Butyric Acid Generation by Clostridium tyrobutyricum from Low-Moisture Anhydrous Ammonia (LMAA) Pretreated Sweet Sorghum Bagasse

Low Moisture Anhydrous Ammonia Pretreatment of Four Lignocellulosic Materials—Distillers Dried Grains With Solubles, Corn Gluten Feed, Corn Fiber, and Oil Palm Frond

“…In this regard, looking more detail into the structure and compositions of each material used in this work, OPF is more closely resembles that of corn stover, however, corn stover required a higher MC requirement might be due to slightly higher cellulose content in it (Mensah et al, 2021). In other aspect, this also proves the requirement of moisture in LMAA pretreatment, although it varies with the cellulose content of materials (Kim et al, 2016;Yang and Rosentrater, 2017;Stoklosa et al, 2021). The difference in MC requirement could also be attributed to the difference in water absorption behavior that somehow related to the compositional difference in materials, which will be described in the following paragraph.…”

“…Nuruddin et al (2016) highlighted that the tandem operation of physical and chemical pretreatment could significantly reduce the energy cost from the reduction of intensity of each single pretreatment (Nuruddin et al, 2016). Chemical pretreatment incurs not only high operating cost from the large volume of chemical used and waste produced, formation of undesired inhibitor compounds and severe cellulose degradation but also from high capital cost due to high corrosion level of equipment as in acid pretreatment (Taylor et al, 2019;Stoklosa et al, 2021). Therefore, physicochemical pretreatment is seen as a viable way to increase the value of some underutilized materials.…”

“…The use of gaseous NH 3 results in a substantial reduction of liquid requirements and also since it is gas, it could easily be removed from the materials with the aid of vacuum or slight increase in temperature, eliminating the need for additional water washing step to remove the residual NH 3 . The study on LMAA pretreatment is still limited with most works focused on specific biomass such as corn stover (Yoo et al, 2011;Cheng and Rosentrater, 2016;Guo et al, 2017;Yang and Rosentrater, 2017), sweet sorghum bagasse (Stoklosa et al, 2021), ryegrass (Yasuda et al, 2015) and napiergrass (Yasuda et al, 2013), limiting the feasibility evaluation for its wider application. Regardless, LMAA pretreatment of corn stover has yielded promising results in a large scale reactor, suggesting the possibility of effectively using LMAA pretreatment for larger-scale application (Cheng and Rosentrater, 2016;Yang and Rosentrater, 2017).…”

Assessing oxygen limiting fermentation conditions for 2,3-butanediol production from Paenibacillus polymyxa

“…A hydrolysate from low-moisture anhydrous ammonia (LMAA) pretreatment of sweet sorghum bagasse (SSB) was generated to conduct aerobic and oxygen limited fermentation with P. polymyxa. This hydrolysate was previously reported to contain 30 g/L of glucose accounting for a 70% theoretical yield, and 15 g/ L of xylose at a 53.4% theoretical yield (Stoklosa et al, 2021). Aerobic fermentations with pretreated SSB hydrolysates produced less generation of both biomass and products compared to molasses media.…”

“…The SSB was pretreated by the low-moisture anhydrous ammonia (LMAA) method that has been previously described (Stoklosa et al, 2019). The pretreated SSB was then enzymatically hydrolyzed with Novozymes (Franklinton, NC, United States) CTec2 and HTec2 enzymes according to a previous method (Stoklosa et al, 2021). Fermentation experiments were performed on the raw hydrolysate, and on a detoxified hydrolysate subjected to treatment with activated carbon at a 10% (w/v) loading.…”