Abstract:[Objective] To construct a full-length expression cDNA library from Aspergillus oryzae RIB40 for screening and cloning genes related to the synthesized pathway of secondary metabolites in Aspergillus oryzae. [Methods] Total RNA was isolated from A. oryzae RIB40 using the method of RNAiso and mRNA was purified by PolyATract mRNA Isolation System III. Single-strand cDNA and double-strand cDNA were synthesized from about 5 μg mRNA using ZAP-cDNA Synthesis Kit and the cDNA were fractionated by the CHROMA SPIN-400 column, then ligated into Uni-ZAP express vector and packaged. [Results] A high quality full-length expression cDNA library from the A. oryzae RIB40 was constructed. The titer of the primary library was 2.96×106 CFU/mL with a recombination rate of 97.8% and the average length of inserted fragments was more than 1.5 kb. Furthermore, the titer of the amplified library achieved to 3.4×1010 CFU/mL. [Conclusion] The cDNA library which constructed in this study provides a basis for basic biological research and screening and cloning of the target gene of Aspergillus oryzae.

Abstract:[Objective] In order to functional analysis the N-terminus of keratinase from Bacillus licheniformis and its effect on the activity and thermostability of keratinase, the N-terminus of keratinase was reconstructed by molecular modification. [Methods] The N-terminus residues of keratinase were deleted individually and replaced by an N-terminus of thermitase from Thermoactinomyces vulgaris through sequence alignment. The recombinant keratinases of wild-type and mutants were production in Bacillus subtilis WB600 and then purified for characterization. [Results] Deletion of N-terminus of keratinase resulted in enzyme activity decreased prominently, when deficiency of five residues the activity of enzyme was completely abolished. Although replacement of N-terminus from thermitase decreased the activity of keratinase, the thermostability of mutant was enhanced compared with wild-type. The half-live of thermal inactivation (t1/2) was enhanced from 9 to 20 min at 60 °C. [Conclusion] The N-terminus of keratinase was important for enzyme activity, replacement of N-terminus between keratinase and thermitase could efficient enhanced thermostability of keratinase.

Abstract:[Objective] To explore the microbial community structures and diversity in pit mud from two typical Chinese Luzhou-flavor liquor producing areas, and to investigate the regional characteristic of microbial community and the effects on the formation of the liquor style. [Methods] Total DNAs were extracted from pit mud from Sichuan and Anhui liquor producing areas, respectively. Bacteria and Archaea were analyzed by PCR-ARDRA and 16S rRNA gene clone sequencing. [Results] The bacteria in pit mud from two Luzhou-flavor liquor producing areas were rich, including Firmicutes, Bacteroidetes, Chloroflexi, Synergistetes, Armatimonadetes and Unclassified bacteria. The predominant bacteria from both areas were clostridia in Firmicute. More Synthrophomonas and Petrimonas were detected in pit mud from Sichuan liquor producing area. Archaea composition was relatively simple. Methanoculleus, Methanosarcina, Methanosaeta and Methanobacterium were the major methane-producing archaeal group. The predominant archaea in Sichuan liquor producing area were Methanoculleus and Methanosarcina; while the predominant archaea in Anhui liquor producing area were Methanosarcina and Methanosaeta. [Conclusion] The 16S rRNA gene clone libraries not only systematically reflect the similarities and differences of microbial community between Sichuan and Anhui liquor producing areas, but also is valuable for revealing the formation of differences in liquor body style between two Chinese Luzhou-flavor producing areas.

Abstract:[Objective] In order to raising yields and reducing production costs, we optimized succinic acid production from Actinobacillus succinogenes GXAS137 by simultaneous saccharification and fermentation (SSF) with cassava flour as carbon source. [Methods] The important parameters were screened by the single factor experiment and Plackeet-Burman design. Then, the optimum values of the parameters were obtained by orthogonal experiment design. [Results] The results showed that corn steep liquor (CSL) was used as a proper nutrient in the succinic acid production from cassava flour. The optimum medium compositions were determined as (g/L): cassava flour 100, CSL 14, glucoamylase dose 2.0 AGU/g substrate and MgCO3 75. The succinic acid yield reached 69.31 g/L at the optimal condition. The conversion rate of cassava to succinic acid reached 90.01% and succinic acid productivity was 1.44 g/(L·h). The succinic acid content increased by 32.42% than that without the optimized condition (56.86 g/L). The simultaneous saccharification fermentation (SSF) and separated hydrolysis and fermentation (SHF) were compared with 1.3 L fermenter. The results showed that the succinic acid of SSF (72.21 g/L) was superior than SHF. [Conclusion] The high-level succinic acid production and low production cost from cassava flour may facilitate industrial scale application in future.

