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Objective To investigate the protective effect of hepatocyte growth-promoting factor (PHGF) against liver ischemia-reperfusion injury in rats and its mechanism of its action. Methods A total of 80 healthy male Sprague-Dawley rats were randomly divided into experimental group (PHGF group) and control group (NS group), with 40 rats in each group. A rat model of liver ischemia-reperfusion injury was established by 70% liver ischemia caused by the occlusion of blood flow in the middle and left lobes of the liver, with an ischemia time of 21 minutes. The rats in the PHGF group were given intraperitoneal injection of PHGF for intervention before surgery, and those in the NS group were given an equal volume of normal saline. Serum and liver tissue samples were collected before surgery and on days 1, 3, 5, and 7 after surgery, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBil) were measured; HE staining was used to observe pathological changes; real-time PCR was used to measure the mRNA expression of mitochondrial transcription factor A (TFAM) in the liver. The independent samples t-test was used for comparison of continuous data between two groups. Results HE staining showed that compared with the NS group, the PHGF group had significantly lower degrees of hepatocyte swelling, inflammatory cell infiltration, and hepatocyte necrosis under a light microscope. Liver biochemistry showed that on days 1, 3, 5, and 7 after surgery, the PHGF group had significantly lower serum levels of ALT, AST, and TBil than the NS group (t=11.879, 16.019, 22168, 10.235, 9.041, 12.936, 18.759, 8.142, 10.108, 11.014, 13.245, and 9.968, all P＜0.001). Real-time PCR showed that on days 1, 3, and 5 after surgery, the PHGF group had a significantly higher mRNA level of TFAM in the liver than the NS group (t=7.998, 14.764, and 13.861, all P＜0.001). Conclusion PHGF preconditioning exerts a protective effect against liver ischemia-reperfusion injury in rats, possibly by upregulating the expression of TFAM to alleviate liver ischemia-reperfusion injury.

Biological pretreatment of rice straw and production of reducing sugars by hydrolysis of bio-pretreated material with Streptomyces griseorubens JSD-1 was investigated. After 10 days of incubation, various chemical compositions of inoculated rice straw were degraded and used for further enzymatic hydrolysis studies. The production of cellulolytic enzyme by S. griseorubens JSD-1 favored the conversion of cellulose to reducing sugars. The culture medium for cellulolytic enzyme production by using agro-industrial wastes was optimized through response surface methodology. According to the response surface analysis, the concentrations of 11.13, 20.34, 4.61, and 2.85 g L(-1) for rice straw, wheat bran, peptone, and CaCO3, respectively, were found to be optimum for cellulase and xylanase production. Then the hydrolyzed spent Streptomyces cells were used as a nitrogen source and the maximum filter paper cellulase, carboxymethylcellulase, and xylanase activities of 25.79, 78.91, and 269.53 U mL(-1) were achieved. The crude cellulase produced by S. griseorubens JSD-1 was subsequently used for the hydrolysis of bio-pretreated rice straw, and the optimum saccharification efficiency of 88.13% was obtained, indicating that the crude enzyme might be used instead of commercial cellulase during a saccharification process. These results give a basis for further study of bioethanol production from agricultural cellulosic waste.

Streptomyces griseorubens JSD-1 is a novel actinomycete that could grow efficiently upon lignin, and the ligninolytic genes active in this biotransformation were expected to be crucial. To investigate the molecular mechanism of utilizing lignin, genome sequencing was carried out to obtain its draft genome, which was deposited at GenBank under the accession No. JJMG00000000. Multiple copper oxidase (MCO) was obtained, which proved to be an extracellular enzyme and have relative high expression with the stimulation of ligninolytic materials. Judging from its putative 3D structure, the N-terminal of MCO was bared, which was fit for the linkage of poly-HIS10 tag. As a result, heterogeneous expression conditions of recombinant laccase was achieved with TransB(DE3) grown in a modified terrific broth (TB) medium with an extra addition of 0.5% glucose at 30 °C until optical density at 600 nm (OD600) reached 0.8 when expression was induced by 25 μM isopropyl β-D-1-thiogalactopyranoside (IPTG) and also 100 μM copper sulphate as supplement. Finally, it exhibited special characters of thermal robustness, alkaline activity profiles, high resistance to metallic ions and chemical inhibitors as well as dye decolourization. In summary, our findings illustrated the genetic basic of utilizing lignin in this isolate. Additionally, a novel laccase expected to be potential in agricultural and industrial application was expressed and characterized as well.

Streptomyces griseorubens JSD-1 is an isolate sourced from compost-treated soil that can utilize xylan as the unique carbon source for growth; xylanlytic genes related to this process were expected to be crucial. However, little is known about the genetic basic of utilizing xylan in this isolate. To further investigate the molecular mechanism of xylan metabolism, genome sequencing was carried out. The draft genome obtained has been deposited with GenBank. Endo-1,4-β-xylanase (Xyn) was acquired, followed by characterization of its cellular localization and expression profiles. Xyn proved to be a novel enzyme, differing from xylanases from similar species according to combined analyses from multiple sequence alignments and putative three-dimensional structure modeling. Moreover, recombinant expression was optimized in heterogeneous hosts to further determine optimum pH and temperature conditions as well as residual activity in the presence of metal ions and inhibitors. Finally, substrate specificity and kinetic parameters were also studied. In conclusion, our findings illustrate the genetic background related to xylan metabolism in this isolate. In addition, a novel Xyn that is expected to have potential in the bio-degradation of hemicellulosic materials was expressed, purified and characterized.

