Abstract:[Objective] An L-aspartate α-decarboxylase gene was amplified from Corynebacterium glutamicum and expressed in Escherichia coli, to catalyze L-aspartate to β-alanine. The catalysis characterization of this α-decarboxylase was also studied. [Methods] The Pand gene was amplified from C. glutamicum and cloned into the expression plasmid pET24a(+), the recombinant plasmid was transformed into E. coli BL21(DE3). Pand was then successfully expressed with induction. To explore the enzymatic characteristics of Pand, high purity of Pand was obtained by DEAE ion exchange chromatography and G-75 chromatography. Then the effects of substrate and product on enzymatic conversion were studied. [Results] The Pand constituted more than 50% of the total cell proteins and achieved the activity of 94.16 U/mL analyzed by SDS-PAGE and AccQ·Tag assays respectively. The optimal reaction temperature of the purified Pand was at 55 °C and stable below 37 °C. The optimal reaction pH of Pand was at 6.0 and stable at 4.0?7.0. The enzymatic synthesis was inhibited by L-aspartate and β-alanine. When L-Asp was added in batches with 3 000 U Pand per gram L-Asp, the conversion ratio of 100 g/L L-Asp reached 97.8%. [Conclusion] The L-aspartate α-decarboxylase gene from C. glutamicum was successfully expressed in E. coli.

Abstract:[Objective] We are aiming to analyze the energy metabolism of A. pasteurianus CICIM B7003-02 during high acidic vinegar fermentation so that we can identify the targets to enhance the energy metabolism for vinegar productivity improvement. [Methods] Tricarboxylic acid cycle metabolism, alcohol respiratory chain enzyme activity and relative transcriptional level of enzyme-coding genes in energy metabolism pathways were investigated during the high acidic vinegar fermentation by B7003-02. [Results] We have characterized the bacterial energy metabolism during high acidic vinegar fermentation. Malic/succinic acid feedback pathway is the major route for energy supply at the beginning of fermentation, and alcohol respiratory chain plays the major role in providing energy to cells during the major acetification phase. Both malic/succinic acid feedback pathway and the alcohol respiratory chain supply energy when fermentation approaches its final stage. [Conclusion] Energy supply influences vinegar productivity, the supplementation of malic acid and succinic acid can strength the malic/succinic acid feedback pathway and improve vinegar productivity.

Abstract:[Objective] In order to understand the functions of lactic acid bacteria (LAB) in the production of Chinese liquor, differences of LAB community in liquor brewing between soy sauce aroma style and light aroma style were analyzed. [Methods] PCR-DGGE was used to analyze LAB community during the liquor fermentation of soy sauce aroma style and light aroma style. The main LAB in the fermented grains of soy sauce aroma style were identified through culture-dependent method. [Results] DGGE profiles showed that Lactobacillus was the main LAB in liquor brewing. However, LAB community structure during the fermentation process of two style liquor appeared different succession rules. Lactobacillus fuchuensis was the dominant species in the fermented grains of light aroma style. And several LAB species with relatively high percentage were detected in soy sauce aroma style by culture-independent method. Five species were isolated from the fermented grains of soy sauce aroma style using MRS media. Results of two methods proved that Lactobacillus homohiochii was predominant in the brewing process of soy sauce aroma style. [Conclusion] This work explored LAB community structure in the fermentation process of Chinese liquor, which would helpful to scientifically understand the important roles of LAB in the liquor production.

Abstract:[Objective] An analysis of the reason for the yeast flocculation in the process of replicative aging by observation and determination to the physiological properties and cell wall proteins was done in the process of yeast continuous subculture. [Methods] 2-D gel electrophoresis method and infrared spectroscopy method were used to detect the protein on yeast cell wall in the process of continuous subculture. [Results] As the process of subculture continued, the number of sports that could be shown clearly in the 2-D gel electrophoresis picture increased. At the same time, the absorption at the wavelength of 890.51 cm?1 and 808.48 cm?1 decreased in the infrared spectroscopy picture. [Conclusion] In the process of yeast continuous subculture, the degree of glycosylation modification is gradually reducing and the protein groups on the yeast cell wall are getting different which brings changes on the strength of cell wall surface to make the flocculation of yeast stronger.

