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Highlights • Use of Southern Pine wood sugars is demonstrated for production of solvents. • Fermentation of C6 and C5-rich streams is shown with productivity above 10 g/L/h. • Membrane assisted continuous fermentation is demonstrated for solvent production. • Use of butyl butyrate as an extractant for solvent extraction demonstrated. • Raffinate after solvent extraction was recycled back without any toxicity issues. Abstract The aim of this work was to demonstrate an industrially relevant pilot scale integrated process to produce butanol and other solvents from lignocellulosic sugars produced with AVAP® biomass fractionation technology from southern pine wood. The concentrated sugars were concurrently fermented using genetically engineered Clostridium acetobutylicum to n-butanol, acetone, isopropanol and ethanol in continuous membrane assisted cell recycle fermentation with steady-state solvent productivity exceeding 10 g/L/h. The solvents from the cell free permeate were recovered with extractant of butyl butyrate in a continuous liquid-liquid extraction column and aqueous product (raffinate) along with unused sugars, nutrients, and metabolic intermediates were recycled back to the fermentors. The total solvent yield approached 0.30 g/g sugars. [ABSTRACT FROM AUTHOR]

Highlights: [•] Advanced and economical production of biobutanol. [•] Continuous two stage fermentation with integrated liquid–liquid recovery technique. [•] Utilization of lignocellulosic sugar mixture (pentoses and hexoses). [•] Long run system operation with high solvent productivity (10.85g/Lh) and yield. [•] Can be integrated to the wood based biorefinery to make it industrially feasible. [ABSTRACT FROM AUTHOR]

Abstract: A process for the fermentative production of propionic acid from whole wheat flour using starch and gluten as nutrients is presented. Hydrolysis of wheat flour starch using amylases was optimized. A batch fermentation of hydrolysate supplemented with various nitrogen sources using Propionibacterium acidipropionici NRRL B 3569 was performed. The maximum production of 48.61, 9.40, and 11.06g of propionic acid, acetic acid and succinic acid, respectively, was found with wheat flour hydrolysate equivalent to 90g/l glucose and supplemented with 15g/l yeast extract. Further, replacement of yeast extract with wheat gluten hydrolysate showed utilization of gluten hydrolysate without compromising the yields and also improving the economics of the process. The process so developed could be useful for production of animal feed from whole wheat with in situ production of preservatives, and also suggest utilization of sprouted or germinated wheat for the production of organic acids. [Copyright &y& Elsevier]

Abstract: The present study proposes the use of market rejected and waste vegetables as a supplement for improved acetone–ethanol–butanol (ABE) solvent production. In the present study, three different perishable vegetables were evaluated as supplements for ABE fermentation. These vegetables were found to stimulate the solvent production at as low as 1% (w/v) concentration. The supplementation showed improved production of solvents using 4-fold diluted SO2–ethanol–water (SEW) spent liquor supplemented with 25g/l glucose as a substrate. The maximum total solvent production obtained with 5% (w/v) supplementation of carrot, cabbage and tomato was 9.96g/l, 10.49g/l and 10.65g/l, respectively as compared to the control value of 7.43g/l. The applicability of vegetables was successfully evaluated as a complex medium for solvent production. [Copyright &y& Elsevier]

Abstract: The objective of this study was to optimize continuous acetone–butanol–ethanol (ABE) fermentation using a two stage chemostat system integrated with liquid–liquid extraction of solvents produced in the first stage. This minimized end product inhibition by butanol and subsequently enhanced glucose utilization and solvent production in continuous cultures of Clostridium acetobutylicum B 5313. During continuous two-stage ABE fermentation, sugarcane bagasse was used as the cell holding material for the both stages and liquid–liquid extraction was performed using an oleyl alcohol and decanol mixture. An overall solvent production of 25.32g/L (acetone 5.93g/L, butanol 16.90g/L and ethanol 2.48g/L) was observed as compared to 15.98g/L in the single stage chemostat with highest solvent productivity and solvent yield of 2.5g/Lh and of 0.35g/g, respectively. Maximum glucose utilization (83.21%) at a dilution rate of 0.051/h was observed as compared to 54.38% in the single stage chemostat. [Copyright &y& Elsevier]