Streptomyces griseorubens JSD-1 is an isolate that can utilize lignocellulose (straw) as its sole carbon source for growth, and these lignocellulolytic genes involved in this biotransformation are expected to be crucial. However, little is known about the genetic basis related to this process. To further investigate the lignocellulose-degrading mechanisms, genome sequencing was carried out using MiSeq platform. After obtaining its draft genome, the key lignocellulolytic genes such as multicopper oxidase, exo-1, 4-β-glucanase, endo-1,4-β-glucanase, and β-xylosidase were identified and characterized. Multiple sequence alignments were performed to find out the identities of these analyzed proteins to those of their similar species. Signal peptide cleavage sites were predicted by SignalP 4.1 to reflect the cellular localization of their mature proteins. Besides, predicted 3D structures of these proteins were modeled by Phyre2, which showed to be highly identical to the templates in the PDB database. Finally, quantitative real-time PCR revealed that expression levels of all analyzed enzymes were significantly and generally up-regulated during the whole cultivation, indicating that they all contributed to the biodegradation.

In this study, the production of cellulase and xylanase by Streptomyces griseorubens JSD-1 was improved by integrating the pH-shift and dissolved oxygen (DO)-constant control strategies. The pH-shift control strategy was carried out by analyzing the specific cell growth rate (μ) and specific enzyme formation rate (Q p) of S. griseorubens JSD-1. The pH was controlled at 8.0 during the first 48 h to maintain high cell growth, which then shifted to 7.5 after 48 h to improve the production of cellulase and xylanase. Using this method, the maximum activities of cellulase, xylanase, and filter paper enzyme (FPase) increased by 47.9, 29.5, and 113.6 %, respectively, compared to that obtained without pH control. On the basis of pH-shift control, the influence of DO concentrations on biomass and enzyme production was further investigated. The maximum production of cellulase, xylanase, and FPase reached 114.38 ± 0.96 U mL(-1), 330.57 ± 2.54 U mL(-1), and 40.11 ± 0.38 U mL(-1), which were about 1.6-fold, 0.6-fold, and 3.2-fold higher than that of neutral pH without DO control conditions. These results supplied a functional approach for improving cellulase and xylanase production.

Background Streptomyces griseorubens JSD-1 is a novel actinomycete isolated from soil that can utilize nitrate as its sole nitrogen source for growth and these nitrate assimilation genes active in this biotransformation are expected to be crucial. However, little is known about its genomic or genetic background related to nitrogen metabolism in this isolate. Thus, this study concentrates on identification and characterization of genes involved in nitrate assimilation. Results To investigate the molecular mechanism of nitrate metabolism, genome sequencing was performed by Illumina Miseq platform. Then the draft genome of a single linear chromosome with 8,463,223 bp and an average G+C content of 72.42% was obtained, which has been deposited at GenBank under the accession number JJMG00000000. Sequences of nitrate assimilation proteins such as nitrate reductase (EC 1.7.99.4), nitrite reductase (EC 1.7.1.4), glutamine synthetase (EC 6.3.1.2), glutamate synthase (EC 1.4.1.13) and glutamate dehydrogenase (EC 1.4.1.2) were acquired. All proteins were predicted to be intracellular enzymes and their sequences were highly identical to those from their similar species owing to the conservative character. Putative 3D structures of these proteins were also modeled based on the templates with the most identities in the PDB database. Through KEGG annotated map, these proteins proved to be located on the key positions of nitrogen metabolic signaling pathway. Finally, quantitative RT-PCR indicated that expression responses of all genes were up-regulated generally and significantly when stimulated with nitrate. Conclusion In this manuscript, we describe the genome features of an isolate of S. griseorubens JSD-1 following with identification and characterization of these nitrate assimilation proteins such as nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase and glutamate dehydrogenase accounts for the ability to utilize nitrate as its sole nitrogen source for growth through cellular localization, multiple sequence alignment, putative 3D modeling and quantitative RT-PCR. In summary, our findings provide the genomic and genetic background of utilizing nitrate of this strain. Electronic supplementary material The online version of this article (doi:10.1186/s12934-014-0174-4) contains supplementary material, which is available to authorized users.

Streptomyces griseorubens JSD-1, isolated from compost-treated soil, is able to utilize lignocellulose and nitrate as its sole carbon and nitrogen source for growth. Here, we announce the draft genome map of this actinomycete. The genes participating in lignocellulose and nitrate metabolism were picked out and identified.

The paper firstly describes the structure of the EQ6110HEV hybrid propulsion system. In order to accelerate the developing process of the hybrid propulsion system, an online calibrating/programming software has been simultaneously developed, and five functions of the system are helpful to develop the hybrid propulsion control system rapidly. Secondly, the online calibration system can monitor the state information of the hybrid propulsion system all the time, and modify the parametric maps or update the control programs. Based on the software package, the hybrid propulsion control system is developed and applied to the EQ6110HEV bus. Finally, experiments verify that the online calibration system is feasible and reliable, and can save about 30 per cent of the development time for the EQ6110HEV control system in comparison with that of the standard calibration system.