Abstract:[Objective] In the present study, response surface methodology (RSM) was used to optimize the fermentation conditions of MFS (metabolite of Fusarium solani FG319) extracted from marine microorganism, Fusarium solani. [Methods] On the basis of single factor tests, Box-Behnken RSM was employed with three factors such as addition of L-ornithine hydrochloride at different concentrations, culture time, and culture temperature on the yield of MFS. [Results] The optimum culture conditions were as follows: the L-ornithine hydrochloride addition was 0.6% (W/V), culture time was 7 d, culture temperature was 22 °C. Under these conditions the yield of MFS was 20.11 mg/L, which is 4 times increased than without any optimization and the relative error with the theoretical value was 0.64%. The inhibition rate of MFS on HMG-CoA reductase was achieved above 100 mg/L, and has a similar inhibition as Lovastatin. [Conclusion] The culture conditions obtained by response surface methodology were effective and reliable, and the effect of MFS on HMG-CoA reductase is obvious in vitro.

Abstract:[Objective] In order to estimate the application of some bacteria and yeast in the treatment of distillers’ grains. [Methods] Three strains of bacteria and 2 strains of yeast isolated from Luzhou flavor liquor brewing environment were mixed in different groups, then inoculated to the distillers’ grains by an inoculum of 2% without any additives. The main constitutions of the grains were detected to estimate the effects of these strains. [Results] The results showed that the content of acid and cellulose of the distillers’ grains decreased, and the protein increased in all treatments, especially, the cellulose in B5 degraded 23.89% and the content of the protein in B4 improved to 17.792% by a rate of 74.01%. [Conclusion] These mixed strains were predictively effective and available in lees feed or organic fertilizer producing.

Abstract:[Objective] We isolated and identified di(2-ethylhexy) phthalate-degrading strains. [Methods] We isolated and domesticated the strain by gradient enrichment culture. We identified the strain by 16S rRNA gene and gyrB gene sequence analysis, combined with morphological, physiological and biochemical characterization. And we analyzed the degradation characteristics of the strain using High Performance Liquid Chromatography (HPLC). [Results] A strain (named HS-NH1) with DEHP-degrading activity was obtained and identified as Gordonia sp.. The optimum temperature and pH for growth and degradation of Gordonia sp. HS-NH1 were 30 °C and 7.0 respectively, strain HS-NH1 was able to almost degrade 500 mg/L di(2-ethylhexy) phthalate to above 90% within 60 hours. One of the major metabolites of di(2-ethylhexy) phthalate degradation were identified as phthalic acid by HPLC. A substrate utilization test showed that HS-NH1was also able to utilize many other common phthalates. [Conclusion] A bacterial strain with a high di(2-ethylhexy) phtha-late-degrading efficiency was obtained, and the strain may have a potential application in dealing with the pollution caused by phthalate esters.

Abstract:[Objective] The diversity of fungi in soils and sediments of Erdos paleo salt lake in Inner Mongolia and the strains containing functional enzymes were identified. [Methods] Three isolation media containing designed concentrations of NaCl were used to separate and cultivate fungi. Based on analysis of morphology and ITS sequences, the phylogenetic of tested bacterial strains was performed. The enzyme activity in the salt lake fungi was qualitatively determined using 6 kinds of screened media. [Results] Total 2 121 strains of fungi were separated from the salt lake. These strains were divided into 45 morphospecies and 27 generas based on the analysis of morphology and ITS sequences. The dominant genus was Aspergillus. Twenty-two of 45 morphospecies produced enzyme, six produced protease(s), six produced cellulase(s), two produced compound enzyme, one produced amylase enzymes and one produced lipase. Meanwhile, four morphospecies could simultaneously produce three. [Conclusion] The fungi from the Erdos salt lake in Inner Mongolia are rich in diversity and can produce various enzymes. This study provides a basis for the further characterization and utilization of halophilic microbes.

