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Background : The bioconversion of phytosterols into high value-added steroidal intermediates, including the 9 α -hydroxy-4-androstene-3,17-dione (9-OHAD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC), is the cornerstone in steroid pharmaceutical industry . However , t he low transportation efficiency of hydrophobic substrates into mycobacterial cells severely limits the transformation . In this study, a robust and stable modification of the cell wall in M. neoaurum strain strikingly enhanced the cell permeability for the high production of steroids. Results: The deletion of the nonessential kasB , encoding a β-ketoacyl-acyl carrier protein synthase, led to a disturbed proportion of mycolic acids (MAs), w hich is one of the most important components in the cell wall of Mycobacterium neoaurum ATCC 25795. The determination of cell permeability displayed about two times improvement in the kasB -deficient strain than that of the wild type M. neoaurum . Thus, the deficiency of kasB in the 9-OHAD-producing strain resulted in a significant increase of 137.7% in the yield of 9 α -hydroxy-4-androstene-3,17-dione (9-OHAD) . Ultimately, the 9-OHAD productivity in an industrial used resting cell system was reached 0.1135 g/L/h (10.9 g/L 9-OHAD from 20 g/L phytosterol) and the conversion time was shortened by 33%. In addition , a similar self-enhancement effect (34.5%) was realized in the 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) producing strain. Conclusions : The modification of kasB resulted in a meaningful change in the cell wall mycolic acids. Deletion of the kasB gene remarkably improved the cell permeability, leading to a self-enhancement of the steroidal intermediate conversion. The results showed a high efficiency and feasibility of this construction strategy.

Eukaryotic genome size data are important both as the basis for comparative research into genome evolution and as estimators of the cost and difficulty of genome sequencing programs for non-model organisms. In this study, the genome size of 14 species of fireflies (Lampyridae) (two genera in Lampyrinae, three genera in Luciolinae, and one genus in subfamily incertae sedis) were estimated by propidium iodide (PI)-based flow cytometry. The haploid genome sizes of Lampyridae ranged from 0. 42 to 1. 31 pg, a 3. 1-fold span. Genome sizes of the fireflies varied within the tested subfamilies and genera. Lamprigera and Pyrocoelia species had large and small genome sizes, respectively. No correlation was found between genome size and morphological traits such as body length, body width, eye width, and antennal length. Our data provide additional information on genome size estimation of the firefly family Lampyridae. Furthermore, this study will help clarify the cost and difficulty of genome sequencing programs for non-model organisms and will help promote studies on firefly genome evolution.

Herein, we proposed a novel, facile method for flocculation of Saccharomyces cerevisiae cells via nanoZnO. According to results, the presence of nanoZnO could significantly facilitate the flocculation of the yeast cells without damage the cellular morphology. Notably, the yeast cells flocculated by using nanoZnO displayed certain antibacterial property. Moreover, the cell activity was almost remained after flocculated by this method.

α-Tocopherol, with antioxidant properties, is synthesized by photosynthetic organisms and play important roles in human and animal nutrition. The final step of the α-tocopherol biosynthetic pathway is catalyzed by γ-tocopherol methyltransferase (γ-TMT). In the major oilseed crops, γ-tocopherol, the biosynthetic precursor of α-tocopherol, is the predominant form. The full-length cDNA of γ-TMT was obtained from Chinese cabbage ( Brassica. rapa , Pekinensis Group), named BoTMT, by reverse transcription polymerase chain reaction (RT-PCR). Sequence analysis indicates that, BoTMT gene consisted of the open reading frame of 1041 nucleotides encoding a protein of 39 kD polypeptide. A BoTMT whole cell system was developed for the production of α-tocopherol through the expression of BoTMT in Escherichia coli BL21 (DE3) strain. Keywords: γ-Tocopherol methyltransferase, Chinese cabbage, Perilla frustescens , tocopherol, high performance liquid chromatography (HPLC)

Organic solvent-tolerant lipases have shown new potential application in biotechnological fields. A novel strain which produced an organic solvent-tolerant lipase was isolated from soils in different areas of China. Based on the morphological, physiological and biochemical features and 16S rDNA sequence of the strain, it was identified asPseudomonas aeruginosaCS-2. The crude lipase had an improved stability in the presence of acetonitrile and it exhibited stability in presence of benzene, chloroform,n-Hexane, petroleum ether and isooctane. The optimized composition of culture medium was as follows: olive oil 1%, peptone 4%, K2HPO40.5%, MgSO4·7H2O 0.1%, gum arabic 0.04%. The optimum condition for lipase production was on the following: temperature 37°C, initial pH 7.5, rotary shaking speed 200 rev/min, culture time 48 h.

