Enzymatic Saccharification Of Corn Stover Research Articles

Combinations of mild chemical and bacterial pretreatment for improving enzymatic saccharification of corn stover

Biological pretreatment of lignocellulosic biomass plays an important role for the enzymatic hydrolysis. In this study, a nitrogen-fixing and lignin-degrading strain of bacteria was isolated from an abandoned termite colony. Then, it was identified and named as R. ornithinolytica RS-1. To improve the degradation and enzymatic saccharification in corn stover, we used pretreatment with strain RS-1 to deplete the lignin, combined with a 2.5% mild NaOH pretreatment to further deplete the hemicellulose. After only seven days, lignin was degraded by the bacteria RS-1 with a 19% decrease, while the relative content of cellulose increased with 21%. Furthermore, the corn stover cellulose conversion was up to 48.58% by a two-stage process with 2.5% NaOH pretreatment. Meanwhile, significant lignin and hemicellulose removal were observed. Manganese peroxidase activity was highest on Day 3 with the value 181.0256 U/L and lignin peroxidase activity was highest on Day 5 with the value 37.473 U/L, respectively. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses showed significant chemical structural changes after the combined pretreatment. Therefore, strain RS-1 provided an efficient strategy to enhance the enzymatic hydrolysis efficiency by pretreatment of corn stover.

Improving enzymatic saccharification of corn stover via thioglycolic acid-mediated Fenton pretreatment

Fenton pretreatment is known as a green and mild approach, but it is usually time-consuming and inefficient in promoting lignocellulose enzymatic hydrolysis. Here we demonstrate that thioglycolic acid (TA) significantly accelerates Fenton pretreatment (FP) of corn stover (CS) and improves enzymatic hydrolysis of cellulose and xylan. The results showed that the reducing sugar yield of CS reached 77.0% with TA-assisted FP in only 16 h, while it was only 34.1% and 38.0% with FP alone in 16 h and 72 h, respectively. Via examination of the changes of composition, physical and chemical characteristics of CS before and after pretreatment, it was found that TA-assisted FP greatly improved the removal of hemicellulose and lignin, resulting in increment of the pore volume, pore size and cellulose exposure of CS substrate, which together promoted the enzymatic saccharification of CS.

Statistical optimization of aqueous ammonia pretreatment and enzymatic saccharification of corn stover for enhancing sugars production

Response surface methodology (RSM) was adopted to optimize aqueous ammonia pretreatment and enzymatic saccharification of corn stover for enhancing sugars production, respectively. Pretreatment variables including pretreatment temperature, aqueous ammonia concentration and pretreatment time and saccharification variables including reaction time, enzyme loading and biomass loading were successfully found to have significant effects on sugars yields. Results indicated that corn stover powder (CSP, particle size < 0.3 mm) pretreated using 13.2 wt % aqueous ammonia solution at 70.0 °C for 7.9 h along with 20.0% ( w/v ) of solid loading was suitable to be applied to saccharification. The optimized pretreatment conditions could result in 98.3% of cellulose recovery, 86.5% of hemicellulose recovery and 60.7% of lignin removal, respectively. After optimization of enzymatic saccharification, maximum yields of reducing sugar (728.33 mg/gds) and xylose (290.43 mg/gds) along with 93.8% of holocellulose conversion and 80.6% of hemicellulose conversion could be obtained while the pretreated CSP was saccharified at 50.0 °C, pH 4.8 for 37.6 h by adopting 12.3 FPU/gds of enzyme loading, 7.6% ( w/v ) of biomass loading and 0.5% ( w/v ) of Tween-80, respectively. This is the first report about systematic optimization of aqueous ammonia pretreatment and enzymatic saccharification of CSP using self production cellulases for enhancing sugars yields in one study. • Aqueous ammonia pretreatment of corn stover was statistically optimized. • Enzymatic saccharification of aqueous ammonia pretreated corn stover was optimized. • Cellulose recovery (98.3%) and hemicellulose recovery (86.5%) were obtained. • Conversions of holocellulose (93.8%) and hemicellulose (80.6%) were obtained.

