• Applied Chemistry for Engineering
• /
• v.33 no.4
• /
• pp.335-342
• /
• 2022

In the agricultural sector where the fossil fuels are primary energy resources, the current global energy crisis together with the dissemination of smart farming has led to the new phase of energy pattern in which the electricity demand is growing faster particularly. Therefore, the fuel cell combined heat and power system, coupling the environmentally friendly fuel cell to biomass treatment and feeding, can be regarded as the most effective energy system in agriculture. In this mini-review, we discuss the R&D trend of the fuel cell combined heat and power system aimed at utilizing agricultural by-products as fuels and highlight the issues in terms of the process configuration and interconnection of individual processes.

• KSBB Journal
• /
• v.11 no.4
• /
• pp.476-480
• /
• 1996

Using Pseudomonas sp. B3, identified and isolated from nature, wastewater containing phenol was treated in a continuous stirred tank reactor and its reaction characteristics were studied. Average concentrations of phenol and COD in effluents were 1.5mg/L and 124mg/L at 0.059h-1 dilution rate, respectively. At the dilution rate higher than 0.063h-1, phenol and COD increased abruptly to 19mg/L and 318mg/L. At the dilution rate higher than 0.059h-1, biomass concentration suddenly decreased and was "washed out". Biomass concentration was 150mg/L at a dilution rate of 0.067h-1. Maximum biomass production rate was 15.98mg/L$.$h at a dilution rate of 0.067h-1. When dilution rate increased above 0.059h-1, effluent phenol concentration abruptly increased and biomass production rate decreased. Maximum cell growth rate(${\mu}$max) and Michaelis-Mentens kinetic constant(Ks) were 0.074h-1 and 0.424mg/L, respectively. From the above result low phenol concentration can be expected at a maximum dilution rate, but reactor becomes unstable due to phenol inhibition.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.3
• /
• pp.263-269
• /
• 1992

Radish green juice was used as a dual source for the production of plant protein precipitate and Candida utilis biomass. Precipitates ranging from 10.0 to 16.5g were obtained from a liter of radish green juice by heating at 80-10$0^{\circ}C$C for 1 to 10 min or by modification of the pH of radish green juice. Crude protein content of the precipitate was between 25 and 38%. The residue remaining after protein precipitation was used in turn for the cultivation of the yeast, C. utilis, in order to produce yeast biomass. C. utilis grew well in radish green residual juice and completed growth within 24 hr at 3$0^{\circ}C$ and 200rpm in shake flask experiments. Maximum dry cell weight obtainable from a liter of radish green residual juice was 19.5g, when the yeast was grown on the juice residue diluted 3 times or more with water to make sugar content be equal to or less than about 1.0%. Supplementation of 3-fold diluted radish green residual juice with yeast extract and (NH$_4$)SO$_4$ enhanced yeast biomass production and cell protein content significantly. Total high protein material obtainable from a liter of radish green juice was 33.0g.

• KSBB Journal
• /
• v.22 no.4
• /
• pp.197-200
• /
• 2007

This study examined the conditions of filtration and concentration of methanol extract from biomass. Filtration efficiency was improved by adding diatomaceous earth as a filter aid. The optimal amount of diatomaceous earth was 6% (w/w) to reduce the filtration time. The filtration time was reduced by 4.2% in first extraction, 30.0% in second extraction, 22.8% in third extraction, and 19.0% in fourth extraction, respectively. The optimal temperature of water bath was below 50$^{\circ}C$ for preventing paclitaxel degradation during concentration of methanol extract using a rotary evaporator. The temperature of concentrated solution in rotary evaporator was relatively low compared to bath temperature because of latent heat of evaporation. The stopping point of concentration in rotary evaporator for the following step was at a specific gravity of 0.96 of the concentrated solution in terms of the purity and yield of paclitaxel. This information is very useful for mass extraction of biomass for the recovery of paclitaxel from plant cell culture.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2023.04a
• /
• pp.12-12
• /
• 2023

Plant biomass, or lignocellulose, is one of the most abundant natural resources on earth. Lignocellulosic biomass, such as agricultural and forestry residue, serves as a renewable feedstock for microbial cell factories due to its low price and abundant availability. However, the recalcitrance of lignocellulosic biomass requires a pretreatment process prior to microbial fermentation, from which fermentable sugars including xylose and glucose are generated along with various inhibitory compounds. The presence of furan derivatives, such as 5-hydroxymethyl-2-furaldehyde and 2-furaldehyde (furfural), hampers the microbial conversion of lignocellulosic biomass into value-added commodities. In this study, furfural tolerance was improved by investigating the detoxification mechanism in non-model yeast. The genes encoding aldehyde dehydrogenases were overexpressed to enhance furfural tolerance and resulted in improving cell growth and lipid production that can be converted into biofuel. Taken together, this approach contributes to the understanding of the reducing toxicity mechanism of furfural by the aldehyde dehydrogenases and provides a promising strategy that the use of microorganism as an industrial workhorse to treat efficiently lignocellulosic biomass as sustainable plant derivatives.

