• Journal of Microbiology and Biotechnology
• /
• v.28 no.7
• /
• pp.1133-1140
• /
• 2018

Pseudomonas fluorescens KLR101 was found to be capable of producing polyhydroxyalkanoate (PHA) using various sugars and fatty acids with carbon numbers ranging from 2 to 6. The PHA granules consisted mainly of a poly(3-hydroxybutyrate) homopolymer and/or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer. Genomic DNA of P. fluorescens was fractionated and cloned into a lambda library, in which a 5.8-kb fragment that hybridized to a heterologous phaC probe from Ralstonia eutropha was identified. In vivo expression in Klebsiella aerogenes KC2671 (pUMS), restriction mapping, Southern hybridization experiments, and sequencing data revealed that PHA biosynthesis by P. fluorescens relied upon a polypeptide encoded by a 1,683-bp non-operonal ORF, which was preceded by a possible -24/-12 promoter and highly similar to DNA sequences of a gene encoding PHA synthase in the genus Pseudomonas. In vivo expression of the putative PHA synthase gene ($phaC_{Pf}$) in a recombinant Escherichia coli strain was investigated by using glucose and decanoate as substrates. E. coli (${phaC_{Pf}}^+$, pUMS) grown in medium containing glucose accumulated PHA granules consisting mainly of 3-hydroxybutyrate, whereas only a trace amount of 3-hydroxydecanoate was detected from an E. coli fadR mutant (${phaC_{Pf}}^+$) grown in medium containing decanoate. In vitro enzymatic assessment experiments showed that 3-hydroxybutyryl-CoA was efficiently used as a substrate of purified $PhaC_{Pf}$, suggesting that the putative PHA synthase of P. fluorescens utilizes mainly short-chain-length PHA precursors as a substrate.

• Anatomy and Cell Biology
• /
• v.56 no.2
• /
• pp.276-279
• /
• 2023

The arterial support of the liver is most commonly from the celiac trunk via the proper hepatic artery (PHA). The PHA divides into left and right branches: the right hepatic artery (RHA) supplies the right and caudate lobes while the left hepatic artery (LHA) supplies the left and quadrate lobes. Aberrant hepatic arteries are relatively common, and the most frequent contributors are the superior mesenteric artery and left gastric artery. Herein we present findings from postmortem dissection of an abdominal cavity that revealed a rare combination of reported variations. Specifically, this subject had three extrahepatic arteries - a replaced LHA (rLHA), a PHA, and a replaced RHA (rRHA). The rLHA originated from the left gastric and the rRHA originated from the superior mesenteric artery. Knowledge of these variations is important for surgical and radiological procedures to avoid complications during treatment and improve patient outcomes.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.321-324
• /
• 2001

Two recombinant Escherichia coli strains, GCSC6576 harboring a plasmid pSYL107 containing the Ralstonia eutropha polyhyclroxyalkanoate (PHA) biosynthesis genes and a fadR atoC mutant LS5218 harboring a plasmid pJC4 containing the Alcaligenes latus PHA biosynthesis genes were compared for their ability to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] from whey as the sale carbon source. With the pH-stat fed-batch culture of E. coli LS5218, 、 ,ve obtained a cell concentration, a P(3HB-co-3HV) concentration. a P(3HB-co-3HV) content, and a 3HV fraction of 31.8 g/L, 10.6 g/L, 33.4 wt%. and 6.26 mol%, respectively at 39 h.

• Journal of Veterinary Clinics
• /
• v.14 no.2
• /
• pp.230-234
• /
• 1997

In vitro effect of cortisol on the proliferation of canine peripheral blood mononuclear cells (MNC) was examined. The MNC was isolated from peripheral blood by a gradient centrifugation with Picoll-Hypaque. The cell proliferation assayed using a noneradioactive 5-Bromo-2'-deoxy-uridine (BrdU) kit. The MNC proliferated well in response to either phrtobeRagg$]$utinin-p (PHA-P) or culture supernatant from MNC stimulated with PHA-p. However, these proliferative responses of MNC were not affected by addition of coitisol of 1 to 1,OOfl ng/ml. The addition of cortisol in MNC culture with either PHA-P or corture supernatBnt from MNC stimulated with PHA-P far 4 days wag not also influenced on the viabilities of cultured MNC. In conclusions it was able to assay the cell proliferation with BrdU instead of radioactive isotope e.g. tritiated thymidine (3H-TdR). These results suggested that cortisol does not at least influence on MNC proliferation in vitro.