Enhancement of saccharification of corn stover by cellulolytic enzyme produced from biomass-degrading bacteria

Enzymatic saccharification of corn stover can be enhanced by partially replacing commercial enzymes with bacterial crude enzyme extracts. Thus, in this study, three bacteria (Bacillus sp. A0, Bacillus sp. CH20S1, and Exiguobacterium sp. AS2B) were cultured in a media with corn stover as the substrate to produce crude enzyme extract and saccharify corn stover. The cultural conditions were monitored and optimized to maximize CMCase and xylanase activity in the crude enzyme extracts. After 72 h of hydrolysis of corn stover with diluted crude enzymes (DCE) from the three strains, reducing sugars ranging from 48.2 to 71.7 mg g-1 were released from non-pretreated and pretreated corn stover. Furthermore, the maximum reducing sugars of 316 and 321 mg g-1 were observed when 12 and 4 FPU g-1 of commercial cellulase were added to the DCE of the CH20S1 strain, respectively. It was shown that an effective combination of bacterial DCE with commercial enzymes could achieve higher saccharification of lignocellulosic biomass, which might be cost-efficient compared to their single-use. Overall, this study aims to show the enhanced enzymatic saccharification of corn stover.

Pretreatment Affects Profits From Xylanase During Enzymatic Saccharification of Corn Stover Through Changing the Interaction Between Lignin and Xylanase Protein.

Effective pretreatment is vital to improve the biomass conversion efficiency, which often requires the addition of xylanase as an accessory enzyme to enhance enzymatic saccharification of corn stover. In this study, we investigated the effect of two sophisticated pretreatment methods including ammonium sulfite (AS) and steam explosion (SE) on the xylanase profits involved in enzymatic hydrolysis of corn stover. We further explored the interactions between lignin and xylanase Xyn10A protein. Our results showed that the conversion rates of glucan and xylan in corn stover by AS pretreatment were higher by Xyn10A supplementation than that by SE pretreatment. Compared with the lignin from SE pretreated corn stover, the lignin from AS pretreated corn stover had a lower Xyn10A initial adsorption velocity (13.56 vs. 10.89 mg g−1 min−1) and adsorption capacity (49.46 vs. 27.42 mg g−1 of lignin) and weakened binding strength (310.6 vs. 215.9 L g−1). Our study demonstrated the low absolute zeta potential and strong hydrophilicity of the lignin may partly account for relative weak interaction between xylanase protein and lignin from AS pretreated corn stover. In conclusion, our results suggested that AS pretreatment weakened the inhibition of lignin to enzyme, promoted the enzymatic hydrolysis of corn stover, and decreased the cost of enzyme in bioconversion.

Pretreatment of Corn Stover Using an Extremely Low-Liquid Ammonia (ELLA) Method for the Effective Utilization of Sugars in Simultaneous Saccharification and Fermentation (SSF) of Ethanol

Extremely low-liquid ammonia (ELLA) pretreatment using aqueous ammonia was investigated in order to enhance the enzymatic saccharification of corn stover and subsequent ethanol production. In this study, corn stover was treated with an aqueous ammonia solution at different ammonia loading rates (0.1, 0.2, and 0.3 g NH3/g biomass) and various liquid-to-solid (L/S) ratios (0.55, 1.12, and 2.5). The ELLA pretreatment was conducted at elevated temperatures (90–150 °C) for an extended period (24–120 h). Thereafter, the pretreated material was saccharified by enzyme digestion and subjected to simultaneous saccharification and fermentation (SSF) tests. The effects of key parameters on both glucan digestibility and xylan digestibility were analyzed using analysis of variance (ANOVA). Under optimal pretreatment conditions (L/S = 2.5, 0.1 g-NH3/g-biomass, 150 °C), 81.2% glucan digestibility and 61.1% xylan digestibility were achieved. The highest ethanol yield achieved on the SSF tests was 85.4%. The ethanol concentration was 14.5 g/L at 96 h (pretreatment conditions: liquid-to-solid ratio (L/S) = 2.5, 0.1 g-NH3/g-biomass, 150 °C, 24 h. SSF conditions: microorganism Saccharomyces cerevisiae (D5A), 15 FPU/g-glucan, CTech2, 3% w/v glucan, 37 °C, 150 rpm).