Abstract:[Objective] In the condition of initial pH ranging from 5.0?10.0, the influence of different valence forms of iron (Fe0, Fe2+ and Fe3+) on 2,4,6-trichlorophenol (2,4,6-TCP) degradation by anaerobic microorganism was studied. [Methods] A batch test in the laboratory was conducted by the addition of Fe0, Fe2+ or Fe3+ in the anaerobic system, through inoculating the anaerobic mixed microorganism acclimated for three months. 2,4,6-TCP concentration, pH value, iron ion concentration and microbial dehydrogenase activity was measured. [Results] When the initial pH value is neutral or acidic, the Fe2+-microorganism system could exert an accelerative effect on the 2,4,6-TCP degradation than the others, while the initial pH value is alkalic, the “Fe0-microorganism” system has better performances on the 2,4,6-TCP degradation than the others; each of the “Fe0/Fe2+/Fe3+-microorganism” system has the ability to adjust pH, furthermore, the “Fe0-microorganism” system performs better; in the condition of different initial pH values, the influence of different valence iron on anaerobic microbial activity and 2,4,6-TCP degradation are the same. [Conclusion] The influence of different valence forms of iron on 2,4,6-TCP degradation by anaerobic microorganism is related to the factors such as initial pH value, real-time pH value, iron valence and its concentration.

Abstract:[Objective] The aim of this study is to isolate efficient cadmium-tolerant fungi from soils contaminated by heavy metals, and thereby to provide strains for heavy metals’ bioremediation. [Methods] Nine soil samples from Bingcun Pb-Zn mining waste land, Mei County, Guangdong Province, were used to isolate by dilution plate coating method with four different media. Strains were identi?ed by morphology and ITS rDNA sequence analyses. Minimum inhibitory concentration (MIC) for the isolated strains was also determined. [Results] Seventy-two cadmium-tolerant filamentous fungi belonging to the genera Aspergillus, Penicillium, Cladosporium, Lecythophora, Paecilomyces, Fusarium and others were isolated from the mining land. Four strains, i.e. Paecilomyces lilacinus (Thom) Samson (6-20p), Penicillium pinophilum Hedgcock (6-16p), Penicillium rolfsii Thom (6-16m) and Fusarium oxysporum Schlecht. (8-11p), were resistant to high cadmium concentrations of 200, 40, 25, and 15 mmol/L, respectively. [Conclusion] The strains isolated from contaminated soils showed minimum cadmium-tolerance to 1 mmol/L, thus they may play a role in the bioremediation of heavy metal pollution soils. The results imply the promising biosorption of cadmium-tolerant strains for bioremediation of heavy metals.

Abstract:[Objective] Microbial soil crusts (MSCs) play an important role in the restoration of the ecological environment and the containment of soil desertification. The microbes in MSCs, especially the cellulose degrading bacteria (CDB), can stablize and repair the related ecological environment. The induction of exogenous cellulose is a major pathway for the full acknowledgment in the CDB’s diversity and their contribution to MSCs’ development. [Methods] Two cellulose materials (crushed wheat straw and sawdust) were added into MSCs separately, to determine the variation of the bacterial community induced by the exogenous cellulose based on PCR-DGGE. [Results] The exogenous cellulose especially wheat straw, rapidly increased the diversity and richness of bacterial community by approximately 66.7% and 15.8%, respectively. Samples subjected to the same treatment well grouped in together in cluster analysis based on DGGE bands profiles, suggesting that cellulose has a crucial effect on the bacterial community. The exogenous cellulose induced a remarkable variation of the structure of the bacterial community, of which the most variable was caused by wheat straw. Firmieutes and Alphaproteobacteria groups were always the predominant group in all samples. Among the obtained sequences, 13 bands were closely and phylogeneticly related to CDB and therefore they may be sourced from CDB. The anaerobic Clostridium group predominated these possible CDB (accounted for 46.1%), followed by Bacillus (30%). The exogenous cellulose degradation also induced the increase of the abundance or richness of some specific bacteria, like Microcoleus vaginatus and some Alphaproteobacteria groups, which had a significant function in MSCs development with the abilities in secreting polysaccharides to enhance the cohesion of soil particles or fixing carbon and/or nitrogen to improve the soil nutrition level. [Conclusion] Results provided a basis for the appreciation of the CDB diversity and the variation of the bacterial community structure induced by exogenous cellulose, and meanwhile lent theory evidence for the practical pathway in desert ecosystem restoration.