The Gluconobacter oxydans M5 with disruption of the pyrroloquinoline quinine-dependent membrane-bound aldehyde dehydrogenase (ALDH) was used for the oxidation of benzyl alcohol. The selectivity toward benzaldehyde showed an obvious increase for the engineered strain, which reached the 67.3%, while the wild strain had only 2.8%. Meantime, the aqueous/isooctane (1:1) biphasic system was used for the further improvement of selectivity. By these methods, nearly 100% selectivity and conversion rate could be obtained within 1 h at the optimum initial benzyl alcohol concentration of 5.0 g/l.

Bagasse, the main coproduct in the sugar industry, has been shown to be the sole carbon source for liquid-state fermentation to produce hydrolytic enzymes (cellulases and xylanases) using Cellulosimicrobium cellulans in flask during 3 days and the enzymatic extracts obtained at different time intervals were analysed. The degradation of bagasse indicate the lignocellulolytic capacity of C. cellulans, 26% decrease in hemicellulose content at 96 h, while 10% decrease in cellulose. This accord to that xylanases fairly predominated over cellulases. A rapid rise in the activity of cellulases and xylanases was observed in the early stages of incubation (within the first 24 h). The optimum pH for these enzymes by C. cellulans in liquid cultures was between 5.0 and 5.6 and the optimum temperature was 50 °C. Thermal stability of the enzymes was appreciable up to 45 °C, pH stability at pH 5.0.

Five specimens of bug-eyed treefrogs of genus Theloderma were collected in Taiyanghe National Forest Park, Simao County, Pu’er Prefecture, Xishuangbanna National Nature Reserve, Mengyang and Menglun Towns, Xishuangbanna Prefecture, and Daweishan National Nature Reserve, Pingbian County, Honghe Prefecture, Yunnan Province, China in September 2015, May, June, and November 2016, respectively. According to our identification these treefrogs refer to Theloderma gordoni Taylor, 1962 and present the first record for China.

Ganoderma lucidum is a well-known traditional Chinese medicinal herb containing many bioactive compounds. Ganoderic acid T (GA-T), which is a lanostane triterpenoid purified from methanol extract of G. lucidum mycelia, was found to exert cytotoxicity on various human carcinoma cell lines in a dose-dependent manner, while it was less toxic to normal human cell lines. Animal experiments in vivo also showed that GA-T suppressed the growth of human solid tumor in athymic mice. It markedly inhibited the proliferation of a highly metastatic lung cancer cell line (95-D) by apoptosis induction and cell cycle arrest at G(1) phase. Moreover, reduction of mitochondria membrane potential (Delta psi(m)) and release of cytochrome c were observed during the induced apoptosis. Our data further indicate that the expression of proteins p53 and Bax in 95-D cells was increased in a time-dependent manner, whereas the expression of Bcl-2 was not significantly changed; thus the ratio of Bcl-2/Bax was decreased. The results show that the apoptosis induction of GA-T was mediated by mitochondrial dysfunctions. Furthermore, stimulation of the activity of caspase-3 but not caspase-8 was observed during apoptosis. The experiments using inhibitors of caspases (Z-VAD-FMK, Z-DEVD-FMK and Z-IETD-FMK) confirmed that caspase-3 was involved in the apoptosis. All our findings demonstrate that GA-T induced apoptosis of metastatic lung tumor cells through intrinsic pathway related to mitochondrial dysfunction and p53 expression, and it may be a potentially useful chemotherapeutic agent.

We study the photo-oxidation of bacteriochlorophylls (BChls) in peripheral light harvesting complexes (LH2) from rhodobacter sphaeroides by using the steady absorption and the femtosecond pump–probe measurement, to realize the detailed dynamics of LH2 in the presence of photo-oxidation. The experimental results reveal that BChl-B850 radical cations may act as an additional channel to compete with the unoxidized BChl-B850 molecules for rapidly releasing the excitation energy, while the B800→B850 energy transfer rate is almost unaffected in the oxidation process.

