Biodegradation of willow sawdust by novel cellulase-producing bacterial consortium from wood-feeding termites for enhancing methane production

Bioresour Technol. 2023 Sep:383:129232. doi: 10.1016/j.biortech.2023.129232. Epub 2023 May 26.

Abstract

This study was designed to develop a cellulase-producing bacterial consortium (CBC) from wood-feeding termites that could effectively degrade willow sawdust (WSD) and consequently enhance methane production. The bacterial strains Shewanella sp. SSA-1557, Bacillus cereus SSA-1558, and Pseudomonas mosselii SSA-1568 exhibited significant cellulolytic activity. Their CBC consortium showed positive effects on cellulose bioconversion, resulting in accelerated WSD degradation. After nine days of pretreatment, the WSD had lost 63%, 50%, and 28% of its cellulose, hemicellulose, and lignin, respectively. The hydrolysis rate of treated WSD (352 mg/g) was much higher than that of untreated WSD (15.2 mg/g). The highest biogas production (66.1 NL/kg VS) with 66% methane was observed in the anaerobic digester M-2, which contained a combination of pretreated WSD and cattle dung in a 50/50 ratio. The findings will enrich knowledge for the development of cellulolytic bacterial consortia from termite guts for biological wood pretreatment in lignocellulosic anaerobic digestion biorefineries.

Keywords: Anaerobic co-digestion; Biological pretreatment; Cellulolytic bacteria; Lignocellulosic biomass, biogas; Wood waste.

MeSH terms

  • Anaerobiosis
  • Animals
  • Bacteria / metabolism
  • Biofuels
  • Cattle
  • Cellulase* / metabolism
  • Cellulose / metabolism
  • Isoptera* / metabolism
  • Lignin / metabolism
  • Methane / metabolism
  • Salix* / metabolism
  • Wood / metabolism

Substances

  • Cellulase
  • Lignin
  • Cellulose
  • Biofuels
  • Methane