Effect of crystallinity on pretreatment and enzymatic hydrolysis of lignocellulosic biomass based on multivariate analysis

In this work, multivariate data analysis was employed to correlate variables of pretreatment process of lignocellulosic biomass. Principal component analysis and partial least square methods were performed to get the inner-relationship and data interpretation between the crystallinity and other parameters of mechanical refining-assisted sodium hydroxide pretreatment followed by enzymatic saccharification of corn stover. The PCA and PLS models showed that Sodium hydroxide dosage, mechanical refining treatment, lignin removal rate and crystallinity had close inner-related relationship with the efficiency of pretreatment and enzymolysis. Alkaline reaction and mechanical refining treatment had strong influence on the crystallinity. Multivariate data analysis revealed that pretreated corn stover samples with lower crystallinity were more easily hydrolyzed by enzyme and could get more final reducing sugar. This work could offer a new methodology to get further understanding of effect of crystallinity on the crop residue lignocellulosic biomass conversion process.

Pretreatment of Corn Stover Using Organosolv with Hydrogen Peroxide for Effective Enzymatic Saccharification

In this study, the chemical pretreatment method using ethanol organosolv with hydrogen peroxide was investigated to improve enzymatic saccharification of corn stover. The pretreatment method using ethanol with hydrogen peroxide in a flow-through reaction was proposed to lower the reaction severity such as the pretreatment temperature. With the same reaction time, the pretreatment process using organosolv (30 wt.% ethanol) containing 1 wt.% hydrogen peroxide at 150 °C resulted in a similar conversion yield as the result of the alkali pretreatment method using 15 wt.% aqueous ammonia at 170 °C. When corn stover was pretreated with 30 wt.% ethanol solution containing 5 wt.% hydrogen peroxide, a glucose conversion yield of 69.7 wt.% and glucose production of 23.8 g were achieved.

Effective Saccharification of Corn Stover Using Low-Liquid Aqueous Ammonia Pretreatment and Enzymatic Hydrolysis.

Low-liquid aqueous ammonia (LLAA) pretreatment using aqueous ammonia was investigated to enhance enzymatic saccharification of corn stover. In this method, ground corn stover was simply contacted with aqueous ammonia mist (ammoniation step), followed by pretreatment at elevated temperature (90–150 °C) for an extended period (24–120 h) at different solid/liquid (S/L) ratios (0.29, 0.47 or 0.67), termed a pretreatment step. After that, excess (unreacted) ammonia was removed by evaporation, and the pretreated material was immediately saccharified by an enzyme without a washing step. The effects of key reaction parameters on both glucan digestibility and XMG digestibility were evaluated by analysis of variance (ANOVA). Under the best pretreatment conditions [S/L = 0.47, 0.16 (g NH3)/(g biomass), 90 °C, 24 h], LLAA pretreatment enhanced enzymatic digestibility from 23.1% for glucan and 11.3% for XMG (xylan + galactan + mannan) of untreated corn stover to 91.8% for glucan and 72.6% for XMG in pretreated solid.

Evaluation of Screened Lignin-degrading Fungi for the Biological Pretreatment of Corn Stover

The biological pretreatment of lignocellulosic biomass is a low-cost and eco-friendly method for facilitating enzymatic hydrolysis. In this study, strains with lignin depletion capability were screened using a high-throughput screening method. Sixty-three strains were screened out and Myrothecium verrucaria secreted three lignin-degrading enzymes simultaneously during the bio-pretreatment process. The activity levels of laccase, lignin peroxidase and manganese peroxidase were 6.61, 0.78 and 1.31 U g−1 dry biomass. The content of lignin in corn stover decreased by 42.30% after bio-pretreatment, and the conversion rate increased by 123.84% during the subsequent saccharification process in comparison with the untreated corn stover. Furthermore, the effects of bio-pretreatment on the structure of corn stover were presented using a scanning electron microscope (SEM), Brunauer-Emmet-Teller (BET), X-ray diffractometer (XRD) and Fourier transform infrared spectroscopy (FTIR). The results showed that M.V. is a promising lignin-degrading fungus. This research demonstrated an efficient pretreatment approach for enhancing the enzymatic saccharification of corn stover.

Enhanced enzymatic saccharification of corn stover by in situ modification of lignin with poly (ethylene glycol) ether during low temperature alkali pretreatment

A novel pretreatment process of corn stover was established in this study by in situ modification of lignin with poly (ethylene glycol) diglycidyl ether (PEGDE) during low temperature alkali pretreatment. The addition of PEGDE obviously improved the enzymatic hydrolysis by covalently modifying the residual lignins in substrates. Under the optimized conditions (pretreated with 10% (w/w) NaOH and 10% (w/w) PEGDE at 70°C for 2.5h), the total fermentable sugar yield was increased by 46.4%, from 23.7g to 34.7g per 100g raw materials. Additionally, the remaining activities of exo-glucanase and β-glucosidase in supernatant were increased by 58.6% and 40.6% respectively, demonstrating that the enhancement of enzymatic hydrolysis was mainly due to the alleviation of enzyme non-productive binding. Although the isolated lignin modified with PEGDE enhanced the enzymatic hydrolysis of substrates as well, this in situ lignin modification provided an efficient but simple way to improve enzymatic saccharification.