Abstract:[Objective] The effect of carbon source regulation (cyclic carbon source addition) to induce PAOs’ extensive P-release on characteristics of the microbial in a continuous anaerobic/aerobic alternating biological filter (AABF) operated for phosphorus (P) removal and accumulation was investigated. [Methods] Intracellular storage polymer dyeing, scanning electron microscopy (SEM) and restriction enzyme analysis technology of polymorphism (RFLP) were employed to characterize the changes of microbial communities in biofilm before and after the terminal carbon source regulation in the AABF’s long-term operation. [Results] During carbon source regulation period, the amount of big coccus and cocco-bacillus microbes decreased and the filamentous microbes increased instead in AABF after carbon source regulation; bacterial diversity reduced greatly, the predominance of β-proteobacteria increasing from 56.9% to 72.5%. [Conclusion] Terminal carbon source addition (induce P-release/P-recovery of operation) with corresponding dosage regulation could cause great changes in microbial morphologies and the dominate bacteria ratio increased rapidly. The results of the study provide informative reference on improving the efficiency of biological phosphorus removal system with process control.

Abstract:[Objective] Comparing the effects of 16S rRNA gene with recA and groEL gene used in the classification and identification of Lactococcus lactis subsp. lactis and cremoris. [Methods] Eight L. lactis isolated from the traditional fermented milk have been classified by 16S rRNA gene, the recA and groEL genes of these strains were amplified by polymerase chain reaction (PCR), and the PCR products were sequenced, the phylogenetic trees were constructed including 16S rRNA gene and above-mentioned two housekeeping genes. [Results] Comparative analysis of genetic relationship of 16S rRNA gene and the recA, groEL genes, the recA and groEL genes possesses the superiority in classification and identification of L. lactis subsp. lactis and cremoris. [Conclusion] Distinction of L. lactis subsp. lactis and cremoris can be achieved by recA and groEL genes sequence analysis. Due to the fast, accurate and stable characteristics, which were more appropriate for differentiation of L. lactis subsp. lactis and cremoris at the levels of subspecies.

Abstract:[Objective] The physiological effect of rare earth element (REE) on microorganism resistance, growth and its mechanism were studied in this work. [Methods] The effects of REE on resistance and growth of Bacillus cereus were investigated through inhibition zone method and photoelectric turbidimetry method, respectively, fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy were used to examine the change in structure of cell wall and nucleic acid (DNA). [Results] Resistance of bacteria to 9% Carbolic acid, 0.135% HgCl2 and 8×105 U/mL Penicillin enhanced by 40?50 mg/L La(NO3)3, meanwhile, resistance to 9% Carbolic acid, 0.135% HgCl2, 8×105 U/mL Penicillin and 75% NaClO3 enhanced by 40?50 mg/L Ce(NO3)3. Fission of bacteria could be faster due to tremeant of REE, effect of more La(NO3)3 or Ce(NO3)3 was better than less them. The structure changes of peptidoglycan characterized by FTIR indicated the effect of La(NO3)3 and Ce(NO3)3 on cell wall. Therefore, modification of resistance was considered related to it. The structure of DNA coubld be affected by REE througth fluorescence spectroscopy. [Conclusion] The change of DNA structure was the basic cause that effect on resistance and growth of REE.

Abstract:[Objective] To explore whether a starch-binding domain (SBD) locates in the newly identified α-amylase (AmyP) that can degrade raw starches. [Methods] Based on sequence alignment and protein domain prediction, a putative SBD was found in the C-terminal sequence of AmyP. The sequence was cloned, expressed and purified, and the recombinant protein was identified by affinity gel electrophoresis and adsorption on raw starch. [Results] The sequence was defined as an SBD that belongs to the carbohydrate-binding module family 20 (CBM20) based on sequenced similarity. SBD binds with higher affinity to raw rice starch compared to raw corn starch, and is unable to adsorb to raw wheat starch, raw potato starch or raw mungbean starch. [Conclusion] The C-terminal region of AmyP was identified as a novel SBD, which may contribute to the specific raw starch-degarding ability of AmyP.

