Bioethanol production from Parthenium hysterophorus involving cellulase from Bacillus amyloliquefaciens SS35: Process development, optimization and intensification” is the result of research conducted by me at the Center for Energy, Indian Institute of Technology Guwahati, Guwahati, India under the guidance of Prof. Bioethanol production from Parthenium hysterophorus involving cellulase from Bacillus amyloliquefaciens SS35: Process development, optimization and intensification” by Mrs. 09615103) for the award of the degree of Doctor of Philosophy is an authentic record of the results obtained from the research work carried out under our supervision at the Center for Energy, Indian Institute of Technology Guwahati, India and this work has not been submitted elsewhere for a degree.
I would like to take this opportunity to express my sincere gratitude to my mentors Prof. I would like to acknowledge the support received from past and present Energy Center staff, Dr. I am grateful to the Center for Energy, Department of Biosciences and Bioengineering, Department of Chemical Engineering and Central Instrument Facility (CIF) for providing facilities to carry out my research work.
I am also grateful to the Indian Institute of Technology Guwahati for providing me with state-of-the-art infrastructure for advanced level of research. Pradeep Verma for their immense care, encouragement and moral support in reaching this level and they always stand by me at all stages of my life.
Chapter 6. Screening, optimization of pretreatment and ultrasound
Effect of NaOH concentration on delinification Effect of biomass concentration on delinification Temperature effect on delinification Ultrasound-assisted alkali treatment of biomass 230 6.2.7 Mathematical model for cavitation bubble dynamics 231 6.2.8 Quantification of physical and chemical effects of ultrasound.
Chapter 7. Ultrasound induced enhancement of ethanol production from Parthenium hysterophorus: separate hydrolysis and
327 7.3.3 Comparative assessment of enzymatic hydrolysis 331 7.3.4 Ethanol fermentation and its simulation Intensification of fermentation with sonication Results of a mathematical model of fermentations.
Chapter 8. Ultrasound induced enhancement of ethanol production
5 Table 1.3 Ethanol used as fuel and other industrial chemicals. million litres) in India (taken from GAIN report 2014). 331 Table 7.3.6 Experimental data for the profiles of ethanol, sugar and. cell mass in control experiments. 332 Table 7.3.7 Experimental data for the profiles of ethanol, sugar and. cell mass in test experiments.
335 Table 7.3.10 Kinetic and physiological parameters in fermentation. model fitted to experimental data with GA optimization. 366 Table 8.3.2 Experimental data for the profiles of ethanol, glucose and. cell mass in test experiments.
Figure 6.3.1
- Prologue
- Aim and scope of present thesis
- Introduction
- Cellulose hydrolysing enzymes (cellulases)
- Cellulase from microbial sources
- Cellulase producing bacteria in nature: isolation, screening and identification strategies
- Optimization of cellulase production
- Purification, characterization and application of cellulase .1 Methods of purification
- Feedstock for bioethanol
- Parthenium hysterophorus (carrot grass)
- Pretreatment of lignocellulosic biomass
- Physical pretreatment
- Chemical pretreatment
- Physicochemical pretreatment
- Biological pretreatment
- Enzymatic hydrolysis of pretreated lignocellulosic biomass
- Fermentation of enzymatic hydrolysate to ethanol
- Intensification of bioprocesses by ultrasound
- Ultrasound
- Objectives of the present study
- Introduction
- Materials and Methods .1 Substrate and chemicals
- Sample collection
- Isolation of cellulolytic bacteria
- Qualitative screening of cellulolytic bacteria by plate staining method Morphologically dissimilar and discrete colonies were picked from different
- Quantitative determination of extracellular carboxymethylcellulase (CMCase) production
- CMCase activity assay
- Reagents for enzyme activity assay
- Calculation of CMCase activity
- Antibiotic sensitivity pattern of isolate SS35
- Identification of isolate SS35 on the basis of 16S ribosomal RNA (rRNA) and partial Gyrase A (gyrA) gene sequence analyses
- Results and Discussion
- Isolation and screening of cellulolytic bacteria by plate staining method After 96 h of incubation colonies were observed on BHM-agar plates (Fig
