An efficient succinic acid production process in a metabolically engineered <Emphasis Type="Italic">Corynebacterium glutamicum</Emphasis> strain

A Corynebacterium glutamicum strain (ΔldhA-pCRA717) that overexpresses the pyc gene encoding pyruvate carboxylase while simultaneously exhibiting a disrupted ldhA gene encoding l-lactate dehydrogenase was investigated in detail for succinic acid production. Succinic acid was shown to be efficiently produced at high-cell density under oxygen deprivation with intermittent addition of sodium bicarbonate and glucose. Succinic acid concentration reached 1.24 M (146 g l⁻¹) within 46 h. The yields of succinic acid and acetic acid from glucose were 1.40 mol mol⁻¹ (0.92 g g⁻¹) and 0.29 mol mol⁻¹ (0.10 g g⁻¹), respectively. The succinic acid production rate and yield depended on medium bicarbonate concentration rather than glucose concentration. Consumption of bicarbonate accompanied with succinic acid production implied that added bicarbonate was used for succinic acid synthesis.     

Succinic acid production by a newly isolated bacterium

A new bacterial strain producing succinic acid was enriched from bovine rumen content. It is facultatively anaerobic, belongs to the family Pasteurellaceae and has similarity to the genus Mannheimia. In batch cultivations with D-glucose or sucrose the strain produced up to 5.8 g succinic acid l⁻¹ with a productivity and a yield of up to 1.5 g l⁻¹ h⁻¹ and 0.6 g g⁻¹, respectively. With crude glycerol up to 8.4 g l⁻¹, 0.9 g l⁻¹ h⁻¹ and 1.2 g g⁻¹ were obtained. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

High-level succinic acid production and yield by lactose-induced expression of phosphoenolpyruvate carboxylase in ptsG mutant Escherichia coli

Escherichia coli strains with foreign genes under the isopropyl-β-d-thiogalactopyranoside-inducible promoters such as lac, tac, and trc were engineered and considered as the promising succinic acid-producing bacteria in many reports. The promoters mentioned above could also be induced by lactose, which had not been attempted for succinic acid production before. Here, the efficient utilization of lactose as inducer was demonstrated in cultures of the ptsG, ldhA, and pflB mutant strain DC1515 with ppc overexpression. A fermentative process for succinic acid production at high level by this strain was developed. In flask anaerobic culture, 14.86 g l⁻¹ succinic acid was produced from 15 g l⁻¹ glucose with a yield of 1.51 mol mol⁻¹ glucose. In two-stage culture carried out in a 3-l bioreactor, the overall yield and concentration of succinic acid reached to 1.67 mol mol⁻¹ glucose and 99.7 g l⁻¹, respectively, with a productivity of 1.7 g l⁻¹ h⁻¹ in the anaerobic stage. The efficient utilization of lactose as inducer made recombinant E. coli a more capable strain for succinic acid production at large scale.     

Enhanced decolourization of Direct Red-80 dye by the white rot fungus <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> employing sequential design of experiments

Decolourization of Direct Red 80 (DR-80) by the white rot fungus Phanerochaete chrysosporium MTCC 787 was investigated employing sequential design of experiments. Media components for growing the white rot fungus were first screened using Plackett-Burman design and then optimized using response surface methodology (RSM), which resulted in enhancement in the efficiency of dye removal by the fungus. For determining the effect of media constituents on the dye removal, both percent dye decolourization and specific dye removal due to maximum enzyme activity were chosen as the responses from the experiments, and the media constituents glucose, veratryl alcohol, KH₂PO₄, CaCl₂ and MgSO₄ were screened to be the most effective with P values less than 0.05. Central composite design (CCD) followed by RSM in the optimization study revealed the following optimum combinations of the screened media constituents: glucose, 11.9 g l⁻¹; veratryl alcohol, 12.03 mM; KH₂PO₄, 23.08 g l⁻¹; CaCl₂, 2.4 g l⁻¹; MgSO₄, 10.47 g l⁻¹. At the optimum settings of the media constituents, complete dye decolourization (100% removal efficiency) and a maximum specific dye removal due to lignin peroxidase enzyme of 0.24 mg U⁻¹ by the white rot fungus were observed.     