Ameliorated enzymatic saccharification of corn stover with a novel modified alkali pretreatment

Enzymatic saccharification/hydrolysis is one of the key steps for the bioconversion of lignocelluloses into sustainable biofuels. In this work, corn stover was pretreated with a novel modified alkali process (NaOH + anthraquinone (AQ) + sodium lignosulfonate (SLS)), and then enzymatically hydrolyzed with an enzyme cocktail (cellulase (Celluclast 1.5L), β-glucosidase (Novozyme 188) and xylanase (from thermomyceslanuginosus)) in the pH range of 4.0-6.5. It was found that the suitable pH for the enzymatic saccharification process to achieve a high glucan yield was between 4.2 and 5.7, while the appropriate pH to obtain a high xylan yield was in the range of 4.0-4.7. The best pH for the enzymatic saccharification process was found to be 4.4 in terms of the final total sugar yield, as xylanase worked most efficiently in the pH range of 4.0-4.7, under the conditions in the study. The addition of xylanase in the enzymatic saccharification process could hydrolyze xylan in the substrates and reduce the nonspecific binding of cellulase, thus improving the total sugar yields.

Hydrogen Peroxide-Assisted Sodium Carbonate Pretreatment for the Enhancement of Enzymatic Saccharification of Corn Stover

In this work, the effectiveness of hydrogen peroxide-assisted sodium carbonate (HSC) pretreatment of corn stover to produce fermentable sugars was investigated. It was found that the addition of H2O2 (a green oxidative agent) in Na2CO3 pretreatment could enhance the lignin removal and increase the hydrophilicity of the residual lignin, leading to the improved enzymatic digestibility and the yield of fermentable sugars. Also, results showed that lignin removal (in the range of 12-65%) was positively and linearly correlated with final total sugar yields. Post PFI refining could further improve the enzyme accessibility by increasing porosity of substrates. After HSC pretreatment (40 wt % Na2CO3 and 15 wt % H2O2 120 degrees C for 60 min) and enzymatic hydrolysis, the final total sugar yield could achieve 79%, which was about 10% higher in comparison with the conventional Na2CO3 pretreatment under the same conditions. HSC pretreatment will have less environmental impact and less barriers for large scale production.

Understanding the Physicochemical Characteristics and the Improved Enzymatic Saccharification of Corn Stover Pretreated with Aqueous and Gaseous Ammonia

AbstractPhysicochemical characteristics of corn stover pretreated by soaking in aqueous ammonia (SAA) and low-moisture anhydrous ammonia (LMAA) were compared and investigated. The glucan digestibility of the treated biomass reached 90 % (SAA) and 84 % (LMAA). The LMAA pretreatment enhanced the digestibility by cleaving cross-linkages between cell wall components, whereas the SAA pretreatment additionally improved the digestibility by efficiently removing a major portion of the lignin under mild reaction conditions without significant loss of carbohydrates. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) revealed the structural and chemical transformations of lignin during the pretreatments. Both pretreatments effectively cleaved ferulate cell wall cross-linking that is associated with the recalcitrance of grass lignocellulosics toward enzymatic saccharification. Extracted lignin from SAA pretreatment was extensively depolymerized but retained “native” character, as evidenced by the retention of β-ether linkages.

Effect and characterization of sodium lignosulfonate on alkali pretreatment for enhancing enzymatic saccharification of corn stover

A modified alkali pretreatment (MAP) process was established in both lab-scale and pilot-scale, based on the on-line production and utilization of lignosulfonate for improving enzymatic saccharification of corn stover. Sodium lignosulfonate (SLS) produced by directly sulfonating lignin in spent liquor separated from alkali pretreatment was reused in the next cycle of alkali pretreatment. The results showed that, by using 11wt% NaOH, 2wt% SLS and 0.1wt% anthraquinone (AQ) in MAP, delignification rate and final total sugar yields could reach about 78% and 80% respectively, which were about 6% and 9% higher compared to the blank conventional NaOH pretreatment under the same conditions. In addition, sulfonation degree of SLS had linearly impact on the final total sugar yields.