Abstract:[Objective] The diversity of fungi in soils and sediments of Erdos paleo salt lake in Inner Mongolia and the strains containing functional enzymes were identified. [Methods] Three isolation media containing designed concentrations of NaCl were used to separate and cultivate fungi. Based on analysis of morphology and ITS sequences, the phylogenetic of tested bacterial strains was performed. The enzyme activity in the salt lake fungi was qualitatively determined using 6 kinds of screened media. [Results] Total 2 121 strains of fungi were separated from the salt lake. These strains were divided into 45 morphospecies and 27 generas based on the analysis of morphology and ITS sequences. The dominant genus was Aspergillus. Twenty-two of 45 morphospecies produced enzyme, 6 produced protease(s), 6 produced cellulase(s), 2 produced compound enzyme, 1 produced amylase enzymes and 1 produced lipase. Meanwhile, 4 morphospecies could simultaneously produce three. [Conclusion] The fungi from the Erdos salt lake in Inner Mongolia are rich in diversity and can produce various enzymes. This study provides a basis for the further characterization and utilization of halophilic microbes.

Abstract:[Objective] Our purpose is to screen the strains that degrade the nitrite. [Methods] We screened the target strains on plate with nitrite selective medium from more than 20 samples such as water, soil and deadwood. We tested the ability of the target strains degrades nitrite by the method of hydrochloric acid naphthalene ethylenediamine. Cadmium column reduction method and test paper method were used to detect the metabolic product of nitrite in the strains. We identified the target strains by morphological characteristics, hyphal and conidial morphology and homology of ITS rDNA sequence and β-Tubulin gene sequence and Calmodulin gene sequence. [Results] We obtained a biodegradable nitrite strains JFS. The strains JFS has a strong ability to degrade nitrite and degrade nitrite to non-toxic nitrate and NH4+. Even concentration of nitrite up to 20% in medium, it also grows very well. According to the morphology, the requirement to culture medium, the 3 gene sequences and phylogenetic studies, the strains JFS belongs to the Aspergillus parasiticus. We identified it as Aspergillus parasiticus. [Conclusion] The strains JFS has a strong ability to degrade nitrite.

Abstract:[Objective] Cloning of a new gene possessing a function of Echinocandin B (ECB) side-chain deacylation from a wild type Streptomyces strain NCPC-1020 of soil source. [Methods] Using degenerate PCR and TAIL PCR strategy, we successfully cloned the target gene, which was heterologously expressed in S. lividans TK24, then a whole-cell catalysis method was developed to dectect the deacylation activity of ECB deacylase by LC-MS. [Results] The ECB deacylase gene was cloned and its function was confirmed. [Conclusion] Combined the two PCR techniques, degenerate and TAIL PCR, a new gene could be cloned quickly. The obtain of the new ECB deacylase gene lays a good foundation for the researches on semibiosynthetic of ECB related drugs.

Abstract:[Objective] Endophytic actinomycete FRo2 with activity against agricultural pathogenic fungi was isolated from the roots of Dongxiang wild rice (Oryza rufipogon). We identified FRo2 and separated its antimicrobial substances. [Methods] Morphological, physiology and biochemistry characteristics, chemotaxonomy analysis and 16S rRNA gene sequences were used to identify FRo2. The bioactivities were determined by tube plate method and mycelium growth inhibition method. According to nuclear magnetic resonance spectroscopy (NMR) extrapolation result, one antimicro-bial substances in the metabolites of FRo2 through normal-phase silica gel column chromatography and gel (Sephadex LH-20) column chromatography with bioassay-guided fractionation was isolated. [Results] FRo2 belonged to Streptomyces sp. and was similar to Streptomyces rochei. The metabo-lites had high inhibitory activities against Fusarium graminearumt, Rhizoctonia solani and other five agricultural pathogenic fungi, and the antimicrobial substances AW2 was elucidated as Dibutyl phthalate. [Conclusion] The material basis of the antibacterial constituents in antagonistic actinomy-cetes strain FRo2 was further clarified, and strain FRo2 is deserved to develop an biocontrol.