Batch and continuous cultivation of Anaerobiospirillum succiniciproducens for the production of succinic acid from whey

Batch and continuous cultivation of Anaerobiospirillum succiniciproducens were systematically studied for the production of succinic acid from whey. Addition of 2.5 g l⁻¹ yeast extract and 2.5 g l⁻¹ polypeptone per 10 g l⁻¹ whey was most effective for succinic acid production from both treated and nontreated whey. When 20 g l⁻¹ nontreated whey and 7 g l⁻¹ glucose were used as cosubstrates, the yield and productivity of succinic acid reached at the end of fermentation were 95% and 0.46 g (l h)⁻¹, respectively. These values were higher than those obtained using nontreated whey alone [93% and 0.24 g (l h)⁻¹ for 20 g l⁻¹ whey]. Continuous fermentation of A. succiniciproducens at an optimal dilution rate resulted in the production of succinic acid with high productivity [1.35 g (l h)⁻¹], high conversion yield (93%), and higher ratio of succinic acid to acetic acid (5.1:1) from nontreated whey. Received: 23 July 1999 / Received revision: 17 November 1999 / Accepted: 24 December 1999     

Fungal autolysate as a nutrient supplement for ethanol and chitosan production by <Emphasis Type="Italic">Mucor indicus</Emphasis>

Mucor indicus can be used to produce ethanol from a variety of sugars, including pentose’s. An extract of it, produced by autolysis, could replace yeast extract in culture medium with improved production of ethanol. At 10 g l⁻¹, the extract gave a higher ethanol yield (0.47 g g⁻¹) and productivity (0.71 g l⁻¹ h⁻¹) compared to medium containing yeast extract (yield 0.45 g g⁻¹; productivity 0.67 g l⁻¹ h⁻¹).     

Continuous butanol production with reduced byproducts formation from glycerol by a hyper producing mutant of <Emphasis Type="Italic">Clostridium pasteurianum</Emphasis>

Butanol, a four-carbon primary alcohol (C₄H₁₀O), is an important industrial chemical and has a good potential to be used as a superior biofuel. Bio-based production of butanol from renewable feedstock is a promising and sustainable alternative to substitute petroleum-based fuels. Here, we report the development of a process for butanol production from glycerol, which is abundantly available as a byproduct of biodiesel production. First, a hyper butanol producing strain of Clostridium pasteurianum was isolated by chemical mutagenesis. The best mutant strain, C. pasteurianum MBEL_GLY2, was able to produce 10.8 g l⁻¹ butanol from 80 g l⁻¹ glycerol as compared to 7.6 g l⁻¹ butanol produced by the parent strain. Next, the process parameters were optimized to maximize butanol production from glycerol. Under the optimized batch condition, the butanol concentration, yield, and productivity of 17.8 g l⁻¹, 0.30 g g⁻¹, and 0.43 g l⁻¹ h⁻¹ could be achieved. Finally, continuous fermentation of C. pasteurianum MBEL_GLY2 with cell recycling was carried out using glycerol as a major carbon source at several different dilution rates. The continuous fermentation was run for 710 h without strain degeneration. The acetone–butanol–ethanol productivity and the butanol productivity of 8.3 and 7.8 g l⁻¹ h⁻¹, respectively, could be achieved at the dilution rate of 0.9 h⁻¹. This study reports continuous production of butanol with reduced byproducts formation from glycerol using C. pasteurianum, and thus could help design a bioprocess for the improved production of butanol.     

Conversion of oleic acid to 10-hydroxystearic acid by whole cells of <Emphasis Type="Italic">Stenotrophomonas nitritireducens</Emphasis>

The optimal reaction conditions for the conversion of oleic acid to 10-hydroxystearic acid by whole cells of Stenotrophomonas nitritireducens were: pH 7.5, 35°C, 0.05% (w/v) Tween 80, 20 g cells l⁻¹, and 30 g oleic acid l⁻¹ in an anaerobic atmosphere. Under these conditions, the cells produced 31.5 g 10-hydroxystearic acid l⁻¹ over 4 h with a conversion yield of 100% (mol/mol) and a productivity of 7.9 g l⁻¹ h⁻¹, indicating that oleic acid was converted completely to 10-hydroxystearic acid, with no detectable byproduct. This is the highest concentration, productivity, and yield of 10-hydroxystearic acid from oleic acid reported thus far.     

