Abstract:[Objective] The genome of the photoheterotrophic bacterium MIM37, possessing anoxygenic photosynthetic gene cluster (PGC) and xanthorhodopsin-like gene, was sequenced and the stimulated growth by illumination was determined, which is helpful in shedding light upon the diversity of photosynthetic pathway and phototrophic bacteria, and the evolution and role of photosynthesis. [Methods] The isolation was performed by the traditional plate spread and streak. To classify and identify the isolate preliminarily, the morphological feature and, the homology and phylogeny of 16S rRNA gene, pufM and rhodopsin genes were analyzed. Spectrophotometry and fluorescence microscopy were employed separately to reveal the concentration and size shifts of the cell cultured under illumination or dark. Illumina PE library of 300?500 bp fragments was constructed for Illumina Hiseq2000 genome sequencing. Sequences were assembled through the software of SOAPdenovo and GapCloser and the online software of RAST was used to annotate. [Results] We obtained a bacterial strain MIM 37 from Lake Swan in Desert Tenggeli in Inner Mongolia. The homology and phylogeny analysis based on 16S rRNA gene, pufM and rhodopsin genes respectively, showed that the strain most closely related to the members of Sphingomonas genus. Compared with the dark condition, light condition increased the maximum of the cell concentration and volume by 1.2 and 5.6 folds respectively. The genome draft sequence demonstrated that MIM37 has diverse metabolic pathways with electron transport chain of the typical aerobic respiration, intact aerobic phototrophic photosynthetic gene cluster and xanthorhodopsin-like genes, siderophore biosynthesis, heavy metal reduction, the degradation of microcystin and polyaromatic hydrocarbon and etc. [Conclusion] The strain MIM37 is a member of the genus Sphingomonas and possesses two different phototrophic pathways. Light may stimulate its growth markedly. The diverse metabolic pathways may be helpful for the strain in the survival and wide distribution in natural ecosystems, and make strain MIM37 useful in environmental pollutes bioremediation.

Abstract:[Objective] To investigate the genetic and biologic characteristics of mycobacteriophage Guo1 with circular genome. [Methods] Sequenced the complete genome of Guo1 with Shot-gun library and config package strategy. Performed DNAStar, tRNAscan-SE, Promoter predictions, TRF, Glimmer, BLAST software for general genome characteristics, tRNA, promoter regions, tandem repeat sequences and putative function of predicted coding sequences, respectively. Utilized BLAST software to search for mycobacteriophages with genome similar as Guo1. Constructed phylogenetic tree to identify the cluster into which Guo1 should be grouped. Then measured the optimal multiplicity of infection and one-step growth curve, and observed the sensibility to ultraviolet, chloroform, alcohol, temperature, pH. [Results] Guo1 contains a double strand circular DNA with a full length of 40 086 nt, which belongs to the cluster G mycobacteriophage and which contains 59 putative genes, 7 promoter regions and three tandem repeat sequences. Guo1 is resistant to ultraviolet but sensitive to alcohol, chloroform and high temperature. The optimal temperature is 37 °C while the optimal pH is 7.0. The optimal MOI of Guo1 is about 0.01. One step growth of it showed that both latent period and burst period are 120 min, and the average burst size is about 47. [Conclusion] Guo1 is a cluster G mycobacteriophage with double strand circular DNA found for the first time. We sequenced the complete genome of Guo1 and identified the circular genetic information and biologic characteristics.

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Abstract:[Objective] The core type of Escherichia coli lipopolysaccharide (LPS) is divided into 5 types, R1, R2, R3, R4 and K12, based on their different chemical structure. The aim of the present study was to study the distribution of LPS core type in avian pathogenic E. coli, and its correlation with virulence genes. [Methods] LPS core type and 17 virulence genes were detected in 76 strains of APEC by PCR. The correlation of LPS core type and virulence was analyzed. [Results] The core types of R1, R3, R4 and R2 were 68.4%, 15.8%, 11.8% and 3.9%, respectively. The virulence genes yijp, mat, fimC, ibeB and ompA were conserved in APEC strains. The R1 core type was significantly positive correlated with neuC, cva/cvi and irp2 (P<0.05), the R4 core type was positive correlated with aatA, whereas the R3 core type was negative correlated with iroN and irp2 (P<0.05). [Conclusion] R1 core type is more prevalent than other LPS core types and associated with high pathogenicity.