Abstract:[Objective] To determine the typical RGS in Colletotrichum graminicola, and its signal peptide, transmembrane region and the secondary structure, and to provide a strong theoretical foundation for studying the positioning and function of RGS, but also provide an important theoretical guidance to clarify the other pathogen in Colletotrichum spp.. [Methods] Based on the four typical RGS sequences have been reported in Saccharomyces cerevisiae, to search RGS related protein sequence from the protein databases of Colletotrichum spp. with the BLASTp as well as the use of words, and to search the conserved domain in the SMART online. Meanwhile, bioinformatics analysis have made including the signal peptide, trans-membrane domain structure and the secondary structure, In addition, analysis of genetic relationships through comparative typical RGS in C. graminicola with homologous sequences of other species. [Results] There are six typical RGSs in C. graminicola, which have higher proportion of helical secondary structure. And these RGS do not contain the typical signal peptide sequence except for CgRGS6, and the half of six RGSs positioned in the nucleus, and the other is positioned in the plasma membrane, endoplasmic reticulum, and mitochondria, respectively. [Conclusion] C. higginsianum, C. gloeosporioides Cg-14/Nara gc5, C. orbiculare has a high sequence homology and close genetic relationship with C. graminicola.

Abstract:[Objective] Ten endophytic strains obtained from Poa angustifolia grown in mountains of Huangjin and Baiyu in Liaoning Province were identified. [Methods] Asymptomatic P. angustifolia samples were collected. Plant culms from each sample were stained by Rose Bengal (1%) for 5 minutes. Hyphae were detected under microscope and the infection level was calculated. The fungal strains were isolated, purified and incubated to observe the morphological properties. Fungal genomic DNA samples were extracted by IQS DNA extraction method. Fragments of β-tubulin (tubB) and translation elongation factor 1-α (tefA) genes were amplified by specific PCR primers for isolated strains. Sequences of tubB and tefA were aligned and analyzed by DNAssist 2.2 and ClustalX 1.81, the model was selected by PAUP 4 beta 10 and MrModeltest 2.3. The phylogenetic characteristic of these strains were analyzed through the maximum likelihood tree performed by MrBayes 3.1.2. [Results] Total of 262 Poa angustifolia samples were collected, 57.3% of the plants were infected while no stroma was discovered on the culms. Ten endophytic strains were isolated and purified from these plants samples. Six strains were used to observe the morphological properties. Each of them was identical with those of epichloid endophytes. Comparing with other endophytes from Poa spp. plants, morphological characteristics of the strain were similar to E. liyangensis except smaller conidia and slower growth rate. Five strains were confirmed to possess single alleles of tubB and tefA. Phylogenetic trees based on tubB and tefA fragments respectively revealed that these 5 strains clustered with the second alleles of E. liyangensis. [Conclusion] These results indicated significant differences between these strains and E. liyangensis. Based on the host species and geographic distribution of other endophytes from Poa spp. plants, they might be a new taxonomic group of epichloid endophyte.

Abstract:[Objective] The composition and diversity of intestinal microbial diversity of wild Sichuan snub-nosed monkey (Rhinopithecus roxellana) were investigated. [Methods] The total DNA extracted from endophytic bacterial was performed 16S rRNA gene specific amplification by used bacteria-specific primers 799F and 1492R and constructed a clone library. Then, 16S rRNA gene phylogenetic tree was established by analyzed positive clones used polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and by sequenced some of the clones. [Results] The 157 clones analyzed were grouped into 27 operational taxonomic units (OTUs), where the clone distribution was as follows: 62.10% of Firmicutes which contained Clostridium, Cellulosilyticum, Robinsoniella, Anaerofustis, Anaerovorax and Blautia, 37.90% of uncultured bacteria. [Conclusion] The intestine bacterial of wild Sichuan snub-nosed monkey has a rich diversity and maybe exist new taxon.