Enhancement of enzymatic saccharification of corn stover with sequential Fenton pretreatment and dilute NaOH extraction

In this study, an effective method by the sequential Fenton pretreatment and dilute NaOH extraction (FT-AE) was chosen for pretreating corn stover. Before dilute NaOH (0.75wt%) extraction at 90°C for 1h, Fenton reagent (0.95g/L of FeSO4 and 29.8g/L of H2O2) was employed to pretreat CS at a solid/liquid ratio of 1/20 (w/w) at 35°C for 30min. The changes in the cellulose structural characteristics (porosity, morphology, and crystallinity) of the pretreated solid residue were correlated with the enhancement of enzymatic saccharification. After being enzymatically hydrolyzed for 72h, the reducing sugars and glucose from the hydrolysis of 60g/L FT-AE-CS pretreated could be obtained at 40.96 and 23.61g/L, respectively. Finally, the recovered hydrolyzates containing glucose had no inhibitory effects on the ethanol fermenting microorganism. In conclusion, the sequential Fenton pretreatment and dilute NaOH extraction has high potential application in future.

Effects of compositional changes of AFEX-treated and H-AFEX-treated corn stover on enzymatic digestibility

Corn stover is one of the main agricultural residues being considered as a cellulosic ethanol feedstock. This work evaluated the effectiveness of AFEX™(1) pretreatment for converting corn stover to fermentable sugars, both with and without pre-soaking in hydrogen peroxide. The compositional changes and enzymatic digestibility of AFEX-treated and H-AFEX-treated biomass were investigated. Results showed that most of the polysaccharides remained intact following each of these two methods. Compared with AFEX pretreatment, the H-AFEX process enhanced delignification and enzymatic hydrolysis yields of both glucose and xylose. The maximum glucan and xylan digestibility of H-AFEX process were 87.78% and 90.64%, respectively, and were obtained using 0.7 (w/w) water loading, 1.0 (w/w) ammonia loading, 0.5 (w/w) 30wt.% hydrogen peroxide loading, and 130°C for 10min. The results of the present work show that H-AFEX is a feasible pretreatment to improve the enzymatic saccharification of corn stover for bioethanol production.

Hydrothermal pretreatment and enzymatic saccharification of corn stover for efficient ethanol production

Corn stover used in this study contained 37.0±0.4% cellulose, 31.3±0.6% hemicellulose and 17.8±0.2% lignin on dry basis. Hydrothermal pretreatment and enzymatic saccharification were evaluated for conversion of corn stover cellulose and hemicellulose to fermentable sugars. Under the optimum conditions of hydrothermal pretreatment of corn stover (10%, w/v; 200°C; 5min) and enzymatic saccharification (45°C, pH 5.0, 72h), a total of 550±5mg of fermentable sugars was obtained per g corn stover which is equivalent to 72% of theoretical sugar yield. The corn stover hydrolyzate was fermented without any detoxification by recombinant Escherichia coli strain FBR 5 at pH 6.5 and 37°C for 74h to produce 20.9±0.5g ethanol from 42.8±1.7g sugars per L with a yield of 0.49g ethanol per g available sugars and 0.27g ethanol per g corn stover which is equivalent to 68.7% of theoretical ethanol yield from corn stover. This is the first report on the production of ethanol from hydrothermally pretreated corn stover by the recombinant bacterium.

Green liquor pretreatment for improving enzymatic hydrolysis of corn stover

Green liquor consists of sodium carbonate and sodium sulfide and is readily available in any kraft mills. The green liquor pretreatment process for bioethanol production was developed for wood chips. This process uses only proven technology and equipment currently used in a kraft pulp mill and has several additional advantages such as high sugar recovery and concentration, no inhibitive substances produced, as compared to acid-based pretreatment methods. The liquor was used to pretreat corn stover for enhancing enzymatic hydrolysis in bioethanol production. Pulp yield of 70% with 45% lignin removal was achieved under optimized conditions (8% total titratable alkali, 40% sulfidity and 140°C). About 70% of the original polysaccharides were converted into fermentable sugars, using 20 FPU/g-pulp of enzyme in the subsequent enzymatic hydrolysis. The result indicates that green liquor is a feasible pretreatment to improve the enzymatic saccharification of corn stover for bioethanol production.