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Abstract:[Objective] This study is to investigate the effect of lactate dehydrogenases on the optical purity of L-lactic acid produced in Bacillus sp. P38. [Methods] Genome annotation result shows that there are three enzymes responsible for lactic acid production: L-lactate dehydrogenase (L-LDH) (encoded by ldhL), D-LDH (encoded by ldhD), and one possible malate/lactate-LDH (M/L-LDH) (encoded by ldhM/L). These enzymes were investigated both in vivo and in vitro to study the relationship between enzymatic activities, gene transcriptions and the optical purity of lactic acid. [Results] M/L-LDH was found mainly to act as L-LDH. The L-LDH catalytic efficiency toward pyruvate was 2.9-fold higher than that of D-LDH and 4.3-fold higher than that of M/L-LDH. The D-LDH activity was not detectable in Bacillus sp. P38 under active staining. The relative transcription levels of ldhL in Bacillus sp. strain P38 were much higher than those of ldhD and ldhM/L at different growth phases, and the transcription ratio of ldhL to ldhD increased from the logarithmic phase to decline phase. [Conclusion] L-LDH is the key enzyme for high optical purity of L-lactic acid produced by Bacillus sp. P38.

Abstract:[Objective] This study was in order to obtain a strain of Rhodosporidium toruloides which can degrade high concentration bioethanol wastewater COD effectively and evaluate the effects of initial COD on the growth of domesticated strain. Especially, the strategy of integrating the treatment of high concentration organic wastewater and microbial lipid production from cassava starch will be explored. Cassava starch hydrolysates was prepared using bioethanol wastewater as water source to obtain a fermentation medium for lipid production. At last, the initial reducing sugar concentration of the medium was optimized for enhancing lipid production and wastewater COD degradation. [Methods] Domestication of the R. toruloides in high concentration bioethanol wastewater was carried out to obtain a strain which could tolerance bioethanol wastewater with high COD concentration; double enzyme hydrolysis method was used to hydrolyze the cassava starch added in wastewater medium; gravimetric method, acid-heating extraction, potassium dichromate method, DNS method, Kjeldahl method and GB 11893-89 were used to determine the biomass concentration, lipid content, COD, reducing sugar concentration, N and P concentration, respectively. [Results] An active oleaginous strain R. toruloides D5 was obtained by domestication in bioethanol wastewater with high COD concentration. With undiluted bioethanol wastewater as cultural medium, the biomass concentration and COD degradation ratio of R. toruloides D5 was 3.8 g/L and 75.0%, respectively; with bioethanol wastewater and cassava starch as the medium, biomass and lipid concentration increased with the initial reducing sugar concentration when it below 30 g/L, the maximum COD degradation ratios were achieved after 120 h; N, P removal ratio was more than 99% and 92%, respectively. [Conclusion] The domesticated strain grew well and reach a high biomass concentration in the bioethanol wastewater without dilution; when the initial reducing sugar concentration was controlled below 30 g/L, the COD degradation ratio did not be affected by the addition of cassava starch, meanwhile the biomass and lipid concentration increased significantly. The strategy recycled the N/P in the wastewater and reduced the cost of microbial lipid production and wastewater treatment. The results of this study could provide useful information for low-cost microbial lipid production.

