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Gurav, Ranjit,Bhatia, Shashi Kant,Moon, Yu-Mi,Choi, Tae-Rim,Jung, Hye-Rim,Yang, Soo-Yeon,Song, Hun-Suk,Jeon, Jong-Min,Yoon, Jeong-Jun,Kim, Yun-Gon,Yang, Yung-Hun Elsevier 2019 JOURNAL OF CLEANER PRODUCTION Vol.209 No.-
<P><B>Abstract</B></P> <P>A novel marine bacterium <I>Arenibacter palladensis</I> YHY2 isolated from Eastern Sea, South Korea revealed hydrolysing ability of crab chitin in shake flask and microbial fuel cell (MFC) systems. Under shake flask cultivation, strain YHY2 demonstrated 71.44 ± 1.90 U/ml chitinase activity with the microbial cell optical density (OD) 0.699 ± 0.021. High performance liquid chromatography (HPLC) results showed N-acetylglucosamine (GlcNAc) as the major by-product of chitin degradation. Furthermore, <I>Ralstonia eutropha</I> H16 which has carbon utilization limited to GlcNAc and fructose was co-cultivated with YHY2 to consume GlcNAc and accumulate polyhydroxyalkanoates (PHA). However, on co-cultivating strain YHY2 with H16 surprisingly showed higher production of chitinase (97.89 ± 2.72 U/ml) and GlcNAc (80.31 mg GlcNAc/g chitin) corresponding to the microbial cell OD (1.065 ± 0.005) at 120 h. In addition, marine strain YHY2 demonstrated biofilm formation, hence co-cultivation of strain YHY2 and H16 under MFC system was performed to check the electricity production. Maximum electricity current output density was 15.15 μA/cm<SUP>2</SUP> at the initial stage and 10.72 μA/cm<SUP>2</SUP> at 204 h. GlcNAc (196.34 mg GlcNAc/g chitin) was produced along with other metabolites like butyrate, acetate, lactate, and propionate in MFC system. The microbial cell biomass from MFC was analysed for PHA content showed 1.020 g/l of 3-polyhydroxybutyrate (PHB) and 0.198 g/l of 3-polyhydroxyvalerate (PHV) as the main components of PHA. Moreover, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) were performed to reveal changes in chitin before and after degradation. Thus, the exploitation of recalcitrant chitin biomass for simultaneous production of GlcNAc, electricity, and PHA in one-pot MFC system was the productive asset for sustainable development.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Coastal soil harbours <I>Arenibacter palladensis</I> YHY2 capable of hydrolysing chitin. </LI> <LI> YHY2 produced electricity in MFC using chitin biomass as a sole source of carbon. </LI> <LI> Co-cultivation of YHY2 with GlcNAc utilizing <I>Ralstonia eutropha</I> H16 accumulated PHA. </LI> <LI> First report on one-pot bioconversion of chitin into electricity, GlcNAc and PHA. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
문유미,Ranjit Gurav,김준영,홍윤기,Shashi Kant Bhatia,장혜림,홍주원,최태림,양수연,박형연,주황수,양영헌 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.4
Itaconic acid is an important organic acid and a major component of various polymers. It is used in resins, superabsorbent polymers, and substitutes for petrochemicalbased monomers such as acrylic and methacrylic acids. Itaconic acid is primarily produced by the fungus Aspergillus terreus, which yields a high titer with albeit long fermentation period and by-products. In our previous study, Escherichia coli JY001 was reported to produce itaconic acid using citric acid in whole-cell reaction resulting in higher itaconic acid productivity with less by-products formation. The present study aimed to increase whole-cell enzyme stability and reusability, via immobilization of E. coli JY001 using barium-alginate beads. We optimized the cations, temperature, pH, alginate, BaCl2 concentration, cell density per bead, and CTAB content to improve transfer rate of substrates and products. Under the optimized conditions, immobilized whole cells were stable for four repeated cycles of itaconic acid production. The present results would strengthen the basis for a continuous itaconic acid production.
