Table 1 Several bioprocesses using waste for biopolymers production
From: Waste biorefinery towards a sustainable circular bioeconomy: a solution to global issues
Microbial strain(s) | Waste material(s) | Culture mode | Results | References |
|---|---|---|---|---|
Production of PHAs | ||||
 Alcaligenes eutrophus (ATCC17699) | Starch wastewater | A two-step process of microbial acidogenesis and acid polymerisation | PHA produced using VFAs 55 g of PHA per 100 g total organic carbon | [37] |
 Bacillus megaterium SRKP-3 | Dairy waste | Fed-batch cultivation | PHB concentration = 11.32 g/L | [38] |
 Burkholderia sacchari DSM 17165 | Wastepaper | Fermentation process | PHB content = 44.2% (using wastepaper hydrolysate as carbon source) | [43] |
 Cupriavidus necator DSM 545 | CO2 | Mixotrophic fermentation | PHBV content of 60% Represented a CCU strategy | [30] |
 Cupriavidus necator DSM 545 | Crude glycerol | Fed-batch cultivation | PHB concentration = 38.1 g/L PHB/cell dry weight = 50% (w/w) | [40] |
 Haloferax mediterranei | Macroalgae biomass hydrolysates (macroalgae-derived carbohydrates; carbon source) | Fermentation process | Promising PHA production feedstock: Ulva sp. PHA concentration of 2.2 ± 0.12 g/L Sustainable PHA production using sea agriculture | [44] |
 Halomonas species | Waste frying oil (carbon source) | Fermentation process | Halomonas hydrothermalis with γ-Butyrolactone accumulated 2.26 g/L of PHA PHB producer: Halomonas neptunia CCM 7107 and Halomonas hydrothermalis CCM 7104 The Halomonas hydrothermalis was capable to accumulate PHV to form PHBV (culture supplemented with valerate) | [41] |
 Pseudomonas aeruginosa 42A2 (NCIB 40045) | Waste frying oil Waste-free fatty acids from soybean oil | Aerobic fermentation | PHA content = 29.4% (using waste frying oil as carbon source) PHA content = 66.1% (using waste-free fatty acids from soybean oil as carbon source) | [36] |
 A highly osmophilic strain | Hydrolysed whey permeate (by-product from cheese industry) Glycerol liquid phase (by-product from biodiesel production using plant oils and tallow) Meat and bone meal | 42-L bioreactor fermentation system | PHA concentration = 5.5 g/L (using hydrolysed whey permeate as carbon source) PHA concentration = 16.2 g/L (using glycerol liquid phase as carbon source) PHA concentration = 5.91 g/L (using glycerol liquid phase as carbon source as well as meat and bone meal as nitrogen and phosphorus source) | [35] |
 Mixed microbial culture: species not mentioned specifically | Dairy waste (deproteinised cheese whey wastes) | A two-step bioprocess of dark fermentation and mixed microbial cultivation | Two bioproducts produced: biohydrogen and PHA Concentrated cheese whey permeate: H2: 1.93 mol H2 mol−1 sugars and 55.1 ± 1.3% g PHA g−1 volatile suspended solids Second cheese whey: H2: 1.37 mol H2 mol−1 sugars and 62.0 ± 4.5% g volatile suspended solids | [42] |
 Mixed microbial culture: species not mentioned specifically | Food waste (or known as unfermented food waste) Acidogenic effluents (from biohydrogen production; or known as fermented food waste) | Aerobic mixed cultivation | PHA content = 39.6% (using acidogenic effluents as substrate) PHA content = 35.6% (using food waste as substrate) PHA production in the form of PHBV; higher fraction of PHB than PHV Two bioproducts produced: biohydrogen and PHBV | [39] |
Production of BC | ||||
 Acetobacter xylinum CGMCC 2955 | Wastewater of candied jujube-processing industry | Fermentation process | BC productivity = 0.375 g/L/day | [51] |
 Komagataeibacter europaeus SGP37 | Sweet lime pulp waste | Static batch cultivation | BC yield = 6.3 g/L | [53] |
 Gluconacetobacter hansenii CGMCC 3917 | Waste beer yeast (hydrolysate obtained through a two-step pre-treatment) | Fermentation process | The highest BC yield = 7.02 g/L (using waste beer yeast hydrolysate treated by ultrasonication and mild acid hydrolysis as well as optimisation of sugar concentration) BC produced shows good physicochemical features (i.e., holding capacity, release rate and absorption rate of water) | [49] |
 Gluconacetobacter hansenii UCP1619 | Corn steep liquor | Static cultivation | BC produced up to 73% | [52] |
 Gluconacetobacter xylinum ATCC 23768 | Black strap molasses Brewery molasses | Fermentation process | BC yield = 3.05 g/L (using black strap molasses) BC yield = 1.78 g/L (using brewery molasses) | [50] |
 Gluconacetobacter xylinus ATCC 23770 (a bacterium used to produce BC) and Trichoderma reesei C-30 (a filamentous fungus used to produce enzyme) | Waste fibre sludge (derived from pulp mills and lignocellulosic biomass) | Sequential fermentation process | Co-production of BC and cellulase using fibre sludge hydrolysates Fiber sludges from sulfate produce 11 g/L of BC Fiber sludges from sulfite produce 10 g/L of BC | [48] |