Optimization of a corn steep medium for production of ethanol from synthesis gas fermentation by <Emphasis Type="Italic">Clostridium ragsdalei</Emphasis>

Fermentation of biomass derived synthesis gas to ethanol is a sustainable approach that can provide more usable energy and environmental benefits than food-based biofuels. The effects of various medium components on ethanol production by Clostridium ragsdalei utilizing syngas components (CO:CO₂) were investigated, and corn steep liquor (CSL) was used as an inexpensive nutrient source for ethanol production by C. ragsdalei. Elimination of Mg²⁺, NH₄ ⁺ and PO₄ ³⁻ decreased ethanol production from 38 to 3.7, 23 and 5.93 mM, respectively. Eliminating Na⁺, Ca²⁺, and K⁺ or increasing Ca²⁺, Mg²⁺, K⁺, NH₄ ⁺ and PO₄ ³⁻ concentrations had no effect on ethanol production. However, increased Na⁺ concentration (171 mM) inhibited growth and ethanol production. Yeast extract (0.5 g l⁻¹) and trace metals were necessary for growth of C. ragsdalei. CSL alone did not support growth and ethanol production. Nutrients limiting in CSL were trace metals, NH₄ ⁺ and reducing agent (Cys: cysteine sulfide). Supplementation of trace metals, NH₄ ⁺ and CyS to CSL (20 g l⁻¹, wet weight basis) yielded better growth and similar ethanol production as compared to control medium. Using 10 g l⁻¹, the nutritional limitation led to reduced ethanol production. Higher concentrations of CSL (50 and 100 g l⁻¹) were inhibitory for cell growth and ethanol production. The CSL could replace yeast extract, vitamins and minerals (excluding NH₄ ⁺). The optimized CSL medium produced 120 and 50 mM of ethanol and acetate, respectively. The CSL could provide as an inexpensive source of most of the nutrients required for the syngas fermentation, and thus could improve the economics of ethanol production from biomass derived synthesis gas by C. ragsdalei.     

Enhanced regeneration of haploid plantlets from microspores of <Emphasis Type="Italic">Brassica napus</Emphasis> L. using bleomycin,PCIB, and phytohormones

The effects of three periods of incubation (10, 20 and 30 min) at different levels of bleomycin (0, 0.1, 0.2, 0.3, 0.4 and 0.5 μg ml⁻¹), as well as three periods of exposure (12, 24 and 48 h) to different levels of the anti-auxin p-chlorophenoxyisobutyric acid (PCIB), including 1, 2, 3, 4 and 5 mg l⁻¹, on microspore embryogenesis of rapeseed cv. ‘Amica’ were investigated. Microspore embryogenesis was significantly enhanced following 20 min treatment with 0.2 μg ml⁻¹ bleomycin compared with untreated cultures. Highest embryo yield (163 embryos Petri dish⁻¹) was observed with 24 h treatment of 4 mg l⁻¹ PCIB. The highest percentage of secondary embryogenesis was observed on B₅ medium containing 0.15 mg l⁻¹ of gibberellic acid (GA₃) and 0.2 mg l⁻¹ 6-benzyladenine (BA) in 4–6 mm microspore-derived embryos (MDEs). Most callus formed on B₅ medium containing 0.15 mg l⁻¹ GA₃, 0.1 mg l⁻¹ BA and 0.1 mg l⁻¹ indole-3-acetic acid (IAA) when 4–6 mm embryos were used. Regeneration was highest on B₅ medium containing 0.05 mg l⁻¹ GA₃ or 0.1 mg l⁻¹ BA and 0.2 mg l⁻¹ IAA with 2–4 mm embryos. Microspore embryogenesis and plant regeneration could be improved by both bleomycin and PCIB when the appropriate MDE length and phytohormone level were selected.     

CO<Subscript>2</Subscript>-enriched microenvironment affects sucrose and macronutrients absorption and promotes autotrophy in the <Emphasis Type="Italic">in vitro</Emphasis> culture of kiwi (<Emphasis Type="Italic">Actinidia deliciosa</Emphasis> Chev. Liang and Ferguson)