Abstract:[Objective] The aim of this work was to investigate the inhibition mechanism of D-cycloserine (DCS) on alanine racemase from Mycobacterium tuberculosis (AlrMtb), and build up a high-throughput screening assay to screen for new inhibitors of AlrMtb. [Methods] The AlrMtb gene was cloned into pET28a vector and over-expressed in soluble form in E. coli strain BL21(DE3). The protein was purified using Ni2+-chelating chromatography followed by anion exchange chromatography. The AlrMtb protein was co-crystallized with DCS to make clear of the inhibitory mechanism. In addition, a high-throughput screening assay for new inhibitors was set up in order to obtain new anti-tuberculosis drugs that inhibited AlrMtb activity. About 384 small-molecule fragments, 792 chemicals and 2 200 components of traditional Chinese Medicine were tested in this assay where DCS was used as the positive reference. [Results] The protein crystals of AlrMtb-DCS complex diffract to 2.5 ?. The space group of the crystals is P41212 with cell parameters a=b=163.92 ?, c=57.44 ?. In the AlrMtb-DCS structure model, DCS was shown to react with PLP and formed a new molecule PMP. This process disrupted previous interaction between the C4? atom of PLP and Lysine 42 in AlrMtb and thereby changed the hydrogen bonding network in the active site. Via the high-throughput screening assay, we successfully identified two new inhibitors of AlrMtb. [Conclusion] The high-throughput inhibitor screening assay we built is an effective and powerful methodfor theidentification of new inhibitors of AlrMtb.

Abstract:[Objective] Response surface analysis was applied to optimize the fermentation conditions for producing fibrinolytic enzyme strain CNY16, and preliminarily studied its enzymology characteristics. [Methods] Through the Plackett-Burman design, the most significant effect on fibrinolytic enzyme production was obtained which include yeast extract, sodium chloride and revolving speed. The highest fibrinolytic activity area was investigated by the steepest climbing experiments, then, the optimal fermentation conditions of producing fibrinolytic enzyme strain CNY16 was analysised by Box-Behnken central composite design experiments. [Results] The optimal fermentation conditions of strain CNY16 was determined for 3.28% yeast extract, 1.14% sodium chloride, rotate speed at 166 r/min, the enzyme activity was 875.932 U/mL, the optimized enzyme activity was 46% higher than before. The optimum temperature for the fibrinolytic enzyme was 30 °C and the optimum pH was 6.5. [Conclusion] This experiment determined the most optimal fermentation conditions for producing fibrinolytic enzyme strain CNY16 and researched part of enzymatic properties, laied a foundation for further research and experiment of the the pilot study.

Abstract:[Objective] To study bacterial translocation of rats with hepatic cirrhosis, and to explore the interventional effect of betaine on bacterial translocation. [Methods] Forty-eight male SD rats were randomly divided into four groups, two groups were normal control group (N group and NB group), and the other two were hepatic cirrhosis models (M group and MB group). In each condition, one group of rats was intragastrically administered with 1 000 mg/kg body weight betaine once daily for 4 weeks and 6 weeks (NB or MB group), whereas the other was treated with an equal volume water (N or M group). The rat model of hepatic cirrhosis was induced by multiple pathogenic factors. The injury of liver and small intestine was observed with HE stain. The organ indices were detected, and the bacterial translocation was assessed by standard microbiological techniques on blood, mesenteric lymph nodes, ascites, liver, spleen and kidney. [Results] The weight of M group was found to be significantly lower compared to N group (P=0, P<0.01), and the weight of MB group was picked up compared to M group, it was significantly higher at the end of 6 weeks (P=0.023, P<0.05). In M group to N group, the liver index (P=0, P<0.01) was significantly higher at the end of 4 weeks; the organ index of liver (P=0, P<0.01) and spleen (P=0.038, P<0.05) was significantly higher, and that of kidney (P=0.019, P<0.05) was significantly lower at the end of 6 weeks. And the organ index of liver (P=0.038, P<0.05) was fell back, that of kidney (P=0.011, P<0.05) was picked up in MB group to M group. The pathologic change of liver and small intestine was obvious in M group to N group, and it was reduced in MB group to M group. The bacterial translocation in M group was higher than that in N group, and it occurred mainly in MLN at the end of 4 weeks, in MLN and kidney at the end of 6 weeks; the bacterial translocation was lower in MB group than that in M group, especially in mesenteric lymph nodes (P=0.046, P<0.05). [Conclusion] The bacterial translocation occurs mainly in MLN and kidney, and it is mainly transferred by lymphatic vessels in rats with hepatic cirrhosis. With the progress of the course of cirrhosis, BT is more and more serious. Betaine can decrease the occurrence of bacterial translocation by the restoration of small intestine mucosal structure in some degree, and it has a protective effect on liver injury in rats with hepatic cirrhosis.