Abstract: SO2–ethanol–water (SEW) spent liquor from spruce chips was successfully used for batch and continuous production of acetone, butanol and ethanol (ABE). Initially, batch experiments were performed using spent liquor to check the suitability for production of ABE. Maximum concentration of total ABE was found to be 8.79g/l using 4-fold diluted SEW liquor supplemented with 35g/l of glucose. The effect of dilution rate on solvent production, productivity and yield was studied in column reactor consisting of immobilized Clostridium acetobutylicum DSM 792 on wood pulp. Total solvent concentration of 12g/l was obtained at a dilution rate of 0.21h−1. The maximum solvent productivity (4.86g/lh) with yield of 0.27g/g was obtained at dilution rate of 0.64h−1. Further, to increase the solvent yield, the unutilized sugars were subjected to batch fermentation. [Copyright &y& Elsevier]

Abstract: In present times, the immunosuppressants have gained considerable importance in the world market. Cyclosporin A (CyA) is a cyclic undecapeptide with a variety of biological activities including immunosuppressive, anti-inflammatory, antifungal and antiparasitic properties. CyA is produced by various types of fermentation techniques using Tolypocladium inflatum. In the present review, we discuss the biosynthetic pathway, fermentative production, downstream processing and pharmacological activities of CyA. [Copyright &y& Elsevier]

Abstract: Response surface methodology (RSM) is the most preferred method for fermentation media optimization so far. In last two decades, artificial neural network-genetic algorithm (ANN-GA) has come up as one of the most efficient method for empirical modeling and optimization, especially for non-linear systems. This paper presents the comparative studies between ANN-GA and RSM in fermentation media optimization. Fermentative production of biopolymer scleroglucan has been chosen as case study. The yield of scleroglucan was modeled and optimized as a function of four independent variables (media components) using ANN-GA and RSM. The optimized media produced 16.22±0.44g/l scleroglucan as compared to 7.8±0.54g/l with unoptimized medium. Two methodologies were compared for their modeling, sensitivity analysis and optimization abilities. The predictive and generalization ability of both ANN and RSM were compared using separate dataset of 17 experiments from earlier published work. The average % error for ANN and RSM models were 6.5 and 20 and the CC was 0.89 and 0.99, respectively, indicating the superiority of ANN in capturing the non-linear behavior of the system. The sensitivity analysis performed by both methods has given comparative results. The prediction error in optimum yield by hybrid ANN-GA and RSM were 2% and 8%, respectively. [Copyright &y& Elsevier]

Abstract: Natural antibiotics are almost universal secondary metabolites, not essential for the growth of the producing organisms generally produced at low growth rates or after growth has ceased. Clavulanic acid (CA), a naturally occurring powerful inhibitor of bacterial β-lactamases is a major β-lactam antibiotic produced by organism Streptomyces clavuligerus and is active against a wide spectrum of Gram-positive and Gram-negative bacteria. The review discusses the biosynthetic pathway, fermentative production, downstream processing and applications of CA. [Copyright &y& Elsevier]

Abstract: In the present work, four strains were screened for schizophyllan production, of which Schizophyllum commune NRCM was selected for further work. The fermentation was carried out for 168h at 28±2°C on an orbital shaker at 180rpm. In the first step, one factor-at-a-time method was used to investigate the effect of media constituents such as carbon and nitrogen sources on schizophyllan production. Subsequently in the second step, concentration of the medium components was optimized using Response Surface Method (RSM). The yield increased from 3.25±0.72g/l in the unoptimized media to 8.03±1.12g/l in the medium optimized by RSM. [Copyright &y& Elsevier]

Abstract: Submerged fermentation was carried out for the production of scleroglucan by Sclerotium rolfsii MTCC 2156 using complex media, such as coconut water, sugarcane molasses and sugarcane juice at 28±2°C and 180rpm for 72h. Sugarcane juice gave maximum scleroglucan production of 23.87g/l as compared to 12.58 and 18.45g/l with coconut water and sugarcane molasses, respectively. Utilization of these substrates would be ecologically sound and economically advantageous. [Copyright &y& Elsevier]

Abstract: The aim of this work was to study the effect of addition of different amino acids and sugar nucleotides as metabolic precursors on the production of scleroglucan. A maximum yield of 20.00g/l and 22.32g/l was obtained with optimized media supplemented with l-lysine (1.1mM) and uridine mono-phosphate (UMP), respectively as compared to 16.52g/l scleroglucan achieved with the control in the absence of metabolic precursors. [Copyright &y& Elsevier]

Abstract: Scleroglucan, a neutral homopolysaccaride consisting of a linear chain of β-d-(1-3)-glucopyranosyl and β-d-(1-6)-glucopyranosyl groups, was produced by pure culture fermentation from Sclerotium rolfsii MTCC 2156 by submerged culture. Fermentation process was optimized in two steps. In the first step, one-factor-at-a-time method was used to investigate the effects of medium constituents such as carbon and nitrogen sources. In the second step, concentration of medium components was optimized using an L16-orthogonal array method. In all, 10 different carbon sources and eight different nitrogen sources were evaluated. Maximum yield of 16.58g/l was obtained in a medium containing sucrose as a carbon source and sodium nitrate and yeast extract as nitrogen source. [Copyright &y& Elsevier]

