Biotransformation of Pequi and Guavira Fruit Wastes via Solid State Bioprocess Using Pleurotus Sajor-Caju

Abstract

Abstract-Fungal microorganisms are widely studied in the bioconversion of substrates. Among them, Pleurotus sajor-caju is well recognized for its known ability to colonize and degrade wastes through solid state bioprocess (SSB). Fruit residues are inexpensive substrates that present characteristics favorable for microorganisms' colonization. The aim of this work was to investigate the mycelial growth of P. sajor-caju on pequi and guavira fruit wastes through SSB, in order to valorize these residues by their biotransformation. Cultivations were carried out with the substrates at pH 5 and with 60% moisture in an incubator at 30 °C for 25 days. Microbiological analyzes for fungi and bacteria beyond proximate composition of the substrates were evaluated every 5 days. It was observed that P. sajor-caju reached maximum growth at the 15 th day in guavira waste and at the 25 th day in pequi waste. The protein enrichments obtained were 30.31% and 37.20% for guavira and pequi wastes, respectively. It was concluded that guavira favored microbial growth and protein concentration, presenting a final product very rich in protein with potential application for animal nutrition.Index Terms-Brazilian savannah, fungi, residues, kinetic.

Production of enzymes from Lichtheimia ramosa using Brazilian savannah fruit wastes as substrate on solid state bioprocesses

“…CMCase activities in the range of 3 to 4 U/g were found on both pequi and guavira substrates with the fungos P. sajor-caju (Silva et al 2013). The same authors found also no xylanase activity on pequi waste substrate, but showed 4.67 U/g activity in substrate composed with guavira residues.…”

“…The authors classified these residues as potential good substrates for alpha amylases (Khan and Yadav, 2011). However, much higher amylase activities were observed for both pequi and guavira waste substrates in solid state bioprocesses with P. sajor-caju (Silva et al 2013). For pequi waste substrate the authors found a higher production (9.4 U/g) after 20 days of cultivation.…”

“…In a previous study, Pleurotus sajor-caju grew in pequi and guavira waste substrates reached 5 and 5.5 log CFU/g after 5 days of cultivation, respectively, starting from an initial concentrations of 3.5 and 4 log CFU/g (Silva et al 2013), being that the lower initial concentration was observed for guavira waste substrate.…”

“…These were subsequently conditioned in plastic bags (Steriflex) and had moisture content (60%) and pH (5.5) adjusted by distilled water and HCl (Vetec) addition, respectively. The thermal treatment was carried out by sterilization (121ºC, 15 min) before packing into the 500 mL Erlenmeyer flasks bioreactors (Silva et al 2013).…”

“…The plates were incubated in biological oxygen demand chamber (BOD) (Marconi, Brazil) at 25ºC for 7 days to serve as inoculum on the main cultivations. Inoculation of the fungus was carried out by the transfer of a 1 cm 2 square area of mycelium contained in a PDA petri dish to the Erlenmeyer flask, with the aid of a spatula previously sterilized (Silva et al 2013).…”