Bhatia, Shashi Kant,Gurav, Ranjit,Choi, Tae-Rim,Jung, Hye-Rim,Yang, Soo-Yeon,Moon, Yu-Mi,Song, Hun-Suk,Jeon, Jong-Min,Choi, Kwon-Young,Yang, Yung-Hun Elsevier 2019 Bioresource technology Vol.271 No.-
<P><B>Abstract</B></P> <P>Pretreatment of lignocellulosic biomass results in the formation of byproducts (furfural, hydroxymethylfurfural [HMF], vanillin, acetate etc.), which affect microbial growth and productivity. Furfural (0.02%), HMF (0.04%), and acetate (0.6%) showed positive effects on <I>Ralstonia eutropha</I> 5119 growth and polyhydroxyalkanoate (PHA) production, while vanillin exhibited negative effects. Response optimization and interaction studies between the variables glucose, ammonium chloride, furfural, HMF, and acetate using the response surface methodology resulted in maximum PHA production (2.1 g/L) at optimal variable values of 15.3 g/L, 0.43 g/L, 0.04 g/L, 0.05 g/L, and 2.34 g/L, respectively. Different lignocellulosic biomass hydrolysates (LBHs), including barley biomass hydrolysate (BBH), <I>Miscanthus</I> biomass hydrolysate (MBH), and pine biomass hydrolysate (PBH), were evaluated as potential carbon sources for <I>R. eutropha</I> 5119 and resulted in 1.8, 2.0, and 1.7 g/L PHA production, respectively. MBH proved the best carbon source, resulted in higher biomass (Y<SUB>x/s,</SUB> 0.31 g/g) and PHA (Y<SUB>p/s,</SUB> 0.14 g/g) yield.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Ralstonia eutropha</I> 5119 can co-metabolize biomass derived byproducts with glucose. </LI> <LI> Furfural, hydroxymethylfurfural and acetate promote biomass and PHA production. </LI> <LI> Vanillin is more toxic followed by furfural > hydroxymethylfurfural > acetate. </LI> <LI> <I>Miscanthus</I> biomass hydrolysate resulted in high PHA (Y<SUB>p/s,</SUB> 0.14 g/g) yield. </LI> <LI> PHA produced from biomass hydrolysate has similar properties to P(3HB-<I>co</I>-3HV). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Bioconversion of barley straw lignin into biodiesel using <i>Rhodococcus</i> sp. YHY01
Bhatia, Shashi Kant,Gurav, Ranjit,Choi, Tae-Rim,Han, Yeong Hoon,Park, Ye-Lim,Park, Jun Young,Jung, Hye-Rim,Yang, Soo-Yeon,Song, Hun-Suk,Kim, Sang-Hyoun,Choi, Kwon-Young,Yang, Yung-Hun Elsevier 2019 Bioresource technology Vol.289 No.-
<P><B>Abstract</B></P> <P> <I>Rhodococcus</I> sp. YHY01 was studied to utilize various lignin derived aromatic compounds. It was able to utilize <I>p</I>-coumaric acid, cresol, and 2,6 dimethoxyphenol and resulted in biomass production i.e. 0.38 g dcw/L, 0.25 g dcw/L and 0.1 g dcw/L, and lipid accumulation i.e. 49%, 40%, 30%, respectively. The half maximal inhibitory concentration (IC<SUB>50</SUB>) value for <I>p</I>-coumaric acid (13.4 mM), cresol (7.9 mM), and 2,6 dimethoxyphenol (3.4 mM) was analyzed. Dimethyl sulfoxide (DMSO) solubilized barley straw lignin fraction was used as a carbon source for <I>Rhodococcus</I> sp. YHY01 and resulted in 0.130 g dcw/L with 39% w/w lipid accumulation. Major fatty acids were palmitic acid (C16:0) 51.87%, palmitoleic acid (C16:l) 14.90%, and oleic acid (C18:1) 13.76%, respectively. Properties of biodiesel produced from barley straw lignin were as iodine value (IV) 27.25, cetane number (CN) 65.57, cold filter plugging point (CFPP) 14.36, viscosity (υ) 3.81, and density (ρ) 0.86.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Rhodococcus</I> sp. YHY01 can utilize <I>p</I>-coumaric acid > cresol > 2,6 dimethoxyphenol. </LI> <LI> IC<SUB>50</SUB> value was; <I>p</I>-coumaric (13.4 mM), cresol (7.9 mM), 2,6 dimethoxyphenol (3.4 mM) </LI> <LI> Biomass and lipid production in order; <I>p</I>-coumaric acid > cresol > 2,6 dimethoxyphenol. </LI> <LI> Barley lignin led to 39% w/w lipid accumulation in <I>Rhodococcus</I> sp. YHY01. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Bhatia, Shashi Kant,Gurav, Ranjit,Choi, Tae-Rim,Jung, Hye-Rim,Yang, Soo-Yeon,Song, Hun-Suk,Kim, Yun-Gon,Yoon, Jeong-Jun,Yang, Yung-Hun Elsevier 2019 Energy conversion and management Vol.192 No.-