• Waste wood is converted to sugars and ethanol on a pilot scale with SO 2 -ethanol-water. • SO 2 -ethanol-water pretreatment of waste wood results in high sugar yields. • Pilot scale sugar yields matched earlier laboratory scale results. Two grades of recycled wood (Waste Wood A and Waste Wood B) were fractionated on a pilot scale (800 BD kg) to monomeric sugars, lignin and lignosulfonates using SO 2 -Ethanol-Water (AVAP®) technology, including pretreatment, separation of cellulosic and hemicellulosic streams, and saccharification. Carbohydrate mass balance was obtained through determination of poly-, oligo- and monosaccharides as well as sugar degradation products in process streams. High monosaccharide yields were obtained confirming laboratory scale findings. Fermentability of mixed cellulosic and hemicellulosic sugar stream was confirmed on bench scale (25 kg). [ABSTRACT FROM AUTHOR]

• Recycled wood is converted to monosugars, lignin and lignosulfonates with SO 2 -ethanol. • SO 2 -ethanol converts recycled wood to digestible cellulose and fermentable sugars. • SO 2 -ethanol process produces monosugars at ~560–610 kg per BD ton recycled wood. • SO 2 -ethanol process produces lignin at ~150–155 kg per BD ton recycled wood. Recycled wood of two grades (A and B) and spruce were converted on bench (100 o.d. g) and pilot (100 o.d. kg) scales to monosugars, lignin and lignosulfonates using SO 2 -Ethanol-Water (AVAP®) technology. After digestion, C6 and C5 sugars were recovered at 98–100% and 87–99% for Wood A and Spruce, respectively, while the values for Wood B were 92% and 74–87%. Cellulose was hydrolysed to glucose at 90% or higher using enzyme charge of 7.1 FPU/g glucan. Hemicellulosic sugars were autohydrolyzed to 95–100% monosugars. At bench scale, monosaccharide yield was 609, 561 and 688 kg (hydrous) per BDT biomass for Wood A, Wood B and Spruce, respectively. Corresponding water insoluble lignin yield was 157, 148 and 189 kg per BDT biomass. The preliminary techno-economic evaluation revealed that conversion of recycled wood to sugars using AVAP® fractionation platform results in higher profitability in comparison to virgin wood. [ABSTRACT FROM AUTHOR]

Acetone being a non-fuel solvent produced during the traditional acetone-butanol-ethanol (ABE) fermentation by Clostridium acetobutylicum ; reduces the overall fuel alcohol yield. However, the conversion of acetone into isopropanol has been recommended to improve the process economy. The present study aims to develop an engineered C. acetobutylicum DSM 792 strain to convert acetone into isopropanol by introducing the secondary alcohol dehydrogenase gene from Clostridium beijerinckii NRRL B593 using the allele-coupled exchange approach. Batch and continuous fermentation experiments were carried out with a modified strain C. acetobutylicum DSM 792-ADH to improve the isopropanol yield and titer. The growth and production behavior of the modified strain in stationary flask culture and controlled batch culture was studied. Almost 50% of acetone was converted into isopropanol with highest total solvent yield to be 0.39 g g −1 glucose. The modified strain also utilized sugar mixture and SO 2 –ethanol–water spent liquor as a substrate to produce the solvents. [ABSTRACT FROM AUTHOR]

The co-production of acetone during traditional butanol fermentation (acetone–butanol–ethanol) lowers the yield of alcohol biofuels. The present study was aimed to develop an improved Clostridium acetobutylicum strain with enhanced alcohol fuel production capability. The previously developed IBE (isopropanol-butanol-ethanol) producing C. acetobutylicum DSM792-ADH strain was further optimized to enhance the solvent productivity and yield. Immobilized cell column reactor was used to investigate the effect of dilution rate on IBE fermentation. Pure glucose, artificial sugar mixture and SEW spent liquor from spruce chips were used as substrates to study the behavior of the modified microorganism. The highest total solvent concentrations of approximately 10.60 g l −1 , 10 g l −1 and 6 g l −1 were obtained when glucose, sugar mixture and SEW spent liquor were used as substrates respectively. The modified microorganism could effectively utilize the lignocellulosic biomass hydrolyzate (SEW spent liquor) to yield a solvent productivity of 1.67 g l −1 h −1 . [ABSTRACT FROM AUTHOR]