Abstract:[Objective] To study the time-course changes in the cell morphology, growth, total lipid contents, lipid fractions and fatty acids profiles of Eustigmatos magnus and Eustigmatos polyphem (Eustigmatophyceae) under two different initial nitrate concentrations. [Methods] The cultured concentration were 18.0 mmol/l (high nitrogen concentration) and 3.6 mmol/l (low nitrogen concentration). [Results] The cell morphology and formation process of oil bodies of E. magnus and E. polyphem were also observed. The results showed that the vegetative cells of E. magnus and E. polyphem are usually oval to spherical. There are a single parietal, lobed chloroplast, conspicuous vacuoles, many vibrating granules and a large reddish pigment body in cytoplasm. The main reproduction way is by forming two D-shaped or four tetragonal autospores. The oil bodies emerged in cytoplasm along with cultivation time extending and nutrients exhausting. The initial nitrate concentration had a significantly influence on the growth and lipids accumulation of these two microalgae (P<0.05). The biomass concentrations of E. magnus and E. polyphem cultured under low nitrogen concentration were 9.0 g/L and 8.5 g/L, respectively, which were less than those gained at high nitrogen group. However, the higher contents and volumetric productivities of total lipids, neutral lipids and total fatty acids of these two microalgae were obtained at low nitrogen concentration. Their highest values reached 59.10%, 51.90%, 46.95%, 0.28 g/(L·d), 0.24 g/(L·d), 0.22 g/(L·d) (E. magnus); 64.20%, 56.80%, 56.80%, 0.32 g/(L·d), 0.28 g/(L·d), 0.25 g/(L·d) (E. polyphem), respectively. The fatty acids analysis indicated that the main fatty acids compositions of these two microalgae were palmitic acid, palmitoleic acid, oleic acid and eicosapentaenoic acid, which were up to 85.83% and 85.48% (of total fatty acids), respectively, among them, the content of palmitoleic acid was highest one. [Conclusion] Low-nitrogen stress is conducive to storage lipids accumulation of E. magnus and E. polyphem, and both two microalgae are promising feedstock for biodiesel production.

Abstract:[Objective] By screening from sand biological soil crusts in Gurban Tonggut Desert, Xinjiang, China, a novel strain Bacillus thuringiensis XJ-27 with high yield of exopolysaccharide (EPS) was obtained. Exopolysaccharide was purified from XJ-27 and its bioflocculant activity in kaolin system was studied. [Methods] Purification of exopolysaccharide was carrried out by DEAE sepharose CL-6B ion-exchange chromatography and Sephadex G100 gel-permeation chromatography. Its physiochemical properties and molecular weight were investigated by chemical analysis and high performance liquid chromatography (HPLC) as well. The bioflocculant activity was studied in kaolin system. [results] Exopolysaccharide EPS-I was purified with DEAE sepharose CL-6B ion-exchange chromatography and Sephadex G100 gel-permeation chromatography. The average molecular weight of the exoploysaccharide EPS-I was 575 kD. The bioflocculant activity in kaolin system of exopolysaccharide was 80.4%. [Conclusion] The average molecular weight of the exoploysaccharide EPS-I was 575 kD. The bioflocculant activity in kaolin system of exopolysaccharide was 80.4%.

Abstract:[Objective] Prp5 proteins were analyzed by bioinformatics in seven model fungi. The purpose is to lay a foundation for further experimental study of Prp5 in RNA splicing and other unique biological function. [Methods] Some basic characteristics, secondary structure, domain and tertiary structure were analyzed and predicted using online webs and softwares in Magnaporthe oryzae, Schizosaccharomyces pombe, Saccharomyces cerevisiae, Neurospora crassa, Aspergillus nidulans, Cryptococcus neoformans and Candida albicans. Meanwhile, the homologies of Prp5 proteins of seven species were compared, based on which a phylogenetic tree was plotted. [Results] The results showed that all studied proteins are unstable hydrophilic protein. Prp5 in Magnaporthe oryzae, Neurospora crassa, Aspergillus nidulans and Prp11 in Schizosaccharomyces pombe were alkaline proteins whereas Prp5 proteins in Cryptococcus neoformans and Candida albicans were acidic. Evolution analysis showed that the seven model fungi are divided into two groups and Magnaporthe oryzae and Neurospora crassa have the closest genetic relationship. Alpha helix is based structure. All proteins contain DEAD and Helicase_C domain. Tertiary structure analysis showed that DEAD domain is stable, while domain Helicase_C showed some changes on the spatial structure. [Conclusion] Prp5 protein may play similar role on account of their conservative structure in different fungi. However, Prp5 protein in Saccharomyces cerevisiae is a little different on spatial structure, suggesting that it may have some unique functions. These results will provide guidance for further study about Prp5 in the experiments.

