Association between LEPR Genotype and Gut Microbiome in Healthy Non-Obese Korean Adults.

The LEPR (leptin receptor) genotype is associated with obesity. Gut microbiome composition differs between obese and non-obese adults. However, the impact of LEPR genotype on gut microbiome composition in humans has not yet been studied. In this study, the association between LEPR single nucleotide polymorphism (rs1173100, rs1137101, and rs790419) and the gut microbiome composition in 65 non-obese Korean adults was investigated. Leptin, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels were also measured in all participants. Mean ± SD (standard deviation) of age, body mass index, and leptin hormone levels of participants was 35.2 ± 8.1 years, 21.4 ± 1.8 kg/m2, and 7989.1 ± 6687.4 pg/mL, respectively. Gut microbiome analysis was performed at the phylum level by 16S rRNA sequencing. Among the 11 phyla detected, only one showed significantly different relative abundances between LEPR genotypes. The relative abundance of Candidatus Saccharibacteria was higher in the G/A genotype group than in the G/G genotype group for the rs1137101 single nucleotide polymorphism (p=0.0322). Participant characteristics, including body mass index, leptin levels, and other lipid levels, were similar between the rs1137101 G/G and G/A genotypes. In addition, the relative abundances of Fusobacteria and Tenericutes showed significant positive relationship with plasma leptin concentrations (p=0.0036 and p=0.0000, respectively). In conclusion, LEPR genotype and gut microbiome may be associated even in normal-weight Korean adults. However, further studies with a greater number of obese adults are needed to confirm whether LEPR genotype is related to gut microbiome composition.

Association of lncRNA SOX2OT rs9839776 polymorphism with gastric cancer risk in Korean: Case-control study.

Aberrant regulation of the long non-coding RNA SRY-box transcription factor 2 overlapping transcript (SOX2OT) has been reported in various diseases including gastric cancer (GC). However, an association between the well-studied rs9839776 single nucleotide polymorphism in SOX2OT and GC susceptibility has not been reported. This study aimed to evaluate the association between the rs9839776 single nucleotide polymorphism in SOX2OT and GC risk. Genotyping of rs9839776 was conducted using TaqMan genotyping assay for 460 patients with GC and 386 controls. We found that the dominant model (CT+TT) and rs9839776 T allele were significantly associated with decreased GC risk (P = .046, adjusted odds ratio [AOR] = 0.72, 95% confidence interval [CI] = 0.52-1.00 and P = .044, AOR = 0.74, 95% CI = 0.56-0.99, respectively). In addition, stratified analysis revealed that the dominant model (CT+TT) and rs9839776 T allele were significantly associated with decreased risk of lymph node metastasis-negative (P = .039, AOR = 0.67, 95% CI = 0.46-0.98 and P = .049, AOR = 0.71, 95% CI = 0.51-1.00, respectively) and tumor stage I (A+B)/II (A+B+C) (P = .028, AOR = 0.66, 95% CI = 0.50-0.96 and P = .041, AOR = 0.71, 95% CI = 0.52-0.99, respectively) GC. Our findings suggest that the rs9839776 T allele may be a protective factor against GC susceptibility. Further research is needed to clarify whether rs9839776 affects SOX2OT expression.

Association of long noncoding RNA MALAT1 polymorphisms with gastric cancer risk in Korean individuals.

BACKGROUND: Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) drives tumorigenesis of various human cancers. However, the association between MALAT1 variants and gastric cancer (GC) risk is unknown. We performed a case-control study to evaluate the possible association between rs619586 and rs3200401 SNPs in MALAT and GC risk. METHODS: Samples from 458 patients with GC and 381 controls were genotyped using the TaqMan genotyping assay. RESULTS: In stratified analyses, we observed that rs3200401 CT in the codominant model and CT+TT in the dominant model were associated with increased GC risk in male patients (CT: odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.09-3.01, p = 0.022; CT+TT: OR = 1.74, 95% CI = 1.07-2.83, p = 0.026), and the differentiated (CT: OR =1.79, 95% CI = 1.18-2.73, p = 0.007; CT+TT: OR = 1.76, 95% CI = 1.17-2.64, p = 0.007), and intestinal (CT: OR = 1.67, 95% CI = 1.11-2.49, p = 0.013; CT+TT: OR = 1.68, 95% CI = 1.14-2.47, p = 0.009) GC subgroups. CONCLUSION: MALAT1 rs3200401 increases GC susceptibility and might affect GC development. Further studies are needed to validate our results in large populations and different ethnic groups.