• Elastomers and Composites
• /
• v.50 no.2
• /
• pp.138-145
• /
• 2015

A series of wholly aromatic poly(hydroxyamide)s(PHAs), containing varying amounts of 2,6-dimethylphenoxy group and quinoxaline ring in the main chain, were synthesized by a direct polycondensation method. The inherent viscosities of the PHAs in either DMAc or DMAc/LiCl solution at $35^{\circ}C$ were found to be in the range of 1.02~1.90 dL/g. In the solubility study, we observed that PHA 1, PHA 2, and PHA 3 were dissolved in aprotic solvents such as DMAc, NMP, DMF, and DMSO with LiCl on heating; however, PHA 4, PHA 5, and PHA 6 could be dissolved in aprotic solvents on heating without LiCl. For poly(benzoxazole)s(PBOs), the 10% and maximum weight loss temperatures were in the range of $582{\sim}622^{\circ}C$ and $630{\sim}659^{\circ}C$, respectively. Residues of PBOs at $900^{\circ}C$ were found to be relatively high, which were in the range of 65.3~70.8%.

• Korean Journal of Veterinary Research
• /
• v.31 no.1
• /
• pp.49-53
• /
• 1991

The present study has been carried out to investigate the optimal condition on lymphocyte blastogenesis of rabbit lymphocytes, whole blood culture and microculture system in conjunction with a semiautomatic multiple sample harvester(SAMSH) was used to study the In vitro optimal condition of rabbit lymphocytes. Data were presented to show many variables that are involved in studying the phytohemagglutinin(PHA) and lipopolysaccharide(LPS) response of rabbit lymphocyte in a microculture system. Analysis indicated that the conditions for optimal PHA as measured by incorporation of $^3H$-TdR include: (1) use of RPMI-1640 as culture medium. (2) use of $6{\mu}g$ of PHA, per culture. (3) 48-hours culture period. Conditions for optimal stimulation with LPS mitogen were similar to those used for PHA.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.11
• /
• pp.4951-4957
• /
• 2016

Background: Apart from reducing occupational exposure to cytotoxic hazards, the PhaSeal(R) closed-system transfer device (CSTD) can extend the beyond-use dates (BUDs) of unfinished vials of antineoplastic drugs for up to 168 hours (seven days). In this study, the total material cost incurred by its use in a Malaysian government-funded hospital was calculated. Methods: A list of vial stability following initial needle punctures of 29 commonly-used antineoplastic drugs was compiled. The amount of the materials used, including drugs, infusion bottles, the PhaSeal(R) CSTD and other consumables, was recorded on a daily basis for three months in 2015. The total cost was calculated based on the actual acquisition costs, and was compared with that of a hypothetical scenario, whereby conventional syringe-needle sets were used for the same amounts of preparations. Results: The use of the PhaSeal(R) CSTD incurred a cost of MYR 383,634.52 (USD 92,072.28) in three months, representing an average of MYR 170.5 (USD 40.92) per preparation or an estimated annual cost of MYR 1,534,538.08 (USD 368,289.14). Compared with conventional syringe-needle approach, it is estimated to lead to an additional spending of MYR 148,627.68 (USD 35,670.64) yearly. Conclusion: Although there was a reduction of drug wastage achieved by extending BUDs of unfinished vials using the PhaSeal(R) CSTD, cost saving was not observed, likely attributable to the wide use of lower-priced generic drugs in Malaysia. Future studies should further evaluate the possibility of cost saving, especially in health settings where branded and high-cost antineoplastic drugs are more commonly used.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.1
• /
• pp.79-90
• /
• 2019

