Pretreatment of spent mushroom substrate for enhancing the conversion of fermentable sugar

Bioresour Technol. 2013 Nov;148:596-600. doi: 10.1016/j.biortech.2013.08.122. Epub 2013 Aug 28.

Abstract

To develop a cost-effective biopesticide, spent mushroom substrate (SMS) extract was studied as a potential carbon source for cultivating Bacillus thuringiensis (Bt). Several pretreatments were compared to determine the optimal method for degrading cellulose to produce reducing sugars, including dilute sulfuric acid (0.5-2.0% v/v, 50-121°C, 1h), sodium hydroxide (0.5-2% w/v, 50-121°C, 1h), calcium hydroxide (0.2-4% w/v, 50-121°C, 1h), and hot water (50-121°C, 1h). Pretreatment was followed by standard enzymatic hydrolysis and fermentation. Results showed that the highest cellulose degradation was obtained using 2% dilute sulfuric acid pretreatment at 121°C for 1h, resulting in a high yield of reducing sugar (284.24 g/kg SMS). Sporulation was also highest using the same pretreatment. Use of SMS is not only an alternative way to commercialize Bt-based biopesticide, but also a potential solution for the environmental pollution associated with accumulation of the spent substrate of the mushroom industry.

Keywords: Bacillus thuringiensis; High performance liquid chromatography; Pretreatment; Spent mushroom substrate; Yield of reducing sugars.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agaricales / chemistry*
  • Agriculture
  • Bacillus thuringiensis / drug effects
  • Biotechnology / methods*
  • Calcium Hydroxide / pharmacology
  • Carbohydrates / chemistry*
  • Fermentation* / drug effects
  • Hot Temperature
  • Hydrolysis / drug effects
  • Monosaccharides / analysis
  • Sodium Hydroxide / pharmacology
  • Spores, Bacterial / drug effects
  • Sulfuric Acids / pharmacology
  • Waste Products / analysis*
  • Water / pharmacology

Substances

  • Carbohydrates
  • Monosaccharides
  • Sulfuric Acids
  • Waste Products
  • Water
  • Sodium Hydroxide
  • sulfuric acid
  • Calcium Hydroxide