<P><B>Abstract</B></P> <P>Food waste-derived volatile fatty acids (VFAs) can act as a renewable feedstock for biodiesel production. In synthetic media, <I>Rhodococcus</I> sp. YHY01 was able to utilize various organic acids (acetate, butyrate, lactate, and propionate) as a carbon source. Butyrate was the optimal carbon source, having a minimum inhibitory effect on growth, and a maximum growth yield coefficient (Y<SUB>x/s</SUB> 0.288 g dcw/g butyrate) and fatty acid yield coefficient (Y<SUB>f/s</SUB> 0.206 g/g butyrate), compared to other organic acids (lactate, propionate, and acetate). Acetate, butyrate, and lactate mostly supported the production of fatty acids with an even number of carbons, whereas propionate enhanced the content of odd-numbered fatty acids. Response surface methodology (RSM) design study resulted in maximum biomass (2.8 g/L) and fatty acid yield (1.9 g/g) with acetate:butyrate:lactate (0.333:0.333:0.333) as a carbon source. Culture of <I>Rhodococcus</I> sp. YHY01 in media containing food waste-derived VFAs as the carbon source had a biomass (3.2 g dcw/L), fatty acid yield (2.2 g/L), and fatty acid accumulation (69% w/w) under nitrogen-limited condition. Biodiesel produced from food waste had an iodine value (IV, 37), cetane number (CN, 63), high heating value (HHV, 39), density (υ, 3.9), and viscosity (ρ, 0.868) that meet international standards.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Rhodococcus</I> sp. YHY01 can utilize volatile fatty acids as carbon source. </LI> <LI> Acetate, butyrate and lactate play role in even number fatty acids synthesis. </LI> <LI> Propionate directly involved in synthesis of odd carbon number fatty acids. </LI> <LI> Higher biomass and fatty acid yield coefficient obtained with butyrate. </LI> <LI> Food waste derived volatile fatty acids are a suitable feedstock for biodiesel production. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
김상현,김현중,Shashi Kant Bhatia,Ranjit Gurav,전종민,윤정준,김상현,안정오,양영헌 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8
Biohydrogen is a clean and efficient source of energy produced easily by anaerobic systems. Therefore, thediscovery of novel and efficient production methods and utilization of inexpensive starting material are crucial for economicalbiohydrogen production. In this study, novel hydrogen producing bacterial strain Clostridium sp. SH25 wasscreened from the anaerobic sludge obtained from a water treatment plant, which showed a higher hydrogen-producingactivity on glycerol than other strains. The effective hydrogen production was evaluated under varying anaerobicculture conditions, and the optimum temperature, initial pH, additional NaCl concentration, and inoculum size were37 oC, 6.0, 0%, and 10% (v/v), respectively. The cumulative hydrogen production volume from crude glycerol was24.30±1.07ml after 36 h. To test the practical application of biohydrogen, a 20ml culture of Clostridium sp. SH25 wasincubated for 12 h and directly applied to a small hydrogen car unit operated for 19.05±0.33 s with 8.37±0.21m displacement. Overall, identification of the efficient Clostridium sp. SH25 strain resulted in the production of a largeamount of biohydrogen, which further supported the operation of a small hydrogen car. This implied a possible applicationof biosystems in biohydrogen production.