Lichens are generally known as self-sufficient, symbiotic life-forms between fungi and algae/cyanobacteria, and they also provide shelter for a wide range of beneficial bacteria. Currently, bacterial-derived biodegradable polyhydroxyalkanoate (PHA) is grabbing the attention of many researchers as a promising alternative to non-degradable plastics. This study was conducted to develop a new method of PHA production using unexplored lichen-associated bacteria, which can simultaneously degrade two ubiquitous industrial toxins, anthracene and naphthalene. Here, 49 lichen-associated bacteria were isolated and tested for PHA synthesis. During the GC-MS analysis, a potential strain of EL19 was found to be a 3-hydroxyhexanoate (3-HHx) accumulator and identified as Pseudomonas sp. based on the 16S rRNA sequencing. GC analysis revealed that EL19 was capable of accumulating 30.62% and 19.63% of 3-HHx from naphthalene and anthracene, respectively, resulting in significant degradation of 98% and 96% of naphthalene and anthracene, respectively, within seven days. Moreover, the highly expressed phaC gene verified the genetic basis of $PHA_{mcl}$ production under nitrogen starvation conditions. Thus, this study strongly supports the hypothesis that lichen-associated bacteria can detoxify naphthalene and anthracene, store energy for extreme conditions, and probably help the associated lichen to live in extreme conditions. So far, this is the first investigation of lichen-associated bacteria that might utilize harmful toxins as feasible supplements and convert anthracene and naphthalene into eco-friendly 3-HHx. Implementation of the developed method would reduce the production cost of $PHA_{mcl}$ while removing harmful waste products from the environment.

• KSBB Journal
• /
• v.18 no.5
• /
• pp.404-407
• /
• 2003

Two recombinant Escherichia coli strains, GCSC6576 harboring a plasmid pSYL107 containing the Ralstonia eutropha polyhydroxyalkanoate (PHA) biosynthesis genes and a fadR atoC mutant LS5218 harboring a plasmid pJC4 containing the Alcaligenes latus PHA biosynthesis genes were compared for their ability to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV) from whey. The 3HV fraction could be increased by acetic acid induction and oleic acid supplementation in flask cultures of recombinant E. coli GCSC6576. With the pH-stat fed-batch culture of recombinant E. coli LS5218, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 31.8 g/L, 10.6 g/L, 33.4%, and 6.26 mol%, respectively in 39 h.

• Journal of Microbiology
• /
• v.43 no.3
• /
• pp.285-294
• /
• 2005

A bacterial strain M4-7 capable of degrading various polyesters, such as poly$(\varepsilon-caprolactone)$, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxyoctanoate), and poly(3-hydroxy-5-phenylvalerate), was isolated from a marine environment and identified as Pseudomonas alcaligenes. The relative molecular mass of a purified extracellular medium-chain-length poly(3-hydroxyalkanoate) (MCL-PHA) depolymerase $(PhaZ_{palM4-7})$ from P. alcaligenes M4-7 was 28.0 kDa, as determined by SDS-PAGE. The $PhaZ_{palM4-7}$ was most active in 50 mM glycine-NaOH buffer (pH 9.0) at $35^{\circ}C$. It was insensitive to dithiothreitol, sodium azide, and iodoacetamide, but susceptible to p-hydroxymercuribenzoic acid, N-bromosuccinimide, acetic anhydride, EDTA, diisopropyl fluorophosphate, phenylmethylsulfonyl fluoride, Tween 80, and Triton X-100. In this study, the genes encoding MCL-PHA depolymerase were cloned, sequenced, and characterized from a soil bacterium, P. alcaligenes LB19 (Kim et al., 2002, Biomacro-molecules 3, 291-296) as well as P. alcaligenes M4-7. The structural gene $(phaZ_{palLB19})$ of MCL-PHA depolymerase of P. alcaligenes LB19 consisted of an 837 bp open reading frame (ORF) encoding a protein of 278 amino acids with a deduced $M_r$ of 30,188 Da. However, the MCL-PHA depolymerase gene $(phaZ_{palM4-7})$ of P. alcaligenes M4-7 was composed of an 834 bp ORF encoding a protein of 277 amino acids with a deduced Mr of 30,323 Da. Amino acid sequence analyses showed that, in the two different polypeptides, a substrate-binding domain and a catalytic domain are located in the N-terminus and in the C-terminus, respectively. The $PhaZ_{palLB19}$ and the $PhaZ_{palM4-7}$ commonly share the lipase box, GISSG, in their catalytic domains, and utilize $^{111}Asn$ and $^{110}Ser$ residues, respectively, as oxyanions that play an important role in transition-state stabilization of hydrolytic reactions.