- Morphological and biochemical characterization of the isolate SS35
- Antibiotic sensitivity pattern of isolate SS35
- Identification of isolate SS35 on the basis of phylogenetic analyses
- Conclusions
- Introduction
- Materials and Methods .1 Materials
- Microorganism and culture conditions
- Medium optimization for enhancing enzyme activity
- Fermentation parameters optimization
- CMCase assay
- Experimental designs for medium optimization .1 Plackett-Burman design
- Experimental design for optimization of fermentation parameters .1 Central composite design
- Results and Discussion
- Optimization of fermentation medium
- Optimization of fermentation parameters
- Overall analysis of optimization of CMCase production
- Comparative assessment of results with published literature
- Conclusions
The main components of enzymatic hydrolysis of lignocellulosic biomass are cellulase and pretreated (cellulose-rich) biomass. In this chapter, an attempt has been made to present an overview of research activities in the field of bioethanol production from lignocellulosic biomass. Enzymes are also used to improve skin degradation, color extraction, clarification, and improve wine quality and stability (Caldini et al. 1994).
Cellulases in the textile industry are used in biopolishing, which involves destacking, aging, abrading and bleaching of the fabric (Sreenath et al. 1996). In this process, cellulases dissolve the small fiber ends on the tissue surface, releasing the dye with less damage to the fibers (Galante et al. 1998). The components of biomass are linked together by hydrogen bonds and glycosidic bonds and therefore the separation of these components requires chemical treatment. The enzymatic hydrolysis of lignocellulose can be limited by several factors, such as cellulose crystallinity (Chang and Holtapple 2000), degree of polymerization (DP), moisture content, available surface area, and lignin content (Koullas et al. 1992).
Thompson and Chen (1992) found that the relative pore size of substrate and enzyme is the major limiting factor in enzymatic hydrolysis of lignocellulosic biomass. This accumulation may enable proton transfer or promote radical scavenging in the interfacial region of the bubble (or in the thin liquid film in contact with the bubble surface). According to a report by Rodha et al. 2011) optimization of the enzymatic hydrolysis of alkaline pretreated sorghum straw increased the efficiency of the process by 70%.
Olsson and Hahn-Hagerdal (1996) performed SSCF of aspen by co-cultivating Pichia stipitis and Brettanomyces clausennii at 38oC. The use of recombinant microorganisms for the use of both pentose and hexose sugars is more currently preferred. The passage of ultrasound wave leads to periodic variation in the pressure as well as the density of the medium. This non-uniformity of pressure leads to the loss of spherical geometry of the bubble.
2013) Optimization of the enzymatic hydrolysis conditions of steam-exploded wheat straw for maximum glucose and xylose recovery. All morphological and biochemical properties of the isolate were compared with the characteristics of the bacteria described in Bergey's Manual of Systematic Bacteriology (Boone et al. 2001). Resistance to penicillin, ampicillin and cephalosporin may also result from the production of a broad spectrum of β-lactamase (Vos et al. 2011).
However, as the CMC concentration exceeds 16 g/L, the maximum enzyme activity is observed at a low yeast extract concentration of ~8 g/L. 2) The maximum enzyme activity is observed at a yeast extract concentration of 8 g/L and a peptone concentration range of 3-6 g/L. As the concentration of peptone and yeast extract increases beyond this range, enzyme activity decreases. These results can be explained on the basis of the amino acid composition of the enzyme CMCase (endoglucanase) given below. As reported in the literature (Immanuel et al. 2006), cellulase production depends on several parameters, such as temperature, initial pH of the medium, and inoculum size.
The conclusion of this study is also supported by the outcome of the study by Deka et al. 2013), where the overall optimization of the medium composition and fermentation parameters resulted in an eightfold improvement in the CMCase activity of Bacillus sp.