최태림,Jong-Min Jeon,Shashi Kant Bhatia,Ranjit Gurav,한영훈,박예림,박준영,송헌석,박형연,윤정준,서승오,양영헌 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.2
Naturally degradable bioplastic polyhydroxyalkanoate (PHA) is a promising biopolymer and its physical properties could be changed by introducing of different monomers such as 3-hydroxybutyrate (3HB), 3- hydroxyvalerate (3HV), and 3-hydroxyhexanoate (3HHx). To produce poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV)) including a high fraction of hydroxyvalerate, we introduced ctfAB into engineered Escherichia coli YJ200 possessing a pLW487 vector containing bktB, phaB, and phaC under control of the trc promoter. To enhance the HV fraction of P(3HB-co-3HV), the optimal concentrations of propionate, which acts as a precursor of 3HV and isopropyl β-D-1-thiogalactopyranoside, were determined and found to be 0.1 mM and 0.3%, respectively. Under the optimized conditions, E. coli, YJ201 produced P(3HB-co-3HV) containing a large amount of 3HV. Comparison with other CoA transferases showed that CtfAB produced relatively lower molecular weight copolymers. This demonstrates the necessity of identifying additional different CoA transferases, because CoA transferase can affect both the monomer fraction and molecular weight of polymers.
( Hun-suk Song ),( Shashi Kant Bhatia ),( Tae-rim Choi ),( Ranjit Gurav ),( Hyun Joong Kim ),( Sun Mi Lee ),( Sol Lee Park ),( Hye Soo Lee ),( Hwang-soo Joo ),( Wooseong Kim ),( Seung-oh Seo ),( Yung- 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.1
Phenol-soluble modulins (PSMs) are responsible for regulating biofilm formation, persister cell formation, pmtR expression, host cell lysis, and anti-bacterial effects. To determine the effect of psm deletion on methicillin-resistant Staphylococcus aureus, we investigated psm deletion mutants including Δpsmα, Δpsmβ, and Δpsmαβ. These mutants exhibited increased β-lactam antibiotic resistance to ampicillin and oxacillin that was shown to be caused by increased Nacetylmannosamine kinase (nanK) mRNA expression, which regulates persister cell formation, leading to changes in the pattern of phospholipid fatty acids resulting in increased anteiso-C<sub>15:0</sub>, and increased membrane hydrophobicity with the deletion of PSMs. When synthetic PSMs were applied to Δpsmα and Δpsmβ mutants, treatment of Δpsmα with PSMα1-4 and Δpsmβ with PSMβ1-2 restored the sensitivity to oxacillin and slightly reduced the biofilm formation. Addition of a single fragment showed that α1, α2, α3, and β2 had an inhibiting effect on biofilms in Δpsmα; however, β1 showed an enhancing effect on biofilms in Δpsmβ. This study demonstrates a possible reason for the increased antibiotic resistance in psm mutants and the effect of PSMs on biofilm formation.
박준영,박예림,최태림,김현중,송훈석,한영훈,이선미,박솔이,이혜수,Shashi Kant Bhatia,Ranjit Gurav,양영헌 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12
γ-Aminobutyric acid (GABA), an important fine chemical in pharmacotherapy and food industries, is used as a novel material in the nylon industry and has attracted attention for its potential application in large scale production. Search for new genes and strains, development of efficient reaction systems, such as fermentation and bioconversion, and use of cheap starting material like monosodium glutamate (MSG) can make GABA production using less expensive bulk chemicals possible. Therefore, in this study, we constructed a recombinant Escherichia coli whole-cell system for GABA production that expressed glutamate decarboxylase (GAD) from Lactobacillus brevis and used MSG as the starting material. We also optimized the reaction conditions for MSG to GABA conversion, such as citrate buffer concentration, pyridoxal 5'-phosphate concentration, temperature, MSG concentration, and cell density (OD600). The optimized whole-cell system converted MSG to GABA via seven repetitive cycles resulting in an average conversion rate of 86% (71.7mM/h) within 42 h.