Table 4.
Overview of industrially relevant alternative feedstocks for solventogenic and acetogenic clostridia
| Carbon source | Feedstock | Pretreatment | Organism | References |
|---|---|---|---|---|
| Lignocellulosic biomass | ||||
| C6 and C5 sugars | Apple pomace ultra-filtration sludge | Dilute sulfuric acid pretreatment and detoxification method | C. beijerinckii NRRL B-466 | [186] |
| Barley straw | Acid hydrolysis and overliming | C. beijerinckii P260 | [236] | |
| Cassava bagasse | Mechanically milling, enzymatic hydrolysis | C. acetobutylicum JB200 | [182] | |
| Corn stover | Hot-water with wheat straw hydrolysate and overliming | C. beijerinckii P260 | [237] | |
| Enzymatic hydrolysis | C. saccharobutylicum DSM 13864 | [213] | ||
| Dilute sulfuric acid pretreatment | C. beijerinckii BA101 | [67] | ||
| Domestic organic waste | Steam explosion and enzymatic hydrolysis | C. beijerinckii B-592, C. acetobutylicum DSM 1731 | [42] | |
| Extruded, enzymatic hydrolysis | C. acetobutylicum ATCC 824 | [180] | ||
| Market refused vegetables | Shredded | C. acetobutylicum DSM 792 | [280] | |
| Municipal solid waste | Dilute acid or hot water treatment and enzymatic hydrolysis | C. acetobutylicum NRRL B-591 | [75] | |
| Pine and elm woods | Enzymatic hydrolysis and organosolv pretreatment | C. acetobutylicum NRRL B-591 | [8] | |
| Pineapple peel | Grounded, dried, saccharification, detoxification method | C. acetobutylicum B 527 | [144] | |
| Rice straw | Enzymatic hydrolysis, alkaline and concentrated phosphoric acid pretreatments | C. acetobutylicum NRRL B-591 | [202] | |
| Starch industry wastewater | Dilute sulfuric acid pretreatment and detoxification method | C. beijerinckii NRRL B-466 | [186] | |
| Suspended brewery liquid waste | Dilute sulfuric acid pretreatment and detoxification method | C. beijerinckii NRRL B-466 | [186] | |
| Switchgrass | Dilute sulfuric acid pretreatment, enzymatic hydrolysis | C. beijerinckii P260 | [237] | |
| Alkali-pretreatment | C. saccharobutylicum DSM 13864 | [87] | ||
| Wheat straw | Grounded, hot dilute sulfuric acid hydrolysis | C. beijerinckii P260 | [235, 238, 239] | |
| Wood pulping hydrolysate | Detoxification: ion exchange resins, overliming and activated charcoal adsorption | C. beijerinckii CC101 | [181] | |
| Starch waste streams | ||||
| Starch | Food waste | Shredding | Clostridium sp. BOH3 | [334] |
| Blending and drying | Clostridium sp. strain HN4 | [224] | ||
| Pulverization | C. beijerinckii P260 | [113] | ||
| Sago | Enzymatic hydrolysis | C. saccharobutylicum DSM 13864 | [171] | |
| Starch-based waste packing peanuts | – | C. beijerinckii BA101 | [129] | |
| Potato waste starch | – | C. acetobutylicum NRRL B-591 | [145] | |
| Defibered-sweet-potato slurry | – | C. acetobutylicum P262 | [12] | |
| Inedible dough | – | C. beijerinckii NCIMB 8053 | [297] | |
| Sugar waste streams | ||||
| Sucrose, fructose, raffinose, stachyose, verbascose | Soy molasses | – | C. beijerinckii BA101 | [232] |
| Glucose, mannose | Konjac waste | Enzymatic hydrolysis, simultaneous saccharification and fermentation | C. acetobutylicum ATCC 824 | [265] |
| Cellobiose, glucose | Waste cotton fibers | Phosphoric acid-acetone process and enzymatic hydrolysis | C. acetobutylicum NRRL B-591 | [261] |
| Lactose | Milk dust powder | – | C. acetobutylicum ATCC 824, C. beijerinckii NCIMB 8052 | [296] |
| Cheese whey | – | C. acetobutylicum P262 | [62, 63] | |
| Gaseous feedstocks | ||||
| CO:CO2:H2:N2 (16.5:15.5:5:56) | Gasified Switchgrass | Ash removal by cyclone, scrubbers with 90% water, 10% acetone | C. carboxidivorans | [6] |
| CO:CO2:H2:N2 (42:20:2:36) | Steel mill waste gas | – | C. autoethanogenum | [198] |
| CO:CO2:H2:N2 (44:22:2:32) | – | C. autoethanogenum, C. ljungdahlii, C. ragsdalei | [148] | |
| CO:H2:CO2 (40:30:30) | Syngas | – | Clostridium ragsdalei PTA-7826 | [277] |
| CO:CO2:H2 (10:60:30) | Electrolysis of CO2 and H2O to form CO and H2 | C. autoethanogenum, C. kluyveri | [104] | |