Abstract:[Objective] To examine the effects of saponin on the metabolism of reactive oxygen species (ROS), the activities and the gene expressions of superoxide dismutase (SOD) and catalase (CAT) in Hypsizygus marmoreus mycelium. [Methods] Hypsizygus marmoreus mycelium were treated with 0, 0.01, 0.05 g/L saponin for 7 to 15 days under shake-flask culture condition. [Results] The content of superoxide radical and MDA increased than the control group during 7 to 11 days adding saponin to the culture, and then decreased than the control group after 13 days. SOD activities enhanced with the increasing of saponin concentration during 7 to 15 days (except the 9th day), especially during 13 to 15 days. CAT activities showed the same trends as SOD activities, and always kept a high level with 0.05 g/L saponin exposure. The abundance of Mn-SOD and CAT genes were up-regulated in all concentration treatments. With 0.05 g/L treatment, the expression of gene encoding Mn-SOD showed the same trend as SOD activities. However, expression of CAT gene was not in accordance with the trend of CAT activities. It inferred that CAT activities might effected by post-translational modification. [Conclusion] Saponin can induce the increase of antioxidant enzyme activities of SOD and CAT, as well as up-regulate corresponding gene expressions, which might slow down the accumulation of MDA and superoxide radical in the later culture period.

Abstract:[Objective] drB0118 gene in Deinococcus radiodurans is predicted to encode a protein associated with the desiccation tolerance. The purpose of this study is to identify and determine the function of drB0118 gene, especially its effects on the bacterial resistance to salt, osmotic and oxidative stresses. [Methods] The drB0118 mutant was constructed and its tolerance to salt, osmotic and oxidative stresses was investigated by the NaCl, D-sorbitol or H2O2 shock experiments. The expression of the genes involved in oxidative stress response was measured by qRT-PCR assay under the oxidative stress. [Results] The mutant ΔB0118 was more sensitive to NaCl, D-sorbitol and H2O2 stresses than the wild type strain. The inactivation of drB0118 resulted in 4-fold or 10-fold decrease in the relative expression of pod and oxyR genes respectively. [Conclusion] The results suggested that drB0118 gene was involved in salt, osmotic and antioxidant stress in D. radiodurans.

Abstract:[Objective] To screen efficient nitrogen fixation and plant growth promoting endophytes from Oryza officinalis wall in Cenxi, Guangxi. [Methods] The nitrogen-fixation ability of the isolates was tested by acetylene reduction assay. The SDS-PAGE patterns of the whole-cell protein electrophoresis and IS-PCR DNA finger-printings were used to group these isolates. Phylogenetic analysis based on 16S rRNA gene and nifH gene was performed. The ability of indole acetic acid secretion and the production of siderophore were tested by the Salkowski colorimetric method and the blue plate assay, separately, and the ability of phosphate solubilization also was detected. The property of plant growth promoting rice was tested by plate and potting. [Results] A total of 35 endophytic diazotrophs were isolated and classified into 6 groups, in which CX24 belonging to the Klebsiella variicola showed the highest nitrogenase activity. The nitrogenase activity (298.64 nmol/(mL·h)) was 9 times as much as the reference strain DSM15968. Besides the secreting siderophore, indole acetic acid and ability of solubilize phosphorus, the strain CX24 could also effectively promote the germination and growth of rice. [Conclusion] The strain CX24 belonging to Klebsiella variicola, was an efficient endophytic diazotroph and had a very good application prospect.