Abstract:[Objective] The taxonomic status and antioxidant properties were studied on the radiation resistant strain W36-1 producing polysaccharide from the radiation-tainted soil of Xinjiang. [Methods] The strain W36-1 with the 60Co gamma rays irradiation was classified in combination with characteristics of hyphae of colony morphology and microscopic observation and Biolog appraisal and the analysis of the 16S rRNA gene sequences. Phenol-sulfuric acid method was employed to determine polysaccharide contents, the polysaccharides on O2- scavenging effect were measured by the Fenton method, the anti-oxidative effects of extracts were studied by using DPPH and pyrogallol autooxidation methods. [Results] The strain W36-1 was a novel species as genera Erwinia, and it could survive at 5 kGy of the 60Co gamma rays irradiation. The crude polysaccharide content was 53.17%, its polysaccharide to the ultra oxygen anion clearance rate was 75.63%, the DPPH clearance rate was 62.43%, the hydroxyl free radical removal rate was 54.89%. [Conclusion] The polysaccharide from the strain W36-1 has the antioxidant capacity.

Abstract:Candida albicans is one of the most important opportunistic pathogens. In order to adapt to the various ecological niches of the host, Candida albicans has evolved a variety of sophisticated metabolic strategies to maintain iron homeostasis, including multiple iron acquisition systems that target the cell membranes, and the mechanisms that coordinate intracellular iron trafficking. Here, combined with our study, we review the research advances of iron acquisition, storage and transportation strategies in recent years, focusing on intracellular iron storage and transport, especially the roles of mitochondria in cellular iron metabolism and homeostasis.

Abstract:γ-PGA hydrogel, a kind of polymer materials with properties of water absorption, water retention and environmental friendly, was introduced. This paper mainly reviewed the synthesis of γ-PGA hydrogel, γ-PGA composite hydrogel and their applications in agriculture and industry.

Abstract:Riboswitches are structured RNA domains usually residing in the 5′-untranslated region of messenger RNAs as RNA sensor elements, which can bind specifically and directly to certain metabolites to induce corresponding changes in their conformation and activate or inhibit the transcription, translation, and splicing of mRNA to regulate gene expression without the need for any regulatory factors. Some riboswitches can be used as novel targets for antibacterial drug discovery. This article reviews the structure of the Flavin mononucleotide (FMN) riboswitch, the mechanism of regulation of gene expression and thermodynamic, kinetic studies for the FMN riboswitch. The design and screen for the new generation of antibiotics based on FMN riboswitch are also discussed.

Abstract:Toxic organic contaminants are widely released into environment, which cause adverse impact on human health and environment due to their high biotoxicant, persistence and bioaccumulation. Recently, it has achieved some research progresses on the use of nitrate as an electron acceptor for the degradation of toxic organic pollutants under anaerobic conditions. In this paper, we reviewed the recent progresses on the anaerobic degradation of some typical toxic organic contaminants (polycyclic aromatic hydrocarbons, single ring or heterocyclic organic pollutants and halogenated organics) under nitrate-reducing conditions. In addition, the next challenges, as well as the new perspectives on this field were also discussed.