Association Between lncRNA HULC rs7763881 Polymorphism and Gastric Cancer Risk.

PURPOSE: Gastric cancer (GC) is one of the most common cancers in the world. Recently, several studies have suggested that single-nucleotide polymorphisms (SNPs) of long noncoding RNA (lncRNA) are associated with GC risk. However, the association of the lncRNA highly upregulated in liver cancer (HULC) SNP with GC risk is not yet known. The aims of this study were to evaluate the association between HULC rs7763881 SNP and the risk of GC and GC subgroups via a case-control study. PATIENTS AND METHODS: rs7763881 was genotyped using TaqMan genotyping assay with 459 GC patients and 379 controls. RESULTS: A significant association between HULC rs7763881 SNP and GC risk was not found. However, after adjustment for age and gender, the rs7763881 recessive model (CC) showed a significant association with an increased GC risk in the undifferentiated (odds ratio (OR) = 1.85, 95% confidence interval (CI) = 1.17-2.94, P = 0.009), diffuse-type GC (OR = 1.72, 95% CI = 1.05-2.82, P = 0.033), LNM-positive (OR = 2.02, 95% CI = 1.24-3.27, P = 0.004), T3/T4 (OR = 1.75, 95% CI = 1.05-2.91, P = 0.032), and tumor stage III (OR = 2.01, 95% CI = 1.17-3.45, P = 0.011) subgroups when compared to the rs7763881 combined genotypes (AA+AC). Furthermore, after adjusting for age and gender, the rs7763881 additive model (CC) indicated a significantly higher GC risk than rs7763881 AA genotype in the undifferentiated (OR = 1.96, 95% CI = 1.15-3.32, P = 0.013), diffuse-type GC (OR = 2.08, 95% CI = 1.23-3.52, P = 0.004), and LNM-positive (OR = 2.00, 95% CI = 1.14-3.49, P = 0.016) subgroups. CONCLUSION: Our findings suggest that the HULC rs7763881 SNP is associated with increased susceptibility to GC. However, further studies are required to validate our results in large populations as well as different ethnic groups.

Correlations between Genetic Polymorphisms in Long Non-Coding RNA PRNCR1 and Gastric Cancer Risk in a Korean Population.

We evaluated the association between prostate cancer non-coding RNA 1 (PRNCR1) polymorphisms and the risk of developing gastric cancer (GC) and GC subgroups in Korea. A case-control study was conducted with 437 GC patients and 357 healthy controls using a TaqMan genotyping assay. A chi-squared test, binary logistic regression, and genetic models were used to explore the association between five PRNCR1 polymorphisms and GC risk. After adjusting for gender and age, overall analyses using the recessive model indicated that the rs13252298 GG genotype was significantly associated with increased risk of intestinal-type gastric cancer (IGC). In the stratification analyses, the recessive model indicated that the rs1016343 TT genotype was significantly associated with decreased GC risk in individuals aged <60 years showing lymph node metastasis (LNM)-negative results. The rs13252298 GG genotype in the recessive model showed increased GC risk in subjects aged ≥60 years showing LNM-positive results and those aged ≥60 years in tumor stage III. In the dominant model, the rs16901946 combined genotype (AG/GG) was significantly associated with increased GC risk in subjects aged <60 years with tumor stage III. In the recessive model, the rs16901946 GG genotype was associated with decreased risk of GC and IGC in males aged ≥60 years. Thus, genetic variations in PRNCR1 may contribute to susceptibility to GC.

α6 and ß1 Integrin Heterodimer Mediates Schwann Cell Interactions with Axons and Facilitates Axonal Regeneration after Peripheral Nerve Injury.

Several isoforms of integrin subunits are expressed in Schwann cells and mediate Schwann cell interactions with axons. Here, we identify α6 and ß1 integrins as heterodimeric proteins expressed in Schwann cells and define their functions in axonal regeneration. α6 and ß1 integrins are induced in Schwann cells in the sciatic nerve after a crush injury, and the blocking of integrin activity by siRNA expression and by treatment with anti-integrin antibodies attenuates Schwann cell contact with cultured neurons and decreases neurite outgrowth. After nerve transection, the levels of α6 and ß1 integrins in the distal nerve stump are lower than those in the corresponding nerve area after a crush injury. Schwann cells prepared from the distal nerves 7 days after transection are less supportive of neurite outgrowth in co-cultured neurons than those prepared from the nerves 7 days after a crush injury. When the transected nerves are reconnected after a delay of 1 to 2 weeks, the induced levels of α6 and ß1 integrins in the reconnected distal nerves are significantly reduced compared to those in the nerves after a crush injury. These changes correlate with retarded axonal regeneration in animals that have experienced nerve transections and delayed coaptation, which implies an attenuated Schwann cell capacity to support axonal regeneration due to delayed Schwann cell contact with axons. The present data suggest that α6 and ß1 integrins induced in Schwann cells after nerve injury may play a role in mediating Schwann cell interactions with axons and promote axonal regeneration.