Abstract:[Objective] Chromosomal rearrangements and integration of alien DNA fragments contribute to the genome-wide genetic diversity of Streptomyces. This paper aims to study the role of actinomycete integrative and conjugative elements (AICEs) in Streptomyces genetic diversity. [Methods] AICEs were identified in the completely sequenced Streptomyces genomes using a profile Hidden Markov Model approach, based on their characteristic modules. [Results] Twenty-nine AICEs were found from 12 chromosome sequences and 35 plasmid sequences of Streptomyces, 12 of which were firstly reported. Four AICEs were identified in S. coelicolor, but none in the closely related S. lividans. [Conclusion] AICEs were found to be inserted into the core regions of the Streptomyces chromosomes. They typically comprised three core genetic modules, implementing chromosomal integration/excision, self-transfer by conjugation and replication, suggesting that they promote the plasticity of Streptomyces genomes.

Abstract:[Objective] This article mainly studied the extraction, purification, structure and anti-tumor effects of a novel polysaccharide purified from the fruit bodies of Catathelasma ventricosum (Pk.) Sing. Armillaria ventricosa Peck. [Methods] The polysaccharides of Catathelasma ventricosum (Pk.) Sing. Armillaria ventricosa Peck were extracted with boiling water and purified by DE-52 column and Sephadex G-100 column. The molecular weight, monosaccharide composition and backbone structure were analysed by HPGPC, HPLC, FT-IR, methylation and NMR; the anti-tumor effect was investigated by S-180 tumor-bearing mice and evaluated by the cytokine levels of IL-2, IL-6 and TNF-α in serum samples of the tumor-bearing mice. [Results] A novel polysaccharide was extracted from the fruit bodies of Catathelasma ventricosum (Pk.) Sing. Armillaria ventricosa Peck and named CVP-A, the results had showed that the molecular weight of CVP-A was 10 289, the monosaccharide composition of CVP-A were mainly composed of glucose and a small amount of xylose, with a ratio near 15:2. The results of HPGPC, HPLC, FT-IR, methylation and NMR revealed that CVP-A had a backbone structure of (1→4)-α-D-glucopyranose which branched at the O-2 of the glucose residues. The results of S-180 tumor-bearing mice model had showed that CVP-A had a good inhibiting effect on the experimental S-180 solid tumor, after injection of 25 mg/(kg?d), 50 mg/(kg?d), 75 mg/(kg?d) CVP-A for ten days, the three Kunming mice group had a tumor inhibition ratio of 31.99%, 42.68%, 60.18%, in which the cytokines levels of IL-2, IL-6 and TNF-α in S-180 tumor-bearing mice were increased significantly. [Conclusion] Catathelasma ventricosum (Pk.) Sing. Armillaria ventricosa Peck may be a potential source for anti-tumor development.

Abstract:[Objective] The aim of the present study is to investigate the anti-microorganisms and anticancer activities of endophytic fungi isolated from Tribulus terrestris L.. [Methods] Endophytic fungi were cultured in PDB or Czapek medium to obtain different liquid fermentation. The activities of fermentative products were tested by using Oxford plate assay system, Magnaporthe oryzae P-2b model and cancer cell model. [Results] The strains with their inhibition zone diameter of the PDB and Czapek broth greater than 10 mm were accounted for 19.05% and 23.81% respectively of the total strains. The strains of which the PDB broth and the Czapek broth with the MIC (Minimum inhibitory concentration) of Magnaporthe oryzae lower than 10%, were accounted for 19.05% and 47.61% respectively of the total strains. The PDB fermentation broth with the inhibitory action on cancer cells over 50% was accounted for 52.38% of the total PDB broth, and the Czapek fermentation broth with the inhibitory action on cancer cells over 50% was accounted for 28.57% of the total Czapek broth. [Conclusion] A certain amount of fermentative broth of endophytic fungi isolated from Tribulus terrestris L. had effective anti-microorganisms and anticancer activities.