In traditional in vitro culture, the low CO₂ concentration inside the vessels restricts photosynthesis and necessitates the addition of sucrose to the culture medium as the main energy source, thus bringing about changes in the absorption of mineral elements from the culture medium. In this study, we investigated macronutrient absorption and sugar consumption in Actinidia deliciosa Chevalier Liang and Ferguson cv. Hayward (kiwi), cultured on medium supplemented with varying amounts of sucrose (0, 10, and 20 g l⁻¹) under both heterotrophy and autotrophy, flushed with different concentrations of CO₂ (non-ventilation, 300, 600, and 2,000 μl l⁻¹). In ventilated systems with 20 g l⁻¹ of sucrose, sucrose absorption was less than under non-ventilation. The lowest rate of sucrose absorption was recorded when the explants were cultured on medium supplemented with 20 g l⁻¹ of sucrose and flushed with 600 μl l⁻¹ CO₂. Absorption of NO₃ ⁻, PO₄ ³⁻, and Mg²⁺ were high (maximum) at the end of the culture period (40 d) in explants flushed with 600 μl l⁻¹ CO₂ that have been cultured 20 d in the presence of sucrose and then transferred to a sucrose-free medium. These autotrophic conditions promoted maximum plant growth in terms of both fresh and dry mass as well as the length and number of shoots and leaves. The study shows that to maintain an optimum regime of mineral nutrition for prolonged culture of kiwi in vitro, an increased amount of these three ions should be supplemented in Murashige and Skoog’s medium.     

Carbon source pulsed feeding to attain high yield and high productivity in poly(3-hydroxybutyrate) (PHB) production from soybean oil using <Emphasis Type="Italic">Cupriavidus necator</Emphasis>

Poly(3-hydroxybutyrate) (PHB) biosynthesis from soybean oil by Cupriavidus necator was studied using a bench scale bioreactor. The highest cell concentration (83 g l⁻¹) was achieved using soybean oil at 40 g l⁻¹ and a pulse of the same concentration. The PHB content was 81% (w/w), PHB productivity was 2.5 g l⁻¹ h⁻¹, and the calculated Y_p/s value was 0.85 g g⁻¹. Growth limitation and the onset of PHB biosynthesis took place due to exhaustion of P, and probably also Cu, Ca, and Fe.     

Kinetic study on succinic acid and acetic acid formation during continuous cultures of Anaerobiospirillum succiniciproducens grown on glycerol

Succinic acid-producing Anaerobiospirillum succiniciproducens was anaerobically grown in a glycerol-fed continuous bioreactor in order to investigate the physiological responses of the cell to different pH values (5.9, 6.2, or 6.5) and various dilution rates, D. In these experiments, A. succiniciproducens showed a pH-dependent glycerol consumption behavior. When pH was maintained at 5.9 or 6.5, glycerol started to accumulate even at a very low D of 0.027 h⁻¹. Succinic acid yield was not significantly affected by the pH of the culture or the Ds. However, more acetic acid formation was observed when the growth rate of A. succiniciproducens was fast on glycerol at pH 6.2 (at D ≥ 0.15 h⁻¹). The highest obtainable succinic acid/acetic acid ratio was 40:1, which was 10 times higher than that obtained by batch cultures grown on glucose. The maximum obtainable productivity of succinic acid was 2.1 g L⁻¹ h⁻¹), which was 14 times higher than that obtained by batch culture.     

Production of ectoine through a combined process that uses both growing and resting cells of <Emphasis Type="Italic">Halomonas salina</Emphasis> DSM 5928<Superscript>T</Superscript>

Using ectoine-excreting strain Halomonas salina DSM 5928^T, we developed a new process for high-efficiency production of ectoine, which involved a combined process of batch fermentation by growing cells and production by resting cells. In the first stage, batch fermentation was carried out using growing cells under optimal fermentation conditions. The second stage was the production phase, in which ectoine was synthesized and excreted by phosphate-limited resting cells. Optimal conditions for synthesis and excretion of ectoine during batch fermentation in a 10 l fermentor were 0.5 mol l⁻¹ NaCl and an initial monosodium glutamate concentration of 80 g l⁻¹ respectively. The pH was adjusted to 7.0 and the temperature was maintained at 33°C. In phosphate-limited resting cells medium, monosodium glutamate and NaCl concentration was 200 g l⁻¹ and 0.5 mol l⁻¹, respectively, as well as pH was 7.0. The total concentration of ectoine produced was 14.86 g l⁻¹, the productivity and yield of ectoine was 7.75 g l⁻¹ day⁻¹ and 0.14 g g⁻¹, respectively, and the percentage of ectoine excreted was 79%. These levels of ectoine production and excretion are the highest reported to date.     