Bogijetong decoction and its active herbal components protect the peripheral nerve from damage caused by taxol or nerve crush.

BACKGROUND: Bogijetong decoction (BGJTD) is a herbal drug formulation used in the traditional Asian medicine to treat neuropathic insults associated with diabetes and anticancer therapy. To understand the biological basis of BGJTD on protective effects against neuropathy, we investigated physiological and biochemical responses of the sciatic nerves deranged by taxol injection or crush injury in the rats. METHODS: Dissociated Schwann cells and neurons were prepared from the sciatic nerve and dorsal root ganglia (DRG) respectively and were treated with taxol and BGJTD. The sciatic nerve in the rat was injected with taxol or given crush injury. Animals were then administered orally with BGJTD. Effects of BGJTD treatment on cultured cells and in vivo sciatic nerves and DRG tissues were examined by immunofluorescence staining and western blot analysis. Sciatic nerve regeneration was assessed by histological observation using retrograde tracing technique and by behavioral hot plate test. Eighteen different herbal components of BGJTD were divided into 4 subgroups and were used to select herbal drugs that enhanced neurite outgrowth in cultured neurons. RESULTS: Morphological abnormalities in the sciatic nerve axons and DRG tissue caused by taxol injection were largely improved by BGJTD treatment. BGJTD treatment enhanced neurite outgrowth in cultured DRG neurons and improved Schwann cell survival. Phospho-Erk1/2 levels were elevated by BGJTD administration in the injured- or taxol-injected sciatic nerves. Vimentin phosphorylation catalyzed by cell division cycle 2 (Cdc2) kinase was induced from Schwann cells in the sciatic nerves after taxol injection and crush injury, and phospho-vimentin levels were further upregulated by BGJTD treatment. Retrograde tracing of DiI-labeled DRG sensory neurons revealed growth-promoting activity of BGJTD on axonal regeneration. A drug group (Be) composed of 4 active herbal components which were selected by neurite growth-enhancing activity was as effective as BGJDT for the recovery of thermal sensitivity of the hind paws which had been suppressed by taxol administration. CONCLUSIONS: These data suggest that BGJTD and its active herbal components may protects the peripheral nerve from damage caused by taxol injection and nerve crush.

Enhanced axonal regeneration of the injured sciatic nerve by administration of Buyang Huanwu decoction.

ETHNOPHARMACOLOGICAL RELEVANCE: Buyang Huanwu decoction (BYHWD) has been used in the traditional Chinese medicine for the treatment of cardiovascular and neurological symptoms, and recent experimental studies have begun to provide evidence showing its protective effects on neural cells. Yet, its function for the regenerative responses of axons in the peripheral nerve after injury is not known. AIM OF THE STUDY: The primary objective of the present study was to explore that BYHWD is involved in growth-promoting activity of the peripheral nerve axons after injury. We further examined whether the effect of BYHWD exerted directly on regrowing axons or Schwann cells. MATERIALS AND METHODS: Sciatic nerves in rats were given crush injury, and BYHWD was injected by oral administration. Sciatic nerves or DRG tissues were prepared for immunofluorescence staining and western blot analysis. Levels of axonal regeneration were quantified by retrograde tracing technique. Cultured DRG sensory neurons and Schwann cells were prepared from rats and used to examine the effects of BYHWD on the neurite outgrowth. Behavioral analysis on functional recovery after nerve injury was assessed in mice by pin prick test, adhesive removal test, and toe-spreading reflex. RESULTS: Immunofluorescence and retrograde tracing analyses showed that the distal extension of the sciatic nerve axons was significantly improved by BYHWD treatment. Levels of axonal growth-associated protein GAP-43 were upregulated by BYHWD treatment in the sciatic nerve after injury and in the neurites of cultured DRG neurons. In vivo administration of BYHWD in rats upregulated the induction level of cell division cycle 2 (Cdc2) and its phosphorylation of vimentin in Schwann cells from injured sciatic nerve. Coculture of DRG neurons with Schwann cells prepared from preinjured sciatic nerves in animals administered with BYHWD led to the enhancement in neurite outgrowth. Behavioral tests in mice given sciatic nerve injury showed a significant improvement in sensorimotor activity by BYHWD administration. CONCLUSIONS: Our results suggest that BYHWD administration into animals given sciatic nerve injury facilitates axonal regeneration by acting on both the axons undergoing regeneration and neighboring Schwann cells and improves functional recovery.