• Journal of Microbiology and Biotechnology
• /
• v.34 no.3
• /
• pp.700-709
• /
• 2024

Polyhydroxybutyrate (PHB) production from lignocellulosic biomass is economically beneficial. Because lignocellulosic biomass is a mixture rich in glucose and xylose, Escherichia coli, which prefers glucose, needs to overcome glucose repression for efficient biosugar use. To avoid glucose repression, here, we overexpressed a xylose regulator (xylR) in an E. coli strain expressing bktB, phaB, and phaC from Cupriavidus necator and evaluated the effect of xylR on PHB production. XylR overexpression increased xylose consumption from 0% to 46.53% and produced 4.45-fold more PHB than the control strain without xylR in a 1% sugar mixture of glucose and xylose (1:1). When the xylR-overexpressed strain was applied to sugars from lignocellulosic biomass, cell growth and PHB production of the strain showed a 4.7-fold increase from the control strain, yielding 2.58 ± 0.02 g/l PHB and 4.43 ± 0.28 g/l dry cell weight in a 1% hydrolysate mixture. XylR overexpression increased the expression of xylose operon genes by up to 1.7-fold. Moreover, the effect of xylR was substantially different in various E. coli strains. Overall, the results showed the effect of xylR overexpression on PHB production in a non-native PHB producer and the possible application of xylR for xylose utilization in E. coli.

• Journal of Plant Biotechnology
• /
• v.48 no.4
• /
• pp.278-288
• /
• 2021

The development of bioenergy through biomass has gained importance due to the increasing rates of fossil fuel depletion. Biomass is important to increase the productivity of bioethanol, and production of biomass with high biomass productivity, low lignin content, and high cellulose content is also important in this regard. Inorganic salts are important in the cultivation of biomass crops for the production of biomass with desirable characteristics. In this study, the roles of various inorganic salts in biomass and bioethanol production were investigated using an in vitro tobacco culture system. The inorganic salts evaluated in this study showed dramatic effects on tobacco plant growth. For example, H₂PO₄ substantially improved plant growth and the root/shoot (R/S) ratio. The chemical compositions of tobacco plants grown in media after removal of various inorganic salts also showed significant differences; for example, lignin content was high after Mg²⁺ removal treatment and low after K⁺ treatment and H₂PO₄ removal treatment. On the other hand, NO₃^- and H₂PO₄ treatments yielded the highest cellulose content, while enzymatic hydrolysis yielded the highest glucose concentration ratio 24 h after NH₄⁺ removal treatment. The ethanol productivity after H₂PO₄ removal treatment was 3.95% (w/v) 24 h after fermentation and 3.75% (w/v) after 36 h. These results can be used as the basis for producing high-quality biomass for future bioethanol production.

• Journal of Plant Biotechnology
• /
• v.5 no.3
• /
• pp.181-185
• /
• 2003

Callus and suspension cultures derived from leaf explants of Plumbago rosea were established on Murashige and Skoog's medium containing 1 mg/L IAA, 0.5 mg/L NAA and 0.3 mg/L BAP. Callus cultures were tested for their growth and accumulation of plumbagin, a naphthoquinone and was identified by $^1H$ NMR and electron ionization mass spectroscopy. While auxins (not 2,4-D) influenced growth and plumbagin accumulation, cytokinins did not influence them much. Increasing concentrations of IAA in presence of NAA and BAP increased plumbagin in suspensions only up to 1 mg/L. Growth of callus was optimum (8.3 g DCW/I) at a hormonal combination of 1.5 mg/L IAA, 0.5 mg/L NAA and 0.3 mg/L BAP, but high plumbagin accumulation (4.9 mg/g DCW) was recorded at 1.0 mg/L IAA plus 0.3 mg/L BAP. Since instability in growth and secondary metabolite accumulation was noticed, several cell lines/clumps of callus were screened for plumbagin accumulation by visual and analytical methods. Biomass and accumulation of plumbagin showed a negative correlation in several cell lines. But one cell line showed stability both in terms of biomass and plumbagin accumulation over a period of 6 months.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.6
• /
• pp.862-879
• /
• 2001

The walls of all higher plants are organized as a cellulosic, fibrillar phase embedded in a matrix phase composed of non-cellulosic polysaccharides, some proteins and, in most secondary walls, lignin. At the effective utilization of plant biomass, qualitative and quantitative analyses of plant cell walls are essential. Structural features of individual components are being clarified using newly developed equipments and techniques. However, "empirical" procedures to elucidate plant cell walls, which are not due to scientific definition of components, are still applied in some fields. These procedures may give misunderstanding for the effective utilization of plant biomass. In addition, interesting the investigation of wall organization is moving towards not only qualitatively characterisation, but also quantitation of the associations between wall components. These involve polysaccharide-polysaccharide and polysaccharide-lignin cross-links. Investigation of the associations is being done in order to understand the chemical structure, organization and biosynthesis of the cell wall and physiology of the plants. Procedures for qualitative and quantitative analyses based on the definition of cell wall components are reviewed focussing in nutritional elucidation of forage grasses by ruminant microorganisms.

• Journal of Plant Biotechnology
• /
• v.6 no.4
• /
• pp.265-268
• /
• 2004

Cell growth and ginseng saponin production by large-scale suspension (bioreactor) cultures of Panax ginseng were investigated under various inoculum sizes. Cell growth was low at an inoculum size of 40 g FW/L, and the maximum cell growth was obtained with increasing inoculum size up to 100 g FW/L. The cell density of 333 g FW/L and 12.7 g DW/L was obtained at inoculum size of 100 g FW/L after 30 days of cultivation. Maximum saponin production of $4.40\;\cal{mg/g}$ DW was achieved at 60 g FW/L of inoculum size. Thus, inoculum size 60 g FW/L was suitable for optimum biomass accumulation as well as saponin production during bioreactor cultivation of ginseng suspension cells.