Abstract:[Objective] To investigate the influence of plant endophytic fungus Piriformospora indica on the model legume Medicago truncatula. [Methods] Root length, root and shoot fresh weight were recorded under the P. indica colonization. Antioxidant enzyme activities were analyzed with special focus on superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT). The proline content was determined by acidic ninhydrin method, and betaine aldehyde dehydrogenase gene (BADH) expression was semi-quantitative identified by RT-PCR. [Results] Root colonization by P. indica increased plant growth and attenuated the NaCl-induced growth inhibition. The endophyte significantly increased antioxidant enzyme activities and proline content. Additionally, P. indica induced the BADH expression under salt treatment. [Conclusion] The experiment data revealed the potential of P. indica in application as a plant growth-promoting mycorrhizal fungus for realizing the salty-soil improvement indirectly.

Abstract:[Objective] Open out the correlation between rhizosphere microbial community of Gossypium spp. and petroleum hydrocarbon (TPH) degradation in the petroleum contaminated saline-alkali soil. [Methods] Phospholipid fatty acid (PLFA) analysis method in different growing periods (seeding, bud and boll opening season) of Gossypium spp. was used to evaluate the microbial community diversity in the soil. [Results] It was found 21 kinds of PLFAs in the soil, including bacteria (except actinomycetes) biomarkers of saturated fatty acids (SAT), fungi species biomarkers of polyunsaturated fatty acid (PUFA), actinomycetes biomarkers of middle branched saturated fatty acids (MBSAT), Gram positive (G+) bacteria (except actinomycetes) biomarkers of terminal branched saturated fatty acids (TBSAT), Gram negative bacteria (G?) biomarkers of monounsaturated fatty acids (MONO) and Cyclopropyl fatty acids (CYCLO). There are significant differences on microbial diversity in the rizosphere soil between the Gossypium spp. and without cotton (CK), the differences were also observed in the different growth periods. Compared with the CK, the microbial diversity increased by 100%, 83.3%, and 20.0% and biomass of soil microbes increased by 53.9%, 6.60 times, and 60.5% for seedling, bud and boll opening periods, respectively. In addition, when Gossypium spp. was grown in the petroleum contaminated saline-alkali soil, the degradation rates of total petroleum hydrocarbon (TPH) in the rhizosphere soils increased by 13.0%, 28.0% and 30.6% in seedling, bud and boll opening periods, respectively. Correlation analysis (Spearman method) was used to determine the correlation between the soil microbial community and the TPH degradation. Although the total soil microbial biomass had a low correlation with TPH degradation with a correlation coefficient |r|=0.5, whereas i15:0, a14:0, a16:0 had a high positive correlation with the correlation coefficient |r|≥0.8. [Conclusion] The study indicate that the structure and the biomass of the soil microbial community have significant changed (p<0.05) and the TPH degradation have improved in the rhizospheres soils of Gossypium spp.. The planting of Gossypium spp. can effectively improve TPH contaminated saline-alkali soil, and the results have a great reference value in application of TPH contaminated saline-alkali soil.

Abstract:[Objective] The aim of this study is to evaluate the feasibility of using purified recombinant OMP28 to diagnose Brucella-infected sheep and goats. [Methods] We expressed and purified recombinant Brucella OMP28 protein in Escherichia coli system as a diagnostic antigen in an I-ELISA. Four different Brucella species (B. melitensis 16M, B. melitensis M28, B. abortus 2308, and B. suis S1330) were used to inoculate sheep and goat and sera samples were collected every two weeks, till 42 weeks post-inoculation. The antibodies against LPS and OMP28 were parallel compared by LPS-based and OMP28-based I-ELISA respectively. [Results] All Brucella-infected individuals could produce high levels of antibodies against LPS, but only B. melitensis 16M- and B. melitensis M28-infected sheep and B. melitensis 16M- and B. abortus 2308-infected goats could produce antibodies against OMP28 and the OMP28 specific antibody were undetectable in the rest groups. [Conclusion] OMP28-based I-ELISA showed specificity for both Brucella species and host kinds, which obviously limited its reliability as an antigen for diagnosing brucellosis in sheep and goats.

