposed SMS should be used singly as basal application or in combination with inorganic fertilizers