Improvement of the diagnostic sensitivity of scrub typhus using a mixture of recombinant antigens derived from Orientia tsutsugamushi serotypes.

Diagnosis of scrub typhus is difficult because its symptoms are very similar to other acute febrile illnesses, such as leptospirosis, murine typhus, and other viral hemorrhagic fevers. To differentiate scrub typhus from other acute febrile diseases, a rapid and reliable serological diagnosis is important. We have developed a chimeric recombinant antigen cr56 and two other recombinant antigens, r21 and kr56, from various serotypes of Orientia tsutsugamushi. They were tested for the detection of antibodies against O. tsutsugamushi in the patient's serum samples using enzyme-linked immunosorbent assay (ELISA) and dot-blot analyses. As of conventional immunofluorescence assay (IFA), when the mixture of these three recombinant antigens was used, both sensitivity and specificity of the recombinant antigens were increased up to 98% in IgM and IgG at ELISA and dot blotting. Additionally, both sensitivity and specificity by detection of IgM and IgG antibodies at rapid diagnostic test (RDT), using the mixture of three antigens and gold conjugated antibodies, were 99%. Our results suggest the use of mixture of these recombinant antigen proteins in ELISA or RDT is suitable as a diagnostic test for scrub typhus.

Induction of regenerative responses of injured sciatic nerve by pharmacopuncture therapy in rats.

Although recent studies report that combined treatment of herbal drugs with acupuncture can improve clinical efficacy in traditional oriental medicine, experimental evidence that supports this pharmacopuncture therapy is rare thus far. Here, we investigated the effects of the herbal drug recipe Sciatica 5 (SCTA5) and acupuncture stimulation on gall bladder 30 (GB30) on regenerative responses of injured sciatic nerve in rats. Treatment of cultured dorsal root ganglion (DRG) neurons with SCTA5 improved neurite outgrowth. In vivo regenerative responses, in terms of distal extension of regenerating axons and retrogradely-labeled DRG neurons, were improved by either injury site application of SCTA5 or GB30 acupuncture stimulation and further increased by SCTA5 pharmacopuncture on GB30 acupoint. Moreover, combined treatment of SCTA5 and GB30 was more effective than singular treatments in inducing Cdc2 kinase and accompanying vimentin phosphorylation in Schwann cells of the injured nerve. These results suggest that SCTA5 and GB30 therapies may be cooperative in facilitating axonal regeneration in the injured peripheral nerves.

Beneficial function of cell division cycle 2 activity in astrocytes on axonal regeneration after spinal cord injury.

Migrating activity of reactive astrocytes induced after spinal cord injury (SCI) controls glial scar formation by limiting inflammatory responses around the injury area, and, therefore, can be beneficial for regenerative responses of spinal axons. Recently, we found that cell division cycle 2 (cdc2) activity in primary astrocytes facilitated neurite outgrowth of co-cultured neurons. Here, we investigated the effects of cdc2 activity on regenerative processes in vivo after SCI. Administration of the cdc2 inhibitor purvalanol A restricted compaction of the injury cavity and astrocyte infiltration into the cavity. After SCI, regenerative responses of anterogradely labeled corticospinal tract (CST) axons were attenuated by purvalanol A treatment. Using the polymeric tube that was implanted into the spinal cord as a nerve guide conduit, we found that purvalanol A treatments reduced astrocyte migration into the tube graft and, in parallel, retarded the extension of spinal axons into the tube. These results suggest that astrocytes with cdc2 activity may play a permissive role in mediating regrowth of spinal axons after lesion.

Permissive role of Cdc2 activity induced from astrocytes in neurite outgrowth.