Abstract:[Objective] Several main cultivated and commercial characteristics of the inbred progenies were comprehensively analyzed to inbred desirable new strain of Pleurotus pulmonarius. [Methods] In this study, we used a commercial strain 3108 of P. pulmonarius as inbreeding parent. The mycelia growth rate, yield, fruit body appearance, anti-hybrid bacteria and stress resistance and cultivation cycle were aggregately analyzed to select new cultivated strains. Inter-simple sequence repeat (ISSR) was used to identify genetic differences between new strain and parent strain. [Results] In the inbred progenies, as for mycelia growth rate and fruit body yield, respectively 19.5% and 8.9% of progenies were apparently better than their parent. However, there was no correlation between mycelia growth rate and yield (R=0.102, P>0.05). The cultivation cycle of 37% progenies strains was shorter than their parent. Pileus of 53% progenies strains were the same flat as their parent, and 11% generations strains were thicker than the parent. Range ability of stipe diameter was 5?13 mm and that of stipe length was 21?75 mm. Yellows incidence, withered or dead fruits and malformation accounted for 23%, 19%, and 5%, respectively. [Conclusion] we selected one new strain of P. pulmonarius named as Shenxiu-1 through comprehensive analysis of progenies strains’ characteristics. Shenxiu-1 had fast growth rate, high yield, thick pileus, thick and length stipe, strong anti-hybrid bacteria and stress resistance, and were not easy to be cracked. The average yield per bag of Shenxiu-1 was 334 g in the first three flushes, which increased 7.1% than the parent strain, and the biological efficiency was up to 74%. Moreover, the new strain was stably cultivated. ISSR identification showed that Shenxiu-1 had its own specificity.

Abstract:[Objective] To analyze the molecular evolution of three protein-coding genes (csp1, MAT1-1-1 and MAT1-2-1) among various Ophiocordyceps sinensis isolates. [Methods] We amplified partial csp1 fragment and complete MAT1-1-1 and MAT1-2-1 gene sequences from 125 broadly sampled O. sinensis isolates, and compared the topological difference of phylogenetic trees constructed by exons and introns, and of those constructed by MAT1-1-1 and MAT1-2-1. We also measured selection pressures and detected evidence of recombination for the three genes. [Results] The length of exons of the three protein-coding genes was conserved among different O. sinensis isolates with 4.5%?5.7% of variable sites. The length of introns was either identical or different among different isolates with more than 1.8%?22% of variable sites. For the two mating-type genes, MAT1-1-1 was less variable than MAT1-2-1. Phylogenetic topology differences were significant between exons and introns, and between MAT1-1-1 and MAT1-2-1 exon sequences. Each of the three genes was undergoing purified selection. Recombination events were detected between different DNA sites within each gene, but not obvious between different gene fragments. [Conclusion] Because different gene fragments and different regions of a gene in O. sinensis might be evolutionarily different, we should use multiple gene fragments in future evolution-related studies in O. sinensis.

Abstract:[Objective] To find difference in whole genome sequence between Chlamydia muridarum standard strain and attenuated strain, screening virulence gene and establish the corresponding isogenic organisms with different genotype, and it may lay a foundation for analyzing pathogenic mechanism. [Methods] C. muridarum strain Nigg G0 and attenuated strain G28 were sequenced by deep sequcencing. virulence-associated genes were identified by whole genome sequencing and alignment. A plaque-forming assay was used to isolate many plaques from both CM.G0 and CM.G28 population organisms. Based on PCR sequencing results from virulence-associated gene, individual clones with different genotype were selected. [Results] Whole genome sequencing and alignment revealed that TC0412, TC0237 and TC0668 gene have much difference between CM.G0 and CM.G28. We had obtained 111 plaque samples by plaque-forming assay, and 56 individual clones from CM.G0 and CM.G28 were selected by PCR identification of TC0412, TC0237 and TC0668. Some clones were matched in three pairs (B3, D1, E1) by TC0412 proteiform, and each pair contained the matched organisms which lack of mutation or carrying 100% mutation of TC0237 and TC0668 gene. [Conclusion] The results showed that TC0412, TC0237 and TC0668 gene may be associated with pathogenicity of C. muridarum. The screened clones which have been matched in pair can be used for next function research of virulence gene.

