Arindam Kuila

Accessibility of Enzymatically Delignified Bambusa bambos for Efficient Hydrolysis at Minimum Cellulase Loading: An Optimization Study

In the present investigation, Bambusa bambos was used for optimization of enzymatic pretreatment and saccharification. Maximum enzymatic delignification achieved was 84%, after 8 h of incubation time. Highest reducing sugar yield from enzyme-pretreated Bambusa bambos was 818.01 mg/g dry substrate after 8 h of incubation time at a low cellulase loading (endoglucanase, β-glucosidase, exoglucanase, and xylanase were 1.63 IU/mL, 1.28 IU/mL, 0.08 IU/mL, and 47.93 IU/mL, respectively). Enzyme-treated substrate of Bambusa bambos was characterized by analytical techniques such as Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The FTIR spectrum showed that the absorption peaks of several functional groups were decreased after enzymatic pretreatment. XRD analysis indicated that cellulose crystallinity of enzyme-treated samples was increased due to the removal of amorphous lignin and hemicelluloses. SEM image showed that surface structure of Bambusa bambos was distorted after enzymatic pretreatment.

Lipase production from a wild (LPF-5) and a mutant (HN1) strain of Aspergillus niger

In this study, a wild (LPF-5) and a mutant (HN1) strain of A. niger were compared for lipase production. Several physical parameters (carbon source, nitrogen source, pH, temperature and incubation period) were optimized for maximization of lipase production. Lipase activity between wild type and mutant strain were compared. Among all carbon sources, mixture of glucose (1%, w/v) and olive oil (1%, v/v) exhibited maximum increase in the production of lipases by both the wild (94.91 ± 0.60 U mL -1 min -1 ) and mutant (118.23 ± 0.73 U mL -1 min -1 ) strain. Addition of glucose into the production medium (containing olive oil) increased the production of lipase up to 20% in case of both the strains. The production of lipase by both the strains was higher in the medium of pH 7.0 containing peptone (1%, w/v) as nitrogen source after 3 days of incubation at 28°C. The activity of lipase from HN1 strain in optimized medium was 40% higher (147.65 ± 1.14 U mL -1 min -1 ) than in un-optimized medium (105.19 ± 0.91 U mL -1 min -1 ), while it was 38% higher for LPF-5 strain in optimized medium. Therefore the mutant strain (A. niger HN1) is prospective for the development of industrial biotechnology for production of extracellular lipase. Lipase enzyme was partially purified by ammonium sulfate precipitation and 70% precipitate showed highest specific activity of 66.12 U mg -1 for mutant strain as compared to specific activity of 29.88 U mg -1 in crude lysate. Keywords: Wild strain, mutant strain, Aspergillus niger , lipase activity, specific activity, ammonium sulfate

Simultaneous Saccharification and Fermentation of Corn Husk by Co-Culture Strategy

Lignocellulosic biofuel production mainly carried out by two ways: simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF). In the present study, simultaneous saccharification and fermentation (SSF) was carried out using microwave assisted thermochemically pretreated (0.5 M NaOH for 20 minutes at 120°C in preheated oven) corn husk. Using co-cultures of Saccharomyces cerevisiae and Fusarium oxysporum, SSF process was optimized. Maximum ethanol production (6.24%, v/v) was observed after 24 h of incubation. Further for enhanced ethanol production, effect of different surfactant was carried out on SSF using co-culture strategy. It was found that addition of Tween 60 enhanced the ethanol production upto 6.38% (v/v). Further for addition enhancement of ethanol production, different co-culture strategy was adopted. It was found that maximum ethanol production (6.58% v/v) was obtained when ethanol fermentation was carried out by Fusarium oxysporum followed by Saccharomyces cerevisiae.

Lignocellulosic Biomass Production and Industrial Applications

Lignocellulosic Biomass Production and Industrial Applications describes the utilization of lignocellulosic biomass for various applications. Although there have been numerous reports on lignocellulosic biomass for biofuel application, there have been very few other applications reported for lignocellulosic biomass-based chemicals and polymers. Therefore, this book covers all of the possible lignocellulosic biomass applications. Besides describing the different types of biofuel production, such as bioethanol, biobutanol, biodiesel and biogas from lignocellulosic biomass, it also presents various other lignocellulosic biomass biorefinery applications for the production of chemicals, polymers, paper and bioplastics. In addition, there are chapters on valorization of lignocellulosic materials, alkali treatment to improve the physical, mechanical and chemical properties of lignocellulosic natural fibers, and a discussion of the major benefits, limitations and future prospects of the use of lignocellulosic biomass.

Cellulase production from thermochemically pretreated Chenopodium album

Lignocelllulosic biofuel production is the area of focus of different researchers. Cellulase mediated saccharification of delignified biomass is the rate limiting stage in biofuel generation. For enzymatic hydrolysis cellulase is key enzyme. There are several researches going on for cost effective cellulose production. In the current research, Chenopodium album was subjected to dilute sodium hydroxide treatment on 120°C. Efficiency of pretreatment was evaluated through scanning electron microscopy (SEM), X-ray diffraction (XRD) and biochemical composition analysis. After pretreatment, pretreated biomass was rinsed with tap water and was subsequently kept at 70°C for complete water removal. The biomass after complete water removal was applied for cellulase production using Fusarium oxysporum. Cellulase production was maximised using statistical technique. Within two days, highest cellulase production of 1.51 IU/mL was attained. The above study can be useful for efficient cellulase production for cost effective biofuel production.