Following spinal cord injury, glial cells are recognized as major environmental factors hampering axon's regenerative responses. However, recent studies suggested that, in certain circumstances, reactive astrocytes may have a permissive role for axonal regeneration and functional recovery. Here, we report that Cdc2 activation in astrocytes is positively linked to axon growth. Cdc2 was strongly, but transiently, induced from reactive astrocytes within and around the injury cavity. Cdc2 levels in primary, non-neuronal cells prepared from injured spinal cord were up-regulated by extending the pre-injury period. Cdc2-mediated vimentin phosphorylation was strongly induced in astrocytes after long-term culture (7 days, LTC) as compared with short-term culture (3 days, STC). Induction levels of phospho-vimentin in LTC astrocytes were positively associated with increased neurite outgrowth in co-cultured dorsal root ganglion neurons. ß3 integrin mRNA was induced in LTC astrocytes and activation of ß3 integrin was regulated by Cdc2 activity. Furthermore, genetic depletion and pharmacological blockade experiments demonstrate that activation of Cdc2 and ß3 integrin in LTC astrocytes is required for neurite outgrowth. Our data suggest that the Cdc2 pathway may play an important role in determining phenotypic expression of astrocytes such that astrocytes provide permissive environments for axonal regeneration following spinal cord injury.

Vimentin phosphorylation by Cdc2 in Schwann cell controls axon growth via ß1-integrin activation.

Although preconditioning injury on the peripheral nerve induces axonal regenerative capacity in neurons, it is not known whether similar lesion effects occur in glial cells. Here we demonstrate that Schwann cells are activated by peripheral nerve preinjury and primed to mediate axon regeneration. Cdc2, which was induced from Schwann cells after sciatic nerve injury, phosphorylated vimentin almost exclusively in the distal nerve area. Phospho-vimentin-positive Schwann cells showed increased migration activity and were in close contact with process outgrowth of co-cultured neurons. Vimentin phosphorylation by Cdc2 was involved in ß1-integrin activation leading to FAK phoshorylation and associated with Erk1/2 activation in Schwann cells. Neurite outgrowth of dorsal root ganglion neurons was increased by co-culture with activated Schwann cells, in which phospho-vimentin signaling was transmitted into ß1-integrin activation. Then neurite outgrowth was suppressed by genetic depletion of phospho-vimentin and ß1 integrin as well as inhibition of vimentin phosphorylation by Cdc2 inhibitor purvalanol A. The sciatic nerve graft harboring activated Schwann cells into the spinal cord induced Schwann cell migration beyond the graft-host barrier and facilitated regeneration of spinal axons, which was inhibited by purvalanol A pretreatment of the graft. This is the first report to our knowledge demonstrating that activation of phospho-vimentin linked to ß1-integrin pathway may mediate transcellular signaling to promote axon growth.

Immune stimulatory effects of Loranthi ramulus on macrophages through the increase of NO and TNF-alpha.

The activation of macrophages by microorganisms plays an important role in host defense and immunopathology. Loranthi ramulus (LR) is commonly used as a traditional drug and health food in Korea. Here, we investigated the regulatory effects of LR on macrophage-mediated immune responses. Treatment of macrophages with LR resulted in the enhanced cell-surface expression of CD80, CD86 and major histocompatibility complex (MHC) class II, as well as the enhanced production of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha, and also iNOS and TNF-alpha mRNA expression. These alterations of LR-treated cells were associated with the activation of NF-kappaB and mitogen-activated protein kinases (MAPKs). LR increased the phosphorylation of MAPKs (JNK, ERK1/2, p38 MAPK) and the activation of NF-kappaB in Raw 264.7 cells. These results suggest that LR has increased NO and TNF-alpha production through phosphorylation of all three MAPKs following IkappaBalpha degradation and NF-kappaB activation. In conclusion, our results demonstrate that LR can effectively promote the activation of macrophages, suggesting that LR may possess the potential to regulate immune responses.

Toll-like receptor 4-mediated immunoregulation by the aqueous extract of Mori Fructus.

