Biological saccharification coupled with anaerobic digestion using corn straw for sustainable methane production.

In this study, accumulated fermentable sugars from biosaccharified corn straw were used to generate methane through anaerobic digestion (AD). The results showed that reducing sugars from biosaccharification expanded corn straw (BECS) treated with Clostridium thermocellum XF811 accumulated with yields of 94.9 mg/g. The BECS used for AD was converted into a high methane yield (7436 mL), which was 49.3 % higher than that of expanded corn straw (ECS). High-throughput microbial analysis suggested that Methanoculleus and Methanobacterium greatly contributed to the high methane yield. Industrial experiments demonstrated that the methane production from BECS by AD was 72,955 m3, which increased by 13.2 % compared to that from ECS. Biosaccharification pretreatment accelerated ECS destruction and accumulated sugars, thereby increasing methane yields. This study provides a strategy for producing clean energy from lignocellulose biomass.

Static composting of cow manure and corn stalk covered with a membrane in cold regions.

The disposal of livestock wastes is an urgent task in China. Compost is highly regarded for its ability to treat livestock wastes and protect arable land. In particular, some problems of livestock manure in cold regions, such as low efficiency because of low environmental temperature in winter, urgently need to be solved. In order to provide valuable composting information in the cold area at low environmental temperatures, the composting experiments were carried out with cow manure and corn stalk as substrates. The properties and bacterial community of compost samples in different stages were investigated. The electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP), and organic matter (OM) of the final compost were 551 µS/cm, 1.12, 0.77, and 63.5%, respectively. No E. coli or Ascaris eggs were detected. The temperature was the key factor to affect the physical-co-chemical and biological properties. The absolutely dominant genera were Sporosarcina, Virgibacillus, Flavobacterium, and Steroidobacter in heating, high temperature, cooling, and maturing stages, respectively. Also, these bacteria could act as biological indicators during the composting process. Cryobacterium, Caldicoprobacter, Virgibacillus, and Sporosarcina were relatively novel genera in the compost piles in a cold environment. The biodegradation of exogenous substances mainly occurs in the initial and maturing stages. It is proven that composting can be carried out successfully in early spring or later autumn after a harvest.

Fungal pretreatment of cornstalk with Phanerochaete chrysosporium for enhancing enzymatic saccharification and hydrogen production.

The feasibility of fungal pretreatment of cornstalk with Phanerochaete chrysosporium for enzymatic saccharification and H(2) production was investigated in this study. Firstly, cornstalk was pretreated with P. chrysosporium at 29 °C under static condition for 15 d, lignin reduction was up to 34.3% with holocellulose loss less than 10%. Microscopic structure observation combined FTIR analysis further demonstrated that the lignin and crystallinity were decreased. Subsequently, the fungal-pretreated cornstalk was subjected to enzymatic hydrolysis by the crude cellulase from Trichoderma viride to produce fermentable sugars which were then fermented to bio-H(2) using Thermoanaerobacterium thermosaccharolyticum W16. The maximum enzymatic saccharification was found to be 47.3% which was 20.3% higher than the control without pretreatment. Upon fermentation of enzymatic hydrolysate, the yield of H(2) was calculated to be 80.3 ml/g-pretreated cornstalk. The present results suggested the potential of using hydrogen-producing bacteria for high-yield conversion of cornstalk into bio-H(2) integrate with biological pretreatment and enzymatic saccharification.

[Progress and technology development on hydrogen production through bioconversion of lignocellulosic biomass].

Hydrogen production from lignocellulosic biomass is both sustainable and environmentally friendly, which is garnering more and more attention across the world, with an expectation to challenge the shortage of fossil fuels supply and climate change as well. In this article, the update research progress and technology development of biohydrogen production are reviewed, with a focus on biomass pretreatment, hydrogen-producing microorganisms and process engineering strategies. And in the meantime, a roadmap for more efficient and economic biohydrogen production is envisioned.