Abstract:Lignocellulose can be degraded by microorganisms including bacteria, fungi, actinomycetes and some virus. The metabolism of these microorganisms is closely related to microorganisms’ enzyme activity, which in turn plays an important role in the conversion and use of biomass energy. Based on the treatment of biomass solid waste and recycling transformative achievements, we summarize the results toward microbial treatment of biomass solid waste and recycling transformative achievements. Using lignocellulose biomass solid waste as an example, we describe microbial treatment of biomass solid waste from two aspects: microbial species and biomass solid waste recycling transformative achievements. We also address the existing problems and prospects.

Abstract:Gold nanoparticles (AuNPs) possess unique optical and electrochemical properties, thus they have been used in various fields such as information storage, chemical sensing, medical imaging, drug delivery and biological labeling. In recent years, microbes-mediated biosynthesis of AuNPs has attracted broad attention due to the nontoxic and eco-friendly nature. Various microorganisms such as bacteria, actinomycetes, fungi and viruses can produce AuNPs. The characteristics, synthesis mechanisms and potential applications of biogenic AuNPs are summarized, and the future research trends on biogenic AuNPs are also prospected.

Abstract:The thermophilic bacilli are an important group of contaminants in milk powder, which are an important factor that influences the quality of milk powder. This review discusses the research progress of the varieties and source of thermophilic bacilli of milk powder, their hazard to dairy manufacture and its control, so as to provide reference for domestic research.

Abstract:This article introduces and compares three similar equations in biology and related major undergraduate teaching: Monod equation related to the kinetics of microbial cell growth, Michaelis-Menten equation related to the enzymatic reaction kinetics, and Langmuir equation related to adsorption separation. We hope this article can provide reference for relevant professional teachers’ teaching and students’ learning.

Abstract:With the goal of cultivating applicable and high comprehensive quality talents, the theory teaching and experiment teaching of microbiology course were integrated and optimized to construct a multi-module, multi-level teaching system based on Gardner’s multiple intelligences and the characteristics of the subject. Many special teaching strategies were applied such as “target responsibility system”, “modular teaching” and “hierarchical experiment teaching”. Good results were obtained for really improving the teaching qualities and the individual abilities through the practice of the teaching reforms, which can give a reference to the similar courses reforms.

Abstract:[Objective] Bifidobacterium adherent to Caco-2 cells were quantitatively analyzed by quantitative real-time PCR, and a rapid and effective method to detach the bacteria from the Caco-2 cells was established. [Methods] Firstly, the Bifidobacterium adherent to the Caco-2 cells were treated by Triton X-100 solution with the aim of separating bifidobacterial cells from the Caco-2 cells. Secondly, quantitative real-time PCR method for quantifying Bifidobacterium was determined by generating a standard curve, evaluating the specificity, sensitivity and reproducibility of the method, respectively. Finally, the adhering capacity of 11 Bifidobacterium to the Caco-2 cells was detected by the method established in this study. [Results] The optimum time for separating Bifidobacterium from Caco-2 cells by Triton X-100 was 10 min. The quantitative real-time PCR method used for determing adherent ability of Bifidobacterium demonstrated a good reproducibility, a high specificity and sensitivity. When the initial template concentration was in the range of 104?108 CFU/mL, a good linear relationship between bacterial cell counts and Ct value was expressed with the equation of y=?3.345 2x+37.637 0, whose correlation coefficient was above 99%. Compared with the gram staining microscopic examination with the detection time of 48 h, the quantitative real-time PCR method established in this study was able to obtain non-significant results of quantifying the adherent capacity of Bifidobacterium (P>0.05), however, the time for detection was greatly shortened to 4 h. [Conclusion] Triton X-100 separation processing combining with quantitative real-time PCR is a rapid, accurate and sensitive method for detecting and quantifying the adhering capacity of Bifidobacterium to the Caco-2 cells.