Biogas digester liquid as a supplement for higher yields of Hypsizgus ulmarius

- Use of biogas digester liquid (BDL) as a nutrient supplement for pre-packed mushroom bags.
- Spraying BDL increase yield,biological efficiency by 205% and C N&P uptake.
- Addition of BDL reduces time for various stages of mushroom growth such as pin head formation, fruiting body formation and first flush.
- Addition of BDL reduces time for various stages of mushroom growth such as pin head formation, fruiting body formation and first flush.
- Low in heavy metal, BDL spraying has not led to the accumulation of heavy metals in Hypzigus Hypsizygusulmarius.
- BDL spray initiated higher lignin degrading enzymes such as Laccase and Peroxidase which can be recovered for further use.

Biogas digester liquid (BDL), one of the output from an ASTRA-PFR biomass based biogas plant was added as a nutrient source to Hypsizgus ulmarius ready to fruit bags. Supplementing the ready to fruit bags with BDL increased the yield from 1.9-3.5 kg/kg substrate and reduced the time for various stages of mushroom formation such as pin head formation, fruiting body formation and first flush. Mass balances of C, N & P were studied and it was shown that spraying pre-packed ready to fruit mushroom bags with BDL could enhance and speedup the utilization of these with addition of BDL. Metal and heavy metal uptake by Hypsizgus ulmarius from BDL shows that few metals like Na, K, Ca and Mg could be effectively incorporated into fungal body. Heavy metals such as Co, Cr and Ni were lower in BDL supplemented Hypsizgus ulmarius. Supplementing BDL also leads to recovery of enzyme cocktail with laccase activity (296 U/gTS on day 58) and peroxidase activity (367 U/gTS on day 52) which could be further used for various industrial applications.

181