Highlights: [•] Oil palm empty fruit bunches (OPEFB) are fractionated by SO2–ethanol–water mixture. [•] Fractionation of OPEFB feedstock produces cellulosic fibers and spent liquor. [•] Spent liquor contains dissolved hemicellulose sugars (mostly monomers) and lignin. [•] Fractionation and sugar hydrolysis is hindered by the high cation content of OPEFB. [•] Acidic leaching of OPEFB only partly removes cations; more intense deashing needed. [Copyright &y& Elsevier]

Highlights: [•] A novel modeling approach for Clostridium acetobutylicum solvenotogenic phase is proposed. [•] Continuous fermentation with immobilized cells is studied. [•] The solvent fluxes are predicted quantitatively. [•] A novel optimization procedure is introduced for constraint-based modeling. [ABSTRACT FROM AUTHOR]

Abstract: Polysaccharides produced by Neisseria meningitidis are pharmaceutically important molecules, and are the active components of vaccines against N. meningitidis serogroups A, C, W135 and Y. Effective vaccines based on capsular polysaccharide, polysaccharide conjugates and outer membrane vesicles have been developed for strains expressing capsular polysaccharides that define the sero groups A, C, Y and W135. However, conventional approaches to develop a vaccine for group B strains have been largely unsuccessful. This review focuses on the various aspects of fermentative production of meningococcal polysaccharide from N. meningitidis, methods of conjugation for improving the immunogenicity of polysaccharide vaccine, and efficient and cost effective methods for the purification of N. meningitidis capsular polysaccharide and outer membrane vesicles. In addition, different analytical techniques for the quantitative determination of polysaccharide vaccine and evaluation of structural integrity of conjugate vaccine have been described. [Copyright &y& Elsevier]

The biomass obtained after the extraction of forskolin from the roots of Coleus forskohlii was evaluated as a substrate for the production of acetone-butanol-ethanol (ABE). The spent biomass constituting more than 90% of the raw material showed 50–70% carbohydrates with starch and cellulose being the major constituents. This study was undertaken to optimize enzymatic hydrolysis of C. forskohlii roots for maximum release of fermentable sugars and subsequent fermentation to ABE. The root biomass was hydrolyzed using the Stargen ® 002 and Accellerase ® 1500. Cocktail of both enzymes (16U Stargen ® 002 and 60 FPU Accellerase ® 1500) could produce 41.2 g/l of total reducing sugars (glucose equivalent to 32.33 g/l). The production of ABE was optimized in a batch fermentation using Clostridium acetobutylicum NCIM 2877. The maximum ABE production using the root hydrolysates was 0.55 g/l. Pretreatment with lime and Amberlite XAD-4 increased the production of total solvent to 5.33 g/l. [ABSTRACT FROM AUTHOR]

Alcohol dehydrogenase was covalently conjugated with three different oxidized carbohydrates i.e., glucose, starch and pectin. All the carbohydrates inhibited the enzyme. The inhibition was studied with respect to the inhibition rate constant, involvement of thiol groups in the binding, and structural changes in the enzyme. The enzyme activity decreased to half of its original activity at the concentration of 2 mg/mL of pectin, 4 mg/mL of glucose and 10 mg/mL of starch within 10 min at pH 7. This study showed oxidized pectin to be a potent inhibitor of alcohol dehydrogenase followed by glucose and starch. Along with the aldehyde-amino group interaction, thiol groups were also involved in the binding between alcohol dehydrogenase and carbohydrates. The structural changes occurring on binding of alcohol dehydrogenase with oxidized carbohydrates was also confirmed by fluorescence spectrophotometry. Oxidized carbohydrates could thus be used as potential inhibitors of alcohol dehydrogenase. [ABSTRACT FROM AUTHOR]

Highlights: [•] Carbohydrate profiling of Coleus forskohlii root. [•] Utilization of Coleus forskohlii root biomass for bioethanol production. [•] Immobilization of yeast on wood chips. [•] Continuous lignocellulosic fermentation to produce bioethanol. [ABSTRACT FROM AUTHOR]

Highlights: [•] Study suggests the preference of biomass feedstocks appropriate for ABE-fermentation. [•] Effect of varying lignocellulosic sugar concentrations in continuous column reactor. [•] Multi linear regression (MLR) modeling successfully used for continuous production of solvents. [•] Scale up of column reactor is successfully demonstrated. [Copyright &y& Elsevier]