Phenol biodegradation by the thermoacidophilic archaeon <Emphasis Type="Italic">Sulfolobus solfataricus</Emphasis> 98/2 in a fed-batch bioreactor

Toxic at low concentrations, phenol is one of the most common organic pollutants in air and water. In this work, phenol biodegradation was studied in extreme conditions (80°C, pH = 3.2) in a 2.7 l bioreactor with the thermoacidophilic archaeon Sulfolobus solfataricus 98/2. The strain was first acclimatized to phenol on a mixture of glucose (2000 mg l⁻¹) and phenol (94 mg l⁻¹) at a constant dissolved oxygen concentration of 1.5 mg l⁻¹. After a short lag-phase, only glucose was consumed. Phenol degradation then began while glucose was still present in the reactor. When glucose was exhausted, phenol was used for respiration and then for biomass build-up. After several batch runs (phenol < 365 mg l⁻¹), specific growth rate (μ_X) was 0.034 ± 0.001 h⁻¹, specific phenol degradation rate (q_P) was 57.5 ± 2 mg g⁻¹ h⁻¹, biomass yield (Y_X/P) was 52.2 ± 1.1 g mol⁻¹, and oxygen yield factor ( \textY_{\textX/\textO 2} ) \left( {{\text{Y}}_{{{\text{X}}/{\text{O}}_{ 2} }} } \right) was 9.2 ± 0.2 g mol⁻¹. A carbon recovery close to 100% suggested that phenol was exclusively transformed into biomass (35%) and CO₂ (65%). Molar phenol oxidation constant ( \textY_{\textO 2 /\textP} ) \left( {{\text{Y}}_{{{\text{O}}_{ 2} /{\text{P}}}} } \right) was calculated from stoichiometry of phenol oxidation and introducing experimental biomass and CO₂ conversion yields on phenol, leading to values varying between 4.78 and 5.22 mol mol⁻¹. Respiratory quotient was about 0.84 mol mol⁻¹, very close to theoretical value (0.87 mol mol⁻¹). Carbon dioxide production, oxygen demand and redox potential, monitored on-line, were good indicators of growth, substrate consumption and exhaustion, and can therefore be usefully employed for industrial phenol bioremediation in extreme environments.     

Isolation of <Emphasis Type="Italic">Aspergillus oryzae</Emphasis> mutants for heterologous protein production from a double proteinase gene disruptant

The recombinant Pichia pastoris harboring an improved methionine adenosyltransferase (MAT) shuffled gene was employed to biosynthesize S-adenosyl-l-methionine (SAM). Two l-methionine (l-Met) addition strategies were used to supply the precursor: the batch addition strategy (l-Met was added separately at three time points) and the continuous feeding strategies (l-Met was fed continuously at the rate of 0.1, 0.2, and 0.5 g l⁻¹ h⁻¹, respectively). SAM accumulation, l-Met conversion rate, and SAM productivity with the continuous feeding strategies were all improved over the batch addition strategy, which reached 8.46 ± 0.31 g l⁻¹, 41.7 ± 1.4%, and 0.18 ± 0.01 g l⁻¹ h⁻¹ with the best continuous feeding strategy (0.2 g l⁻¹ h⁻¹), respectively. The bottleneck for SAM production with the low l-Met feeding rate (0.1 g L⁻¹ h⁻¹) was the insufficient l-Met supply. The analysis of the key enzyme activities indicated that the tricarboxylic acid cycle and glycolytic pathway were reduced with the increasing l-Met feeding rate, which decreased the adenosine triphosphate (ATP) synthesis. The MAT activity also decreased as the l-Met feeding rate rose. The reduced ATP synthesis and MAT activity were probably the reason for the low SAM accumulation when the l-Met feeding rate reached 0.5 g l⁻¹ h⁻¹.     

Biotreatment of phenol-contaminated wastewater in a spiral packed-bed bioreactor

A spiral packed-bed bioreactor inoculated with microorganisms obtained from activated sludge was used to conduct a feasibility study for phenol removal. The reactor was operated continuously at various phenol loadings ranging from 53 to 201.4 g m⁻³ h⁻¹, and at different hydraulic retention times (HRT) in the range of 20–180 min to estimate the performance of the device. The results indicated that phenol removal efficiency ranging from 82.9 to 100% can be reached when the reactor is operated at an HRT of 1 h and a phenol loading of less than 111.9 g m⁻³ h⁻¹. At an influent phenol concentration of 201.4 g m⁻³, the removal efficiency increased from 18.6 to 76.9% with an increase in the HRT (20–120 min). For treatment of phenol in the reactor, the maximum biodegradation rate (V _m) was 1.82 mg l⁻¹ min⁻¹; the half-saturation constant (K _s), 34.95 mg l⁻¹.     