From the cultured cells of Panax notoginseng, a kind of ginseng saponin-ginsenoside Rg2, was separated and purified, and its structure was elucidated as 6-O-[alpha-L-rhamnose (l-->2)-beta-D-glucopyranosyl]3beta, 12beta, 20(S)-trihydroxydammar-24-ene [20(S)-ginsenoside Rg2]. Moreover, its bioactivity stimulates human umbilical cord vein endothelial cell proliferation; the growth of the cells treated with 20(S)-ginsenoside Rg2 was 14-fold higher than that of untreated ones, and the level of the cell's plasminogen activator (PA) was also twofold higher.

The known members of inhibitor of growth (ING) gene family are considered as candidate tumor suppressor genes. ING4, a novel member of ING family, is recently reported to interact with tumor suppressor p53, p300 (a major component of histone acetyl transferase complexes), and p65(RelA) subunit of NF-κB. In this study, we investigated the cellular behaviors of HepG2 cells with exogenous ING4. Interestingly, the overexpression of ING4 negatively regulated the cell growth with significant G2/M arrest of cell cycle, and moreover, enhanced the cell apoptosis triggered by serum starvation in HepG2 cells. Furthermore, the exogenous ING4 could upregulate endogenous p21 and Bax in HepG2 cells, not in p53-deficient Saos-2 cells, suggesting that G2/M arrest induced by ING4 could be mediated by the increased p21 expression in a p53-dependent manner, although there is no significant increase of p53 expression in HepG2 cells. Moreover, HepG2 cells with exogenous ING4 could significantly increase cell death, as exposed to some DNA-damage agents, such as etoposide and doxorubicin, implying that ING4 could enhance chemosensitivity to certain DNA-damage agents in HepG2 cells.

Recent studies have shown abnormal microRNA (miRNA) expression levels in the central nervous system (CNS) of cancer patients, suggesting that miRNAs may serve as promising biomarkers for cancers of CNS. However, other studies have arrived at conflicting results. Therefore, this meta-analysis aims to systematically measure the potential diagnostic value of miRNAs for CNS cancers. Electronic databases as well as other sources were searched until to April 12, 2014 for relevant articles. Data from different studies were pooled using the random-effects model. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative LR (NLR), diagnostic odds ratio (DOR), together with the summary receiver operator characteristic (SROC) curve, and area under the SROC curve (AUC) value were used to estimate overall diagnostic performance. Twenty-three studies from 6 articles were included in the current meta-analysis with a total of 299 CNS cancer patients and 418 controls. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.85 (95 % CI, 0.80–0.89), 0.83 (95 % CI, 0.76–0.88), 5.1 (95 % CI, 3.4–7.5), 0.18 (95 % CI, 0.12–0.26), 28 (95 % CI, 14–58), and 0.91 (95 % CI, 0.88–0.93), respectively. Subgroup analyses showed that cerebrospinal fluid (CSF)-based miRNAs assays yielded more accurate results and seemed to be more sensitive in diagnosing of primary central nervous system lymphoma (PCNSL). In conclusion, miRNAs may be suitable for serving as noninvasive biomarkers for CNS cancers detection. However, further validation based on a larger sample of patients and controls is still required.

Formation of inclusion bodies is an important obstacle to the production of active recombinant protein in Escherichia coli. Thus, soluble expression of penicillin G acylase from Kluyvera citrophila was investigated in BL21(DE3). In this study, the yield of active enzyme was significantly enhanced by the composition of the medium and induction opportunity. When 0.5 mmol/L IPTG was added to complex medium at 15 h after incubation, the volumetric and specific activities of penicillin G acylase both achieved the highest values, respectively. However, aggravation of intracellular proteolysis and decline of enzyme expression were also observed if induction occurred too much later. Ca2+ ion was another critical factor in cell growth and protein expression. When 24 mmol/L Ca2+ ion was adding to the medium at the beginning of fermentation, a greater than 2-fold increase in cell density and a 7-fold increase in volumetric activity of penicillin G acylase were reached. Nevertheless, no significant benefit for recombination protein expression was found when excess Ca2+ was added after induction time. This study demonstrates that the induction starting time and Ca2+ ion are two critical factors for the expression of active penicillin G acylase.