Fermentative Production of Value-Added Products from Lignocellulosic Biomass

Bioconversion of lignocellulosic biomass (agro residues, grasses, wood, weed, dedicated energy crops and others) into biofuels and other value-added products offers numerous geopolitical, environmental, and strategic benefits. Lignocellulosic biomass (LB) is the most abundant renewable organic resources (~200 billion tons annually) on earth that are readily available for conversion to biofuels and other value-added products (industrial enzymes, organic acids, pharmaceuticals, commodity chemicals, and food/feed). However, they have not yet been tapped for the commercial production of these products. The last three decades witnessed the success made in research and development for the conversion of LB into biofuels and other commercially viable products. Despite the success achieved in the laboratory, there are several challenges for the successful bioconversion of lignocellulosic substrates into value-added products at commercial scale. The future of lignocellulosics conversion is expected to lie in improvement in pretreatment technologies, cellulolytic enzymes producing microorganisms, fullest exploitation of biomass components, and process integration. Further, advancement in system-biology-based “OMICS” approaches may provide new breakthroughs for the development of biocatalysts/enzyme titers for the cost effective production of commodity chemicals and fuels from biomass. This special issue presents a diverse range of experimental advancements on biomass pretreatment, enzymatic saccharification, production of cellulosic biofuels, polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), and lovastatin and blends of polyacrylonitrile (PAN) and lignin. Authors here report on process variables including feedstock types (grasses and sugarcane-based agro residues), bioprocess engineering simulations, multivisual structural analysis of lignocellulosics after pretreatment, improvements in cellulase-mediated hydrolysis, and modification in fermentation strategies for the production of a range of value-added products. Selection of suitable lignocellulosic substrates plays a key role for the economic cellulosic ethanol production. Factors such as availability of feedstock and presence of high amount of carbohydrates and lignin amounts are critical for biofuels production at large scale under the biorefinery concept. Of particular interest in this regard is the use of sugarcane residues, corn stover, and grasses as a second-generation feedstock. L. Canilha et al. comprehensively reviewed the technologies (pretreatment methods, detoxification, hydrolysis, fermentation, and end-product distillation) for second-generation (2G) ethanol production from sugarcane residues (sugarcane bagasse and straw). Grasses are another excellent feedstock for 2G ethanol production in countries like Thailand. J. Wongwatanapaiboon et al. collected data on composition of cellulose, hemicellulose, and lignin in 18 types of grasses followed by the alkaline peroxide mediated pretreatment. The pretreated materials were evaluated for ethanol production under simultaneous saccharification and fermentation approach employing yeasts cocultures. J. Lu et al. explored the Reed as a primary source for 2G ethanol production. They presented the data on sugar recovery after liquid hot water pretreatment followed by enzymatic hydrolysis and conversion of sugars into ethanol under separate hydrolysis and fermentation. J. E. Jessen and J. Orlygsson examined the 2G ethanol production from various feedstocks (hemp stem, grass, wheat straw, newspaper, and cellulose) employing a new thermophilic isolate, Thermoanaerobacter J1, from a hot spring in Iceland in addition to the exploration of a mechanism of electron-scavenging systems on end-product formation. For the economization of biofuel or any value-added product formation from lignocellulosic materials, the efficient bioconversion of cellulose and hemicellulose into monomeric sugars is inevitable. In this line, A. D. Eckard et al. demonstrated the mechanism of casein (skimmed milk protein) action to improve the enzymatic saccharification of corn stover. Pretreatment is the key technology for the direct methanation of agroresidues. Y. Feng et al. investigated the changes in the maize straw characteristics during the methanation process. M. A. K. M. Zahari et al. optimized major influential parameters for poly(3-hydroxybutyrate) production from oil palm frond (OPF) juice by Cupriavidus necator CCUG52238T and concluded that OPF juice could be a competitive carbon source for the economic production of PHB. P. Chakraborty et al. presented the data on modified feeding strategies using a mixture of volatile fatty acids and artificial rumen fluid to maximize the PHA production by Ralstonia eutropha. Towards the pharmaceuticals intermediate production, M. F. Jahromi et al. investigated the lovastatin production by Aspergillus terreus under solid-state fermentation using rice straw and oil palm frond. M. O. Seydibeyoglu examined the properties of blends of polyacrylonitrile (PAN) and lignin followed by the structural analysis employing modern structural tools. We sincerely hope readers will find these papers helpful to their research pursuits. It has been our pleasure to put together this special issue in Journal of Biomedicine and Biotechnology.