Ethanol and xylitol production from glucose and xylose at high temperature by <Emphasis Type="Italic">Kluyveromyces</Emphasis> sp. IIPE453

A yeast strain Kluyveromyces sp. IIPE453 (MTCC 5314), isolated from soil samples collected from dumping sites of crushed sugarcane bagasse in Sugar Mill, showed growth and fermentation efficiency at high temperatures ranging from 45°C to 50°C. The yeast strain was able to use a wide range of substrates, such as glucose, xylose, mannose, galactose, arabinose, sucrose, and cellobiose, either for growth or fermentation to ethanol. The strain also showed xylitol production from xylose. In batch fermentation, the strain showed maximum ethanol concentration of 82 ± 0.5 g l⁻¹ (10.4% v/v) on initial glucose concentration of 200 g l⁻¹, and ethanol concentration of 1.75 ± 0.05 g l⁻¹ as well as xylitol concentration of 11.5 ± 0.4 g l⁻¹ on initial xylose concentration of 20 g l⁻¹ at 50°C. The strain was capable of simultaneously using glucose and xylose in a mixture of glucose concentration of 75 g l⁻¹ and xylose concentration of 25 g l⁻¹, achieving maximum ethanol concentration of 38 ± 0.5 g l⁻¹ and xylitol concentration of 14.5 ± 0.2 g l⁻¹ in batch fermentation. High stability of the strain was observed in a continuous fermentation by feeding the mixture of glucose concentration of 75 g l⁻¹ and xylose concentration of 25 g l⁻¹ by recycling the cells, achieving maximum ethanol concentration of 30.8 ± 6.2 g l⁻¹ and xylitol concentration of 7.35 ± 3.3 g l⁻¹ with ethanol productivity of 3.1 ± 0.6 g l⁻¹ h⁻¹ and xylitol productivity of 0.75 ± 0.35 g l⁻¹ h⁻¹, respectively.     

Fed-batch production of a bioflocculant from <Emphasis Type="Italic">Corynebacterium glutamicum</Emphasis>

The constant-rate fed-batch production of the polygalacturonic acid bioflocculant REA-11 was studied. A controlled sucrose-feeding strategy resulted in a slight improvement in biomass and a 7% reduction in flocculating activity compared with the batch process. When fed with a 3 g l⁻¹ urea solution, the flocculating activity was enhanced to 720 U ml⁻¹ in 36 h. High cell density (2.12 g l⁻¹) and flocculating activity (820 U ml⁻¹) were obtained in a 10-l fermentor by feeding with a sucrose-urea solution, with values of nearly two times and 50% higher than those of the batch process, respectively. Moreover, the residual sucrose declined to 2.4 g l⁻¹, and residual urea decreased to 0.03 g l⁻¹. Even higher flocculating activity of 920 U ml⁻¹ and biomass of 3.26 g l⁻¹ were obtained by feeding with a sucrose-urea solution in a pilot scale fermentation process, indicating the potential industrial utility of this constant-rate feeding strategy in bioflocculant production by Corynebacterium glutamicum.     

<Emphasis Type="Italic">Clostridium beijerinckii</Emphasis> mutant with high inhibitor tolerance obtained by low-energy ion implantation

Clostridium beijerinckii mutant strain IB4, which has a high level of inhibitor tolerance, was screened by low-energy ion implantation and used for butanol fermentation from a non-detoxified hemicellulosic hydrolysate of corn fiber treated with dilute sulfuric acid (SAHHC). Evaluation of toxicity showed C. beijerinckii IB4 had a higher level of tolerance than parent strain C. beijerinckii NCIMB 8052 for five out of six phenolic compounds tested (the exception was vanillin). Using glucose as carbon source, C. beijerinckii IB4 produced 9.1 g l⁻¹ of butanol with an acetone/butanol/ethanol (ABE) yield of 0.41 g g⁻¹. When non-detoxified SAHHC was used as carbon source, C. beijerinckii NCIMB 8052 grew well but ABE production was inhibited. By contrast, C. beijerinckii IB4 produced 9.5 g l⁻¹ of ABE with a yield of 0.34 g g⁻¹, including 2.2 g l⁻¹ acetone, 6.8 g l⁻¹ butanol, and 0.5 g l⁻¹ ethanol. The remarkable fermentation and inhibitor tolerance of C. beijerinckii IB4 appears promising for ABE production from lignocellulosic materials.