modification (i.e., pegyla-tion) is an effective approach to enhancing pharmaceuticalprotein’s delivery (e.g., increasing stability and solubility,prolonging plasma half-life, decreasing toxicity, and antige-nicity) [1]. The protein determination is very important forthe quantification of pegylated proteins, and the Lowrymethod [2] has been recommended or used for this purpose[3–5]. However, Abuchowski and co-workers [6] found thatthe Lowry method gave erroneously high values with pegy-lated bovine serum albumin (BSA). We also encounteredthis problem when determining several pegylated proteinssuch as recombinant interleukin 2 (rIL-2) and interferona-2b. Because Abuchowski and co-workers [6] mentionedsuch a phenomenon without a detailed report, we did thisresearch to analyze the reason for this error and hopedto find a method to eliminate it. The Bradford method [7]was used as a comparison because it was faster and moresensitive than the Lowry method and has even been recom-mended as a replacement of the latter [8,9].Standard BSA was used for the preparation of bothstandard curve and pegylated samples so that we couldget the theoretical concentration of a sample by preciseweighing and dilution and could know the accuracy of amethod by comparison of the theoretical and determinedvalues.BSA was dissolved in 0.2 M phosphate buffer at pH 7.5to form a 1-mg/ml solution. The solution was divided intothree aliquots and treated with unactivated mPEG5000 inmolar amounts equal to 25-, 50-, and 100-fold of BSA.These three samples were labeled as A, B, and C, respec-tively. Another three samples (1 mg/ml) were prepared byintroducing BSA into 0.2 M phosphate buffer at pH 7.0,7.5, and 8.0. Then SC-PEG5000, which was synthesizedand activated according to the procedure of Zalipsky andco-workers [10], was added at a 50:1 molar ratio ofSC-PEG to BSA. These three samples were labeled asD, E, and F, respectively.The samples were kept at room temperature for30 min. Then reactions were terminated with excessiveacetic acid. Modification extents (i.e., polymer contentin pegylated proteins) were determined according toTNBS method [11] and were 0, 0, 0, 8.2, 14.8, and26.6% for samples A, B, C, D, E, and F, respectively.Samples were diluted precisely to theoretical concentra-tions 100, 50, and 25 lg/ml. The Lowry method [2]and the Bradford method [7] were carried out to deter-mine protein concentrations. The relative error (Er) wascalculated according to Eq. (1):Er ¼d tt 100%; ð1Þwhere Er is the relative error, d is the determined concen-tration, and t is the theoretical concentration. The absolutevalue of Er was taken for two-way analysis of variance(ANOVA). The Duncan’s simple sequence repeat (SSR)test was chosen for multiple means comparison. Thecriterion of statistical significance was taken as P 0.05), but activated SC-PEG had a verysignificant influence on it (P < 0.01). Some of the

Background Understanding the metabolic mechanism of sterols to produce valuable steroid intermediates in mycobacterium by a noncoding small RNA (sRNA) view is still limited. In the work, RNA-seq was implemented to investigate the noncoding transcriptome of Mycobacterium neoaurum (Mn) in the transformation process of sterols to valuable steroid intermediates, including 9α-hydroxy-4-androstene-3,17-dione (9OHAD), 1,4-androstadiene-3,17-dione (ADD), and 22-hydroxy-23, 24-bisnorchola-1,4-dien-3-one (1,4-BNA). Results A total of 263 sRNA candidates were predicted from the intergenic regions in Mn. Differential expression of sRNA candidates was explored in the wide type Mn with vs without sterol addition, and the steroid intermediate producing Mn strains vs wide type Mn with sterol addition, respectively. Generally, sRNA candidates were differentially expressed in various strains, but there were still some shared candidates with outstandingly upregulated or downregulated expression in these steroid producing strains. Accordingly, four regulatory networks were constructed to reveal the direct and/or indirect interactions between sRNA candidates and their target genes in four groups, including wide type Mn with vs without sterol addition, 9OHAD, ADD, and BNA producing strains vs wide type Mn with sterol addition, respectively. Based on these constructed networks, several highly focused sRNA candidates were discovered to be prevalent in the networks, which showed comprehensive regulatory roles in various cellular processes, including lipid transport and metabolism, amino acid transport and metabolism, signal transduction, cell envelope biosynthesis and ATP synthesis. To explore the functional role of sRNA candidates in Mn cells, we manipulated the overexpression of candidates 131 and 138 in strain Mn-9OHAD, which led to enhanced production of 9OHAD from 1.5- to 2.3-fold during 6 d’ fermentation and a slight effect on growth rate. Conclusions This study revealed the complex and important regulatory roles of noncoding small RNAs in the metabolism of sterols to produce steroid intermediates in Mn, further analysis of which will promote the better understanding about the molecular metabolism of these sRNA candidates and open a broad range of opportunities in the field. Electronic supplementary material The online version of this article (doi:10.1186/s12934-016-0462-2) contains supplementary material, which is available to authorized users.