Abstract:Cyanophages are a group of viruses infecting the cyanobacteria, and are widespread in both marine and freshwater environments. As important components of microbial communities,cyanophages play significant roles in cyanobacterial population structure and diversity and aquatic ecological environments. yanophages contain some host-like metabolic genes, as to auxiliary metabolic genes, which encode proteins involved in the light reactions of photosynthesis, pentose phosphate pathway, nutrient acquisition and DNA biosynthesis during the process of infecting cyanobacteria. Recently, some auxiliary metabolic genes have been used as target genes for investigating cyanophage diversity, and the interactions between cyanophages and nobacteria. In this review, we summarized advances in studying the origin, biological function and genetic diversity of cyanophage auxiliary metabolic genes at home and abroad.

Abstract:Bacterial cellulose is a porous, mesh, nanoscale and biological polymer, which syntheses by microbial fermentation. Due to its special properties of high ability of hydrophile and ventilate, good biocompatibility, high mechanical strength and three-dimensional net structure etc. It will have broad applications in textile industry, the medical dressings, tissue engineering, food and conductive material etc. In this paper, the latest research progress in recent years is reviewed and its future development is also discussed.

Abstract:Pexophagy is an important self-regulation mechanism. It is composed of various interactions by many autophagy related proteins (Atgs) according to strict spatial and temporal orders. Pichia pastoris was selected as the model to clarify the pexophagy mechanism for following reasons: two pexophagy modes, genome sequenced, and well-established gene manipulation protocols. In this review, the mechanism for Atgs involved in pexophagy activation, two pexophagy modes formation, and peroxisome degradation in vacuole of Pichia pastoris were organized, which provided a solid foundation for further research.

Abstract:[Objective] CAS(Chrome azurol S) overlay plate method was used for the detection of siderophore from hydrogen-oxidizing bacteria, to address the problem of growth inhibition for fungi and certain bacteria caused by hexadecyltrimethyl-ammonium bromide (HDTMA) in the popular CAS assay. [Methods] We just need to coverage the modified CAS medium on iron-free culture agar plates covered with colonies, then the problem of growth inhibition could be removed, due to the microorganisms tested with no direct contact with the hexadecyltrimethyl-ammonium bromide (HDTMA). [Results] Three strains of hydrogen-oxidizing bacteria, SDW-5, SDW-9, AaP-13 could form single colony, the siderophore halo around the colonies will form in an hour after a modified CAS medium is covered on iron-free culture agar plates. [Conclusion] This method successfully avoided growth inhibition problems, hence it could become a universal method for the detection of microorganisms siderophores.

Abstract:

Abstract:[Objective] Surface alteration of realgar by Acidithiobacillus ferrooxidans BY-3 were investigated in this work. The fundamental knowledge derived from this study should provide an experimental and theoretical foundation for further investigation into the biotechnological applications in realgar extraction. [Methods] The bioleaching experiment was divided into four groups (each containing 100 mL of 9K medium without ferrous iron and 0.500 g of realgar): the first group had no additions; the second group had 4.469 g of FeSO4·7H2O added; the third group had 0.100 g of sulfur added; and the fourth group had 4.469 g of FeSO4·7H2O and 0.100 g of sulfur added. A. ferrooxidans BY-3 were used throughout the bioleaching experiments. Before and after bioleaching on the surface alteration and chemical properties of realgar were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy and inductively coupled plasma atomic emission spectroscope (ICP-AES). [Results] All of bioleaching systems shown that A. ferrooxidans BY-3 cells were attached to the surface of the realgar particles. The results suggested that A. ferrooxidans BY-3 cells must be essentially attached so that the direct action occurs. Bioleaching systems in the presence of ferrous iron indicated that surface alteration of realgar was discernible change, whereas bioleaching systems with sulfur was the other way round. Compared to the other three bioleaching systems, there was a higher ratio of As/S by A. ferrooxidans in the medium with ferrous iron as the only substrate. In addition, the mineral composition found in the solid residues after bioleaching comprised jarosite, sulfur, hematite, gothite and magnetit, whereas As2O3 and pararealgar were not observed. [Conclusion] A. ferrooxidans has plays an important role in the alteration of realgar. The effect of ferrous irons could enhance the alteration of realgar by A. ferrooxidans BY-3, while sulfur plays a negative role in the bioleaching of realgar. This study shown that bioleaching technology can effectively solve the problems which oxidation and photochemistry of realgar due to the traditional preparation and the storage of realgar.

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