Abstract:[Objective] To study the effect of proanthocyanidins on the growth and oxidation status of Saccharomyces cerevisiae in the fermentation process. [Methods] Two strains of Saccharomyces cerevisiae (one industrial strain AWRI and one newly selected strain BH8) were chosen in this study, and proanthocyanidins were added into model synthetic medium to give a final concentration of 0.1 and 1.0 g/L. Cell growth at the end of the fermentation and the activity of superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) content at different fermentation stages were determined. [Results] Proanthocyanidins could increase the viable count and survival rate of the yeast, enhance the activity of SOD and CAT, and decrease the concentration of intracellular MDA. In addition, the effect of proanthocyanidins was postively associated with their concentrations. [Conclusion] Adding proanthocyanidins can scavenge intracellular reactive oxygen species (ROS) to protect cells and process of the fermentation.

Abstract:Microbial lipid is the novel and promising oil resource for biodiesel production, whereas its production is difficult to meet industrial demand because of the low lipid productivity at the nitrogen-limited condition or inefficient conversion of cheap biomass into lipid. In the last decade, as the development of fermentation engineering, bioinformatics and molecular technologies, many strategies were used to modify the metabolic pathway for lipid accumulation and build up an excellent lipid-producing strain. In this paper, three potential strategies for enhancing the lipid productivity of oleaginous microorganism was reviewed, which includes the biochemical engineering (BE) approach, the genetic engineering (GE) approach, and the transcription factor engineering (TFE) approach. A comprehensive strategy based on the genomic information, the inverse metabolic engineering and the modular pathway engineering (MOPE) was described for rational construction of an industrial oleaginous strain.

Abstract:Soil respiration is the primary pathway by which plant-fixed CO2 is released back to the atmosphere. Litter decomposition is the key process of nutrient cycling in terrestrial ecosystem. Most terrestrial plants have symbiotic mycorrhizal fungi, which distributed throughout all the terrestrial ecosystems. However, most of the previous studies have been conducted on its contribution to nutrient cycling. The contributions of mycorrhizal fungi to soil carbon release and litter decomposition were poorly understood. In this paper, we systematically reviewed the progress at home and abroad and comprehensively analyzed how the mycorrhizal fungi influenced carbon release and decomposition and its involving mechanisms. Finally, we pointed out the major problems in the previous studies and raised the future scientific directions.

Abstract:Fecal pollution by human and animals has seriously threatened the safety of drinking and recreation water and negatively impacted on economy. Currently, bacteria of total coliform, total fecal coliform, Escherichia coli, Enterococcus spp. and Clostridium spp. are used as the standard fecal indicator bacteria (FIB). However, recent studies demonstrate that the density of the FIB correlates only with the degree of a fecal pollution and provides no information about the sources of pollution. To accurately identify the sources of fecal pollution, microbial source tracking (MST) methods have been developed and used in the United States and other developed countries for effective management of water resource and monitoring. MST methods are techniques matching microbe(s) from a polluted site with that (or those) from an animal source to suggest the source of fecal pollution. This paper is to critically review the recent studies on fecal indicator bacteria and techniques used for MST and to discuss the latest developments of using Faecalibacterium as an alternative FIB for MST, including its future applications in water management and monitoring.

Abstract:As a mature communication software, wechat has evolved into the most widely used eommunication plat form in the world and has a profound impact on people’s daily life. Brief list of the current existing problems in teaching of Veterinary Microbiology, propose the use of wechat platform through the advantages and characteristics of the wechat between teachers and students to build platforms to support teaching action. Wechat platform for improving student achievement teaching model, teachers and students to promote emotional communication, motivation and enthusiasm of teachers’ work to promote the exchange of teaching experience are great beneficial.

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Abstract:[Objective] Crude oil degradation by Sphingobacterium bambusaue and its UV mutants were studied. [Methods] The efficient crude oil degrading strains were obtained by UV mutagenesis, and the crude oil degradation rate was tested by gravimetric method in the culture conditions of different crude oil concentration, pH and salt concentration. [Results] The crude oil degradation rate of the strain Sphingobacterium bambusaue and UV mutant IBFC2009-S3 cultured in crude oil medium for 5 d was 25.86% and 42.85% respectively, and the crude oil degradation rate of UV mutant IBFC2009-S3 increased 65.7% than that of the originating strains; the crude oil degradation rate of the strain IBFC2009-S3 was 50.51% in the optimum condition which was 0.5 g/L crude oil, pH 7.0, and 10 g/L NaCl. [Conclusion] Crude oil degradation by Sphingobacterium bambusaue and its UV mutants IBFC2009-S3 have the higher ability of crude oil degradation.

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