The aqueous extract of Mori Fructus (MF) exerts a change of phenotype and a cytoprotective effect in macrophages. The present study was carried out to investigate the immunomodulating activity of MF on the expression of nitric oxide (NO), tumor necrosis factor alpha (TNF-alpha), co-stimulatory molecules and also interferon-gamma (IFN-gamma) in macrophages and splenocytes. Toll-like receptor 4 (TLR4) is a promising molecular target for immune-modulating drugs. It was hypothesized that one possible upstream signaling pathway leading to immunoregulation of MF may be mediated by TLRs. Multiple signaling molecules (NF-kappaB, ERK1/2, p38 and JNK) of the TLR4 signaling pathway were also detected. It was found that MF increased NO production and TNF-alpha secretion in RAW 264.7 and peritoneal macrophages, co-stimulatory molecules expression in peritoneal macrophages and IFN-gamma expression in splenocytes. Further studies indicated that MF could significantly induce the phosphorylation of signal molecules of MAPKs and the degradation of IkappaBalpha which finally led to the activation and nuclear translocation of nuclear factor-kappaB (NF-kappaB) for the target gene expression. All those notions disclosed that the aqueous extract MF is a new TLR4 activator, which induces a Th1 immune response as a consequence of induction of cytokines secretion, especially TNF-alpha and IFN-gamma.

ERK1/2-mediated Schwann cell proliferation in the regenerating sciatic nerve by treadmill training.

Proliferation of Schwann cells in the injured peripheral nerve supports axonal regeneration, and physical training in experimental animals has been shown to promote nerve regeneration. Extracellular signal-regulated kinase 1/2 (ERK1/2) activity can mediate neuronal responses to lesion signals, but its role in non-neuronal cells in the injured area is largely unknown. Here we report that treadmill training (TMT) facilitates axonal regeneration via the upregulation of phospho-ERK1/2 protein levels in Schwann cells in the injured sciatic nerve. Low-intensity, but not high-intensity, TMT increased neurite outgrowth of dorsal root ganglion (DRG) sensory neurons and potentiated Schwann cell proliferation. TMT elevated levels of GAP-43 mRNA and protein, and phospho-ERK1/2 protein in the injured sciatic nerves. TMT also enhanced phospho-c-Jun protein levels in the injured nerve. In-vivo administration of the ERK1/2 inhibitor PD98059 eliminated phospho-c-Jun, suggesting ERK1/2 phosphorylation of the c-Jun protein. PD98059 treatment decreased levels of BrdU-labeled proliferating Schwann cells in the distal portion of the injured nerve, and delayed the axonal regrowth that was promoted by TMT. The present data suggest that increased ERK1/2 activity in Schwann cells may play an important role in TMT-mediated enhancement of axonal regeneration in the injured peripheral nerve.

Environmental optimization for bioconversion of triolein into 7,10-dihydroxy-8(E)-octadecenoic acid by Pseudomonas aeruginosa PR3.

Hydroxy fatty acids (HFAs), originally found in small amount mainly from plant systems, are well known to have special properties such as higher viscosity and reactivity compared with other normal fatty acids. Recently, various microbial strains were tested to produce HFAs from different unsaturated fatty acids. Among those microbial strains tested, Pseudomonas aeruginosa PR3 are well known to utilize various unsaturated fatty acids to produce mono-, di-, and tri-HFAs. Previously, we reported that strain PR3 could utilize triolein as a substrate for the production of 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) via the induction of lipase activity (Chang et al., Appl Microbiol Biotechnol, 74:301-306, 2007). In this study, we focused on the development of the optimal environmental conditions for DOD production from triolein by PR3. Optimal initial medium pH and incubation temperature were pH 8.0 and 25 degrees C, respectively. Magnesium ion was essentially required for DOD production. Optimal inoculum size, time for substrate addition, and substrate concentration were 1%, 12 to 24 h, and 300 mg, respectively.

Production of 7, 10-dihydroxy-8(E)-octadecenoic acid from triolein via lipase induction by Pseudomonas aeruginosa PR3.

Hydroxy fatty acids (HFA) have gained importance because of their special properties such as higher viscosity and reactivity compared with other non-hydroxy fatty acids. The bacterial isolate Pseudomonas aeruginosa (PR3) was reported to produce mono-, di-, and trihydroxy fatty acids from different unsaturated fatty acids. Of those, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced with high yield from oleic acid by PR3. Up to now, the substrates used for microbial HFA production were free fatty acids. However, it is possible to utilize triacylglycerides, specifically triolein containing three oleic groups, as a substrate by microbial enzyme system involved in HFA production from oleic acid. In this study we used triolein as a substrate and firstly report that triolein could be efficiently utilized by PR3 to produce DOD. Triolein was first hydrolyzed into oleic acid by the triolein-induced lipase and then the released oleic acid was converted to DOD by PR3. Results from this study demonstrated that natural vegetable oils, without being intentionally hydrolyzed, could be used as efficient substrates for the microbial production of value-added hydroxy fatty acids.