Table 2 Acidogenic fermentation from various types of lignocellulosic biomass wastes and the operating parameters

Grass clipping

Ultrasound-Ca(OH)₂

4 and 32 g/g volatile solids (VS) glucose and xylan released

250 mL, 35 °C, 120 rpm

Batch 12d

578 mg/g volatile solids (VS), increase 116%

82% acetic, 4% propionic and 4% butyric acids

Bacteria class: Clostridia and Bacteroidia

Wang et al. (2019a)

Grass

Carbide slag

Reduced 6% lignin and 8% hemicellulose

250 mL, 35 °C

Batch

220 mg/g volatile solids (VS), increase 38%

78% acetate, 4% propionate and 8% butyrate

Clostridium, Bacteroides

Tao et al. (2019)

Napier grass

Milling

–

250 mL flasks, 37 °C, 100 rpm, micro O₂,

Batch

107.25 mg/g volatile solids (VS)

50–70% acetic and 20–50% propionic acids

–

Sawatdeenarunat et al. (2017)

Japanese cedar

Vibration milling

–

2 L, 39 °C, 30–40 rpm, pH 6.5

Semi-continuous

76 mg/g volatile solids (VS)

37% acetic and 60% propionic acids

F. succinogenes (cellulolytic bacterium), P. ruminicola (synergistically with cellulolytic bacteria), S. ruminis (propionate-producing)

Agematu et al. (2017)

Fallen leaves

Lime pretreatments

–

250-mL flasks with 10% inoculum, 37 °C, pH 8

Batch 5d

1.06 g/g volatile solids (VS), increase 160%

70% acetic and 20% butyric acids

–

Kim et al. (2013)

Sorghum stalks

Milling and acid

Hemicellulose degraded by 60%

135 mL, 55 °C,

Two steps

424 mg/g volatile solids (VS), increase 84% acetate and 116% butyrate

2.17 g/L acetic and 2.07 g/L butyric acids

–

Islam et al. (2018)

Corn stalk

Acid pretreatment

Hemicellulose reduced by 12%, cellulose increased by 15%

500 mL flask, 50 °C, 15 days, pH 7

Batch

150 mg/g volatile solids (VS)

0.86 g/L formic, 0.59 g/L acetic, 0.62 g/L butyric and 0.64 g/L lactic acid

–

Guo et al. (2011)

Corn stover

Hydrothermal

Lignin removal of 8%

500 mL, 35 °C

Batch

1.4 g/g volatile solids (VS), 3.5 times higher

20% ethanol, 66% acetic, 8% iso-butyric acid

–

Song et al. (2019b)

Corn stover

Wet-exploded

–

3 L, 37 °C, 150 rpm, pH 6.5

Batch

1.14 g/g volatile solids (VS)

50–70% acetate, 20–45% propionate

–

Murali et al. (2017)

Rice straw

1% NaOH

–

6.5 L, pH 6, HRT 8, 9 days

Semi-continuous

1 g/g volatile solids (VS)

40–60% acetate, 20–33% propionate, 12% butyrate

Predominant class: Clostridia, Bacteroidia, Bacteroidetes_vadin HA17 and Deltaproteobacteria

Lu et al. (2018)

Wheat straw

7.4% Ca(OH)₂

Release 0.16 g Hemicellulose/g volatile solids (VS)

600 mL, 35 °C

Batch

223 mg/g volatile solids (VS)

60 mg/g volatile solids (VS) acetic, 150 mg/g volatile solids (VS) butyric acid

–

Reilly et al. (2014)

Wheat straw

–

–

6 L, lead bed reactor, 37 °C, solid-state

Batch

560 mg/g volatile solids (VS)

–

–

Rouches et al. (2019)

Palm fruit bunch

Cutting

–

40 L leach bed reactor, solid-state

Semi-continuous

196.5 mg/gTS

–

–

Saritpongteeraka et al. (2015)

Xylose

Acidic and thermal pretreatments

–

500 mL, pH 6.5, 30 °C

Batch

124 g/g volatile solids (VS), increase 187%

Acetate higher than 85%

Dominant: Clostridia, related with acidogenic and solventogenic processes

Mockaitis et al. (2020)